TY - CHAP A1 - Risch, Lucie A1 - Bashford, Greg A1 - Kulig, Kornelia A1 - Kaplick, Hannes A1 - Mayer, Frank A1 - Cassel, Michael T1 - Spatial frequency analysis identifies altered local Micromorphology in adolescent athletes with Achilles tendinopathy T2 - Medicine and science in sports and exercise : MSSE ; official journal of the American College of Sports Medicine Y1 - 2020 U6 - https://doi.org/10.1249/01.mss.0000670932.99564.57 SN - 0195-9131 SN - 1530-0315 VL - 52 SP - 82 EP - 82 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Quarmby, Andrew A1 - Mönnig, Jamal A1 - Mugele, Hendrik A1 - Henschke, Jakob A1 - Kim, MyoungHwee A1 - Cassel, Michael A1 - Engel, Tilman T1 - Biomechanics and lower limb function are altered in athletes and runners with achilles tendinopathy compared with healthy controls: A systematic review JF - Frontiers in Sports and Active Living N2 - Achilles tendinopathy (AT) is a debilitating injury in athletes, especially for those engaged in repetitive stretch-shortening cycle activities. Clinical risk factors are numerous, but it has been suggested that altered biomechanics might be associated with AT. No systematic review has been conducted investigating these biomechanical alterations in specifically athletic populations. Therefore, the aim of this systematic review was to compare the lower-limb biomechanics of athletes with AT to athletically matched asymptomatic controls. Databases were searched for relevant studies investigating biomechanics during gait activities and other motor tasks such as hopping, isolated strength tasks, and reflex responses. Inclusion criteria for studies were an AT diagnosis in at least one group, cross-sectional or prospective data, at least one outcome comparing biomechanical data between an AT and healthy group, and athletic populations. Studies were excluded if patients had Achilles tendon rupture/surgery, participants reported injuries other than AT, and when only within-subject data was available.. Effect sizes (Cohen's d) with 95% confidence intervals were calculated for relevant outcomes. The initial search yielded 4,442 studies. After screening, twenty studies (775 total participants) were synthesised, reporting on a wide range of biomechanical outcomes. Females were under-represented and patients in the AT group were three years older on average. Biomechanical alterations were identified in some studies during running, hopping, jumping, strength tasks and reflex activity. Equally, several biomechanical variables studied were not associated with AT in included studies, indicating a conflicting picture. Kinematics in AT patients appeared to be altered in the lower limb, potentially indicating a pattern of “medial collapse”. Muscular activity of the calf and hips was different between groups, whereby AT patients exhibited greater calf electromyographic amplitudes despite lower plantar flexor strength. Overall, dynamic maximal strength of the plantar flexors, and isometric strength of the hips might be reduced in the AT group. This systematic review reports on several biomechanical alterations in athletes with AT. With further research, these factors could potentially form treatment targets for clinicians, although clinical approaches should take other contributing health factors into account. The studies included were of low quality, and currently no solid conclusions can be drawn. KW - achilles tendinopathy KW - biomechanics KW - neuromuscular KW - kinetics KW - electromyography KW - athletes KW - runners KW - kinematics Y1 - 2023 U6 - https://doi.org/10.3389/fspor.2022.1012471 SN - 2624-9367 PB - Frontiers CY - Lausanne, Schweiz ER - TY - THES A1 - Cassel, Michael T1 - Klinische Analyse der physiologischen und pathologischen Sehnenadaptation an sportliche Belastung BT - belastungsabhängige Veränderungen und diagnostische Abgrenzbarkeit Y1 - 2021 ER - TY - GEN A1 - Joost, Theresa Anna A1 - Brecht, Pia A1 - Mayer, Frank A1 - Cassel, Michael T1 - Feasibility of open low-field MRI measurements in adolescent athletes with spondylolisthesis T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine N2 - PURPOSE: To determine the feasibility of upright compared to supine MRI measurements to determine characteristics of the lumbar spine in AA with spondylolisthesis. METHODS: Ten AA (n=10; m/f: 4/6; 14.5±1.7y; 163±7cm; 52±8kg) from various sports, diagnosed with spondylolisthesis grade I-II Meyerding confirmed by x-ray in standing lateral view, were included. Open low-field MRI images (0.25 Tesla) in upright (82°) and supine (0°) position were evaluated by two observers. Medical imaging software was used to measure the anterior translation (AT, mm), lumbosacral joint angle (LSJA, °) and lordosis angle (LA, °). Reliability was analyzed by the intra-rater correlation coefficient (ICC) and standard error of measurements (SEM). RESULTS: Due to motion artifacts during upright position, measures of three participants had to be excluded. Between observers, AT ranged from 4.2±2.7mm to 5.5±1.9mm (ICC=0.94, SEM=0.6mm) in upright and from 4.9±2.4mm to 5.9±3.0mm (ICC=0.89, SEM=0.9mm) in supine position. LSJA varied from 5.1±2.2° to 7.3±1.5° (ICC=0.54, SEM=1.5°) in upright and from 9.8±2.5° to 10±2.4° (ICC=0.73, SEM=1.1°) in supine position. LA differed from 58.8±14.6° to 61.9±6° (ICC=0.94, SEM=1.19°) in upright and from 51.9±11.7° to 52.6±11.1° (ICC=0.98, SEM=1.59°) in supine position. CONCLUSIONS: Determination of AT and LA showed good to excellent reliability in both, upright and supine position. In contrast, reliability of LSJA had only moderate to good correlation between observers and should therefore be interpreted with caution. However, motion artifacts should be taken into consideration during upright imaging procedures. Y1 - 2020 U6 - https://doi.org/10.1249/01.mss.0000683832.74059.9d SN - 0195-9131 SN - 1530-0315 VL - 52 IS - 17 SP - 790 EP - 790 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Rector, Michael V. A1 - Intziegianni, Konstantina A1 - Müller, Steffen A1 - Mayer, Frank A1 - Cassel, Michael T1 - Reproducibility of an ankle joint rotation correction method for assessment of Achilles tendon elongation JF - Isokinetics and exercise science : official journal of the European Isokinetic Society N2 - BACKGROUND: The Achilles tendon (AT) requires optimal material and mechanical properties to function properly. Calculation of these properties depends on accurate measurement of input parameters (i.e. tendon elongation). However, the measurement of AT elongation with ultrasound during maximum voluntary isometric contraction (MVIC) is overestimated by ankle joint rotation (AJR). Methods to correct the influence of this rotation on AT elongation exist, yet their reproducibility in clinical settings is unknown. OBJECTIVE: To evaluate the test-retest reproducibility of AT elongation during MVIC after AJR correction. METHODS: Ten participants attended test and retest measurements where they performed plantar-flexion MVIC on a dynamometer. Simultaneously, ultrasound recorded AT elongation as the displacement of the medial gastrocnemius-myotendinous junction, while an electrogoniometer measured AJR. The ankle was then passively rotated to the AJR achieved during MVIC and AT elongation again determined. Elongation was corrected by subtracting this passive AT elongation from the total AT elongation during MVIC. Reproducibility was evaluated using ICC (2.1), test-retest variability (TRV, %), Bland-Altman analyses (Bias +/- LoA [1.96*SD]) and standard error of the measurement (SEM). RESULTS: Corrected AT elongation reproducibility exhibited an ICC = 0.79, SEM = 0.2 cm and TRV = 20 +/- 19%. Bias +/- LoA were determined to be 0.0 +/- 0.8 cm. CONCLUSIONS: Using this ultrasound and electrogoniometer-based method, corrected AT elongation can be assessed reproducibly. KW - Ultrasonography KW - Achilles tendon KW - reproducibility KW - isokinetic KW - ankle joint rotation Y1 - 2017 U6 - https://doi.org/10.3233/IES-160644 SN - 0959-3020 SN - 1878-5913 VL - 25 IS - 1 SP - 47 EP - 52 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Risch, Lucie A1 - Cassel, Michael A1 - Mayer, Frank T1 - Acute effect of running exercise on physiological Achilles tendon blood flow JF - Scandinavian journal of medicine & science in sports N2 - Sonographically detectable intratendinous blood flow (IBF) is found in 50%-88% of Achilles tendinopathy patients as well as in up to 35% of asymptomatic Achilles tendons (AT). Although IBF is frequently associated with tendon pathology, it may also represent a physiological regulation, for example, due to increased blood flow in response to exercise. Therefore, this study aimed to investigate the acute effects of a standardized running exercise protocol on IBF assessed with Doppler ultrasound (DU) Advanced dynamic flow in healthy ATs. 10 recreationally active adults (5 f, 5m; 29 +/- 3years, 1.72 +/- 0.12m, 68 +/- 16kg, physical activity 206 +/- 145minute/wk) with no history of AT pain and inconspicious tendon structure performed 3 treadmill running tasks on separate days (M1-3) with DU examinations directly before and 5, 30, 60, and 120minutes after exercise. At M1, an incremental exercise test was used to determine the individual anaerobic threshold (IAT). At M2 and M3, participants performed 30-minute submaximal constant load tests (CL1/CL2) with an intensity 5% below IAT. IBF in each tendon was quantified by counting the number of vessels. IBF increased in five ATs from no vessels at baseline to one to four vessels solely detectable 5minutes after CL1 or CL2. One AT had persisting IBF (three vessels) throughout all examinations. Fourteen ATs revealed no IBF at all. Prolonged running led to a physiological, temporary appearance of IBF in 25% of asymptomatic ATs. To avoid exercise-induced IBF in clinical practice, DU examinations should be performed after 30minutes of rest. KW - advanced dynamic flow KW - doppler ultrasound KW - hyperemia KW - neovascularization KW - sonography Y1 - 2017 U6 - https://doi.org/10.1111/sms.12874 SN - 0905-7188 SN - 1600-0838 VL - 28 IS - 1 SP - 138 EP - 143 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Risch, Lucie A1 - Stoll, Josefine A1 - Schomöller, Anne A1 - Engel, Tilman A1 - Mayer, Frank A1 - Cassel, Michael T1 - Intraindividual Doppler Flow Response to Exercise Differs Between Symptomatic and Asymptomatic Achilles Tendons JF - Frontiers in physiology N2 - Objective: This study investigated intraindividual differences of intratendinous blood flow (IBF) in response to running exercise in participants with Achilles tendinopathy. Design: This is a cross-sectional study. Setting: The study was conducted at the University Outpatient Clinic. Participants: Sonographic detectable intratendinous blood flow was examined in symptomatic and contralateral asymptomatic Achilles tendons of 19 participants (42 ± 13 years, 178 ± 10 cm, 76 ± 12 kg, VISA-A 75 ± 16) with clinically diagnosed unilateral Achilles tendinopathy and sonographic evident tendinosis. Intervention: IBF was assessed using Doppler ultrasound “Advanced Dynamic Flow” before (Upre) and 5, 30, 60, and 120 min (U5–U120) after a standardized submaximal constant load run. Main Outcome Measure: IBF was quantified by counting the number (n) of vessels in each tendon. Results: At Upre, IBF was higher in symptomatic compared with asymptomatic tendons [mean 6.3 (95% CI: 2.8–9.9) and 1.7 (0.4–2.9), p < 0.01]. Overall, 63% of symptomatic and 47% of asymptomatic Achilles tendons responded to exercise, whereas 16 and 11% showed persisting IBF and 21 and 42% remained avascular throughout the investigation. At U5, IBF increased in both symptomatic and asymptomatic tendons [difference to baseline: 2.4 (0.3–4.5) and 0.9 (0.5–1.4), p = 0.05]. At U30 to U120, IBF was still increased in symptomatic but not in asymptomatic tendons [mean difference to baseline: 1.9 (0.8–2.9) and 0.1 (-0.9 to 1.2), p < 0.01]. Conclusion: Irrespective of pathology, 47–63% of Achilles tendons responded to exercise with an immediate acute physiological IBF increase by an average of one to two vessels (“responders”). A higher amount of baseline IBF (approximately five vessels) and a prolonged exercise-induced IBF response found in symptomatic ATs indicate a pain-associated altered intratendinous “neovascularization.” KW - achilles tendinopathy KW - tendinosis KW - neovascularization KW - ultrasound KW - advanced dynamic flow KW - sonography Y1 - 2021 U6 - https://doi.org/10.3389/fphys.2021.617497 SN - 1664-042X VL - 12 SP - 1 EP - 8 PB - Frontiers Research Foundation CY - Lausanne, Schweiz ER - TY - JOUR A1 - Risch, Lucie A1 - Wochatz, Monique A1 - Messerschmidt, Janin A1 - Engel, Tilman A1 - Mayer, Frank A1 - Cassel, Michael T1 - Reliability of evaluating achilles tendon vascularization assessed with doppler ultrasound advanced dynamic flow JF - Journal of ultrasound in medicine N2 - The reliability of quantifying intratendinous vascularization by high-sensitivity Doppler ultrasound advanced dynamic flow has not been examined yet. Therefore, this study aimed to investigate the intraobserver and interobserver reliability of evaluating Achilles tendon vascularization by advanced dynamic flow using established scoring systems. Methods-Three investigators evaluated vascularization in 67 recordings in a test-retest design, applying the Ohberg score, a modified Ohberg score, and a counting score. Intraobserver and interobserver agreement for the Ohberg score and modified Ohberg score was analyzed by the Cohen kappa and Fleiss kappa coefficients (absolute), Kendall tau b coefficient, and Kendall coefficient of concordance (W; relative). The reliability of the counting score was analyzed by intraclass correlation coefficients (ICC) 2.1 and 3.1, the standard error of measurement (SEM), and Bland-Altman analysis (bias and limits of agreement [LoA]). Results-Intraobserver and interobserver agreement (absolute/relative) ranged from 0.61 to 0.87/0.87 to 0.95 and 0.11 to 0.66/0.76 to 0.89 for the Ohberg score and from 0.81 to 0.87/0.92 to 0.95 and 0.64 to 0.80/0.88 to 0.93 for the modified Ohberg score, respectively. The counting score revealed an intraobserver ICC of 0.94 to 0.97 (SEM, 1.0-1.5; bias, -1; and LoA, 3-4 vessels). The interobserver ICC for the counting score ranged from 0.91 to 0.98 (SEM, 1.0-1.9; bias, 0; and LoA, 3-5 vessels). Conclusions-The modified Ohberg score and counting score showed excellent reliability and seem convenient for research and clinical practice. The Ohberg score revealed decent intraobserver but unexpected low interobserver reliability and therefore cannot be recommended. KW - advanced dynamic flow KW - intratendinous blood flow KW - musculoskeletal KW - reliability KW - ultrasound Y1 - 2017 U6 - https://doi.org/10.1002/jum.14414 SN - 0278-4297 SN - 1550-9613 VL - 37 IS - 3 SP - 737 EP - 744 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Risch, Lucie A1 - Mayer, Frank A1 - Cassel, Michael T1 - Doppler flow response following running exercise differs between healthy and tendinopathic Achilles tendons JF - Frontiers in Physiology N2 - Background: The relationship between exercise-induced intratendinous blood flow (IBF) and tendon pathology or training exposure is unclear. Objective: This study investigates the acute effect of running exercise on sonographic detectable IBF in healthy and tendinopathic Achilles tendons (ATs) of runners and recreational participants. Methods: 48 participants (43 ± 13 years, 176 ± 9 cm, 75 ± 11 kg) performed a standardized submaximal 30-min constant load treadmill run with Doppler ultrasound “Advanced dynamic flow” examinations before (Upre) and 5, 30, 60, and 120 min (U5-U120) afterward. Included were runners (>30 km/week) and recreational participants (<10 km/week) with healthy (Hrun, n = 10; Hrec, n = 15) or tendinopathic (Trun, n = 13; Trec, n = 10) ATs. IBF was assessed by counting number [n] of intratendinous vessels. IBF data are presented descriptively (%, median [minimum to maximum range] for baseline-IBF and IBF-difference post-exercise). Statistical differences for group and time point IBF and IBF changes were analyzed with Friedman and Kruskal-Wallis ANOVA (α = 0.05). Results: At baseline, IBF was detected in 40% (3 [1–6]) of Hrun, in 53% (4 [1–5]) of Hrec, in 85% (3 [1–25]) of Trun, and 70% (10 [2–30]) of Trec. At U5 IBF responded to exercise in 30% (3 [−1–9]) of Hrun, in 53% (4 [−2–6]) of Hrec, in 70% (4 [−10–10]) of Trun, and in 80% (5 [1–10]) of Trec. While IBF in 80% of healthy responding ATs returned to baseline at U30, IBF remained elevated until U120 in 60% of tendinopathic ATs. Within groups, IBF changes from Upre-U120 were significant for Hrec (p < 0.01), Trun (p = 0.05), and Trec (p < 0.01). Between groups, IBF changes in consecutive examinations were not significantly different (p > 0.05) but IBF-level was significantly higher at all measurement time points in tendinopathic versus healthy ATs (p < 0.05). Conclusion: Irrespective of training status and tendon pathology, running leads to an immediate increase of IBF in responding tendons. This increase occurs shortly in healthy and prolonged in tendinopathic ATs. Training exposure does not alter IBF occurrence, but IBF level is elevated in tendon pathology. While an immediate exercise-induced IBF increase is a physiological response, prolonged IBF is considered a pathological finding associated with Achilles tendinopathy. KW - neovascularization KW - tendinopathy KW - Doppler ultrasound KW - Advanced Dynamic Flow KW - athlete KW - sonography Y1 - 2021 U6 - https://doi.org/10.3389/fphys.2021.650507 SN - 1664-042X VL - 12 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Cassel, Michael A1 - Risch, Lucie A1 - Intziegianni, Konstantina A1 - Mueller, Juliane A1 - Stoll, Josefine A1 - Brecht, Pia A1 - Mayer, Frank T1 - Incidence of achilles and patellar tendinopathy in adolescent elite athletes JF - International journal of sports medicine N2 - The study investigated the incidence of Achilles and patellar tendinopathy in adolescent elite athletes and non-athletic controls. Furthermore, predictive and associated factors for tendinopathy development were analyzed. The prospective study consisted of two measurement days (M1/M2) with an interval of 3.2 +/- 0.9 years. 157 athletes (12.1 +/- 0.7 years) and 25 controls (13.3 +/- 0.6 years) without Achilles/patellar tendinopathy were included at Ml. Clinical and ultrasound examinations of both Achilles (AT) and patellar tendons (PT) were performed. Main outcome measures were incidence tendinopathy and structural intratendinous alterations (hypo-/hyperechogenicity, vascularization) at M2 [%]. Incidence of Achilles tendinopathy was 1% in athletes and 0% in controls. Patellar tendinopathy was more frequent in athletes (13 %)than in controls (4%). Incidence of intratendinous alterations in ATs was 1-2% in athletes and 0 % in controls, whereas in PTs it was 4-6 % in both groups (p >0.05). Intratendinous alterations at M2 were associated with patellar tendinopathy in athletes (p <= 0.01). Intratendinous alterations at M1, anthropometric data, training amount, sports or sex did not predict tendinopathy development (p>0.05). Incidence often dinopathy and intratendinous alterations in adolescent athletes is low in ATs and more common in PTs. Development of intratendinous alterations in PT is associated with tend in opathy. However, predictive factors could not be identified. KW - epidemiology KW - young athletes KW - sonography KW - vascularization KW - hypoechogenicities Y1 - 2018 U6 - https://doi.org/10.1055/a-0633-9098 SN - 0172-4622 SN - 1439-3964 VL - 39 IS - 9 SP - 726 EP - 732 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Cassel, Michael A1 - Stoll, Josefine A1 - Schugardt, Monique A1 - Mayer, Frank T1 - Overuse and injury prevention JF - Elite youth cycling Y1 - 2019 SN - 978-1-315-11077-6 SN - 978-1-138-08684-5 SP - 141 EP - 159 PB - Routledge CY - London ER - TY - JOUR A1 - Cassel, Michael A1 - Risch, Lucie A1 - Mayer, Frank A1 - Kaplick, Hannes A1 - Engel, Aaron A1 - Kulig, Kornelia A1 - Bashford, Greg T1 - Achilles tendon morphology assessed using image based spatial frequency analysis is altered among healthy elite adolescent athletes compared to recreationally active controls JF - Journal of science and medicine in sport : official journal of Sports Medicine Australia N2 - Objectives: Although expected, tendon adaptations in adolescent elite athletes have been underreported. Morphologically, adaptations may occur by an increase in collagen fiber density and/or organization. These characteristics can be captured using spatial frequency parameters extracted from ultrasound images. This study aims to compare Achilles tendon (AT) morphology among sports-specific cohorts of elite adolescent athletes and to compare these findings to recreationally active controls by use of spatial frequency analysis. Design: Cross-sectional observational study. Method: In total, 334 healthy adolescent athletes from four sport categories (ball, combat, endurance, explosive strength) and 35 healthy controls were included. Longitudinal ultrasound scans were performed at the AT insertion and midportion. Intra-tendinous-morphology was quantified by performing spatial frequency analysis assessing eight parameters at standardized ROls. Increased values in five parameters suggest a higher structural organization, and in two parameters higher fiber density. One parameter represents a quotient combining both organization and fiber density. Results: Among athletes, only ball sport athletes exhibited an increase in one summative parameter at pre-insertion site compared to athletes from other sport categories. When compared to athletes, controls had significantly higher values of four parameters at pre-insertion and three parameters at midportion site reflecting differences in both, fiber organization and density. Conclusions: Intra-tendinous-morphology was similar in all groups of adolescent athletes. Higher values found in non-athletes might suggest higher AT fiber density and organization. It is yet unclear whether the lesser structural organization in young athletes represents initial AT pathology, or a physiological adaptive response at the fiber cross-linking level. (C) 2019 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved. KW - Tendon structure KW - Adaptation KW - Ultrasound KW - Athletic loading KW - Tendinopathy Y1 - 2019 U6 - https://doi.org/10.1016/j.jsams.2019.03.011 SN - 1440-2440 SN - 1878-1861 VL - 22 IS - 8 SP - 882 EP - 886 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Müller, Steffen A1 - Stoll, Josefine A1 - Mueller, Juliane A1 - Cassel, Michael A1 - Mayer, Frank T1 - Trunk Muscle Activity during Drop Jump Performance in Adolescent Athletes with Back Pain JF - Frontiers in physiology N2 - In the context of back pain, great emphasis has been placed on the importance of trunk stability, especially in situations requiring compensation of repetitive, intense loading induced during high-performance activities, e.g., jumping or landing. This study aims to evaluate trunk muscle activity during drop jump in adolescent athletes with back pain (BP) compared to athletes without back pain (NBP). Eleven adolescent athletes suffering back pain (BP: m/f: n = 4/7; 15.9 +/- 1.3 y; 176 +/- 11 cm; 68 +/- 11 kg; 12.4 +/- 10.5 h/we training) and 11 matched athletes without back pain (NBP: m/f: n = 4/7; 15.5 +/- 1.3 y; 174 +/- 7 cm; 67 +/- 8 kg; 14.9 +/- 9.5 h/we training) were evaluated. Subjects conducted 3 drop jumps onto a force plate (ground reaction force). Bilateral 12-lead SEMG (surface Electromyography) was applied to assess trunk muscle activity. Ground contact time [ms], maximum vertical jump force [N], jump time [ms] and the jump performance index [m/s] were calculated for drop jumps. SEMG amplitudes (RMS: root mean square [%]) for all 12 single muscles were normalized toMIVC (maximum isometric voluntary contraction) and analyzed in 4 time windows (100 ms pre- and 200 ms post-initial ground contact, 100 ms pre- and 200 ms post-landing) as outcome variables. In addition, muscles were grouped and analyzed in ventral and dorsal muscles, as well as straight and transverse trunk muscles. Drop jump ground reaction force variables did not differ between NBP and BP (p > 0.05). Mm obliquus externus and internus abdominis presented higher SEMG amplitudes (1.3-1.9-fold) for BP (p < 0.05). Mm rectus abdominis, erector spinae thoracic/lumbar and latissimus dorsi did not differ (p > 0.05). The muscle group analysis over the whole jumping cycle showed statistically significantly higher SEMG amplitudes for BP in the ventral (p = 0.031) and transverse muscles (p = 0.020) compared to NBP. Higher activity of transverse, but not straight, trunk muscles might indicate a specific compensation strategy to support trunk stability in athletes with back pain during drop jumps. Therefore, exercises favoring the transverse trunk muscles could be recommended for back pain treatment. KW - SEMG-pattern KW - back pain KW - pre-activity KW - drop jump KW - neuromuscular KW - trunk KW - performance KW - young athletes Y1 - 2017 U6 - https://doi.org/10.3389/fphys.2017.00274 SN - 1664-042X VL - 8 SP - 124 EP - 132 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Cassel, Michael A1 - Intziegianni, Konstantina A1 - Risch, Lucie A1 - Mueller, Steffen A1 - Engel, Tilman A1 - Mayer, Frank T1 - Physiological Tendon Thickness Adaptation in Adolescent Elite Athletes: A Longitudinal Study JF - Frontiers in physiology N2 - Increased Achilles (AT) and Patellar tendon (PT) thickness in adolescent athletes compared to non-athletes could be shown. However, it is unclear, if changes are of pathological or physiological origin due to training. The aim of this study was to determine physiological AT and PT thickness adaptation in adolescent elite athletes compared to non-athletes, considering sex and sport. In a longitudinal study design with two measurement days (M1/M2) within an interval of 3.2 +/- 0.8 years, 131 healthy adolescent elite athletes (m/f: 90/41) out of 13 different sports and 24 recreationally active controls (m/f: 6/18) were included. Both ATs and PTs were measured at standardized reference points. Athletes were divided into 4 sport categories [ball (B), combat (C), endurance (E) and explosive strength sports (S)]. Descriptive analysis (mean SD) and statistical testing for group differences was performed (cy = 0.05). AT thickness did not differ significantly between measurement days, neither in athletes (5.6 +/- 0.7 mm/5.6 +/- 0.7 mm) nor in controls (4.8 +/- 0.4 mm/4.9 +/- 0.5 mm, p > 0.05). For PTs, athletes presented increased thickness at M2 (Ml: 3.5 +/- 0.5 mm, M2: 3.8 +/- 0.5 mm, p < 0.001). In general, males had thicker ATs and PTs than females (p < 0.05). Considering sex and sports, only male athletes from B, C, and S showed significant higher PT-thickness at M2 compared to controls (p <= 0.01). Sport-specific adaptation regarding tendon thickness in adolescent elite athletes can be detected in PTs among male athletes participating in certain sports with high repetitive jumping and strength components. Sonographic microstructural analysis might provide an enhanced insight into tendon material properties enabling the differentiation of sex and influence of different sports. KW - Achilles and patellar tendon KW - training adaptation KW - sonography KW - young athletes KW - non-athletes Y1 - 2017 U6 - https://doi.org/10.3389/fphys.2017.00795 SN - 1664-042X VL - 8 SP - 599 EP - 611 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Cassel, Michael A1 - Carlsohn, Anja A1 - Fröhlich, Katja A1 - John, Mareike A1 - Riegels, N. A1 - Mayer, Frank T1 - Tendon Adaptation to Sport-specific Loading in Adolescent Athletes JF - International journal of sports medicine N2 - Tendon adaptation due to mechanical loading is controversially discussed. However, data concerning the development of tendon thickness in adolescent athletes is sparse. The purpose of this study was to examine possible differences in Achilles (AT) and patellar tendon (PT) thickness in adolescent athletes while considering age, gender and sport-specific loading. In 500 adolescent competitive athletes of 16 different sports and 40 recreational controls both ATs and PTs were sonographically measured. Subjects were divided into 2 age groups (< 13; ≥ 13 years) and 6 sport type categories (ball, combat, and water sports, combined disciplines, cycling, controls). In addition, 3 risk groups (low, moderate, high) were created according to the athlete’s risk of developing tendinopathy. AT and PT thickness did not significantly differ between age groups (AT/PT:<13: 5.4±0.7 mm/3.6±0.5 mm;≥13: 5.3±0.7 mm/3.6±0.5 mm). In both age groups males presented higher tendon thickness than females (p<0.001). AT thickness was highest in ball sports/cyclists and lowest in controls (p≤0.002). PT thickness was greatest in water sports and lowest in controls (p=0.02). High risk athletes presented slightly higher AT thickness compared to the low risk group (p=0.03). Increased AT and PT thickness in certain sport types compared to controls supports the hypothesis of structural tendon adaptation due to sport-specific loading. KW - achilles and patellar tendon KW - training adaptation KW - tendon thickness KW - standard values KW - sonography Y1 - 2016 U6 - https://doi.org/10.1055/s-0035-1559772 SN - 0172-4622 SN - 1439-3964 VL - 37 SP - 159 EP - 164 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Bisi-Balogun, Adebisi A1 - Cassel, Michael A1 - Mayer, Frank T1 - Reliability of Various Measurement Stations for Determining Plantar Fascia Thickness and Echogenicity JF - Diagnostics : open access journal N2 - This study aimed to determine the relative and absolute reliability of ultrasound (US) measurements of the thickness and echogenicity of the plantar fascia (PF) at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet) were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was performed using Image J, a digital image analysis and viewer software. A sonography evaluation of the thickness and echogenicity of the PF showed a high relative reliability with an Intra class correlation coefficient of 0.88 at all measurement stations. However, the measurement stations for both the PF thickness and echogenicity which showed the highest intraclass correlation coefficient (ICCs) did not have the highest absolute reliability. Compared to other measurement stations, measuring the PF thickness at 3 cm distal and the echogenicity at a region of interest 1 cm to 2 cm distal from its insertion at the medial calcaneal tubercle showed the highest absolute reliability with the least systematic bias and random error. Also, the reliability was higher using a mean of three measurements compared to one measurement. To reduce discrepancies in the interpretation of the thickness and echogenicity measurements of the PF, the absolute reliability of the different measurement stations should be considered in clinical practice and research rather than the relative reliability with the ICC. KW - plantar fascia KW - reliability KW - sonography KW - musculoskeletal Y1 - 2016 U6 - https://doi.org/10.3390/diagnostics6020015 SN - 2075-4418 VL - 6 SP - 506 EP - 519 PB - MDPI CY - Basel ER - TY - JOUR A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - Rauf, S. A1 - White, S. A1 - Rector, Michael V. A1 - Kaplick, Hannes A1 - Wahmkow, Gunnar A1 - Kratzenstein, S. A1 - Mayer, Frank T1 - Influence of Age and Pathology on Achilles Tendon Properties During a Single-leg Jump JF - International journal of sports medicine N2 - Prevalence of Achilles tendinopathy increases with age leading to a weaker tendon with predisposition to rupture. Conclusive evidence of the influence of age and pathology on Achilles tendon (AT) properties remains limited, as previous studies are based on standardized isometric conditions. The study investigates the influence of age and pathology on AT properties during single-leg vertical jump (SLVJ). 10 children (C), 10 asymptomatic adults (A), and 10 tendinopathic patients (T) were included. AT elongation [mm] from rest to maximal displacement during a SLVJ on a force-plate was sonographically assessed. AT compliance [mm/N]) and strain [%] was calculated by dividing elongation by peak ground reaction force [N] and length, respectively. One-way ANOVA followed by Bonferroni post-hoc correction (=0.05) were used to compare C with A and A with T. AT elongation (p=0.004), compliance (p=0.001), and strain were found to be statistically significant higher in C (27 +/- 3mm, 0.026 +/- 0.006[mm/N], 13 +/- 2%) compared to A (21 +/- 4mm, 0.017 +/- 0.005[mm/N], 10 +/- 2%). No statistically significant differences (p0.05) was found between A and T (25 +/- 5mm, 0.019 +/- 0.004[mm/N], 12 +/- 3%). During SLVJ, tendon responded differently in regards to age and pathology with children having the most compliant AT. Higher compliance found in healthy tendons might be considered as a protective factor against load-related injuries. KW - children KW - tendinopathy KW - compliance KW - dynamic KW - ultrasonography Y1 - 2016 U6 - https://doi.org/10.1055/s-0042-108198 SN - 0172-4622 SN - 1439-3964 VL - 37 SP - 973 EP - 978 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Cassel, Michael A1 - Müller, Juliane A1 - Moser, Othmar A1 - Strempler, Mares Elaine A1 - Reso, Judith A1 - Mayer, Frank T1 - Orthopedic Injury Profiles in Adolescent Elite Athletes BT - A Retrospective Analysis From a Sports Medicine Department JF - Frontiers in Physiology N2 - Aim: The aim of the study was to identify common orthopedic sports injury profiles in adolescent elite athletes with respect to age, sex, and anthropometrics. Methods: A retrospective data analysis of 718 orthopedic presentations among 381 adolescent elite athletes from 16 different sports to a sports medical department was performed. Recorded data of history and clinical examination included area, cause and structure of acute and overuse injuries. Injury-events were analyzed in the whole cohort and stratified by age (11–14/15–17 years) and sex. Group differences were tested by chi-squared-tests. Logistic regression analysis was applied examining the influence of factors age, sex, and body mass index (BMI) on the outcome variables area and structure (a = 0.05). Results: Higher proportions of injury-events were reported for females (60%) and athletes of the older age group (66%) than males and younger athletes. The most frequently injured area was the lower extremity (47%) followed by the spine (30.5%) and the upper extremity (12.5%). Acute injuries were mainly located at the lower extremity (74.5%), while overuse injuries were predominantly observed at the lower extremity (41%) as well as the spine (36.5%). Joints (34%), muscles (22%), and tendons (21.5%) were found to be the most often affected structures. The injured structures were different between the age groups (p = 0.022), with the older age group presenting three times more frequent with ligament pathology events (5.5%/2%) and less frequent with bony problems (11%/20.5%) than athletes of the younger age group. The injured area differed between the sexes (p = 0.005), with males having fewer spine injury-events (25.5%/34%) but more upper extremity injuries (18%/9%) than females. Regression analysis showed statistically significant influence for BMI (p = 0.002) and age (p = 0.015) on structure, whereas the area was significantly influenced by sex (p = 0.005). Conclusion: Events of soft-tissue overuse injuries are the most common reasons resulting in orthopedic presentations of adolescent elite athletes. Mostly, the lower extremity and the spine are affected, while sex and age characteristics on affected area and structure must be considered. Therefore, prevention strategies addressing the injury-event profiles should already be implemented in early adolescence taking age, sex as well as injury entity into account. KW - overuse injuries KW - epidemiology KW - complaints KW - symptoms KW - risk factors KW - sports Y1 - 2019 U6 - https://doi.org/10.3389/fphys.2019.00544 SN - 1664-042X VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Cassel, Michael A1 - Intziegianni, Konstantina A1 - Risch, Lucie A1 - Müller, Steffen A1 - Engel, Tilman A1 - Mayer, Frank T1 - Physiological Tendon Thickness Adaptation in Adolescent Elite Athletes BT - A Longitudinal Study JF - Frontiers in physiology N2 - Increased Achilles (AT) and Patellar tendon (PT) thickness in adolescent athletes compared to non-athletes could be shown. However, it is unclear, if changes are of pathological or physiological origin due to training. The aim of this study was to determine physiological AT and PT thickness adaptation in adolescent elite athletes compared to non-athletes, considering sex and sport. In a longitudinal study design with two measurement days (M1/M2) within an interval of 3.2 ± 0.8 years, 131 healthy adolescent elite athletes (m/f: 90/41) out of 13 different sports and 24 recreationally active controls (m/f: 6/18) were included. Both ATs and PTs were measured at standardized reference points. Athletes were divided into 4 sport categories [ball (B), combat (C), endurance (E) and explosive strength sports (S)]. Descriptive analysis (mean ± SD) and statistical testing for group differences was performed (α = 0.05). AT thickness did not differ significantly between measurement days, neither in athletes (5.6 ± 0.7 mm/5.6 ± 0.7 mm) nor in controls (4.8 ± 0.4 mm/4.9 ± 0.5 mm, p > 0.05). For PTs, athletes presented increased thickness at M2 (M1: 3.5 ± 0.5 mm, M2: 3.8 ± 0.5 mm, p < 0.001). In general, males had thicker ATs and PTs than females (p < 0.05). Considering sex and sports, only male athletes from B, C, and S showed significant higher PT-thickness at M2 compared to controls (p ≤ 0.01). Sport-specific adaptation regarding tendon thickness in adolescent elite athletes can be detected in PTs among male athletes participating in certain sports with high repetitive jumping and strength components. Sonographic microstructural analysis might provide an enhanced insight into tendon material properties enabling the differentiation of sex and influence of different sports. KW - Achilles and patellar tendon KW - training adaptation KW - sonography KW - young athletes KW - non-athletes Y1 - 2017 U6 - https://doi.org/10.3389/fphys.2017.00795 SN - 1664-042X VL - 8 SP - 1 EP - 8 PB - Frontiers CY - Lausanne ER - TY - JOUR A1 - Wahmkow, Gunnar A1 - Cassel, Michael A1 - Mayer, Frank A1 - Baur, Heiner T1 - Effects of different medial arch support heights on rearfoot kinematics JF - PLoS one N2 - Background Foot orthoses are usually assumed to be effective by optimizing mechanically dynamic rearfoot configuration. However, the effect from a foot orthosis on kinematics that has been demonstrated scientifically has only been marginal. The aim of this study was to examine the effect of different heights in medial arch-supported foot orthoses on rear foot motion during gait. Methods Nineteen asymptomatic runners (36±11years, 180±5cm, 79±10kg; 41±22km/week) participated in the study. Trials were recorded at 3.1 mph (5 km/h) on a treadmill. Athletes walked barefoot and with 4 different not customized medial arch-supported foot orthoses of various arch heights (N:0 mm, M:30 mm, H:35 mm, E:40mm). Six infrared cameras and the `Oxford Foot Model´ were used to capture motion. The average stride in each condition was calculated from 50 gait cycles per condition. Eversion excursion and internal tibia rotation were analyzed. Descriptive statistics included calculating the mean ± SD and 95% CIs. Group differences by condition were analyzed by one factor (foot orthoses) repeated measures ANOVA (α = 0.05). Results Eversion excursion revealed the lowest values for N and highest for H (B:4.6°±2.2°; 95% CI [3.1;6.2]/N:4.0°±1.7°; [2.9;5.2]/M:5.2°±2.6°; [3.6;6.8]/H:6.2°±3.3°; [4.0;8.5]/E:5.1°±3.5°; [2.8;7.5]) (p>0.05). Range of internal tibia rotation was lowest with orthosis H and highest with E (B:13.3°±3.2°; 95% CI [11.0;15.6]/N:14.5°±7.2°; [9.2;19.6]/M:13.8°±5.0°; [10.8;16.8]/H:12.3°±4.3°; [9.0;15.6]/E:14.9°±5.0°; [11.5;18.3]) (p>0.05). Differences between conditions were small and the intrasubject variation high. Conclusion Our results indicate that different arch support heights have no systematic effect on eversion excursion or the range of internal tibia rotation and therefore might not exert a crucial influence on rear foot alignment during gait. Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0172334 SN - 1932-6203 VL - 12 IS - 3 PB - PLoS CY - Lawrence, Kan. ER - TY - JOUR A1 - Müller, Steffen A1 - Stoll, Josefine A1 - Cassel, Michael A1 - Mayer, Frank T1 - Trunk Muscle Activity during Drop Jump Performance in Adolescent Athletes with Back Pain JF - Frontiers in physiology N2 - In the context of back pain, great emphasis has been placed on the importance of trunk stability, especially in situations requiring compensation of repetitive, intense loading induced during high-performance activities, e.g., jumping or landing. This study aims to evaluate trunk muscle activity during drop jump in adolescent athletes with back pain (BP) compared to athletes without back pain (NBP). Eleven adolescent athletes suffering back pain (BP: m/f: n = 4/7; 15.9 ± 1.3 y; 176 ± 11 cm; 68 ± 11 kg; 12.4 ± 10.5 h/we training) and 11 matched athletes without back pain (NBP: m/f: n = 4/7; 15.5 ± 1.3 y; 174 ± 7 cm; 67 ± 8 kg; 14.9 ± 9.5 h/we training) were evaluated. Subjects conducted 3 drop jumps onto a force plate (ground reaction force). Bilateral 12-lead SEMG (surface Electromyography) was applied to assess trunk muscle activity. Ground contact time [ms], maximum vertical jump force [N], jump time [ms] and the jump performance index [m/s] were calculated for drop jumps. SEMG amplitudes (RMS: root mean square [%]) for all 12 single muscles were normalized to MIVC (maximum isometric voluntary contraction) and analyzed in 4 time windows (100 ms pre- and 200 ms post-initial ground contact, 100 ms pre- and 200 ms post-landing) as outcome variables. In addition, muscles were grouped and analyzed in ventral and dorsal muscles, as well as straight and transverse trunk muscles. Drop jump ground reaction force variables did not differ between NBP and BP (p > 0.05). Mm obliquus externus and internus abdominis presented higher SEMG amplitudes (1.3–1.9-fold) for BP (p < 0.05). Mm rectus abdominis, erector spinae thoracic/lumbar and latissimus dorsi did not differ (p > 0.05). The muscle group analysis over the whole jumping cycle showed statistically significantly higher SEMG amplitudes for BP in the ventral (p = 0.031) and transverse muscles (p = 0.020) compared to NBP. Higher activity of transverse, but not straight, trunk muscles might indicate a specific compensation strategy to support trunk stability in athletes with back pain during drop jumps. Therefore, exercises favoring the transverse trunk muscles could be recommended for back pain treatment. KW - SEMG-pattern KW - back pain KW - pre-activity KW - drop jump KW - neuromuscular KW - trunk KW - performance KW - young athletes Y1 - 2017 U6 - https://doi.org/10.3389/fphys.2017.00274 SN - 1664-042X VL - 8 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - König, Niklas A1 - Müller, Steffen A1 - Fröhlich, Katja A1 - Mayer, Frank T1 - Ultrasonography for the assessment of the structural properties of the Achilles tendon in asymptomatic individuals: An intra-rater reproducibility study JF - Isokinetics and exercise science : official journal of the European Isokinetic Society N2 - BACKGROUND: Reproducible measurements of tendon structural properties are a prerequisite for accurate diagnosis of tendon disorders and for determination of their mechanical properties. Despite the widely used application of Ultrasonography (US) in musculoskeletal assessment, its operator dependency and lack of standardization influences the consistency of the measurement. OBJECTIVE: To evaluate the intra-rater reproducibility of a standardized US method assessing the structural properties of the Achilles tendon (AT). METHODS: Sixteen asymptomatic participants were positioned prone on an isokinetic dynamometer with the knee extended and ankle at 90. flexion. US was used to assess AT-length, cross-sectional area (CSA), and AT-elongation during isometric plantarflexion contraction. The intra-rater reproducibility was assessed by ICC (2.1), Test-Retest Variability (TRV, %), Bland-Altman analyses (Bias +/- LoA [1.96*SD]), and Standard-Error of Measurement (SEM). RESULTS: Measurements of AT-length demonstrated an ICC of 0.93, TRV of 4.5 +/- 3.9%, Bias +/- LoA of -2.8 +/- 25.0 mm and SEM of 6.6 mm. AT-CSA showed an ICC of 0.79, TRV of 8.7 +/- 9.6%, Bias +/- LoA of 1.7 +/- 19.4 mm(2) and SEM of 5.3 mm(2). AT-elongation revealed an ICC of 0.92, TRV of 12.9 +/- 8.9%, Bias +/- LoA of 0.3 +/- 5.7 mm and SEM of 1.5 mm. CONCLUSIONS: The presented methodology allows a reproducible assessment of Achilles tendon structural properties when performed by a single rater. KW - Ultrasonography KW - Achilles tendon KW - reproducibility KW - isokinetic Y1 - 2015 U6 - https://doi.org/10.3233/IES-150586 SN - 0959-3020 SN - 1878-5913 VL - 23 IS - 4 SP - 263 EP - 270 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Cassel, Michael A1 - Baur, Heiner A1 - Hirschmueller, Anja A1 - Carlsohn, Anja A1 - Fröhlich, Katja A1 - Mayer, Frank T1 - Prevalence of Achilles and patellar tendinopathy and their association to intratendinous changes in adolescent athletes JF - Scandinavian journal of medicine & science in sports N2 - Achilles (AT) and patellar tendons (PT) are commonly affected by tendinopathy in adult athletes but prevalence of symptoms and morphological changes in adolescents is unclear. The study aimed to determine prevalence of tendinopathy and intratendinous changes in ATs and PTs of adolescent athletes. A total of 760 adolescent athletes (13.0 +/- 1.9 years; 160 +/- 13cm; 50 +/- 14kg) were examined. History, local clinical examination, and longitudinal Doppler ultrasound analysis for both ATs and PTs were performed including identification of intratendinous echoic changes and vascularization. Diagnosis of tendinopathy was complied clinically in case of positive history of tendon pain and tendon pain on palpation. Achilles tendinopathy was diagnosed in 1.8% and patellar tendinopathy in 5.8%. Vascularizations were visible in 3.0% of ATs and 11.4% of PTs, hypoechogenicities in 0.7% and 3.2% as well as hyperechogenicities in 0% and 0.3%, respectively. Vascularizations and hypoechogenicities were statistically significantly more often in males than in females (P0.02). Subjects with patellar tendinopathy had higher prevalence of structural intratendinous changes than those without PT symptoms (P0.001). In adolescent athletes, patellar tendinopathy is three times more frequent compared with Achilles tendinopathy. Longitudinal studies are necessary to investigate physiological or pathological origin of vascularizations and its predictive value in development of tendinopathy. KW - Prevalence KW - tendinopathy KW - sonography KW - Doppler ultrasound KW - vascularization KW - hypoechogenicities KW - hyperechogenicities KW - adolescent athletes Y1 - 2015 U6 - https://doi.org/10.1111/sms.12318 SN - 0905-7188 SN - 1600-0838 VL - 25 IS - 3 SP - e310 EP - e318 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Cassel, Michael A1 - Stoll, Josefine A1 - Mayer, Frank T1 - Tendinopathies of the Lower Extremities in Sport - Diagnostics and Therapy JF - Sportverletzung, Sportschaden : Grundlagen, Prävention, Rehabilitation N2 - Tendinopathies are frequently the cause of chronic, load-dependent complaints of the lower extremity. Commonly, the large tendons of the ankle and knee joints are affected, especially the Achilles and patellar tendons. Repeated overuse in sports and/or daily activities is assumed as the aetiology. Besides the clinical examination including a comprehensive anamnesis of pain and training/loading, sonographic imaging has a high training/loading relevance for the diagnosis of tendon pathologies of the lower extremity. Training concepts are considered in first line as the treatment of choice. A combination with physical therapy interventions can be useful. In cases of a more severe pathology and long-standing complaints multimodal therapeutic options should be employed. The use of surgical treatment procedures should only be taken into account in case of failed response to conservative treatment. KW - Tendinopathy KW - sonography KW - principles of therapy Y1 - 2015 U6 - https://doi.org/10.1055/s-0034-1399668 SN - 0932-0555 SN - 1439-1236 VL - 29 IS - 2 SP - 87 EP - 98 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Kopinski, Stephan A1 - Engel, Tilman A1 - Cassel, Michael A1 - Fröhlich, Katja A1 - Mayer, Frank A1 - Carlsohn, Anja T1 - Ultrasound Applied to Subcutaneous Fat Tissue Measurements in International Elite Canoeists JF - International journal of sports medicine N2 - Subcutaneous adipose tissue (SAT) measurements with ultrasound have recently been introduced to assess body fat in elite athletes. However, appropriate protocols and data on various groups of athletes are missing. We investigated intra-rater reliability of SAT measurements using ultrasound in elite canoe athletes. 25 international level canoeists (18 male, 7 female; 23 +/- 4 years; 81 +/- 11 kg; 1.83 +/- 0.09 m; 20 +/- 3 training h/wk) were measured on 2 consecutive days. SAT was assessed with B-mode ultrasound at 8 sites (ISAK): triceps, subscapular, biceps, iliac crest, supraspinal, abdominal, front thigh, medial calf, and quantified using image analysis software. Data was analyzed descriptively (mean +/- SD, [range]). Coefficient of variation (CV %), intraclass correlation coefficient (ICC, 2.1) and absolute (LoA) and ratio limits of agreement (RLoA) were calculated for day-to-day reliability. Mean sum of SAT thickness was 30.0 +/- 19.4 mm [8.0, 80.1 mm], with 3.9 +/- 1.8 mm [1.2 mm subscapular, 8.0 mm abdominal] for individual sites. CV for the sum of sites was 4.7 %, ICC 0.99, LoA 1.7 +/- 3.6 mm, RLoA 0.940 (*/divided by 1.155). Measuring SAT with ultrasound has proved to have excellent day-to-day reliability in elite canoe athletes. Recommendations for standardization of the method will further increase accuracy and reproducibility. KW - subcutaneous adipose tissue KW - skinfold thickness KW - elite athletes KW - body composition KW - ultrasonography Y1 - 2015 U6 - https://doi.org/10.1055/s-0035-1555857 SN - 0172-4622 SN - 1439-3964 VL - 36 IS - 14 SP - 1134 EP - 1141 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - König, Niklas A1 - Cassel, Michael A1 - Intziegianni, Konstantina A1 - Mayer, Frank T1 - Inter-rater reliability and measurement error of sonographic muscle architecture assessments JF - Journal of ultrasound in medicine N2 - Objectives-Sonography of muscle architecture provides physicians and researchers with information about muscle function and muscle-related disorders. Inter-rater reliability is a crucial parameter in daily clinical routines. The aim of this study was to assess the inter-rater reliability of sonographic muscle architecture assessments and quantification of errors that arise from inconsistent probe positioning and image interpretation. Results-Inter-rater reliability was good overall (ICC, 0.77-0.90; IRV, 9.0%-13.4%; bias LoA, 0.2 +/- 0.2-1.7 +/- 3.0). Superior and inferior pennation angles showed high systematic bias and LoA in all setups, ranging from 2.0 degrees +/- 2.2 degrees to 3.4 degrees +/- 4.1 degrees. The highest IRV was found for muscle thickness (13.4%). "When the probe position was standardized, the SEM for muscle thickness decreased from 0.1 to 0.05 cm. Conclusions-Sonographic examination of muscle architecture of the medial gastrocnemius has good to high reliability. In contrast to pennation angle measurements, length measurements can be improved by standardization of the probe position. KW - gastrocnemius muscle KW - inter-rater variability KW - muscle architecture KW - musculoskeletal ultrasound KW - sonography Y1 - 2014 U6 - https://doi.org/10.7863/ultra.33.5.769 SN - 0278-4297 SN - 1550-9613 VL - 33 IS - 5 SP - 769 EP - 777 PB - American Institute of Ultrasound in Medicine CY - Laurel ER - TY - CHAP A1 - Reschke, Antje A1 - Cassel, Michael A1 - Intziegianni, Konstantina A1 - Mayer, Frank T1 - Intra- and inter-rater reliability of sonographic cross-sectional area measurements in asymptomatic patella tendons T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 927 EP - 928 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Müller, Steffen A1 - Cassel, Michael A1 - Müller, Juliane A1 - Stoll, Josefine A1 - Baur, Heiner A1 - Mayer, Frank T1 - Trunk strength in adolescent athletes with Spondylolisthesis with/without back pain during training: Pilot study T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 642 EP - 642 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Kopinski, Stephan A1 - Engel, Tilman A1 - Cassel, Michael A1 - Carlsohn, Anja A1 - Mayer, Frank T1 - Reliability of ultrasound measurements for subcutaneous adipose tissue in elite canoe athletes T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 539 EP - 539 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Engel, Tilman A1 - Kopinski, Stephan A1 - Carlsohn, Anja A1 - Cassel, Michael A1 - Mayer, Frank T1 - Correlation of sonographic subcutaneous adipose tissue measurements with air displacement plethysmography and calipermetry T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 539 EP - 539 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - Hain, Gerrit A1 - Fröhlic, Katja A1 - Mayer, Frank T1 - Reliability of sonographic assessment of Achilles tendon cross-sectional area at rest and maximal voluntary contraction T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 47 EP - 47 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Hain, Gerrit A1 - Cassel, Michael A1 - Intziegianni, Konstantina A1 - Mayer, Frank T1 - Achilles tendon cross-sectional area changes during maximal voluntary isometric plantar-flexion contraction in healthy individuals. T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 47 EP - 47 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Risch, Lucie A1 - Cassel, Michael A1 - Messerschmidt, Janin A1 - Intziegianni, Konstantina A1 - Mayer, Frank T1 - Consistency and reliability of examining intratendinous blood flow in Achilles tendinopathy patients using doppler ultrasonography T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 46 EP - 46 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Koch, Sarah A1 - Cassel, Michael A1 - Linne, Karsten A1 - Mayer, Frank A1 - Scharhag, Jürgen T1 - ECG and echocardiographic findings in 10-15-year-old elite athletes JF - European journal of preventive cardiology : the official ESC journal for primary & secondary cardiovascular prevention, rehabilitation and sports cardiology N2 - Background: Data on electrocardiographic and echocardiographic pre-participation screening findings in paediatric athletes are limited. KW - ECG KW - echocardiography KW - paediatric athlete KW - pre-participation screening KW - sudden cardiac death Y1 - 2014 U6 - https://doi.org/10.1177/2047487312462147 SN - 2047-4873 SN - 2047-4881 VL - 21 IS - 6 SP - 774 EP - 781 PB - Sage Publ. CY - London ER - TY - JOUR A1 - Scharhag-Rosenberger, Friederike A1 - Wochatz, Monique A1 - Otto, Christoph A1 - Cassel, Michael A1 - Mayer, Frank A1 - Scharhag, Jürgen T1 - Blood lactate concentrations are mildly affected by mobile gas exchange measurements JF - International journal of sports medicine N2 - We sought to investigate the effects of wearing a mobile respiratory gas analysis system during a treadmill test on blood lactate (bLa) concentrations and commonly applied bLa thresholds. A total of 16 recreational athletes (31 +/- 3 years, V0205: 58 6 ml min(-1)-kg(-1)) performed one multistage treadmill test with and one without gas exchange measurements (GEM and noGEM). The whole bLa curve, the lactate threshold (LT), the individual anaerobic thresholds according to Stegmann(IAT(sr)) and Dickhuth (IAT(Di)), and a fixed bLa concentration of 4 mmob.l(-1) (OBLA) were evaluated. The bLa curve was shifted slightly leftward in GEM compared to noGEM (P<0.05), whereas the heart rate response was not different between conditions (P= 0.89). There was no difference between GEM and noGEM for LT (2.61 +/- 0.34 vs. 2.64 +/- 0.39 m(-1) s(-1) P=0.49) and IAT(st) (3.47 +/- 0.42 vs. 3.55 +/- 0.47m-s(-1), P=0.12). However, IATD(Di) (3.57 +/- 0.39 vs. 3.66 +/- 0.44m-s(-1), P<0.01) and OBLA (3.85 +/- 0.46 vs. 3.96 +/- 0.47m-s-1, P<0.01) occurred at slower running velocities in GEM. The bLa response to treadmill tests is mildly affected by wearing a mobile gas analysis system. This also applies to bLa thresholds located at higher exercise intensities. While the magnitude of the effects is of little importance for recreational athletes, it might be relevant for elite athletes and scientific studies. KW - cardiopulmonary exercise testing KW - performance diagnostics KW - lactate threshold KW - VO2mdx KW - metabolic device Y1 - 2014 U6 - https://doi.org/10.1055/s-0033-1354386 SN - 0172-4622 SN - 1439-3964 VL - 35 IS - 7 SP - 590 EP - 594 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Carlsohn, Anja A1 - Scharhag-Rosenberger, Friederike A1 - Cassel, Michael A1 - Mayer, Frank T1 - Resting metabolic rate in elite rowers and canoeists difference between indirect calorimetry and prediction JF - Annals of nutrition & metabolism : journal of nutrition, metabolic diseases and dietetics ; an official journal of International Union of Nutritional Sciences (IUNS) N2 - Background: Athletes may differ in their resting metabolic rate (RMR) from the general population. However, to estimate the RMR in athletes, prediction equations that have not been validated in athletes are often used. The purpose of this study was therefore to verify the applicability of commonly used RMR predictions for use in athletes. Methods: The RMR was measured by indirect calorimetry in 17 highly trained rowers and canoeists of the German national teams (BMI 24 +/- 2 kg/m(2), fat-free mass 69 +/- 15 kg). In addition, the RMR was predicted using Cunningham (CUN) and Harris-Benedict (HB) equations. A two-way repeated measures ANOVA was calculated to test for differences between predicted and measured RMR (alpha = 0.05). The root mean square percentage error (RMSPE) was calculated and the Bland-Altman procedure was used to quantify the bias for each prediction. Results: Prediction equations significantly underestimated the RMR in males (p < 0.001). The RMSPE was calculated to be 18.4% (CUN) and 20.9% (HB) in the entire group. The bias was 133 kcal/24 h for CUN and 202 kcal/24 h for HB. Conclusions: Predictions significantly underestimate the RMR in male heavyweight endurance athletes but not in females. In athletes with a high fat-free mass, prediction equations might therefore not be applicable to estimate energy requirements. Instead, measurement of the resting energy expenditure or specific prediction equations might be needed for the individual heavyweight athlete. KW - Energy requirement KW - Calorimetry KW - Fat-free mass KW - Nutritional counseling KW - Athletes Y1 - 2011 U6 - https://doi.org/10.1159/000330119 SN - 0250-6807 VL - 58 IS - 3 SP - 239 EP - 244 PB - Karger CY - Basel ER - TY - JOUR A1 - Scharhag-Rosenberger, Friederike A1 - Carlsohn, Anja A1 - Cassel, Michael A1 - Mayer, Frank A1 - Scharhag, Jürgen T1 - How to test maximal oxygen uptake a study on timing and testing procedure of a supramaximal verification test JF - Applied physiology, nutrition, and metabolism = Physiologie appliquée, nutrition et métabolisme N2 - On utilise de plus en plus les tests de verification pour confirmer l'atteinte du consommation d'oxygene maximale (VO(2 max)). Toutefois, le moment et les methodes d'evaluation varient d'un groupe de travail a l'autre. Les objectifs de cette etude sont de constater si on peut administrer un test de verification apres un test d'effort progressif ou s'il est preferable de le faire une autre journee et si on peut determiner le VO(2 max) tout de meme lors de la premiere seance chez des sujets ne repondant pas au critere de verification. Quarante sujets (age, 24 +/- 4 ans; VO(2 max), 50 +/- 7 mL center dot min(-1)center dot kg(-1)) participent a un test d'effort progressif sur tapis roulant et, 10 min plus tard, a un test de verification (VerifDay1) a 110 % de la velocite maximale (v(max)). Le critere de verification est un VO(2) de pointe au VerifDay1 < 5,5 % a la valeur retenue au test d'effort progressif. Les sujets ne repondant pas au critere de verification passent un autre test de verification, mais a 115 % du VerifDay1', et ce, 10 min plus tard pour confirmer le VO(2) de pointe du VerifDay1 en tant que VO(2 max). Tous les autres sujets repassent le VerifDay1 a un jour different (VerifDay2). Six sujets sur quarante ne repondent pas au critere de verification. Chez quatre d'entre eux, on confirme l'atteinte du VO(2 max) au VerifDay1'. Le VO(2) de pointe au VerifDay1 est equivalent a celui du VerifDay2 (3722 +/- 991 mL center dot min(-1) comparativement a 3752 +/- 995 mL center dot min(-1), p = 0,56), mais le temps jusqu'a l'epuisement est significativement plus long au VerifDay2 (2:06 +/- 0:22 min:s comparativement a 2:42 +/- 0:38 min:s, p < 0,001, n = 34). Le VO(2) de pointe obtenu au test de verification ne semble pas conditionne par un test d'effort progressif maximal prealable. On peut donc realiser le test d'effort progressif et le test de verification lors de la meme seance d'evaluation. Chez presque tous les individus ne repondant pas au critere de verification, on peut determiner le VO(2 max) au moyen d'un autre test de verification plus intense. Y1 - 2011 U6 - https://doi.org/10.1139/H10-099 SN - 1715-5312 VL - 36 IS - 1 SP - 153 EP - 160 PB - NRC Research Press CY - Ottawa ER - TY - JOUR A1 - Carlsohn, Anja A1 - Scharhag-Rosenberger, Friederike A1 - Cassel, Michael A1 - Weber, Josefine A1 - Guzman, Annette de Guzman A1 - Mayer, Frank T1 - Physical activity levels to estimate the energy requirement of adolescent athletes JF - Pediatric exercise science N2 - Adequate energy intake in adolescent athletes is considered important. Total energy expenditure (TEE) can be calculated from resting energy expenditure (REE) and physical activity level (PAL). However, validated PAL recommendations are available for adult athletes only. Purpose was to comprise physical activity data in adolescent athletes and to establish PAL recommendations for this population. In 64 competitive athletes (15.3 +/- 1.5yr, 20.5 +/- 2.0kg/m(2)) and 14 controls (15.1 +/- 1.1yr, 21 +/- 2.1kg/m(2)) TEE was calculated using 7-day activity protocols validated against doubly-labeled water. REE was estimated by Schofield-HW equation, and PAL was calculated as TEE:REE. Observed PAL in adolescent athletes (1.90 +/- 0.35) did not differ compared with controls (1.84 +/- 0.32, p = .582) and was lower than recommended for adult athletes by the WHO. In conclusion, applicability of PAL values recommended for adult athletes to estimate energy requirements in adolescent athletes must be questioned. Instead, a PAL range of 1.75-2.05 is suggested. Y1 - 2011 SN - 0899-8493 VL - 23 IS - 2 SP - 261 EP - 269 PB - Human Kinetics Publ. CY - Champaign ER - TY - JOUR A1 - Mayer, Frank A1 - Scharhag-Rosenberger, Friederike A1 - Carlsohn, Anja A1 - Cassel, Michael A1 - Müller, Steffen A1 - Scharhag, Jürgen T1 - The intensity and effects of strength training in the elderly JF - Deutsches Ärzteblatt international : a weekly online journal of clinical medicine and public health N2 - Background: The elderly need strength training more and more as they grow older to stay mobile for their everyday activities. The goal of training is to reduce the loss of muscle mass and the resulting loss of motor function. The dose-response relationship of training intensity to training effect has not yet been fully elucidated. Methods: PubMed was selectively searched for articles that appeared in the past 5 years about the effects and dose-response relationship of strength training in the elderly. Results: Strength training in the elderly (> 60 years) increases muscle strength by increasing muscle mass, and by improving the recruitment of motor units, and increasing their firing rate. Muscle mass can be increased through training at an intensity corresponding to 60% to 85% of the individual maximum voluntary strength. Improving the rate of force development requires training at a higher intensity (above 85%), in the elderly just as in younger persons. It is now recommended that healthy old people should train 3 or 4 times weekly for the best results; persons with poor performance at the outset can achieve improvement even with less frequent training. Side effects are rare. Conclusion: Progressive strength training in the elderly is efficient, even with higher intensities, to reduce sarcopenia, and to retain motor function. Y1 - 2011 U6 - https://doi.org/10.3238/arztebl.2011.0359 SN - 1866-0452 VL - 108 IS - 21 SP - 359 EP - U30 PB - Dt. Ärzte-Verl. CY - Cologne ER - TY - JOUR A1 - Carlsohn, Anja A1 - Cassel, Michael A1 - Linne, Karsten A1 - Mayer, Frank T1 - How much is too much? - a case report of nutritional supplement use of a high-performance athlete JF - The British journal of nutrition : an international journal devoted to the science of human and animal nutrition N2 - Although dietary nutrient intake is often adequate, nutritional supplement use is common among elite athletes. However, high-dose supplements or the use of multiple supplements may exceed the recommended daily allowance (RDA) of particular nutrients or even result in a daily intake above tolerable upper limits (UL). The present case report presents nutritional intake data and supplement use of a highly trained male swimmer competing at international level. Habitual energy and micronutrient intake were analysed by 3 d dietary reports. Supplement use and dosage were assessed, and total amount of nutrient supply was calculated. Micronutrient intake was evaluated based on RDA and UL as presented by the European Scientific Committee on Food, and maximum permitted levels in supplements (MPL) are given. The athlete's diet provided adequate micronutrient content well above RDA except for vitamin D. Simultaneous use of ten different supplements was reported, resulting in excess intake above tolerable UL for folate, vitamin E and Zn. Additionally, daily supplement dosage was considerably above MPL for nine micronutrients consumed as artificial products. Risks and possible side effects of exceeding UL by the athlete are discussed. Athletes with high energy intake may be at risk of exceeding UL of particular nutrients if multiple supplements are added. Therefore, dietary counselling of athletes should include assessment of habitual diet and nutritional supplement intake. Educating athletes to balance their diets instead of taking supplements might be prudent to prevent health risks that may occur with long-term excess nutrient intake. KW - Dietary supplements KW - Tolerable upper limits KW - Elite athletes KW - Vitamins KW - Minerals Y1 - 2011 U6 - https://doi.org/10.1017/S0007114510005556 SN - 0007-1145 VL - 105 IS - 12 SP - 1724 EP - 1728 PB - Cambridge Univ. Press CY - Cambridge ER - TY - JOUR A1 - Baur, Heiner A1 - Müller, Steffen A1 - Hirschmüller, Anja A1 - Cassel, Michael A1 - Weber, Josefine A1 - Mayer, Frank T1 - Comparison in lower leg neuromuscular activity between runners with unilateral mid-portion Achilles tendinopathy and healthy individuals JF - Journal of electromyography and kinesiology N2 - Neuromuscular control in functional situations and possible impairments due to Achilles tendinopathy are not well understood. Thirty controls (CO) and 30 runners with Achilles tendinopathy (AT) were tested on a treadmill at 3.33 m s(-1) (12 km h(-1)). Neuromuscular activity of the lower leg (tibialis anterior, peroneal, and gastrocnemius muscle) was measured by surface electromyography. Mean amplitude values (MAV) for the gait cycle phases preactivation, weight acceptance and push-off were calculated and normalised to the mean activity of the entire gait cycle. MAVs of the tibialis anterior did not differ between CO and AT in any gait cycle phase. The activation of the peroneal muscle was lower in AT in weight acceptance (p = 0.006), whereas no difference between CO and AT was found in preactivation (p = 0.71) and push-off (p = 0.83). Also, MAVs of the gastrocnemius muscle did not differ between AT and CO in preactivity (p = 0.71) but were reduced in AT during weight acceptance (p = 0.001) and push-off (p = 0.04). Achilles tendinopathy does not seem to alter pre-programmed neural control but might induce mechanical deficits of the lower extremity during weight bearing (joint stability). This should be addressed in the therapy process of AT. KW - Ankle joint KW - Electromyography KW - Overuse injury KW - Running gait Y1 - 2011 U6 - https://doi.org/10.1016/j.jelekin.2010.11.010 SN - 1050-6411 VL - 21 IS - 3 SP - 499 EP - 505 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Wojcinski, Sebastian A1 - Cassel, Michael A1 - Farrokh, Andre A1 - Soliman, Amr A. A1 - Hille, Ursula A1 - Schmidt, Werner A1 - Degenhardt, Friedrich A1 - Hillemanns, Peter T1 - Variations in the elasticity of breast tissue during the menstrual cycle determined by real-time sonoelastography JF - Journal of ultrasound in medicine N2 - Objectives-The purpose of this study was to determine the dependence of breast tissue elasticity on the menstrual cycle of healthy volunteers by means of real-time sonoelastography. Methods-Twenty-two healthy volunteers (aged 18-33 years) were examined once weekly during two consecutive menstrual cycles using sonoelastography. Group 1 (n = 10) was not taking hormonal medication; group 2 (n = 12) was taking oral contraceptives. Results-The breast parenchyma appeared softer than the dermis and harder than the adipose tissue, and elasticity varied over the menstrual cycle and between groups. Group 1 (no hormone intake) showed continuously increasing elasticity with relatively soft breast parenchyma in the menstrual and follicular phases and harder parenchyma in the luteal phase (P = .012). Group 2 (oral contraceptives) showed no statistically significant changes in breast parenchymal elasticity according to sonoelastography. The parenchyma was generally softer in group 1 compared with group 2 throughout the menstrual cycle (P = .033). The dermis, the subcutaneous adipose tissue, and the pectoralis major muscle showed no changes in elasticity. Comparison of measurements made during the first and the second menstrual cycles showed similar patterns of elasticity in both groups. Conclusions-Sonoelastography is a reproducible method that can be used to determine the dependence of breast parenchyma elasticity on the menstrual cycle and on the intake of hormonal contraceptives. KW - breast tissue KW - elasticity imaging KW - real-time tissue elastography KW - sonoelastography Y1 - 2012 SN - 0278-4297 SN - 1550-9613 VL - 31 IS - 1 SP - 63 EP - 72 PB - American Institute of Ultrasound in Medicine CY - Laurel ER - TY - JOUR A1 - Baur, Heiner A1 - Hirschmüller, Anja A1 - Müller, Steffen A1 - Cassel, Michael A1 - Mayer, Frank T1 - Is EMG of the lower leg dependent on weekly running mileage? JF - International journal of sports medicine N2 - Neuromuscular activity of the lower leg is dependent on the task performed, speed of movement and gender. Whether training volume influences neuromuscular activity is not known. The EMG of physically active persons differing in running mileage was analysed to investigate this. 55 volunteers were allocated to a low (LM: < 30 km), intermediate (IM: > 30 km & < 45 km) or high mileage (HM: > 45 km) group according to their weekly running volume. Neuromuscular activity of the lower leg was measured during running (3.33 m.s(-1)). Mean amplitude values for preactivation, weight acceptance and push-off were calculated and normalised to the mean activity of the entire gait cycle. Higher activity in the gastrocnemius group was observed in weight acceptance in LM compared to IM (+30%) and HM (+25%) but lower activity was present in the push-off for LM compared to IM and HM. For the peroneal muscle, differences were present in the push-off where HM showed increased activity compared to IM (+24%) and LM (+60%). The tibial muscle revealed slightly lower activity during preactivation for the high mileage runners. Neuromuscular activity differs during stance between the high and intermediate group compared to low mileage runners. Slight adaptations in neuromuscular activation indicate a more target-oriented activation strategy possibly due to repetitive training in runners with higher weekly mileage. KW - locomotion KW - neuromuscular control KW - running gait KW - training volume Y1 - 2012 U6 - https://doi.org/10.1055/s-0031-1286250 SN - 0172-4622 VL - 33 IS - 1 SP - 53 EP - 57 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Cassel, Michael A1 - Müller, Steffen A1 - Carlsohn, Anja A1 - Baur, Heiner A1 - Jerusel, N. A1 - Mayer, Frank T1 - Intra- and interrater variability of sonographic investigations of patella and achilles tendons JF - Sportverletzung, Sportschaden : Grundlagen, Prävention, Rehabilitation N2 - Background: Clinical examinations of tendon disorders routinely include ultrasound examinations, despite the fact that availability of data concerning validity criteria of these measurements are limited. The present study therefore aims to evaluate the reliability of measurements of Achilles- and Patella tendon diameter and in the detection of structural adaptations. Materials and Methods: In 14 healthy, recreationally active subjects both asymptomatic Achilles (AT) and patella tendons (PT) were measured twice by two examiners in a test-retest design. Besides the detection of anteroposterior (a.p.-) and mediolateral (m.l.-) diameters, areas of hypoechogenicity and neovascularisation were registered. Data were analysed descriptively with calculation of test-retest variability (TRV), intraclass-correlation coefficient (ICC) and Bland and Altman's plots with bias and 95% limits of agreement (LOA). Results: Intra- and interrater differences of AT- and PT-a.p.-diameter varied from 0.2 - 1.2 mm, those of AT- and PT-m.l-diameter from 0.7-5.1 mm. Areas of hypoechogenicity were visible in 24% of the tendons, while 15% showed neovascularisations. Intrarater AT-a.p.-diameters showed sparse deviations (TRV 4.5-7.4%; ICC 0.60-0.84; bias -0.05-0.07 mm; LOA-0.6-0.5 to -1.1 - 1.0 mm), while interrater AT- and PT-m.l.-diameters were highly variable (TRV 13.7-19.7%; ICC 0.11-0.20; bias -1.4-4.3 mm; LOA-5.5-2.7 to -10.5 - 1.9 mm). Conclusion: Our results suggest that the measurement of AT- and PT-a.p.-diameters is a reliable parameter. In contrast, reproducibility of AT- and PT-m.l.-diameters is questionable. The study corroborates the presence of hypoechogenicity and neovascularisation in asymptomatic tendons. KW - ultrasound KW - Achilles tendon KW - Patella tendon KW - intra- and inter-rater variability KW - tendon diameter Y1 - 2012 U6 - https://doi.org/10.1055/s-0031-1281839 SN - 0932-0555 VL - 26 IS - 1 SP - 21 EP - 26 PB - Thieme CY - Stuttgart ER - TY - CHAP A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - Müller, Steffen A1 - Mayer, Frank T1 - Ultrasound evaluation of the patellar tendon cross-sectional area and its relation to maximum force T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2012 SN - 0195-9131 VL - 44 SP - 714 EP - 714 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Mayer, Frank A1 - Bonaventura, Klaus A1 - Cassel, Michael A1 - Müller, Steffen A1 - Weber, Josefine A1 - Scharhag-Rosenberger, Friederike A1 - Carlsohn, Anja A1 - Baur, Heiner A1 - Scharhag, Jürgen T1 - Medical results of preparticipation examination in adolescent athletes JF - British journal of sports medicine : the journal of sport and exercise medicine N2 - Background Preparticipation examinations (PPE) are frequently used to evaluate eligibility for competitive sports in adolescent athletes. Nevertheless, the effectiveness of these examinations is under debate since costs are high and its validity is discussed controversial. Purpose To analyse medical findings and consequences in adolescent athletes prior to admission to a sports school. Methods In 733 adolescent athletes (318 girls, 415 boys, age 12.3+/-0.4, 16 sports disciplines), history and clinical examination (musculoskeletal, cardiovascular, general medicine) was performed to evaluate eligibility. PPE was completed by determination of blood parameters, ECG at rest and during ergometry, echocardiography and x-rays and ultrasonography if indicated. Eligibility was either approved or rated with restriction. Recommendations for therapy and/or prevention were given to the athletes and their parents. Results Historical (h) and clinical (c) findings (eg, pain, verified pathologies) were more frequent regarding the musculoskeletal system (h: 120, 16.4%; c: 247, 33.7%) compared to cardiovascular (h: 9, 1.2%; c: 23, 3.1%) or general medicine findings (h: 116, 15.8%; c: 71, 9.7%). ECG at rest was moderately abnormal in 46 (6.3%) and severely abnormal in 25 athletes (3.4%). Exercise ECG was suspicious in 25 athletes (3.4%). Relevant echocardiographic abnormalities were found in 17 athletes (2.3%). In 52 of 358 cases (14.5%), x-rays led to diagnosis (eg, Spondylolisthesis). Eligibility was temporarily restricted in 41 athletes (5.6%). Three athletes (0.4%) had to be excluded from competitive sports. Therapy (eg, physiotherapy, medication) and/or prevention (sensorimotor training, vaccination) recommendations were deduced due to musculoskeletal (t:n = 76,10.3%; p:n = 71,9.8%) and general medicine findings (t:n = 80, 10.9%; p:n = 104, 14.1%). Conclusion Eligibility for competitive sports is restricted in only 5.5% of adolescent athletes at age 12. Eligibility refusals are rare. However, recommendations for therapy and prevention are frequent, mainly regarding the musculoskeletal system. In spite of time and cost consumption, adolescent preparticipation before entering a career in high-performance sports is supported. Y1 - 2012 U6 - https://doi.org/10.1136/bjsports-2011-090966 SN - 0306-3674 VL - 46 IS - 7 SP - 524 EP - 530 PB - BMJ Publ. Group CY - London ER - TY - JOUR A1 - Wojcinski, Sebastian A1 - Dupont, Jennifer A1 - Schmidt, Werner A1 - Cassel, Michael A1 - Hillemanns, Peter T1 - Real-time ultrasound elastography in 180 axillary lymph nodes elasticity distribution in healthy lymph nodes and prediction of breast cancer metastases JF - BMC medical imaging N2 - Background: To determine the general appearance of normal axillary lymph nodes (LNs) in real-time tissue sonoelastography and to explore the method's potential value in the prediction of LN metastases. Methods: Axillary LNs in healthy probands (n=165) and metastatic LNs in breast cancer patients (n=15) were examined with palpation, B-mode ultrasound, Doppler and sonoelastography (assessment of the elasticity of the cortex and the medulla). The elasticity distributions were compared and sensitivity (SE) and specificity (SP) were calculated. In an exploratory analysis, positive and negative predictive values (PPV, NPV) were calculated based upon the estimated prevalence of LN metastases in different risk groups. Results: In the elastogram, the LN cortex was significantly harder than the medulla in both healthy (p=0.004) and metastatic LNs (p=0.005). Comparing healthy and metastatic LNs, there was no difference in the elasticity distribution of the medulla (p=0.281), but we found a significantly harder cortex in metastatic LNs (p=0.006). The SE of clinical examination, B-mode ultrasound, Doppler ultrasound and sonoelastography was revealed to be 13.3%, 40.0%, 14.3% and 60.0%, respectively, and SP was 88.4%, 96.8%, 95.6% and 79.6%, respectively. The highest SE was achieved by the disjunctive combination of B-mode and elastographic features (cortex >3mm in B-mode or blue cortex in the elastogram, SE=73.3%). The highest SP was achieved by the conjunctive combination of B-mode ultrasound and elastography (cortex >3mm in B-mode and blue cortex in the elastogram, SP=99.3%). Conclusions: Sonoelastography is a feasible method to visualize the elasticity distribution of LNs. Moreover, sonoelastography is capable of detecting elasticity differences between the cortex and medulla, and between metastatic and healthy LNs. Therefore, sonoelastography yields additional information about axillary LN status and can improve the PPV, although this method is still experimental. KW - Breast ultrasound KW - Axillary lymph nodes KW - Sonoelastography KW - Real-time tissue elastography KW - Cancer detection KW - Elasticity imaging KW - HI-RTE KW - Lymph node metastases Y1 - 2012 U6 - https://doi.org/10.1186/1471-2342-12-35 SN - 1471-2342 VL - 12 PB - BioMed Central CY - London ER - TY - CHAP A1 - Cassel, Michael A1 - Carlsohn, Anja A1 - Froehlich, Katja A1 - Mayer, Frank T1 - Achilles tendinopathy in adolescent athletes using ultrasound and clinical examination T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2013 SN - 0195-9131 SN - 1530-0315 VL - 45 IS - 5 SP - 350 EP - 350 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Wochatz, Monique A1 - Cassel, Michael A1 - König, Niklas A1 - Fröhlich, Katja A1 - Mayer, Frank T1 - Intra- and inter-observer variability of a retrospective analysis of achilles tendon ultrasound scans T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2013 SN - 0195-9131 SN - 1530-0315 VL - 45 IS - 5 SP - 239 EP - 239 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - König, Niklas A1 - Mayer, Frank T1 - Reliability of variables defining mechanical and material properties of the achilles tendon T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2013 SN - 0195-9131 SN - 1530-0315 VL - 45 IS - 5 SP - 238 EP - 239 PB - Lippincott Williams & Wilkins CY - Philadelphia ER -