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 - 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 - 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 - GEN 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 BT - elasticity distribution in healthy lymph nodes and prediction of breast cancer metastases T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 626 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 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431584 SN - 1866-8364 IS - 626 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 - Müller, Steffen A1 - Müller, Juliane A1 - Stoll, Josefine A1 - Prieske, Olaf A1 - Cassel, Michael A1 - Mayer, Frank T1 - Incidence of back pain in adolescent athletes BT - a prospective study JF - BMC sports science, medicine & rehabilitation N2 - Background Recently, the incidence rate of back pain (BP) in adolescents has been reported at 21%. However, the development of BP in adolescent athletes is unclear. Hence, the purpose of this study was to examine the incidence of BP in young elite athletes in relation to gender and type of sport practiced. Methods Subjective BP was assessed in 321 elite adolescent athletes (m/f 57%/43%; 13.2 ± 1.4 years; 163.4 ± 11.4 cm; 52.6 ± 12.6 kg; 5.0 ± 2.6 training yrs; 7.6 ± 5.3 training h/week). Initially, all athletes were free of pain. The main outcome criterion was the incidence of back pain [%] analyzed in terms of pain development from the first measurement day (M1) to the second measurement day (M2) after 2.0 ± 1.0 year. Participants were classified into athletes who developed back pain (BPD) and athletes who did not develop back pain (nBPD). BP (acute or within the last 7 days) was assessed with a 5-step face scale (face 1–2 = no pain; face 3–5 = pain). BPD included all athletes who reported faces 1 and 2 at M1 and faces 3 to 5 at M2. nBPD were all athletes who reported face 1 or 2 at both M1 and M2. Data was analyzed descriptively. Additionally, a Chi2 test was used to analyze gender- and sport-specific differences (p = 0.05). Results Thirty-two athletes were categorized as BPD (10%). The gender difference was 5% (m/f: 12%/7%) but did not show statistical significance (p = 0.15). The incidence of BP ranged between 6 and 15% for the different sport categories. Game sports (15%) showed the highest, and explosive strength sports (6%) the lowest incidence. Anthropometrics or training characteristics did not significantly influence BPD (p = 0.14 gender to p = 0.90 sports; r2 = 0.0825). Conclusions BP incidence was lower in adolescent athletes compared to young non-athletes and even to the general adult population. Consequently, it can be concluded that high-performance sports do not lead to an additional increase in back pain incidence during early adolescence. Nevertheless, back pain prevention programs should be implemented into daily training routines for sport categories identified as showing high incidence rates. KW - Pain occurrence KW - Young athletes KW - Injury KW - Training volume Y1 - 2016 U6 - https://doi.org/10.1186/s13102-016-0064-7 SN - 2052-1847 VL - 8 PB - BioMed Central CY - London 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 - GEN 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 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 319 KW - SEMG-pattern KW - back pain KW - drop jump KW - neuromuscular KW - performance KW - pre-activity KW - trunk KW - young athletes Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-395261 ER - TY - GEN A1 - Bisi-Balogun, Adebisi A1 - Cassel, Michael A1 - Mayer, Frank T1 - Reliability of various measurement stations for determining plantar fascia thickness and echogenicity 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 339 KW - plantar fascia KW - reliability KW - sonography KW - musculoskeletal Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400615 ER - TY - GEN 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 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/m2, 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 (α = 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 329 KW - Energy requirement KW - Calorimetry KW - Fat-free mass KW - Nutritional counseling KW - Athletes Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-399837 ER - TY - GEN 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 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 355 KW - Achilles and patellar tendon KW - non-athletes KW - sonography KW - training adaptation KW - young athletes Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-403823 ER - TY - GEN 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 N2 - Background: Data on electrocardiographic and echocardiographic pre-participation screening findings in paediatric athletes are limited. Methods and results: 10-15 year-old athletes (n = 343) were screened using electro- and echocardiography. The electrocardiogram (ECG) was normal in 220 (64%), mildly abnormal in 108 (31%), and distinctly abnormal in 15 (4%) athletes. Echocardiographic upper reference limits (URL, 97.5 percentile) for the left ventricular (LV) wall thickness in 10-11-year-old boys and girls were 9-10 mm and 8-9 mm, respectively; in 12-13-year-old boys and girls 9-10 mm; and in 14-15-year-old boys and girls 10-11 mm and 9-10 mm, respectively. Three athletes were excluded from competitive sports: one for symptomatic Wolff-Parkinson-White syndrome with a normal echocardiogram; one for negative T-waves in V-1-V-4 and a dilated right ventricle by echocardiography suggestive of (arrhythmogenic) right ventricular disease; and one for normal ECG and biscupid aortic valve including an aneurysm of the ascending aorta detected by echocardiography. Related to echocardiographic findings, the sensitivity and specificity of the ECG to identify cardiovascular abnormalities was 38% and 64%, respectively. The ECG's positive-predictive and negative-predictive values were 13% and 88%, respectively. The numbers needed to screen and calculated costs were 172 for ECG ( 7049), 172 for echocardiography ( 11,530), and 114 combining ECG and echocardiography ( 9323). Conclusions: Compared to adults, paediatric athletes presented with fewer distinctly abnormal ECGs, and there was no gender difference in paediatric athletes' ECG-pattern distribution. A combination of ECG and echocardiography for pre-participation screening of paediatric athletes is superior to ECG alone but 30% more costly. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 368 KW - ECG KW - echocardiography KW - paediatric athlete KW - pre-participation screening KW - sudden cardiac death Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-403186 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 - 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 - GEN 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 T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 559 KW - overuse injuries KW - epidemiology KW - complaints KW - symptoms KW - risk factors KW - sports Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434953 SN - 1866-8364 IS - 559 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 - GEN A1 - Risch, Lucie A1 - Mayer, Frank A1 - Cassel, Michael T1 - Doppler flow response following running exercise differs between healthy and tendinopathic Achilles tendons T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 715 KW - neovascularization KW - tendinopathy KW - Doppler ultrasound KW - Advanced Dynamic Flow KW - athlete KW - sonography Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-521367 SN - 1866-8364 ER - TY - JOUR A1 - Kim, MyoungHwee A1 - Lin, Chiao-I A1 - Henschke, Jakob A1 - Quarmby, Andrew James A1 - Engel, Tilman A1 - Cassel, Michael T1 - Effects of exercise treatment on functional outcome parameters in mid-portion achilles tendinopathy BT - a systematic review JF - Frontiers in Sports and Active Living N2 - Exercise interventions are evident in the treatment of mid-portion Achilles tendinopathy (AT). However, there is still a lack of knowledge concerning the effect of different exercise treatments on improving a specific function (e.g., strength) in this population. Thus, this study aimed to systematically review the effect of exercise treatments on different functional outcomes in mid-portion AT. An electronic database of Pubmed, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception to 21 February 2023. Studies that investigated changes in plantar flexor function with exercise treatments were considered in mid-portion AT. Only randomized controlled trials (RCTs) and clinical controlled trials (CCTs) were included. Functional outcomes were classified by kinetic (e.g., strength), kinematic [e.g., ankle range of motion (ROM)], and sensorimotor (e.g., balance index) parameters. The types of exercise treatments were classified into eccentric, concentric, and combined (eccentric plus concentric) training modes. Quality assessment was appraised using the Physiotherapy Evidence Database scale for RCTs, and the Joanna Briggs Institute scale for CCTs. The search yielded 2,260 records, and a total of ten studies were included. Due to the heterogeneity of the included studies, a qualitative synthesis was performed. Eccentric training led to improvements in power outcomes (e.g., height of countermovement jump), and in strength outcomes (e.g., peak torque). Concentric training regimens showed moderate enhanced power outcomes. Moreover, one high-quality study showed an improvement in the balance index by eccentric training, whereas the application of concentric training did not. Combined training modalities did not lead to improvements in strength and power outcomes. Plantarflexion and dorsiflexion ROM measures did not show relevant changes by the exercise treatments. In conclusion, eccentric training is evident in improving strength outcomes in AT patients. Moreover, it shows moderate evidence improvements in power and the sensorimotor parameter "balance index". Concentric training presents moderate evidence in the power outcomes and can therefore be considered as an alternative to improve this function. Kinematic analysis of plantarflexion and dorsiflexion ROM might not be useful in AT people. This study expands the knowledge what types of exercise regimes should be considered to improve the functional outcomes in AT. KW - exercise treatments KW - eccentric training KW - concentric training KW - combined training KW - kinetic parameters KW - kinematic parameters KW - sensorimotor parameters KW - mid-portion achilles tendinopathy Y1 - 2023 U6 - https://doi.org/10.3389/fspor.2023.1144484 SN - 2624-9367 VL - 5 PB - Frontiers Media CY - Lausanne ER - TY - GEN A1 - Müller, Steffen A1 - Müller, Juliane A1 - Stoll, Josefine A1 - Prieske, Olaf A1 - Cassel, Michael A1 - Mayer, Frank T1 - Incidence of back pain in adolescent athletes BT - a prospective study N2 - Background Recently, the incidence rate of back pain (BP) in adolescents has been reported at 21%. However, the development of BP in adolescent athletes is unclear. Hence, the purpose of this study was to examine the incidence of BP in young elite athletes in relation to gender and type of sport practiced. Methods Subjective BP was assessed in 321 elite adolescent athletes (m/f 57%/43%; 13.2 ± 1.4 years; 163.4 ± 11.4 cm; 52.6 ± 12.6 kg; 5.0 ± 2.6 training yrs; 7.6 ± 5.3 training h/week). Initially, all athletes were free of pain. The main outcome criterion was the incidence of back pain [%] analyzed in terms of pain development from the first measurement day (M1) to the second measurement day (M2) after 2.0 ± 1.0 year. Participants were classified into athletes who developed back pain (BPD) and athletes who did not develop back pain (nBPD). BP (acute or within the last 7 days) was assessed with a 5-step face scale (face 1–2 = no pain; face 3–5 = pain). BPD included all athletes who reported faces 1 and 2 at M1 and faces 3 to 5 at M2. nBPD were all athletes who reported face 1 or 2 at both M1 and M2. Data was analyzed descriptively. Additionally, a Chi2 test was used to analyze gender- and sport-specific differences (p = 0.05). Results Thirty-two athletes were categorized as BPD (10%). The gender difference was 5% (m/f: 12%/7%) but did not show statistical significance (p = 0.15). The incidence of BP ranged between 6 and 15% for the different sport categories. Game sports (15%) showed the highest, and explosive strength sports (6%) the lowest incidence. Anthropometrics or training characteristics did not significantly influence BPD (p = 0.14 gender to p = 0.90 sports; r2 = 0.0825). Conclusions BP incidence was lower in adolescent athletes compared to young non-athletes and even to the general adult population. Consequently, it can be concluded that high-performance sports do not lead to an additional increase in back pain incidence during early adolescence. Nevertheless, back pain prevention programs should be implemented into daily training routines for sport categories identified as showing high incidence rates. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 310 KW - Injury KW - Pain occurrence KW - Training volume KW - Young athletes Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-101874 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 -