@article{HirschmuellerFreyKonstantinidisetal.2012, author = {Hirschmueller, Anja and Frey, Victoria and Konstantinidis, Lukas and Baur, Heiner and Dickhuth, Hans-Hermann and Suedkamp, Norbert P. and Helwig, Peter}, title = {Prognostic value of achilles tendon doppler sonography in asymptomatic runners}, series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, volume = {44}, journal = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, number = {2}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {0195-9131}, doi = {10.1249/MSS.0b013e31822b7318}, pages = {199 -- 205}, year = {2012}, abstract = {HIRSCHMULLER, A., V. FREY, L. KONSTANTINIDIS, H. BAUR, H-H. DICKHUTH, N. P. SUDKAMP, and P. HELWIG. Prognostic Value of Achilles Tendon Doppler Sonography in Asymptomatic Runners. Med. Sci. Sports Exerc., Vol. 44, No. 2, pp. 199-205, 2012. Introduction: Midportion Achilles tendinopathy (MPT) is a common problem in running athletes. Nevertheless, its etiology is not fully understood, and no valid prognostic criterion to predict the development of MPT could be identified to date. The purpose of the present study, therefore, was to evaluate whether power Doppler ultrasonography (PDU) is a suitable method to identify a predisposition to MPT in yet asymptomatic runners. Methods: At 23 major running events, 634 asymptomatic long-distance runners were tested for Achilles tendon thickness, vascularization, and structural abnormalities using a high-resolution PDU device (Toshiba Aplio SSA-770A/80, 12 MHz). In addition, their medical history and anthropometric data were documented. All subjects were contacted 6 and 12 months later and asked about any new symptoms. The collected anamnestic, anthropometric, and ultrasonographic data were subjected to regression analysis to determine their predictive value concerning the manifestation of midportion Achilles tendon complaints (P < 0.05). Results: The highest odds ratio (OR) for manifestation of MPT within 1 yr was found for intratendinous blood flow ("neovascularization,'' OR = 6.9, P < 0.001). An increased risk was also identified for subjects with a positive history of Achilles tendon complaints (OR = 3.8, P < 0.001). A third relevant parameter, just above the level of significance, was a spindle-shaped thickening of the tendon on PDU (Wald chi(2) = 3.42). Conclusions: PDU detection of intratendinous microvessels in the Achilles tendons of healthy runners seems to be a prognostically relevant factor concerning the manifestation of symptomatic MPT. This finding lays the foundation for an early identification of a predisposition to MPT as well as prophylactic intervention in as yet asymptomatic runners.}, language = {en} } @article{CasselBaurHirschmuelleretal.2015, author = {Cassel, Michael and Baur, Heiner and Hirschmueller, Anja and Carlsohn, Anja and Fr{\"o}hlich, Katja and Mayer, Frank}, title = {Prevalence of Achilles and patellar tendinopathy and their association to intratendinous changes in adolescent athletes}, series = {Scandinavian journal of medicine \& science in sports}, volume = {25}, journal = {Scandinavian journal of medicine \& science in sports}, number = {3}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0905-7188}, doi = {10.1111/sms.12318}, pages = {e310 -- e318}, year = {2015}, abstract = {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.}, language = {en} } @article{KoenigReschkeWolteretal.2013, author = {K{\"o}nig, Niklas and Reschke, Antje and Wolter, Martin and M{\"u}ller, Steffen and Mayer, Frank and Baur, Heiner}, title = {Plantar pressure trigger for reliable nerve stimulus application during dynamic H-reflex measurements}, series = {Gait \& posture}, volume = {37}, journal = {Gait \& posture}, number = {4}, publisher = {Elsevier}, address = {Clare}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2012.09.021}, pages = {637 -- 639}, year = {2013}, abstract = {In dynamic H-reflex measurements, the standardisation of the nerve stimulation to the gait cycle is crucial to avoid misinterpretation due to altered pre-synaptic inhibition. In this pilot study, a plantar pressure sole was used to trigger the stimulation of the tibialis nerve with respect to the gait cycle. Consequently, the intersession reliability of the soleus muscle H-reflex during treadmill walking was investigated. Seven young participants performed walking trials on a treadmill at 5 km/h. The stimulating electrode was placed on the tibial nerve in the popliteal fossa. An EMG was recorded from the soleus muscle. To synchronize the stimulus to the gait cycle, initial heel strike was detected with a plantar pressure sole. Maximum H-reflex amplitude and M-wave amplitude were obtained and the Hmax/Mmax ratio was calculated. Data reveals excellent reliability, ICC = 0.89. Test-retest variability was 13.0\% (+/- 11.8). The Bland-Altman analysis showed a systematic error of 2.4\%. The plantar pressure sole was capable of triggering the stimulation of the tibialis nerve in a reliable way and offers a simple technique for the evaluation of reflex activity during walking.}, language = {en} } @article{MuellerEngelMuelleretal.2016, author = {Mueller, Juliane and Engel, Tilman and Mueller, Steffen and Kopinski, Stephan and Baur, Heiner and Mayer, Frank}, title = {Neuromuscular response of the trunk to sudden gait disturbances: Forward vs. backward perturbation}, series = {Journal of electromyography and kinesiology}, volume = {30}, journal = {Journal of electromyography and kinesiology}, publisher = {Elsevier}, address = {Oxford}, issn = {1050-6411}, doi = {10.1016/j.jelekin.2016.07.005}, pages = {168 -- 176}, year = {2016}, abstract = {The study aimed to analyse neuromuscular activity of the trunk comparing four different perturbations during gait. Thirteen subjects (28 +/- 3 yrs) walked (1 m/s) on a split-belt treadmill, while 4 (belt) perturbations (F1, F2, B1, B2) were randomly applied. Perturbations differed, related to treadmill belt translation, in direction (forward (F)/backward (B)) and amplitude (20 m/s(2) (1)/40 m/s(2) (2)). Trunk muscle activity was assessed with a 12-lead-EMG. EMG-RMS [\%] (0-200 ms after perturbation; normalized to RMS of normal gait) was analyzed for muscles and four trunk areas (ventral left/right; dorsal left/right). Ratio of ventral: dorsal muscles were calculated. Muscle onset [ms] was determined. Data analysis was conducted descriptively, followed by ANOVA (post hoc Tukey-Kramer (alpha = 0.05)). All perturbations lead to an increase in EMG-RMS (428 +/- 289\%). F1 showed the lowest and F2 the highest increase for the flexors. B2 showed the highest increase for the extensors. Significant differences between perturbations could be observed for 6 muscles, as well as the 4 trunk areas. Ratio analysis revealed no significant differences (range 1.25 (B1) to 1.71 (F2) between stimuli. Muscle response time (ventral: 87.0 +/- 21.7 ms; dorsal: 88.4 +/- 17.0 ms) between stimuli was only significant (p = 0.005) for the dorsal muscles. Magnitude significantly influences neuromuscular trunk response patterns in healthy adults. Regardless of direction ventral muscles always revealed higher relative increase of activity while compensating the walking perturbations. (C) 2016 Elsevier Ltd. All rights reserved.}, language = {en} } @article{BaurHirschmuellerMuelleretal.2011, author = {Baur, Heiner and Hirschm{\"u}ller, Anja and M{\"u}ller, Steffen and Mayer, Frank}, title = {Neuromuscular activity of the peroneal muscle after foot orthoses therapy in runners}, series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, volume = {43}, journal = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, number = {8}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {0195-9131}, doi = {10.1249/MSS.0b013e31820c64ae}, pages = {1500 -- 1506}, year = {2011}, abstract = {BAUR, H., A. HIRSCHMULLER, S. MULLER, and F. MAYER. Neuromuscular Activity of the Peroneal Muscle after Foot Orthoses Therapy in Runners. Med. Sci. Sports Exerc., Vol. 43, No. 8, pp. 1500-1506, 2011. Purpose: Foot orthoses are a standard option to treat overuse injury. Biomechanical data providing mechanisms of foot orthoses' effectiveness are sparse. Stability of the ankle joint complex might be a key factor. The purpose was therefore to analyze neuromuscular activity of the musculus peroneus longus in runners with overuse injury symptoms treated with foot orthoses. Methods: A total of 99 male and female runners with overuse injury symptoms randomized in a control group (CO) and an orthoses group (OR) were analyzed on a treadmill at 3.3 m.s(-1) before and after an 8-wk foot orthoses intervention. Muscular activity of the musculus peroneus longus was measured and quantified in the time domain (initial onset of activation (T-ini), time of maximal activity (T-max), total time of activation (T-tot)) and amplitude domain (amplitude in preactivation (A(pre)), weight acceptance (A(wa)), push-off (A(po))). Results: Peroneal activity in the time domain did not differ initially between CO and OR, and no effect was observed after therapy (T-ini: CO = -0.88 +/- 0.09, OR = -0.88 +/- 0.08 / T-max: CO = 0.14 +/- 0.06, OR = 0.15 +/- 0.06 / T-tot: CO = 0.40 +/- 0.09, OR = 0.41 +/- 0.09; P > 0.05). In preactivation (Apre), muscle activity was higher in OR after intervention (CO = 0.97 +/- 0.32, 95\% confidence interval = 0.90-1.05; OR = 1.18 +/- 0.43, 95\% confidence interval = 1.08-1.28; P = 0.003). There was no group or intervention effect during stance (A(wa): CO = 2.33 +/- 0.66, OR = 2.33 +/- 0.74 / A(po): CO = 0.80 +/- 0.41, OR = 0.88 +/- 0.40; P > 0.05). Conclusions: Enhanced muscle activation of the musculus peroneus longus in preactivation suggests an altered preprogrammed activity, which might lead to better ankle stability providing a possible mode of action for foot orthoses therapy.}, language = {en} } @article{BuschBlasimannHenleetal.2019, author = {Busch, Aglaja and Blasimann, Angela and Henle, Philipp and Baur, Heiner}, title = {Neuromuscular activity during stair descent in ACL reconstructed patients}, series = {The Knee}, volume = {26}, journal = {The Knee}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0968-0160}, doi = {10.1016/j.knee.2018.12.011}, pages = {310 -- 316}, year = {2019}, abstract = {Background: The anterior cruciate ligament (ACL) rupture is a severe knee injury. Altered kinematics and kinetics in ACL reconstructed (ACL-R) patients compared to healthy participants (ACL-I) are known and attributed to an altered sensorimotor control. However, studies on neuromuscular control often lack homogeneous patient cohorts. The objective was to examine neuromuscular activity during stair descent in patients one year after ACL reconstruction. Method: Neuromuscular activity of vastus medialis (VM) and lateralis (VL), biceps femoris (BF) and semitendinosus (ST) was recorded by electromyography in 10 ACL-R (age: 26 +/- 10 years; height: 175 +/- 6 cm; mass: 75 +/- 14 kg) and 10 healthy matched controls (age: 31 +/- 7 years; height: 175 +/- 7 cm; mass: 68 +/- 10 kg). A 10-minute walking treadmill warm-up was used for submaximal normalization. Afterwards participants descended 10 times a six-step stairway at a self-selected speed. The movement was separated into pre-activation (PRE), weight acceptance (WA) and push-off phase (PO). Normalized root mean squares for each muscle, limb and movement phase were calculated. Kruskal-Wallis ANOVA compared ACL-R injured and contralateral leg and the ACL-I leg (alpha = 0.05). Results: Significant increased normalised activity in ST during WA in ACL-R injured leg compared to ACL-I and during PO in VL in the ACL-R contralateral leg compared to ACL-I. Decreased activity was shown in VM in ACL-R injured compared to contralateral leg (p < 0.05). Conclusion: Altered neuromuscular activations are present one year after ACL reconstruction compared to the contralateral and healthy matched control limb. Current standard rehabilitation programs may not be able to fully restore sensorimotor control and demand further investigations. (C) 2018 Elsevier B.V. All rights reserved.}, language = {en} } @article{MayerBonaventuraCasseletal.2012, author = {Mayer, Frank and Bonaventura, Klaus and Cassel, Michael and M{\"u}ller, Steffen and Weber, Josefine and Scharhag-Rosenberger, Friederike and Carlsohn, Anja and Baur, Heiner and Scharhag, J{\"u}rgen}, title = {Medical results of preparticipation examination in adolescent athletes}, series = {British journal of sports medicine : the journal of sport and exercise medicine}, volume = {46}, journal = {British journal of sports medicine : the journal of sport and exercise medicine}, number = {7}, publisher = {BMJ Publ. Group}, address = {London}, issn = {0306-3674}, doi = {10.1136/bjsports-2011-090966}, pages = {524 -- 530}, year = {2012}, abstract = {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.}, language = {en} } @article{VerchHirschmuellerMuelleretal.2018, author = {Verch, Ronald and Hirschm{\"u}ller, Anja and M{\"u}ller, Juliane and Baur, Heiner and Mayer, Frank and M{\"u}ller, Steffen}, title = {Is in-toing gait physiological in children?}, series = {Gait \& posture}, volume = {66}, journal = {Gait \& posture}, publisher = {Elsevier}, address = {Clare}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2018.08.019}, pages = {70 -- 75}, year = {2018}, abstract = {Research question: This study aimed to establish reference values in 1-14 year old healthy children and to implement FPA-percentile curves for daily clinical use. Methods: 5910 healthy children performed at least 3 repetitions of barefoot walking over an instrumented walkway using a pressure measurement platform. The FPA [degrees] was extracted and analyzed by age and gender (mean +/- standard deviation; median with percentiles, MANOVA (age, gender) and Wilcoxon-Signed-Rank test for intra-individual side differences (alpha = 0.05). Results: FPA maximum was observed in 2-year-old children and diminished significant until the age of 4 to moderate out-toeing. For ages 5-14, no statistically significant differences in FPA values were present (p > 0.05). MANOVA confirmed age (p < 0.001) and gender (p < 0.001) as significant FPA influencing factors, without combined effect (p > 0.05). In every age group, right feet showed significantly greater out-toeing (p < 0.05). Significance: Percentile values indicate a wide FPA range in children. FPA development in young children shows a spontaneous shift towards moderate external rotation (age 2-4), whereby in-toeing <= 1-5 degrees can be present, but can return to normal. Bilateral in-toeing after the age of four and unilateral in-toeing after the age of seven should be monitored.}, language = {en} } @article{BaurHirschmuellerMuelleretal.2012, author = {Baur, Heiner and Hirschm{\"u}ller, Anja and M{\"u}ller, Steffen and Cassel, Michael and Mayer, Frank}, title = {Is EMG of the lower leg dependent on weekly running mileage?}, series = {International journal of sports medicine}, volume = {33}, journal = {International journal of sports medicine}, number = {1}, publisher = {Thieme}, address = {Stuttgart}, issn = {0172-4622}, doi = {10.1055/s-0031-1286250}, pages = {53 -- 57}, year = {2012}, abstract = {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.}, language = {en} } @inproceedings{KoenigStollMayeretal.2012, author = {K{\"o}nig, Niklas and Stoll, Andreas and Mayer, Frank and Baur, Heiner}, title = {Intrasession reliability of insole in-shoe plantar pressure measurements in different foot areas}, series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, volume = {44}, booktitle = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {0195-9131}, pages = {941 -- 941}, year = {2012}, language = {en} }