TY - JOUR A1 - Khajooei, Mina A1 - Lin, Chiao-I A1 - Mayer, Frank A1 - Mueller, Steffen T1 - Muscle activity and strength in maximum isokinetic legpress testing with unstable footplates in active individuals JF - Isokinetics and exercise science : official journal of the European Isokinetic Society N2 - BACKGROUND: Compensating unstable situations is an important functional capability to maintain joint stability, to compensate perturbations and to prevent (re-)injury. Therefore, reduced maximum strength and altered neuromuscular activity are expected by inducing instability to load test situations. Possible effects are not clear for induced instability during maximum legpress tests in healthy individuals. OBJECTIVE: To compare isokinetic legpress (LP) strength and lower-leg muscle activity using stable (S) and unstable (UN) footplates. METHODS: 16 males (28 +/- 4 yrs, 179 +/- 7 cm, 75 +/- 8 kg) performed five maximum LP in concentric (CON) and eccentric (ECC) mode. The maximum force (Fmax) and muscle activity were measured under conditions of S and UN footplates. The tested muscles comprised of the tibialis anterior (TA), peroneus longus (PL) and soleus (SOL) and their activity were quantified against the MVIC of each muscle respectively. RESULTS: The main finding revealed a significant reduction in Fmax under UN condition: 11.9 +/- 11.3% in CON and 23.5 +/- 47.8% in ECC (P < 0.05). Significant findings were also noted regarding the RMS derived values of the EMG of PL and TA. CONCLUSION: Unstable LP reduced force generation and increased the activity of PL and TA muscles which confirmed greater neuromuscular effort to compensate instability. This may have some implications for resistance testing and training coupled with an unstable base in the prevention and rehabilitation of injury to the neuromusculoskeletal system. KW - Tibialis anterior KW - peroneus longus KW - soleus KW - instability Y1 - 2019 U6 - https://doi.org/10.3233/IES-182206 SN - 0959-3020 SN - 1878-5913 VL - 27 IS - 3 SP - 177 EP - 183 PB - IOS Press CY - Amsterdam ER - TY - GEN A1 - Khajooei, Mina A1 - Lin, Chiao-I A1 - Steffan, Müller A1 - Mayer, Frank T1 - Effect of Instability in Legpress Testing on Strength & Muscle Activity in Functional Ankle Instability T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2018 U6 - https://doi.org/:10.1249/01.mss.0000537073.01736.db SN - 0195-9131 SN - 1530-0315 VL - 50 IS - 5S SP - 602 EP - 602 PB - Lippincott Williams & Wilkins CY - Philadelphia 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 - THES A1 - Lin, Chiao-I T1 - The survey of the prevalence of chronic ankle instability in elite Taiwanese basketball athletes T1 - Studie zur Prävalenz von chronischer Sprunggelenkinstabilität bei taiwaneschen Elite-Basketball-Athleten*innen N2 - BACKGROUND: Ankle sprains are common in basketball. It could develop into Chronic Ankle Instability (CAI) causing decreased quality of life, functional performance, early osteoarthritis, and increased risk of other injuries. To develop a strategy of CAI prevention, localized epidemiology data and a valid/reliable tool are essential. However, the epidemiological data of CAI is not conclusive from previous studies and the prevalence of CAI in Taiwanese basketball athletes are not clear. In addition, a valid and reliable tool among the Taiwan-Chinese version to evaluate ankle instability is missing. PURPOSE: The aims were to have an overview of the prevalence of CAI in sports population using a systematic review, to develop a valid and reliable cross-cultural adapted Cumberland Ankle Instability Tool Questionnaire (CAIT) in Taiwan-Chinese (CAIT-TW), and to survey the prevalence of CAI in elite basketball athletes in Taiwan using CAIT-TW. METHODS: Firstly, a systematic search was conducted. Research articles applying CAI related questionnaires in order to survey the prevalence of CAI were included in the review. Second, the English version of CAIT was translated and cross-culturally adapted into the CAIT-TW. The construct validity, test-retest reliability, internal consistency, and cutoff score of CAIT-TW were evaluated in an athletic population (N=135). Finally, the cross-sectional data of CAI prevalence in 388 elite Taiwanese basketball athletes were presented. Demographics, presence of CAI, and difference of prevalence between gender, different competitive levels and play positions were evaluated. RESULTS: The prevalence of CAI was 25%, ranging between 7% and 53%. The prevalence of CAI among participants with a history of ankle sprains was 46%, ranging between 9% and 76%. In addition, the cross-cultural adapted CAIT-TW showed a moderate to strong construct validity, an excellent test-retest reliability, a good internal consistency, and a cutoff score of 21.5 for the Taiwanese athletic population. Finally, 26% of Taiwanese basketball athletes had unilateral CAI while 50% of them had bilateral CAI. In addition, women athletes in the investigated cohort had a higher prevalence of CAI than men. There was no difference in prevalence between competitive levels and among play positions. CONCLUSION: The systematic review shows that the prevalence of CAI has a wide range among included studies. This could be due to the different exclusion criteria, age, sports discipline, or other factors among the included studies. For future studies, standardized criteria to investigate the epidemiology of CAI are required. The CAI epidemiological study should be prospective. Factors affecting the prevalence of CAI ability should be investigated and described. The translated CAIT-TW is a valid and reliable tool to differentiate between stable and unstable ankles in athletes and may further apply for research or daily practice in Taiwan. In the Taiwanese basketball population, CAI is highly prevalent. This might relate to the research method, preexisting ankle instability, and training-related issues. Women showed a higher prevalence of CAI than men. When applying the preventive measure, gender should be taken into consideration. N2 - HINTERGRUND: Verstauchungen des Sprunggelenks sind beim Basketball häufig. Daraus kann sich eine chronische Sprunggelenkinstabilität (Chronic Ankle Instability, CAI) entwickeln, die zu verminderter Lebensqualität, funktioneller Leistung, früher Arthrose und einem erhöhten Risiko für andere Verletzungen führt. Um eine Strategie zur CAI-Prävention zu entwickeln, sind lokalisierte epidemiologische Daten und ein valides/zuverlässiges Instrument erforderlich. Allerdings sind die epidemiologischen Daten von CAI aus früheren Studien nicht schlüssig und die Prävalenz von CAI bei taiwanesischen BasketballsportlerInnen ist nicht klar. Darüber hinaus fehlt ein valides und zuverlässiges Werkzeug in der taiwanesisch-chinesischen Version zur Beurteilung der Sprunggelenkinstabilität. ZIEL: Die Ziele waren, anhand einer systematischen Übersichtsarbeit einen Überblick über die Prävalenz von CAI in der Leistungssportlerpopulation zu erhalten. Zudem sollte ein valides, reliables und kulturübergreifendes Tool für Umfragen der Sprunggelenkinstabilität, in Form des Cumberland Ankle Instability Tool Questionnaire (CAIT) in Taiwan-Chinesisch (CAIT-TW) entwickelt, sowie die Prävalenz von CAI bei Elite-Basketball- Athleten*innen in Taiwan mit Hilfe des CAIT-TW erhoben werden. METHODEN: Zunächst wurde eine systematische Suche durchgeführt. Forschungsartikel, die CAI-bezogene Fragebögen verwenden, um die Prävalenz von CAI zu erheben, wurden in den Reviews aufgenommen. Als nächster Schritt wurde die englische Version des CAIT übersetzt und kulturübergreifend in den CAIT-TW adaptiert. Die Konstruktvalidität, die Test-Retest-Reliabilität, die interne Konsistenz und der Schwellenwert des CAIT-TW wurden in einer Leistungssportlerpopulation (N=135) evaluiert. Schließlich wurden die Querschnittsdaten der CAI-Prävalenz bei 388 taiwanesischen Elite-Basketball-Athleten vorgestellt. Es wurden demografische Daten, das Vorhandensein von CAI und der Unterschied der Prävalenz zwischen den Geschlechtern in verschiedenen Wettkampfniveaus und Spielpositionen ausgewertet. ERGEBNISSE: Die Prävalenz von CAI betrug 25 % und lag zwischen 7 % und 53 %. Die Prävalenz von CAI unter den Teilnehmern mit einer Vorgeschichte von Sprunggelenksverstauchungen lag bei 46 % und reichte von 9 % bis 76 %. Darüber hinaus zeigte der kulturübergreifend adaptierte CAIT-TW eine mäßige bis starke Konstruktvalidität, eine ausgezeichnete Test-Retest-Reliabilität, eine gute interne Konsistenz und einen Grenzwert von 21,5 für die taiwanesische Sportlerpopulation. Schließlich wiesen 26% der taiwanesischen Basketball-Athletinnen ein unilaterales CAI auf, während 50% von ihnen ein bilaterales CAI hatten. Darüber hinaus hatten weibliche Sportler in der untersuchten Kohorte eine höhere Prävalenz von CAI als Männer. Es gab keinen Unterschied in der Prävalenz zwischen den Leistungsniveaus und zwischen den Spielpositionen. SCHLUSSFOLGERUNG: Der systematische Review zeigt, dass die Prävalenz von CAI unter den eingeschlossenen Studien eine große Bandbreite aufweist. Dies könnte auf die unterschiedlichen Ausschlusskriterien, das Alter, die Sportdisziplin oder andere Faktoren in den berücksichtigten Studien zurückzuführen sein. Für zukünftige Studien werden standardisierte Kriterien zur Untersuchung der Epidemiologie von CAI benötigt. Epidemiologische Studien zu CAI sollten daher prospektiv angelegt sein. Zudem sollten Faktoren, die die Prävalenz der CAI-Fähigkeit beeinflussen, untersucht und beschrieben werden. Der übersetzte CAIT-TW ist ein valides und zuverlässiges Instrument zur Unterscheidung zwischen stabilen und instabilen Sprunggelenken bei Sportlerinnen und kann für die Forschung oder die tägliche Praxis in Taiwan weiterverwendet werden. In der taiwanesischen Basketballpopulation ist CAI stark verbreitet. Dies könnte mit der Untersuchungsmethode, einer vorbestehenden Sprunggelenksinstabilität und trainingsbedingten Problemen zusammenhängen. Frauen zeigten eine höhere Prävalenz von CAI als Männer. Bei der Anwendung der Präventionsmaßnahme sollte das Geschlecht berücksichtigt werden. KW - chronic ankle instability KW - ankle sprain KW - sports injury KW - Cumberland Ankle Instability Tool KW - prevalence KW - chronische Sprunggelenkinstabilität KW - Verstauchungen des Sprunggelenks KW - Sportverletzung KW - Cumberland Ankle Instability Tool KW - Prävalenz Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-535534 ER - TY - GEN A1 - Lin, Chiao-I A1 - Houtenbos, Sanne A1 - Lu, Yu-Hsien A1 - Mayer, Frank A1 - Wippert, Pia-Maria T1 - The epidemiology of chronic ankle instability with perceived ankle instability BT - a systematic review T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Background: Chronic ankle instability, developing from ankle sprain, is one of the most common sports injuries. Besides it being an ankle issue, chronic ankle instability can also cause additional injuries. Investigating the epidemiology of chronic ankle instability is an essential step to develop an adequate injury prevention strategy. However, the epidemiology of chronic ankle instability remains unknown. Therefore, the purpose of this study was to investigate the epidemiology of chronic ankle instability through valid and reliable self-reported tools in active populations. Methods: An electronic search was performed on PubMed and Web of Science in July 2020. The inclusion criteria for articles were peer-reviewed, published between 2006 and 2020, using one of the valid and reliable tools to evaluate ankle instability, determining chronic ankle instability based on the criteria of the International Ankle Consortium, and including the outcome of epidemiology of chronic ankle instability. The risk of bias of the included studies was evaluated with an adapted tool for the sports injury review method. Results: After removing duplicated studies, 593 articles were screened for eligibility. Twenty full-texts were screened and finally nine studies were included, assessing 3804 participants in total. The participants were between 15 and 32 years old and represented soldiers, students, athletes and active individuals with a history of ankle sprain. The prevalence of chronic ankle instability was 25%, ranging between 7 and 53%. The prevalence of chronic ankle instability within participants with a history of ankle sprains was 46%, ranging between 9 and 76%. Five included studies identified chronic ankle instability based on the standard criteria, and four studies applied adapted exclusion criteria to conduct the study. Five out of nine included studies showed a low risk of bias. Conclusions: The prevalence of chronic ankle instability shows a wide range. This could be due to the different exclusion criteria, age, sports discipline, or other factors among the included studies. For future studies, standardized criteria to investigate the epidemiology of chronic ankle instability are required. The epidemiology of CAI should be prospective. Factors affecting the prevalence of chronic ankle instability should be investigated and clearly described. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 734 KW - Ankle sprain KW - Sports injury KW - Functional ankle instability Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-531375 SN - 1866-8364 ER - TY - JOUR A1 - Lin, Chiao-I A1 - Houtenbos, Sanne A1 - Lu, Yu-Hsien A1 - Mayer, Frank A1 - Wippert, Pia-Maria T1 - The epidemiology of chronic ankle instability with perceived ankle instability BT - a systematic review JF - Journal of foot and ankle research / Australasian Podiatry Council; Society of Chiropodists and Podiatrists (UK) N2 - Background: Chronic ankle instability, developing from ankle sprain, is one of the most common sports injuries. Besides it being an ankle issue, chronic ankle instability can also cause additional injuries. Investigating the epidemiology of chronic ankle instability is an essential step to develop an adequate injury prevention strategy. However, the epidemiology of chronic ankle instability remains unknown. Therefore, the purpose of this study was to investigate the epidemiology of chronic ankle instability through valid and reliable self-reported tools in active populations. Methods: An electronic search was performed on PubMed and Web of Science in July 2020. The inclusion criteria for articles were peer-reviewed, published between 2006 and 2020, using one of the valid and reliable tools to evaluate ankle instability, determining chronic ankle instability based on the criteria of the International Ankle Consortium, and including the outcome of epidemiology of chronic ankle instability. The risk of bias of the included studies was evaluated with an adapted tool for the sports injury review method. Results: After removing duplicated studies, 593 articles were screened for eligibility. Twenty full-texts were screened and finally nine studies were included, assessing 3804 participants in total. The participants were between 15 and 32 years old and represented soldiers, students, athletes and active individuals with a history of ankle sprain. The prevalence of chronic ankle instability was 25%, ranging between 7 and 53%. The prevalence of chronic ankle instability within participants with a history of ankle sprains was 46%, ranging between 9 and 76%. Five included studies identified chronic ankle instability based on the standard criteria, and four studies applied adapted exclusion criteria to conduct the study. Five out of nine included studies showed a low risk of bias. Conclusions: The prevalence of chronic ankle instability shows a wide range. This could be due to the different exclusion criteria, age, sports discipline, or other factors among the included studies. For future studies, standardized criteria to investigate the epidemiology of chronic ankle instability are required. The epidemiology of CAI should be prospective. Factors affecting the prevalence of chronic ankle instability should be investigated and clearly described. KW - Ankle sprain KW - Sports injury KW - Functional ankle instability Y1 - 2020 U6 - https://doi.org/10.1186/s13047-021-00480-w SN - 1757-1146 VL - 14 PB - BioMed Central CY - London ER - TY - GEN A1 - Lin, Chiao-I A1 - Khajooei, Mina A1 - Engel, Tilman A1 - Nair, Alexandra A1 - Heikkila, Mika A1 - Kaplick, Hannes A1 - Mayer, Frank T1 - The effect of chronic ankle instability on muscle activations in lower extremities T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Background/Purpose Muscular reflex responses of the lower extremities to sudden gait disturbances are related to postural stability and injury risk. Chronic ankle instability (CAI) has shown to affect activities related to the distal leg muscles while walking. Its effects on proximal muscle activities of the leg, both for the injured- (IN) and uninjured-side (NON), remain unclear. Therefore, the aim was to compare the difference of the motor control strategy in ipsilateral and contralateral proximal joints while unperturbed walking and perturbed walking between individuals with CAI and matched controls. Materials and methods In a cross-sectional study, 13 participants with unilateral CAI and 13 controls (CON) walked on a split-belt treadmill with and without random left- and right-sided perturbations. EMG amplitudes of muscles at lower extremities were analyzed 200 ms after perturbations, 200 ms before, and 100 ms after (Post100) heel contact while walking. Onset latencies were analyzed at heel contacts and after perturbations. Statistical significance was set at alpha≤0.05 and 95% confidence intervals were applied to determine group differences. Cohen’s d effect sizes were calculated to evaluate the extent of differences. Results Participants with CAI showed increased EMG amplitudes for NON-rectus abdominus at Post100 and shorter latencies for IN-gluteus maximus after heel contact compared to CON (p<0.05). Overall, leg muscles (rectus femoris, biceps femoris, and gluteus medius) activated earlier and less bilaterally (d = 0.30–0.88) and trunk muscles (bilateral rectus abdominus and NON-erector spinae) activated earlier and more for the CAI group than CON group (d = 0.33–1.09). Conclusion Unilateral CAI alters the pattern of the motor control strategy around proximal joints bilaterally. Neuromuscular training for the muscles, which alters motor control strategy because of CAI, could be taken into consideration when planning rehabilitation for CAI. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 712 KW - Electromyography KW - Hip KW - Skeletal joints KW - Knees KW - Legs KW - Musculoskeletal injury KW - Walking KW - Ankles Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515632 SN - 1866-8364 ER - TY - JOUR A1 - Lin, Chiao-I A1 - Khajooei, Mina A1 - Engel, Tilman A1 - Nair, Alexandra A1 - Heikkila, Mika A1 - Kaplick, Hannes A1 - Mayer, Frank T1 - The effect of chronic ankle instability on muscle activations in lower extremities JF - PLOS ONE / Public Library of Science N2 - Background/Purpose Muscular reflex responses of the lower extremities to sudden gait disturbances are related to postural stability and injury risk. Chronic ankle instability (CAI) has shown to affect activities related to the distal leg muscles while walking. Its effects on proximal muscle activities of the leg, both for the injured- (IN) and uninjured-side (NON), remain unclear. Therefore, the aim was to compare the difference of the motor control strategy in ipsilateral and contralateral proximal joints while unperturbed walking and perturbed walking between individuals with CAI and matched controls. Materials and methods In a cross-sectional study, 13 participants with unilateral CAI and 13 controls (CON) walked on a split-belt treadmill with and without random left- and right-sided perturbations. EMG amplitudes of muscles at lower extremities were analyzed 200 ms after perturbations, 200 ms before, and 100 ms after (Post100) heel contact while walking. Onset latencies were analyzed at heel contacts and after perturbations. Statistical significance was set at alpha≤0.05 and 95% confidence intervals were applied to determine group differences. Cohen’s d effect sizes were calculated to evaluate the extent of differences. Results Participants with CAI showed increased EMG amplitudes for NON-rectus abdominus at Post100 and shorter latencies for IN-gluteus maximus after heel contact compared to CON (p<0.05). Overall, leg muscles (rectus femoris, biceps femoris, and gluteus medius) activated earlier and less bilaterally (d = 0.30–0.88) and trunk muscles (bilateral rectus abdominus and NON-erector spinae) activated earlier and more for the CAI group than CON group (d = 0.33–1.09). Conclusion Unilateral CAI alters the pattern of the motor control strategy around proximal joints bilaterally. Neuromuscular training for the muscles, which alters motor control strategy because of CAI, could be taken into consideration when planning rehabilitation for CAI. KW - Ankles KW - Walking KW - Electromyography KW - Hip KW - Skeletal joints KW - Knees KW - Legs KW - Musculoskeletal injury Y1 - 2020 U6 - https://doi.org/10.1371/journal.pone.0247581 SN - 1932-6203 VL - 16 IS - 2 PB - PLOS CY - San Francisco ER - TY - GEN A1 - Lin, Chiao-I A1 - Khajooei, Mina A1 - Nair, Alexandra A1 - Heikkila, Mika A1 - Kaplick, Hannes A1 - Tilman, Engel A1 - Mayer, Frank T1 - Activities of hip muscles in response to perturbed walking in individual with chronic ankle instability T2 - Medicine and science in sports and exercise : MSSE N2 - Chronic ankle instability (CAI) is not only an ankle issue, but also affects sensorimotor system. People with CAI show altered muscle activation in proximal joints such as hip and knee. However, evidence is limited as controversial results have been presented regarding changes in activation of hip muscles in CAI population. PURPOSE: To investigate the effect of CAI on activity of hip muscles during normal walking and walking with perturbations. METHODS: 8 subjects with CAI (23 ± 2 years, 171 ± 7 cm and 65 ± 4 kg) and 8 controls (CON) matched by age, height, weight and dominant leg (25 ± 3 years, 172 ± 7 cm and 65 ± 6 kg) walked shoed on a split-belt treadmill (1 m/s). Subjects performed 5 minutes of baseline walking and 6 minutes walking with 10 perturbations (at 200 ms after heel contact with 42 m/s2 deceleration impulse) on each side. Electromyography signals from gluteus medius (Gmed) and gluteus maximus (Gmax) were recorded while walking. Muscle amplitudes (Root Mean Square normalized to maximum voluntary isometric contraction) were calculated at 200 ms before heel contact (Pre200), 100 ms after heel contact (Post100) during normal walking and 200 ms after perturbations (Pert200). Differences between groups were examined using Mann Whitney U test and Bonferroni correction to account for multiple testing (adjust α level p≤ 0.0125). RESULT: In Gmed, CAI group showed lower muscle amplitude than CON group after heel contact (Post100: 18±7 % and 47±21 %, p< .01) and after walking perturbations ( 31±13 % and 62±26 %, p< .01), but not before heel contact (Pre200: 5±2 % and 11±10 %, p= 0.195). In Gmax, no difference was found between CAI and CON groups in all three time points (Pre200: 12±5 % and 17±12 %, p= 0.574; Post100: 41±21 % and 41±13 %, p= 1.00; Pert200: 79±46 % and 62±35 %, p= 0.505). CONCLUSION: People with CAI activated Gmed less than healthy control in feedback mechanism (after heel contact and walking with perturbations), but not in feedforward mechanism (before heel contact). Less activation on Gmed may affect the balance in frontal plane and increase the risk of recurrent ankle sprain, giving way or feeling ankle instability in patients with CAI during walking. Future studies should investigate the effect of Gmed strengthening or neuromuscular training on CAI rehabilitation. Y1 - 2020 U6 - https://doi.org/10.1249/01.mss.0000671060.98581.0b SN - 0195-9131 SN - 1530-0315 VL - 52 IS - 17 SP - 94 EP - 94 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - GEN A1 - Lin, Chiao-I A1 - Mayer, Frank A1 - Wippert, Pia-Maria T1 - The prevalence of chronic ankle instability in basketball athletes: a cross-sectional study T2 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe N2 - Background Ankle sprain is the most common injury in basketball. Chronic ankle instability develops from an acute ankle sprain may cause negative effects on quality of life, ankle functionality or on increasing risk for recurrent ankle sprains and post-traumatic osteoarthritis. To facilitate a preventative strategy of chronic ankle instability (CAI) in the basketball population, gathering epidemiological data is essential. However, the epidemiological data of CAI in basketball is limited. Therefore, this study aims to investigate the prevalence of CAI in basketball athletes and to determine whether gender, competitive level, and basketball playing position influence this prevalence. Methods In a cross-sectional study, in total 391 Taiwanese basketball athletes from universities and sports clubs participated. Besides non-standardized questions about demographics and their history of ankle sprains, participants further filled out the standard Cumberland Ankle Instability Tool applied to determine the presence of ankle instability. Questionnaires from 255 collegiate and 133 semi-professional basketball athletes (male = 243, female = 145, 22.3 ± 3.8 years, 23.3 ± 2.2 kg/m2) were analyzed. Differences in prevalence between gender, competitive level and playing position were determined using the Chi-square test. Results In the surveyed cohort, 26% had unilateral CAI while 50% of them had bilateral CAI. Women had a higher prevalence than men in the whole surveyed cohort (X2(1) = 0.515, p = 0.003). This gender disparity also showed from sub-analyses, that the collegiate female athletes had a higher prevalence than collegiate men athletes (X2(1) = 0.203, p = 0.001). Prevalence showed no difference between competitive levels (p > 0.05) and among playing positions (p > 0.05). Conclusions CAI is highly prevalent in the basketball population. Gender affects the prevalence of CAI. Regardless of the competitive level and playing position the prevalence of CAI is similar. The characteristic of basketball contributes to the high prevalence. Prevention of CAI should be a focus in basketball. When applying the CAI prevention measures, gender should be taken into consideration. T3 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe - 2 KW - Functional ankle instability KW - Perceived ankle instability KW - Ankle sprain KW - Ankle injury KW - Survey KW - Basketball Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-565898 SP - 1 EP - 9 PB - Universitätsverlag Potsdam CY - Potsdam ER -