Taekwondo is a high-intensity combat sport characterized by repeated explosive kicking actions and rapid changes in body position, requiring well-developed postural control to maintain technical performance and reduce injury risk. Although fatigue has been reported to impair balance performance, previous studies have primarily induced fatigue using non-specific laboratory protocols that do not adequately reflect the physiological and neuromuscular demands of taekwondo competition. Consequently, the effects of taekwondo-specific fatigue on static and dynamic balance performance remain insufficiently understood. The primary objective of this study will be to investigate the effects of a taekwondo match-simulated fatigue protocol on static and dynamic balance performance in female taekwondo athletes. Eighteen competitive female taekwondo athletes will participate in this single-group repeated-measures study. Following a familiarization session, participants will complete a standardized taekwondo match-simulated fatigue protocol consisting of three 2-minute rounds separated by 1-minute passive recovery periods, replicating the official Olympic competition format. Static and dynamic balance performance will be assessed before and immediately after the fatigue protocol using the Biodex Balance System (Biodex Medical Systems Inc., Shirley, NY, USA). Balance performance will be evaluated under static and dynamic testing conditions, and the Overall Stability Index, Anteroposterior Stability Index, and Mediolateral Stability Index will be recorded. The findings of this study are expected to improve understanding of the acute effects of sport-specific fatigue on postural control in female taekwondo athletes and may contribute to the development of evidence-based training and injury prevention strategies.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
20
Participants will perform a standardized taekwondo match-simulated fatigue protocol designed to reproduce the physiological and neuromuscular demands of an official taekwondo match. Static and dynamic balance performance will be evaluated immediately before and after completion of the protocol.
Static balance performance will be assessed using the Biodex Balance System (Biodex Medical Systems Inc., Shirley, NY, USA). Mean Overall Stability Index (OSI) score, mean Anteroposterior Stability Index (APSI) score, and mean Mediolateral Stability Index (MLSI) score will be calculated automatically by the system. The static balance condition will be combined with an eyes-closed stance with the platform locked at a static level (a fixed support); this condition will designed to reflect support-fixed, vision-deprived postural control, where the participant must maintain postural stability without visual cues on a stable surface.
Dynamic balance performance will be assessed using the Biodex Balance System (Biodex Medical Systems Inc., Shirley, NY, USA). Mean Overall Stability Index (OSI) score, mean Anteroposterior Stability Index (APSI) score, and mean Mediolateral Stability Index (MLSI) score will be calculated automatically by the system. The dynamic balance condition combines an eyes-open stance with the platform stability set to level 5 (an unstable platform that requires active postural adjustments). This condition will be designed to reflect visually guided, mechanically unstable postural control, where the participant must rely on real-time visual feedback to compensate for continuous platform tilt.
Selcuk University
Konya, Turkey (Türkiye)
Mean Overall Stability Index (OSI) Score
The Mean Overall Stability Index Score is the arithmetic mean of Overall Stability Index values automatically calculated by the Biodex system at the end of each 20-second single-leg stance trial. This index is a unitless score representing the standard deviation of platform tilt about both the anteroposterior and mediolateral axes combined; it reflects composite postural sway during the trial. Each participant completed the trial barefoot on her dominant lower extremity, under two within-subject conditions: (i) dynamic balance (eyes-open stance with the Biodex platform stability set to level 5), and (ii) static balance (eyes-closed stance with the platform locked at a static level). The index is a unitless score representing the standard deviation of platform tilt about the corresponding axis; the theoretical minimum score is 0, which represents perfect postural stability. There is no fixed theoretical upper limit of these indices. Higher scores indicate poorer balance performance.
Time frame: Baseline and immediately after the taekwondo match-simulated fatigue protocol.
Mean Mediolateral Stability Index (MLSI) Score
The Mean Mediolateral Stability Index Score is the arithmetic mean of Mediolateral Stability Index values automatically calculated by the Biodex Balance System at the end of each 20-second single-leg stance trial. This index is a unitless score representing the standard deviation of platform tilt about the frontal axis only; it reflects mediolateral sway and is associated with hip-abductor-driven postural control. Each participant will complete the trial barefoot on her dominant lower extremity (the foot preferred for kicking a ball) under two within-subject conditions: (i) dynamic balance (eyes-open stance with the Biodex platform stability set to level 5), and (ii) static balance (eyes-closed stance with the platform locked at a static level). Theoretically, this index has a minimum value of 0, which represents perfect postural stability; there is no fixed theoretical upper limit. Higher scores indicate poorer balance performance.
Time frame: Baseline and immediately after the taekwondo match-simulated fatigue protocol.
Mean Anterior-Posterior Stability Index (APSI) Score
The Mean Anterior-Posterior Stability Index Score is the arithmetic mean of Anterior-Posterior Stability Index values automatically calculated by the Biodex system at the end of each 20-second single-leg stance trial. This index is a unitless score representing the standard deviation of platform tilt about the sagittal axis only; it reflects anteroposterior sway and is associated with the ankle strategy of postural control. Each participant will complete the trial barefoot on her dominant lower extremity (the foot preferred for kicking a ball) under two within-subject conditions: (i) dynamic balance (eyes-open stance with the Biodex platform stability set to level 5), and (ii) static balance (eyes-closed stance with the platform locked at a static level). Theoretically, this index has a minimum value of 0, which represents perfect postural stability; there is no fixed theoretical upper limit. Higher scores indicate poorer balance performance.
Time frame: Baseline and immediately after the taekwondo match-simulated fatigue protocol.
Mean Age
The mean chronological age of participants at the time of enrollment will be reported in years. Age will be derived from each participant's official identification date of birth and the calendar date of the first balance testing session. It will be used solely as a descriptive baseline demographic variable.
Time frame: Only baseline.
Mean Body Mass Index
Mean Body Mass Index is the arithmetic mean of participant-level BMI values aggregated from body mass (kg) and height (m) according to the standard formula BMI = body mass (kg) / height² (m²). Body mass will be measured in kilograms and standing height in centimeters by a single trained experimenter during the enrollment session. Each participant-level BMI is therefore a single aggregated value derived from two distinct unit-of-measure measurements; height (centimeters) and body mass (kilograms) are not reported separately. It will be used solely as a descriptive baseline demographic variable.
Time frame: Only baseline.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.