Effects of Ankle Evertor Fatigue on Force Sense and Neuromuscular Activation During Submaximal Isometric Contractions in Individuals With and Without Chronic Ankle Instability
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 50
- 试验地点
- 1
- 主要终点
- Constant Error (CE)
研究概览
简要总结
The goal of this observational study is to investigate whether ankle evertor muscle fatigue impairs force perception and alters neuromuscular activation patterns during submaximal isometric contractions, and whether these effects differ between individuals with chronic ankle instability (CAI) and individuals without CAI.
详细描述
Participants will first be familiarized with the research protocol for approximately 20 minutes. After a short break, the experimental protocol with data collection will begin and last between 45 and 60 minutes. Measurements will be performed on the side where the participant reports symptoms of chronic ankle instability. In cases of bilateral CAI, the leg with the lower CAIT score will be tested.
Participants will be tested on an isokinetic dynamometer (Humac Norm, CSMi, USA) in a semi-recumbent position with the hip and knee flexed to ensure comfort and alignment. The trunk and tested leg will be secured with straps to minimize accessory movement. After initial maximal voluntary isometric contraction (MVIC) of ankle evertors, participants will perform force-matching tasks at 25% and 50% of MVIC. Each trial will consist of 5 seconds with visual feedback followed by 5 seconds without feedback, repeated three times per intensity. After completing these tasks, participants will undergo a fatigue protocol for the ankle evertors. After the fatigue protocol, participants will repeat the force-matching tasks at both 25% and 50% MVIC.
The muscle fatigue protocol consists of consecutive isotonic contractions of ankle eversion, performed through the full range of motion at 30% of MVIC torque until visible fatigue. Fatigue will be defined as a clear inability to perform full range of eversion, i.e. the range of motion fell below 10% of the initial value despite evident effort by the participant. The test will be paced using a metronome, with a 1-second concentric and a 1-second eccentric phase to ensure consistent movement velocity.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Control
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- 未提供
排除标准
- 未提供
结局指标
主要结局
Constant Error (CE)
时间窗: Baseline (Day 1, prior to fatigue protocol) and immediately post-fatigue (Day 1, within 5 minutes after fatigue protocol).
Muscle force sense will be assessed by the accuracy of force reproduction during force-matching tasks. Constant Error (CE) will be calculated as the mean difference in force (Nm) between reproduction with and without visual feedback during the middle three seconds, averaged across three repetitions at each load level. Unit of measure: Newton-meters (Nm).
Absolute Error (AE)
时间窗: Baseline (Day 1, prior to fatigue protocol) and immediately post-fatigue (Day 1, within 5 minutes after fatigue protocol).
Muscle force sense will be assessed by the accuracy of force reproduction during force-matching tasks. Absolute Error (AE) will be calculated as the mean absolute difference in force (Nm) between reproduction with and without visual feedback during the middle three seconds, averaged across three repetitions at each load level. Unit of measure: Newton-meters (Nm).
Variable Error (VE)
时间窗: Time Frame: Baseline (Day 1, prior to fatigue protocol) and immediately post-fatigue (Day 1, within 5 minutes after fatigue protocol).
Muscle force sense will be assessed by the accuracy of force reproduction during force-matching tasks. Variable Error (VE) will be calculated as the standard deviation of errors across three repetitions at each load level. Unit of measure: Newton-meters (Nm).
Coefficient of Variation (CV) of generated force
时间窗: Baseline (Day 1, prior to fatigue protocol) and immediately post-fatigue (Day 1, within 5 minutes after fatigue protocol).
Ratio of the standard deviation to the mean force during the middle three seconds of sustained contraction in each trial, calculated separately for trials with and without visual feedback. Unit of Measure: Percentage (%).
次要结局
- Surface EMG root mean square (RMS) amplitude of ankle muscles(Baseline (Day 1, prior to fatigue protocol) and immediately post-fatigue (Day 1, within 5 minutes after fatigue protocol).)
- Surface EMG median frequency of peroneus longus mucle(Baseline (Day 1, prior to fatigue protocol) and immediately post-fatigue (Day 1, within 5 minutes after fatigue protocol).)
- Maximal voluntary isometric contraction (MVIC)(Baseline (Day 1, prior to fatigue protocol) and immediately post-fatigue (Day 1, within 5 minutes after fatigue protocol).)
- Ratings of perceived exertion(Baseline (Day 1, prior to fatigue protocol) and immediately post-fatigue (Day 1, within 5 minutes after fatigue protocol).)
研究者
Alan Kacin
Head of Laboratory
University of Ljubljana