Related Experiment Video
Updated: Jan 10, 2026
05:52
Lower-Limb Biomechanical Characteristics Associated with Unplanned Gait Termination Under Different Walking Speeds
Published on: August 25, 2020
5.0K
Effect of Running Speed on Gait Variability in Individuals with Functional Ankle Instability
Wenhui Mao1, Kanglong Zhao1, Xiangguo Xu1
1School of Sports Science, Nanjing Normal University, Nanjing 210023, China.
Entropy (Basel, Switzerland)
|November 26, 2025
Summary
Individuals with functional ankle instability (FAI) exhibit reduced lower limb joint angle variability during running, suggesting more rigid control. Slower running speeds alter this variability across different joints and planes.
Area of Science:
- Biomechanics
- Motor Control
- Sports Medicine
Background:
- Functional ankle instability (FAI) is a common condition affecting joint stability.
- Understanding altered movement patterns in FAI is crucial for rehabilitation and injury prevention.
- Running involves complex lower limb coordination, and its variability may differ in individuals with FAI.
Purpose of the Study:
- To compare lower limb joint angle variability between individuals with FAI and healthy controls (CONs) across different running speeds.
- To investigate the effects of running speed on joint angle variability using linear and nonlinear methods.
- To determine if FAI influences the complexity and predictability of running gait.
Main Methods:
- Participants included 15 males with FAI and 15 matched CONs.
- Running trials were conducted on a treadmill at self-selected, slower, and faster speeds.
- Linear (coefficient of variation) and nonlinear (Sample Entropy, largest Lyapunov Exponent) methods analyzed hip, knee, and ankle joint angles over 25 gait cycles.
Main Results:
- No significant differences in linear variability (CV) were found between groups.
- Nonlinear analysis revealed reduced Sample Entropy (SampEn) in FAI for several joint planes, indicating less complex movements, except for the hip sagittal plane.
- The largest Lyapunov Exponent (LyE) was reduced in FAI across sagittal planes, suggesting decreased dynamic instability. Slower speeds generally increased SampEn and LyE in certain planes.
- FAI demonstrated reduced joint angle variability, particularly in the sagittal plane, indicative of rigid control.
Conclusions:
- Individuals with FAI exhibit altered lower limb joint dynamics during running, characterized by reduced variability and potentially more rigid control, especially in the sagittal plane.
- Running speed significantly influences joint angle variability, with slower speeds impacting hip, knee, and ankle dynamics differently in individuals with and without FAI.
- These findings highlight the need for tailored rehabilitation strategies that address altered movement patterns and variability in FAI patients.
