Effect of muscle activity intrinsic foot muscles in single-leg standing in those with ankle instability
2025 Volume 3 Issue 1 Pages 13-21
Details
2025 Volume 3 Issue 1 Pages 13-21
Objective: In this study, we investigated the difference in the muscle activity onset time between patients with chronic ankle instability (CAI) and healthy subjects by measuring the time of onset of muscle activity in intrinsic muscles of the foot during single-leg standing in patients with CAI.
Methods: The subjects were 50 persons aged 20 to 44 years, divided into two groups: 25 CAI subjects and 25 healthy subjects. Surface electromyographs and foot switches were used. The reaction time for raising the lower limb and the onset of muscle activity of extrinsic and intrinsic muscles of the foot were measured during the transition from a double leg stance to a single-leg stance. The difference in the onset time of muscle activity between the extrinsic and intrinsic muscles of the foot was measured. They were compared between CAI and healthy subjects.
Results: Compared with the control group, the CAI group showed significantly delayed lower extremity raising reaction time and also significantly delayed muscle activity onset time in the tibialis anterior and abductor hallucis muscles. Differences between the two groups were observed in two combinations of the abductor hallucis muscle and peroneus longus, the abductor hallucis and peroneus brevis.
Conclusion: Compared with the control group, the CAI group showed significantly delayed muscle activity onset time in the abductor hallucis muscle during single-leg standing, which suggests a disturbance in neuromuscular control of the abductor hallucis muscle.
