Hip Strength and Activation in Individuals With Ankle Instability During the Single-Leg Squat Test

Area of Science:

• Biomechanics
• Neuromuscular Control
• Sports Medicine

Background:

• Chronic ankle instability (CAI) is associated with altered hip muscle function.
• Proximal muscle deficits may contribute to CAI pathophysiology.

Purpose of the Study:

• To assess if the single-leg squat test (SLST) can differentiate proximal muscle activation in individuals with CAI.
• To compare hip muscle strength between individuals with and without CAI.

Main Methods:

• A case-control study compared hip muscle activation and strength during SLST across CAI, coper, and control groups.
• Surface electromyography measured gluteus maximus and medius activation.
• Handheld dynamometry assessed hip muscle strength (lateral rotators, extensors, abductors).

Main Results:

• The CAI group exhibited significantly greater gluteus maximus activation during SLST compared to coper and control groups.
• Individuals with CAI demonstrated weaker hip lateral rotator strength than both coper and control groups.
• Hip extensor strength was also weaker in the CAI group compared to controls.

Conclusions:

• Findings support existing literature on proximal neuromuscular alterations in CAI.
• The SLST shows potential as a clinical tool for assessing gluteus maximus activation in CAI.
• Further research is needed to confirm clinical detectability of these activation differences.