Does fatigue expose functional deficits in chronic lateral ankle sprain?

Area of Science:

• Sports Medicine
• Biomechanics
• Orthopedics

Background:

• Unilateral lateral ligament ankle injuries can lead to chronic stability deficits.
• Assessing functional deficits post-injury requires understanding the impact of fatigue.
• Previous research has not fully explored fatigue's effect on balance and jump performance in this population.

Purpose of the Study:

• To investigate if functional fatigue exacerbates balance and vertical jump impairments in individuals with a history of unilateral lateral ankle ligament injury.
• To compare the effects of induced fatigue on balance and jump performance between injured and healthy individuals.

Main Methods:

• Twenty-three participants (12 injured, 11 healthy) underwent balance (single-leg stance, Center-of-Pressure analysis) and maximal single-leg vertical jump height (VJH) testing.
• Ankle fatigue was induced using the modified Square-hop test until exhaustion.
• Center-of-Pressure (COP) excursion (X and Y axes) and VJH were measured pre- and post-fatigue.

Main Results:

• A significant Time X Group interaction was found for mediolateral (X-axis) COP excursion, with a significant post-fatigue increase in the injured group.
• Pre-fatigue VJH showed significant differences between groups, indicating baseline performance deficits.
• Mediolateral balance (COP-X) was significantly impaired post-fatigue in the injured group compared to controls.

Conclusions:

• Functionally induced fatigue can reveal significant balance deficits in individuals with unilateral lateral ankle ligament injuries that may not be apparent during baseline testing.
• Fatigue serves as a valuable tool for uncovering subtle impairments in balance control following ankle ligament injuries.
• These findings suggest that fatigue-provoking assessments may be beneficial for evaluating functional stability and guiding rehabilitation in this patient group.