Another Look at Fatigued Individuals with and without Chronic Ankle Instability: Posturography and Proprioception

Area of Science:

• Biomechanics
• Human Physiology
• Sports Medicine

Background:

• Fatigue negatively impacts the vestibular, visual, and somatosensory systems crucial for postural balance.
• Individuals with chronic ankle instability (CAI) may experience more pronounced balance impairments following fatigue.

Purpose of the Study:

• To investigate the influence of anaerobic and aerobic exercise protocols on the three sensory systems' function in individuals with and without CAI.
• To compare the effects of fatigue on sensory system function between CAI and non-CAI participants.

Main Methods:

• Sixty healthy physical education students (45% with CAI) were assessed using Tetrax® Posturography and the Active Movement Extent Discrimination Assessment (AMEDA).
• Assessments were conducted before and after participants completed anaerobic or aerobic exercise protocols.
• Posturography measured Stability-Index and Fourier frequencies (visual, vestibular, somatosensory input).

Main Results:

• Significant effects of time (pre-post fatigue), CAI status, and their interaction were observed for Fourier frequencies, Stability-Index, and AMEDA scores.
• Participants with CAI showed greater pre-post fatigue deterioration in sensory function compared to those without CAI (p < .05).
• Somatosensory input (F5-F6 frequencies) and active ankle somatosensory ability (AMEDA) demonstrated the most significant deterioration in CAI participants post-fatigue.

Conclusions:

• Fatigue impairs visual, vestibular, and somatosensory systems in both individuals with and without CAI.
• Individuals with CAI exhibit greater declines in passive and active somatosensory abilities after fatigue.
• Intervention programs targeting vestibular system enhancement are recommended for all individuals, particularly after fatigue.