Individuals with both perceived ankle instability and mechanical laxity demonstrate dynamic postural stability...

Area of Science:

• Biomechanics
• Sports Medicine
• Orthopedics

Background:

• Chronic ankle instability frequently follows lateral ankle sprains.
• The interplay between perceived instability, mechanical laxity, and dynamic postural stability is not fully understood.
• This study investigates dynamic postural stability differences in individuals with mechanical laxity.

Purpose of the Study:

• To compare dynamic postural stability between individuals with mechanical laxity and controls, copers, and those with perceived instability.
• To determine if mechanical laxity is associated with reduced dynamic postural stability.
• To elucidate the contribution of mechanical laxity to overall postural deficits.

Main Methods:

• 93 participants were categorized into four groups: controls, copers, perceived instability, and perceived instability with mechanical laxity.
• Ankle instability was assessed using the Cumberland Ankle Instability Tool and an arthrometer.
• Dynamic postural stability was measured during a single-limb jump landing task using ground reaction force data.

Main Results:

• The mechanically lax group exhibited significantly poorer medial-lateral dynamic postural stability compared to the coper group.
• Individuals with mechanical laxity also showed significantly reduced composite dynamic postural stability compared to both the perceived instability and coper groups.
• No significant differences were found in anterior-posterior or vertical stability indices among the groups.

Conclusions:

• Combined mechanical laxity and perceived instability are associated with significant dynamic postural deficits.
• Mechanical laxity appears to be a contributing factor to impaired dynamic postural stability in chronic ankle instability.
• These findings highlight the importance of assessing mechanical laxity in managing chronic ankle instability.