Possible factors related to functional ankle instability.

Area of Science:

• Biomechanics and Kinesiology
• Sports Medicine
• Orthopedics

Background:

• Functional ankle instability (FAI) is linked to proprioceptive deficits, muscle weakness, poor balance, delayed neuromuscular response, and joint laxity.
• Limited research has explored the prevalence and interrelationships of these factors in individuals with FAI.

Purpose of the Study:

• To classify individuals with functional ankle instability (FAI) into deficit and non-deficit groups.
• To evaluate common factors associated with FAI, including proprioception, muscular strength, balance, reaction time, and joint laxity.

Main Methods:

• A case-control study involving 21 individuals with FAI and 16 healthy controls.
• Bilateral testing of five key factors: ankle proprioception, muscular strength, balance, reaction time, and joint laxity.
• Statistical analysis included within- and between-group comparisons, classification into deficit categories, and correlation analysis.

Main Results:

• Individuals with FAI exhibited significantly poorer balance control and weaker evertor strength on the affected side compared to the unaffected side.
• Passive ankle stiffness correlated significantly with balance control, ankle proprioception, and evertor strength.
• A wide range of deficit profiles was observed in individuals with FAI, from multiple deficits to none.

Conclusions:

• Mechanical ankle alterations can impact functional abilities and afferent processes, such as proprioception and muscle strength.
• The findings suggest a potential reciprocal relationship between ankle proprioception and evertor strength.
• Functional ankle instability presents with considerable variability in deficit presentation among individuals.