COMPARISONS OF FOOT POSTURE AND ANKLE AND KNEE STRENGTH BETWEEN ATHLETES WITH AND WITHOUT CHRONIC ANKLE INSTABILITY

Abstract

This study aims to evaluate foot posture and muscle strength around the ankle and knee joints in athletes with and without unilateral chronic ankle instability (CAI). Forty-one male athletes, aged between 18-36 years, were assigned to two groups; CAI and non-CAI groups. Handheld dynamometer was used to test isometric muscle strength in inverter, evertor, dorsiflexor, plantarflexor, knee flexor and knee extensor. Foot posture was evaluated using the foot posture index (FPI).

The results showed no significant differences in inverter, evertor, dorsiflexor, plantarflexor, knee flexor and knee extensor muscle strength and agonist/antagonist ratios between both groups (p>0.05). Subjects in both groups had normal foot posture on both feet. Subjects exhibited no significant differences in FPI score between groups (p>0.05). Moderate to high positive correlations were noted among the strength of these muscles (r=0.61 to 0.96, p<0.01). Additionally, 30% of subjects in CAI groups demonstrated musculoskeletal pain around the knee joint. The results of this study confirmed that all muscles in lower extremity work together, thus alteration of muscle strength of a muscle group might be affected to muscle strength of other joints. Therefore, clinicians should consider it for the assessment and prevention of injuries or for a rehabilitation program for athletes with CAI.

(Journal of Sports Science and Technology 2012;12 (2): 107 - 116)