Single Leg Hop Landing Analysis in Patients with Chronic Ankle Instability, Lateral Ankle Sprain Copers, and Healthy Individuals

Abstract

CONTEXT: There are an estimated 28,000 ankle injuries that occur per day in the United States, thus making the pathology one of the most common sports-related injuries. Lateral ankle sprains account for 80% of all athletic injuries and approximately 73% will suffer from a recurrent injury. The residual symptoms that linger following repetitive lateral ankle sprains are often correlated with chronic ankle instability (CAI). Lateral ankle sprain (LAS) copers successfully cope with the damage that results from sustaining a lateral ankle sprain, whereas CAI patients suffer from residual symptoms. Traditional measures of COP from force-plate data are useful in evaluating the function and stability of the foot. Compared to healthy individuals, patients diagnosed with CAI demonstrate poor postural control that results in altered COP locations during a single-limb static balance task on a force-plate. Most of the literature within CAI research has attributed movement dysfunction to impaired sensorimotor function. This somatic dysfunction reduces the ability of the neuromuscular system to provide proprioceptive feedback as well as producing efficient movement outcomes. PURPOSE: The purpose of this study was to determine the differences that exist in dynamic postural control strategies between CAI vs LAS copers vs healthy individuals in a single leg hopping task. METHODS: This was a case-control analytical study conducted in the biomechanics lab at Illinois State University that used previously collected data by Jagodinsky et. al. Forty-five recreationally active individuals (14 healthy, 15 copers, and 16 with CAI) between the ages of 19 and 30 were instructed to hop on a force plate for 3 blocks of nine hops each. Center of pressure (COP) data was analyzed in both the x and y directions by conducting a MANOVA to detect between group differences. RESULTS:Three MANOVAs were performed evaluating seven different variables that were grouped by measures of excursion, variability, and velocity. There was no significant difference between groups for the excursion (p = 0.82), variability (p = 0.63), and velocity (p= 0.79) measures on the combined dependent variables. CONCLUSION: Our findings suggest that there were no biomechanical differences present amongst individuals with ankle dysfunction during a SL hop task. Future research should examine a more difficult dynamic stabilization task since we believe that the SL hop was not difficult enough to truly examine the between groups differences that might exist.