LAUSR

CONTEXT Patients with chronic ankle instability (CAI) have demonstrated sensorimotor impairments. Submaximal force steadiness and accuracy measure sensory, motor, and visual function via a feedback mechanism, which helps researchers and clinicians to comprehend sensorimotor deficits associated with CAI. OBJECTIVE To determine if participants with chronic ankle instability experience deficits in hip and ankle submaximal force steadiness and accuracy compared to healthy controls. DESIGN A case-controlled study Setting: Research Laboratory Patients and Other Participants: Twenty-one CAI patients and 21 uninjured controls participated in this study. INTERVENTION(S) n/a. MAIN OUTCOME MEASURE(S) Maximal voluntary isometric contraction (MVIC), force steadiness and accuracy (10% and 30% of their MVIC) of ankle evertors, invertors, and hip abductors. The central 10-sec (20-87% of the total time) of the 3 trials were analyzed. An independent t-test was used to assess MVIC. Two-way, 2 × 3, ANOVAs were used to assess force steadiness and accuracy. RESULTS Relative to controls, the CAI group demonstrated lower accuracy in invertors (p =.0006). Across all motions, the CAI group showed less steadiness (p = .0005) and lower accuracy (p = .0074) than the controls in 10% MVIC. In terms of MVIC, the CAI group showed less force output in hip abduction compared with the control group (p < .0001). CONCLUSIONS CAI patients showed an inability to control ongoing fine force (10% and 30% of their MVIC) through a feedback mechanism during an active test. These findings suggest deficits in sensorimotor control that lead CAI patients to be more susceptible to injury positions since they have difficulty integrating the peripheral information and correcting their movement in relation to visual information.