Mark A Feger1, Luke Donovan2, Joseph M Hart3, Jay Hertel4. 1. Department of Kinesiology, University of Virginia, 210 Emmet Street South Charlottesville, VA 22904(∗). Electronic address: mf3de@virginia.edu. 2. Department of Kinesiology, University of Virginia, Charlottesville, VA(†). 3. Department of Kinesiology, University of Virginia, Charlottesville, VA(‡). 4. Department of Kinesiology, University of Virginia, Charlottesville, VA(§).
Abstract
OBJECTIVE: To determine whether individuals with chronic ankle instability (CAI) exhibit altered neuromuscular control as demonstrated by surface electromyography (EMG) amplitudes compared with healthy controls during single-limb eyes-closed balance, Star Excursion Balance Test, forward lunge, and lateral hop exercises. DESIGN: A cross-sectional laboratory study. SETTING: A research laboratory. PARTICIPANTS: Fifteen young adults with CAI and 15 healthy controls. INTERVENTIONS: The subjects performed functional exercises while surface EMG signals were recorded from the tibialis anterior, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius. MAIN OUTCOME MEASUREMENTS: Surface EMG amplitudes (root mean square area) for each muscle, muscles of the shank (distal 3 muscles), muscles of the thigh (proximal 3 muscles), and total muscle activity (all 6 muscles) of the lower extremity were analyzed and compared between the groups. RESULTS: Individuals with CAI demonstrated significantly less EMG activity in the muscles of the lower extremity during all 4 functional exercises. Effect sizes for significant differences between groups ranged from -0.75 to -1.08, none of which had 95% confidence intervals that crossed zero, which indicates moderate to large decreases in muscle activity in patients with CAI compared with healthy controls. CONCLUSIONS: Patients with CAI demonstrated decreased muscle activity of ankle, knee, and hip musculature during common functional rehabilitative tasks. Clinicians may benefit from implementing functional exercises for patients with CAI that target both distal and proximal muscles of the lower extremity.
OBJECTIVE: To determine whether individuals with chronic ankle instability (CAI) exhibit altered neuromuscular control as demonstrated by surface electromyography (EMG) amplitudes compared with healthy controls during single-limb eyes-closed balance, Star Excursion Balance Test, forward lunge, and lateral hop exercises. DESIGN: A cross-sectional laboratory study. SETTING: A research laboratory. PARTICIPANTS: Fifteen young adults with CAI and 15 healthy controls. INTERVENTIONS: The subjects performed functional exercises while surface EMG signals were recorded from the tibialis anterior, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius. MAIN OUTCOME MEASUREMENTS: Surface EMG amplitudes (root mean square area) for each muscle, muscles of the shank (distal 3 muscles), muscles of the thigh (proximal 3 muscles), and total muscle activity (all 6 muscles) of the lower extremity were analyzed and compared between the groups. RESULTS: Individuals with CAI demonstrated significantly less EMG activity in the muscles of the lower extremity during all 4 functional exercises. Effect sizes for significant differences between groups ranged from -0.75 to -1.08, none of which had 95% confidence intervals that crossed zero, which indicates moderate to large decreases in muscle activity in patients with CAI compared with healthy controls. CONCLUSIONS:Patients with CAI demonstrated decreased muscle activity of ankle, knee, and hip musculature during common functional rehabilitative tasks. Clinicians may benefit from implementing functional exercises for patients with CAI that target both distal and proximal muscles of the lower extremity.
Authors: Luke Donovan; Joseph M Hart; Susan A Saliba; Joseph Park; Mark Anthony Feger; Christopher C Herb; Jay Hertel Journal: J Athl Train Date: 2016-03-02 Impact factor: 2.860
Authors: Mark A Feger; Shannon Snell; Geoffrey G Handsfield; Silvia S Blemker; Emily Wombacher; Rachel Fry; Joseph M Hart; Susan A Saliba; Joseph S Park; Jay Hertel Journal: Orthop J Sports Med Date: 2016-06-16