Movement Strategies among Groups of Chronic Ankle Instability, Coper, and Control

• Published in: Medicine and science in sports and exercise 2017-08, Vol.49 (8), p.1649-1661
• Main Authors: SON, S JUN, KIM, HYUNSOO, SEELEY, MATTEW K, HOPKINS, J TY
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Ankle Injuries - physiopathology; Ankle Joint - physiopathology; Biomechanical Phenomena; Electromyography; Female; Humans; Joint Instability - etiology; Joint Instability - physiopathology; Lower Extremity - physiopathology; Male; Movement - physiology; Muscle, Skeletal - physiopathology; Task Performance and Analysis; Young Adult
• ISSN: 0195-9131; 1530-0315
• DOI: 10.1249/MSS.0000000000001255

INTRODUCTIONComprehensive evaluation of movement strategies during functional movement is a difficult undertaking. Because of this challenge, studied movements have been over simplified. Furthermore, evaluating movement strategies at only a discrete time point(s) provide limited insight into how movement strategies may change or adapt in chronic ankle instability (CAI) patients. This study aimed to identify abnormal movement strategies in individuals with a history of ankle sprain injury during a sports maneuver compared to healthy controls. METHODSSixty-six participants, consisting of 22 CAI patients, 22 ankle sprain copers, and 22 healthy controls, participated in this study. Functional profiles of lower extremity kinematics, kinetics, and electromyography (EMG) activation from initial contact (0% of stance) to toe-off (100% of stance) were collected and analyzed during a jump landing/cutting task using a functional data analysis approach. RESULTSCompared with copers, CAI patients displayed landing positions of less plantarflexion, less inversion, more knee flexion, more hip flexion, and less hip abduction during the first 25% of stance. However, restricted dorsiflexion angle was observed in both CAI patients and copers relative to controls during the mid-landing to mid side-cutting phase when the ankle and knee reached its peak range of motion (e.g., dorsiflexion and knee flexion). Reduced EMG activation of tibialis anterior, peroneus longus, medial gastrocnemius, and gluteus medius may be due to altered kinematics that reduce muscular demands on the involved muscles. CONCLUSIONCAI patients displayed altered movement strategies, perhaps in an attempt to avoid perceived positions of risk. While sagittal joint positions seemed to increase the external torque on the knee and hip extensors, frontal joint positions appeared to reduce the muscular demands on evertor and hip abductor muscles.