Authors: Cailbhe Doherty, BSc
Journal of Orthopaedic & Sports Physical Therapy, Ahead of Print Pages: 1-29 doi:10.2519/jospt.2015.5653
Study Design
Controlled laboratory study.
Objective
To utilize kinematic and stabilometric measures to compare dynamic balance during performance of the Star Excursion Balance Test (SEBT) between persons 6-months post first-time lateral ankle sprain (LAS) and a non-injured control group.
Background
Biomechanical evaluation of dynamic balance in persons following first-time LAS during SEBT performance could provide insight into the mechanism(s) by which individuals proceed to recover fully, or develop chronic ankle instability.
Methods
Sagittal-plane kinematics of the lower extremity and the center of pressure (COP) path during the performance of the anterior (ANT), posterior-lateral (PL) and posterior-medial (PM) reach directions of the SEBT were obtained from 69 participants, 6 months following first-time acute LAS. Data also were obtained from 20 non-injured controls.
Results
The LAS group displayed lower normalized reach distances in all 3 reach directions compared to control participants on their injured and non-injured limbs with the largest observed effect size in the PL direction (p = 0.001, ηp2 = 0.07). The performance impairment was associated with less hip and knee flexion and ankle dorsiflexion at the point of maximum reach (p<0.02) for all 3 reach directions, and coincided with less complexity of the COP path (p<0.05) in the PL direction only.
Conclusion
Participants with a 6-month history of LAS exhibit persistence of deficits previously established in the acute phase of injury.