The Effects of Open versus Closed Kinetic Chain Exercises on Ankle Joint Function in Athletes with Chronic Ankle Instability
Objective: Lateral ankle sprains are common sport injuries that often result in structural and functional alterations leading to chronic ankle instability (CAI). Insufficiencies in proprioception, neuromuscular control, and strength are suggested as contributing factors to CAI. Open Kinetic Chain (OKC) and Closed Kinetic Chain (CKC) exercises often constitute the core of ankle specific training before progression to advanced training. Though commonly used in the management of CAI, there is no consensus regarding their efficacy on physical therapy outcomes. The purpose of this study was to compare the effect of OKC and CKC exercises on dynamic postural control, self-reported function, and subjective sense of instability in subjects with CAI.
Methods: Subjects with unilateral CAI were randomly assigned into three groups: OKC (n=5), CKC (n=6), and control (n=6). Outcome measures included star excursion balance test (SEBT) reach distance, center of pressure (COP) sway velocity, sway area, and path length; and Foot and Ankle Ability Measure-Sport Subscale. Intervention groups completed 6 weeks of exercises. Also, subjects completed a global rating of change (GROC) form at week 6 post-intervention.
Results: Following intervention, both OKC and CKC groups had significant improvements in the outcome measures, indicating an improvement in dynamic postural control and subjective function; however, CKC had greater improvements than OKC. The control group did not show improvements. GROC revealed a significant difference in median score for CKC group when compared to OKC and control groups (p=0.04 and p=0.03, respectively).
Conclusion: The 6-week of OKC and CKC exercise programs improved parameters of postural control and subjective function in CAI subjects. CKC exercises, however, were more effective than OKC exercises. Hence, exercise programs should become more functional and task oriented. Further research is needed in a larger cohort of subjects to determine effects of both training programs on ankle joint injury risk factors.