Validity and Reliability of a Smartphone Application for Assessing Balance in Patients With Chronic Ankle Instability

Lateral ankle sprain (LAS) is a common injury in athletic and regular activities; with an incidence of 7 per 1000 exposure. After LAS, residual symptoms may persist leading to chronic ankle instability (CAI). This instability is believed to arise from dysfunctional postural control, defective proprioception, weak muscles, or reduced ankle range of motion (ROM).Thus, assessment of postural control is essential for proper clinical decision-making and treatment selection.

With advances in technology, smartphone has been introduced as an assessment tool for the musculoskeletal system. For example, it was used in assessment of ROM and mobility in stroke patients and frail elderly conditions. Further, it was used to assess balance and falling risk in those population. In addition, it was used to assess balance in healthy and participants with chronic ankle sprain. These studies proved that smartphone is a valid and reliable tool that is light in weight and inexpensive. Yet, these studies have some methodological concerns. For example, the application was not validated against gold standard or was validated only in healthy volunteers rather than in patients with musculoskeletal dysfunction. Further, a few of these studies did not establish the application discriminative validity between patients and healthy controls. Thus, this study will try to answer the following question: "Is smartphone application a valid and reliable tool to assess balance in patients with CAI compared to gold standards?