Intra- and Inter-Session Reliability of Methods for Measuring Reaction Time in Participants with and without Patellofemoral Pain Syndrome.

Abstract

To evaluate the relative and absolute reliability of reaction time measuring methods during different conditions in participants with and without patellofemoral pain syndrome (PFPS). 30 patients with PFPS and 30 healthy controls were recruited in the present study. The upper extremity reaction time, upper extremity error rate, involved and non-involved lower extremity braking reaction times, and involved and non-involved knee extension reaction times were measured. Each condition was repeated three times, 2 sessions with a 5-7 days interval. The intra-session reliability was evaluated in three-trial (A), second- and third-trial (B) modes. In addition, the inter-session reliability was evaluated in mode A, mode B, and best score (C) mode. The result of inter-session reliability of mode A showed that all measurements except upper extremity reaction time in PFPS group showed high to very high relative reliability (ICC: 0.74-0.94). In mode B, all measurements except non-involved knee extension reaction time in PFPS group showed high to very high relative reliability (ICC: 0.71-0.93). In mode C, all measurements showed high to very high relative reliability (ICC: 0.70-0.94) except upper extremity error rate and non-involved knee extension reaction time in PFPS group. The result of intra-session reliability showed that all measurements had high to very high relative reliability (ICC: 0.78-0.94) in mode A. In mode B, all measurements showed high to very high relative reliability (0.78-0.94). The braking time seems more reliable than other reaction time tasks. In addition, the results showed that mode A is more reliable than other modes. The newly designed package is a reliable tool to measure the knee extension reaction time in patients with knee musculoskeletal disorders.