Testing the reliability of the patellofemoral joint reaction force (PFJRF) measurement in different taped conditions of the patellofemoral joint during single leg squatting: a pilot study

Introduction: Measuring patellofemoral joint reaction forces (PFJRF) may provide reliable evidence for correcting probable malalignment using patellar taping in subjects with patellofemoral pain syndrome (PFPS). The aim of the present study was to examine the reliability of PFJRF measurements in different patellofemoral conditions during squatting in healthy subjects.Materials and Methods: PFJRF of eight healthy subjects were assessed using the motion analysis system and the forceplate during single leg squatting. Data were collected from superficial markers taped to the selected landmarks. This procedure was performed on the right knee, before (BT), during (WT) and shortly after removing the patellar taping (SAT). The PFJRF was calculated using a biomechanical model of the patellofemoral joint.Results: There were no significant differences between the PFJRF (mean values ± standard deviation) for the three conditions of BT (2100.55 ± 455.25), WT (2026.20 ± 516.45) and SAT (2055.35 ± 669.30) (P > 0.05). The CV (coefficient of variation), ICC (intra class correlation coefficient), LSD (least significant difference) and SEM (standard error of measurement) values revealed the high reliability of the PFJRF measurements during single leg squatting (P < 0.05).Conclusion: The high reliability of the PFJRF measurements signify that future studies can rely on these measurements during single leg squatting.Keywords: Patellofemoral pain syndrome, PFJRF reliability test, Patellar taping