Reliability testing of vasti activity measurements in taped and untaped patellofemoral conditions during single leg squatting in healthy subjects: A pilot study

SummaryIntroductionMeasuring vasti muscles activity may provide reliable evidence for patellar taping to correct probable malalignment in subjects with patellofemoral pain syndrome (PFPS). The aim of present study was to examine the reliability of vasti activity measurements in different patellofemoral conditions during squatting in healthy subjects.MethodsUsing an electromyography (EMG) unit, the ratio amplitudes and onsets of VMO and VL muscles of twelve healthy subjects were assessed during single leg squatting. Data was collected from surface electrodes placed over the muscle bellies of the VMO and VL. This procedure was performed on the right knees, before (BT), during (WT) and shortly after patellar taping (SAT).ResultsWhile 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 VMO/VL amplitude measurements during single leg squatting (p < 0.05), the related values demonstrated poor to moderate reliability of VMO-VL onset measurements during the similar activity (p > 0.05).ConclusionReliability tests conducted during the current study showed that, while the relative amplitude of vasti could be used as highly reliable parameter, the muscle onsets of vasti had poor to moderate reliability.