['To investigate the effect of patellar taping on the amplitude of electromyographic activity (EMG) of vasti activation in subjects with and without patellofemoral pain (PFP).', 'Ten participants with PFP and 12 asymptomatic controls were recruited to the study. The study was designed as a randomised crossover trial. Participants completed a stair stepping task. Three experimental conditions were assessed: no tape, therapeutic medially directed tape, and placebo vertically directed tape. The main outcome measure was the EMG amplitude of the vastus medialis obliquus and vastus lateralis during the concentric phase of stair stepping.', 'The application of medially directed therapeutic tape significantly decreased pain in subjects with PFP. However, application of tape over the patella (therapeutic or placebo) did not alter the amplitude of vasti EMG when either the PFP or control participants completed the concentric stair stepping task.'] Does patellar taping change the amplitude of electromyographic activity of the vasti in a stair stepping task?