Patellar taping affects vastus medialis obliquus activation in subjects with patellofemoral pain before and after quadriceps muscle fatigue

Objective: To investigate the effects of patellar taping on the electromyographic onset of vastus medialis obliquus and vastus lateralis, and their magnitudes of reflex contraction before and after quadriceps muscle fatigue in subjects with patellofemoral pain. Methods: Sixteen adults (5 males) diagnosed with patellofemoral pain were studied. The timing of surface electromyography onset and magnitude of vastus medialis obliquus and vastus lateralis contractions were measured during a postero-anterior knee perturbation test. The tests were conducted in random order under three conditions of real taping, placebo taping and no taping. Afterwards, the subjects performed knee extension exercises until fatigue and the above tests were repeated, so as to examine the effects of patellar taping in a muscle fatigued condition. Results: There was no significant difference in electromyographic onset timing of vastus medialis obliquus and vastus lateralis or in the amplitude of vastus lateralis contraction among the different testing conditions. For vastus medialis obliquus amplitude, however, it was significantly higher in the no taping than the real taping condition regardless of the state of fatigue (P = 0.013). Conclusions: The present study suggests that patellar taping might not enhance the temporal activation of vastus medialis obliquus in subjects with patellofemoral pain before and after muscle fatigue. Furthermore, vastus medialis obliquus contraction might be inhibited by patellar taping.