Date of Award


Degree Type


Degree Name

Physical Therapy (M.S.)


Physical Therapy


Patellofemoral dysfunction (PFD) usually involves patellar maltracking. Vastus medialis oblique (VMO) and vastus lateralis (VL) are two key muscles that help maintain patellar alignment. Open kinetic chain (OKC) studies suggested that the optimum ratio of VMO:VL is about 1:1. With PFD the VMO becomes much weaker. Purpose: To determine which of four partial squat exercises, often used in rehabilitation, best favors VMO firing: partial squat, partial squat squeezing a ball between knees, partial squat with pulley resistance and partial squat with 45° oblique pulley resistance. Analysis of EMG for 31 normal subjects randomly performing all four exercises using repeated ANOVA were insignificant (p<.05) except for 10 males performing plain partial squat. In all 4 closed kinetic chain exercises VMO:VL mean ratios (1.30-1.43) were greater than the reported 1:1 OKC norm. Conclusion: No partial squat exercise was any better at favoring VMO over VL output except males performing partial squat.

