To compare average electromyogram (EMG) activity of the vastus medialis obliquus (VMO) and vastus lateralis (VL) during straight-leg raise (SLR) and knee extension (KE) with the hip in neutral and lateral rotation.
1 × 4 factorial repeated-measures.
13 male college students.
SLR with hip flexed at 40°, in neutral position, and maximally laterally rotated and KE with hip in neutral and maximally laterally rotated.
Main Outcome Measure:
Average EMG activity during each of the 4 conditions, normalized against peak muscle activity during that trial.
No differences were observed between exercises in VMO activity (F3,36 = 0.646, P > .05), VL activity (F3,36 = 1.08, P > .05), or VMO:VL ratio (F3,36 = 0.598, P > .05).
Electrical activity of the VMO or VL and VMO:VL ratio do not change with hip position or exercise.
Livecchi is with the University of Wisconsin Oshkosh, Oshkosh, WI 54901. Armstrong and Rankin are with the Dept of Kinesiology, University of Toledo, Toledo, OH, 43606. Cordova is with the Athletic Training Dept, Indiana State University, Terre Haute, IN 47809. Merrick is with the School of Allied Medical Professions, The Ohio State University, Columbus, OH 43210.