Secondary Logo

Share this article on:

Signorile Joseph F.; Kwiatkowski, Keith; Caruso, John F.; Robertson, Bobby
Journal of Strength and Conditioning Research: August 1995
Article: PDF Only

ABSTRACTMany strength trainers believe that varying the foot position during the parallel squat or knee extension can target specific muscles of the quadriceps group. To test this theory, 10 men performed 3 parallel squats at added resistance equal to their body weight and 3 knee extensions at 8- to 10-RM resistance under 3 treatment conditions: toes pointed out, lateral rotation of the tibia (LR); toes straight forward, no rotation of the tibia (N); and inward, medial rotation of the tibia (MR). Lifts were separated by a 5-min rest. Bipolar surface electrodes placed on the bellies of the v. lateralis and v. medialis and on the lateral and medial portions of the rectus femoris revealed no significant differences in electrical activity for any muscle due to changes in foot position during the squat. During the knee extension, however, LR produced a significantly greater mean rmsEMG than the other foot positions across all muscles. Thus for the squat a lifter should choose the most stable and comfortable position. For the knee extension, however, maintaining a laterally rotated position is best.

Many strength trainers believe that varying the foot position during the parallel squat or knee extension can target specific muscles of the quadriceps group. To test this theory, 10 men performed 3 parallel squats at added resistance equal to their body weight and 3 knee extensions at 8- to 10-RM resistance under 3 treatment conditions: toes pointed out, lateral rotation of the tibia (LR); toes straight forward, no rotation of the tibia (N); and inward, medial rotation of the tibia (MR). Lifts were separated by a 5-min rest. Bipolar surface electrodes placed on the bellies of the v. lateralis and v. medialis and on the lateral and medial portions of the rectus femoris revealed no significant differences in electrical activity for any muscle due to changes in foot position during the squat. During the knee extension, however, LR produced a significantly greater mean rmsEMG than the other foot positions across all muscles. Thus for the squat a lifter should choose the most stable and comfortable position. For the knee extension, however, maintaining a laterally rotated position is best.

© 1995 National Strength and Conditioning Association