Effect of decline squatting versus neutral squatting exercises on quadriceps strength and functional performance

Abstract

The purpose of this study is to find the effect of decline squatting and neutral squatting exercises on quadriceps strength and functional performance in normal healthy individuals.
Method: Physically active male samples (n=30) in the age group of 18-25 years were included after they met the inclusion criteria. Participants were randomly assigned to one of the two groups: a decline group and a neutral group. The Mean+SD characteristics of 15 male Neutral squatting subjects were: Age=23.27+1.49 years; Height=170.93+4.92 cm; Weight=66.13+7.04 Kg and of 15 male Decline squatting subjects were: Age=23.33+1.5 years; Height=170.46+6.22 cm; Weight=65.07+8.22 Kg. The decline group (n=15) was required to perform Modified unilateral squat protocol on a 250 decline board: 4 sets of 10 repetitions with 75% of 1 RM squat with 2 minutes of rest between each set thrice a week for 6 weeks. The neutral group (n=15) performed the same protocol of single-leg squats on a horizontal surface. Dynamic strength (1RM) of quadriceps and squat was calculated based on formula using amount of weight lifted and number of repetitions. Quadriceps chair with an addition of a strain gauge was used to measure quadriceps maximum isometric strength. Vertical jump test (VJT) was performed by asking subject to jumps vertically as high as possible using single arm and leg to assist in projecting the body upwards.
Results: Both groups showed significant gains in quadriceps strength (dynamic & isometric) and functional performance (1 RM squat) over 6 weeks of training. The decline squat protocol offered greater gains in quadriceps strength and 1RM squat strength after 6 weeks of training. There was however, no significant difference in vertical jump height improvement between the two groups.

Key words:

neutral squatting, decline squatting, quadriceps strength training, functional performance, vertical jump test