Effects of Full Verses Parallel Squats on Quadriceps Muscular Hypertrophy in Healthy Male Athletes

Abstract

Introduction: The modern powerlifter utilizes relatively shallow squatting technique to the parallel plane. This is in sharp contrast to the traditional and modern Olympic-style squatting technique of full-depth squats as part of the snatch and the clean and jerk. While alteration of foot direction (i.e., inward vs. outward) has been recently shown to have very little bearing on quad stimulation (Journal of Strength & Conditioning Research 14[4]:379-382,2000), providing a slight heal lift in order to achieve greater depth has long since been repeatedly demonstrated as advantageous for achieving maximum quadriceps stimulation via performance, kinethatic model, force analysis, biomechanical analysis, 3-D cinematography, and electromyographic testing, as beneficial in the way I describe (1–6). Slightly lifting the heal brings the center of gravity away from your lower back and glutes and toward the maximum mass of the quadriceps muscles, thus maximizing direct quad tension. The Soviets have known this for generations and thus were the first to introduce the slight but standard heal-lift built in under every pair of hard Olympic-style weightlifting shoes made to date. This standard of practice affords the squatter a decided technical advantage by allowing the weight lifter to perform a deep squat without compromising proper spine position (7). Our objective was to determine if there is a measurable difference in muscular hypertrophy (quadriceps mass) from performing full squats verses parallel squats in healthy male athletes. Method: Eighteen (18) male athletes between the ages of 18 and 25, of equal size and stature, with no significant quadriceps size difference at baseline (p > 0.05) took part in this prospective, comparative study. Each subject was randomized to one of two (2) groups: parallel squatting (PS) or full squatting (FS), and received guidance in proper modern technique for each respective version. Subjects incorporated their respective techniques in to their regular workout two (2) times each week for six (6) months. Quadriceps mass (defined as a mid-range circumference measurement at the level marked between the center of the patella and the anterior iliac crest) was measured at four (4) time points (baseline, 2, 4, and 6 months). Data was analyzed for inter- and intra- group changes over time). Results: Over the time course of the study and within-group, the PS group experienced only a trend (P = 0.0859) toward quadriceps muscular hypertrophy, while the FS group achieved statistically significant mass gain (P = 0.0073). In terms of between-group differences, the FS group achieved statistically significant greater degree of quadriceps muscular hypertrophy when compared to PS (P = 0.0035). Discussion: Our findings clinically demonstrated that the full squat is superior to the parallel squat for stimulating muscular hypertrophy of the quadriceps. This fact confirms the comparative advantage of the full squat, and applies to amateur, professional, and Olympic athletes alike.