A comparison of hip and knee torques produced during a maximal effort full and partial back squat

This study examined the levels of hip and knee torques produced during a one repetition maximum (1RM partial) squat and full squat in order to determine if there would be a difference in the peak torque created at the two depths. Eight male athletes (standing height = 1.84  0.07 m; mass = 87  14 kg; age 23 ± 2.1 years) volunteered for the study. Each subject performed a 1RM squat at full squat (as low as the participant could go, at least 0° or thigh parallel in relation to the ground) and partial squat (thigh at 45° in relation to the ground). The trials were collected in two sessions one week apart. The joint torques were calculated at the instant they reached the maximum depth for each trial, as well as at 45° in the full squat trials. The difference in knee and hip extension torques achieved was not significant at maximum depth (p ≥ .05). The full squat achieved the same level of hip and knee torque as the partial squat with significantly less barbell load. Participants averaged a 60.5% increase in barbell load, which was significant (p < .05), in the partial squat when compared to the full squat. Due to the large increase in barbell load during the partial squat, the participants mentioned much more discomfort and were less inclined to approach a true 1RM as they did with the full squat. The partial squat also slightly changed the mechanics of the squat with the subjects maintaining a more erect posture to alleviate some of the strain placed on the spine and back musculature which could place the spine at an increased risk for injury. For the partial squat to be an effective training lift, the participants would have to increase the load to a point that they find uncomfortable and place the spine under excess stress than would a full squat that would achieve the same levels of joint torques. A COMPARISON OF HIP AND KNEE TORQUES PRODUCED DURING A MAXIMAL EFFORT FULL AND PARTIAL BACK SQUAT A Thesis Submitted in partial fulfillment of the requirements for the Degree Master of Arts Jordan Alexander Williams University of Northern Iowa July 2015