Differences in Muscle Activation in the Lower Extremities While Performing Traditional Squats and Non-Traditional Squats

Purpose: To determine if muscle activation in the lower back and lower extremities differ when performing traditional squats compared to non-traditional (forward center of pressure on foot) squats. The erector spinae, hamstrings, quadriceps, adductor longus, gastrocnemius, and gluteus maximus muscles were monitored for differences in this study. There are several variations of the back squat and each variation may possibly target muscles differently. Determining if non-traditional squats leads to larger erector spinae muscle activation, which in turn may lead to more lower back fatigue and possible lower back injury is a major aim of this study. Participants: Thirteen healthy males (age = 25.15 ± 2.38 yrs, height = 70.35 ± 3.2 in, weight = 174.45 ± 18.35 lbs and body fat = 10.31% ± 2.97%), which have participated in a steady exercise program for at least a year and included a version of the squat exercise in their routine at least once a week, were the participants in this study. Participants could not have sustained a serious knee, back, or ankle injury in order to qualify for this study. Participants were recruited from Boise State University via flyers and word of mouth. Methods: This study consisted of individuals performing traditional squats for one set of ten reps and non-traditional squats for one set of ten reps. Prior to testing, each subject performed maximum voluntary isometric contraction tests for each muscle being monitored (vastus medialis, vastus lateralis, gluteus maximus, bicep femoris, semitendinosus, adductor longus, gastrocnemius, and erector spinae) in order to normalize data collected during the two squatting variations. All testing took place at the biomechanics lab in the Micron Engineering Center at BSU. Statistical Analysis: Data was analyzed using the SPSS statistical software package. An ANOVA with a post hoc test consisting of paired t-tests were used to compare differences in activity between the two squatting techniques. Hypothesis: The gluteus maximus, biceps femoris, and semitendinosus muscle activation will be significantly larger during the traditional squats. The erector spinae and gastrocnemius muscle activation will be significantly larger during the nontraditional squats. The vastus medialis, vastus lateralis, and adductor longus muscle activation will not be significantly different between the two squat variations. Results: The semitendinosus and gastrocnemius muscle activation was significantly larger during the non-traditional squat. The vastus medialis and vastus lateralis muscle activation was significantly larger during the traditional squats. Conclusions:When performing back squats, keeping one’s center of pressure on the heels of their feet will activate the quadriceps to a larger degree than if performing squats while the center of pressure is on one’s toes. Participants claimed their lower back felt more activated during the nontraditional squats; however, the quantitative data did not support this claim