The health and performance benefits of the squat, deadlift, and bench press

Abstract

Research which has investigated the effects of squat depth on gluteus maximus activity have found that gluteus maximus activity increases with depth. 8 However, these results appear to vary with different loads (% of 1RM). Other researchers have found Gluteus maximus recruitment may increase with increases in squat stance width. For example, observed a significant increase in gluteus maximus activity when squats were performed with wider stances. Finally, 9 analyzed the back squat and the overhead squat and found; the back squat elicited greater gluteus maximus activity than the overhead squat. Interestingly, when compared to the front, full, or parallel squats, squatting at full range, did not elicit greater Gluteus maximus activation, suggesting either front, full, or parallel squats are equally effective exercises for Glut development (Contreras, Vigotsky, Schoenfeld. In conclusion, the results from these studies suggest the squat is an excellent exercise to strengthen the musculature of lower limbs. Also, muscle activity during a squat can be affected foot position, depth, support, and load. Quadriceps activity During a squat, the quadriceps are the prime movers, particularly the vasti muscle group, which show significantly higher activity than the rectus femoris. Peak quadriceps activity occurs at 80-90 degrees of a squat, with no further increases with greater knee flexion. 10 This data indicates, half squats (to 90 degrees of knee flexion) will maximize quadriceps activity. Descending beyond 90 degrees of knee flexion, which is near the parallel squat position, may not enhance quadriceps development. 10 Finally, when compared to hack squat-machines, wall squats with hip support, appear to increase quadriceps activity. 11 Also, this researcher observed greater quadriceps activity when performing squats on both the hack squat-machine and against a wall. Taken together, these data suggest when, squatting to smaller ranges of motion, placing the feet forward or performing squats against a wall with hip support may be a more efficient means of targeting quadriceps. Vastus medial obliquus (VMO) The vastus medial obliquus muscle is the most distal segment of the vastus medial muscle. Its specific training plays a major role in maintaining patella position and limiting injuries to the knee. 12 Weakness, timing, and dysfunction of the VMO cause mal-tracking of the patella and subsequent damage to surrounding structures which leads to increased forces on the knees, often resulting in injuries. 13 Furthermore, imbalances between vastus lateral and VMO enhance the risk for patellofemoral pain, 14 this data demonstrates the importance of early VMO training following a knee injury. Research on VMO activity during a squat shows the VMO contributes 30.88% to the activity of the thigh during the partial squat; yet, it contributes only 18.85 and 20.23% during the parallel and full squats. 15 Other research 16 has investigated if wider foot positions affect VMO activity relative to VL activity (VMO: VL ratio). The researchers reported a wider foot position does not increase VMO activity. However VMO was more active throughout a 90° range, and increasing knee flexion angles can increase the activity of the VMO relative to the VL. Taken together, these findings suggest squatting to no greater than 90 degrees of knee flexion; may be the optimal squat depth for VMO.