This overview covers research by McBride et al (2010) comparing the squat and box squat. The authors made a tentative hypothesis that by removing the stretch shortening cycle from the movement, by using a box squat, they would find negative effects on kinetic variables and muscle activity.
8 competitive powerlifters with at least 3 years squatting experience (Height: 179.61 ± 13.43 cm; Body Mass: 107.65 ± 29.79 kg; Age: 24.77 ± 3.22 years; and 1 repetition maximum (RM): 200.11 ± 58.91 kg) were used as participants in the study.
Participants visited the laboratory on 2 occasions separated by at least a week. On the first occasion they underwent 1RM squat testing. 1RM squat was obtained using a standard 1RM procedure achieving a knee angle of 70° measured with a goniometer. On the second occasion participants performed 1 repetition at 60%, 70% and 80% each for the squat and the box squat in a randomised order. The box squat involved an eccentric phase of movement to sitting on a box for 1 second followed by a concentric phase and the squat was performed with a quick transition between both phases. Peak force and power were measured during the concentric phase as was muscle activity of the vastus lateralis, vastus medialis, biceps femoris and longissimus.
Peak force was found to be significantly higher during the box squat in the 70% of 1RM trials and peak power was significantly higher during the box squat in the 80% of 1RM trials. Muscle activity of the biceps femoris was significantly greater during the squat at 60% of 1RM trials and the vastus lateralis was significantly more active during the squat in the 70% of 1RM trials.
The authors conclude by stating that there is little difference between the kinetic variables and muscle activity involved during the squat and box squat. They state that the box squat may be a useful tool for training athletes that have a concentric only component to their sport but that a stretch shortening cycle is a vital component in most sports and as such a squat that utilises a stretch shortening cycle may be of greater benefit.
McBride, J.M., Skinner, J.W., Schafer, P.C., Haines, T.L. & Kirby, T.J. (2010). Comparison of kinetic variable and muscle activity during a squat vs a box squat. Journal of Strength and Conditioning Research 24:12 pp. 3195-3199.