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

The squat is a well‒known exercise to strengthen the muscles of the lower limb. Conditioning specialists universally agree the squat is among the top three prescribed exercises for sports training, rehabilitation and prehabilitation.1 Previously, there has been much debate about the safety of deep (full range) squats. Strength and conditioning coaches often define a deep squat by amount knee range of motion (120‒140 degrees), or by observation of thigh position, which during a deep squat is below parallel to the floor. Historically, some researchers2 have raised concerns about the levels of knee compressive forces that occur during full range squats, however this concern has been rejected by leading strength and conditioning authorities such as the National Strength and Conditioning Association. In the NSCA Position Paper on the squat exercise, the NCSA has rejected these concerns, providing substantial scientific evidence that full range of motion squats do not expose the knee to damaging compressive forces.3 Interestingly, researchers have reported knee joint compression may be higher in the partial range of motion squat, as peak patellofemoral joints experience peak forces at 90‒100 degrees of knee flexion during the squat.4 According to Chandler and Stone the squat when performed correctly regardless of depth, and with appropriate supervision, not only is safe but maybe a significant deterrent to knee injuries. Importantly, however,4 also report that bouncing out of the bottom position of a squat, to help initiate the ascent increases the mechanical load on the knee joint. This is because the highest forces and muscular tension during a squat typically occur at the transition from descent (eccentric) to ascent (concentric), as muscle lengthening is much higher during full range of motion squats. Altogether, these data suggest deep squats, when adequately supervised, do not impose damaging forces to the knees.