Quarter squats are bad for your knees and spine. Evidence:
Hartmann, H., Wirth, K., and Klusemann,M. (2013). Analysis of the load on the knee joint and vertebral column with changes in squatting depth and weight load. Sports Medicine 43/10:993-1008.
‘With the same load configuration as in the deep squat, half and quarter squat training with comparatively supra-maximal loads will favour degenerative changes in the knee joints and spinal joints in the long term. Provided that technique is learned accurately under expert supervision and with progressive training loads, the deep squat presents an effective training exercise for protection against injuries and strengthening of the lower extremity. Contrary to commonly voiced concern, deep squats do not contribute increased risk of injury to passive tissues.’
Quarter squats irritate me, sooo many ego lifters claiming a big squat, and they are only quarter squatting