Standard and natural motion protocols for the kinetic measurements of the squat

Two motion protocols that describe the sequence of movements to be complied with by a subject to perform a controlled squat are presented. The protocols are intended to be used in gait analysis to obtain repeatable and reproducible results that can be compared among different studies. The first protocol (“standard”) is closer to other studies in the literature, in order to improve comparison with previous experimental results. The second protocol (“natural”) reproduces a squat movement more similar to natural conditions, also allowing a deeper knee flexion. The two motion protocols are tested by a volunteer on a gait lab. Results of experimental tests in terms of joint and foot-ground angles, ground reaction force and centre of pressure show the characteristics of the standard and natural squat, and the repeatability of the tests.