Biomechanical and ergonomical adjustable crutch

A rotatable shock absorber assembly for a crutch. A guide pin is removably fixable within the upper portion of a support leg. A piston comprises a flange arranged proximate a saddle, comprising a top surface having two or more arcuate rotation grooves defined therein, and a main body defining an elongate slot enabling the guide pin to be inserted therethrough, such that the piston can translate along the elongate axis relative to the guide pin. A joint, can operably couple the piston to the saddle. The joint can rotate about the elongate axis relative to the piston. A biasing mechanism is configured to urge the piston along the elongate axis toward the armpit of the user whereby the saddle can be held stable in the armpit of the user and the support leg can rotate about, and translate along the elongate axis during use.