The pneumatic Achilles sleeve assembly comprises a sleeve and at least one strap for fastening the sleeve around the ankle. The sleeve assembly positions an arch cell which contains a dynamic volume of air within the sleeve under a human foot. The arch cell is fabricated from a flexible material and is in communication with a conduit member. Upon application of external pressure to the arch cell, air is expelled from said air cell through said conduit member. The sleeve assembly also positions a tendon cell which contains a dynamic volume of air within the sleeve against the Achilles tendon. The tendon cell is in communication with the arch cell via the conduit member. The tendon cell is also fabricated from a flexible material. Upon the expelling of air from said arch cell, the air enters through the conduit member into the tendon cell which exerts a greater pressure against the Achilles tendon.