Medical advantages are provided by the novel improvements made to the inflatable foot cushion of the present invention to the inflatable foot cushion of U.S. patent application Ser. No. 13/432,068 and the Inflatable Foot Cushion of U.S. Pat. No. 5,328,445, including better protection of a patient's Achilles' tendon areas; better unloading of the pressures on the patient's heels due to the increased elevation of the patient's heels above substrates; and the prevention of left and right lateral rotation of the ankles of patients wearing the novel inflatable foot cushion of the present invention by its two novel lateral cushions formed by expanding the main chamber of the improved inflatable foot cushion of the present invention there between, which novel lateral cushions cradle and stabilize the improved inflatable chamber of the present invention when it is pivoted under the improved inflatable foot cushion of the present invention.