AliMed® Swanson Grip-X® is an isometric exerciser that is ideal for strengthening grip and forearm musculature. Developed by Alfred B. Swanson, M.D., FACS, and Mary DeBoer, RPT, for hand rehabilitation after finger-joint arthoplasty. Grip-X is shaped to fit inside flexed fingers and support the MP joints during isometric exercise of the forearm. Choose from three, color-coded firmnesses. Effective exercise for improving golf and tennis grip. PVC rubber.