The STAK Knee Stretcher is a clinically proven device for home use that helps patients regain full knee movement after surgery or injury. It restores knee flexion and, with the high-intensity extension add-on, targets knee straightening deficits. Lightweight and easy to use, STAK helps break down scar tissue, reduce pain, and improve function. The extension add-on is particularly effective for restoring full extension, improving walking, and preventing joint stress.