Knee supports can be more rigid or elastic, depending on what each patient needs. They range from slip-on compression knee sleeves and knee wraps to orthopedic knee braces with various types of supports and stabilizers. The most rigid of all the knee supports is the knee immobilizer, which ensures everything stays in place after surgery or injury. More sophisticated knee supports can control leg rotation, special leg straps can aid in rehabilitating a stroke patient, and knee cages help control hyperextension. Besides these, some leg injuries may also require calf sleeves or thigh support. The most unusual type of knee support is probably the turnbuckle knee orthosis. This is used by therapists to gradually apply a low-load force to the knees, which helps reduce knee contracture and increase the range of motion.