Abstract: An adjustable splint for a human knee comprising upper and lower leg engaging portions and a foot engaging portion. With a knee injury, it is important to splint the knee in the position in which it is found because changing the position can damage the blood vessels and nerves that pass through the knee. Therefore, the splint has hinged connections between its upper and lower leg engaging portions and between its lower leg and foot engaging portions so that its angular position can conform to that of the leg and foot. The upper and lower leg engaging portions of the splint each have a length adjustment, and the splint includes means for releasably securing its upper and lower portions in the required position of angular adjustment.