An orthosis for stretching tissue around a joint of a patient between first and second relatively pivotable body portions. The orthosis includes a first arm member affixable to the first body portion and including a first extension member extending therefrom. A second arm member affixable to the second body portion is also included and has a second extension member having an arcuate shape extending therefrom. The second extension member is operatively connected to the first extension member and travels trough the first extension member along an arcuate pat when the second arm member is moved from a first position to a second position relative to the first arm member.