A, Diagram of controlled passive motion exercise. Metacarpophalangeal joint should remain in normal balanced position. Extension of distal interphalangeal joint is sufficient to move anastomosis 3 to 5 mm. Only distal interphalangeal joint moves during this exercise. B, Note distal migration of anastomosis of flexor digitorum profundus tendon away from that of flexor digitorum sublimis tendon. C, When middle phalanx is extended, both anastomoses glide distally. Only proximal interphalangeal joint moves during this exercise. D, Anastomoses are moved away from fixed structures that may have been injured. Elastic traction returns finger to original position.