Abstract: Devices, especially orthotic, prosthetic and manipulative devices, articles of wear, and apparatus utilizing a coil spring are provided for self-adjustable support, flexion, and/or extension of limb members of a body joint. The devices have first and second support arms each having a planar face at one end joinable in co-axial face-to-face relation at a pivot point, in combination with a coplanar co-axial coil spring allowing for flexion and extension. The respective faces in one preferred embodiment have a range-of-motion guide channel and a channel-following stop member and at least one groove pair located on opposite sides of the channel for holding a stop bar across the channel to limit the range of motion of the stop member in the channel.