The upper and lower sections (12, 14) of a splint (10) are pivotable about a pivot axis (17) by a pair of pivot assemblies (16). Each pivot assembly (16) includes a housing (18) having a cylindrical side wall (20) and a spacer (30) having a cam track (34). The housing (18) is closed by a closure plate (36) which pivotably mounts an arcuate brake shoe (46) and which mounts a cam (60). Relative rotation of the housing (18) and closure plate (36) causes the cam (60) to follow on the cam track (34) for pivoting the brake shoe (46) to engage the side wall (20) with variable braking force. In preferred forms, a compression block (80) having an aperture (82) formed therein is positioned between the brake shoe axis and the end of the brake shoe (46) to provide a visual indication of the resistance force. In preferred forms, a V-shaped projection (90) is formed on the brake shoe (46) for slideable receipt in a V-shaped groove (84) formed in the side wall (20).