Higher grip strength increases the risk of incident radiographic osteoarthritis in proximal hand joints

Quadriceps strength may protect against knee osteoarthritis (OA), but muscle activity is a major determinant of forces at the hand joints. Gripping objects is a common task during which high muscular forces are sustained, particularly at the proximal hand joints (metacarpophalangeal (MCP) joints and thumb base). The association between maximal grip strength and incident OA at different hand joints was examined in a longitudinal study of radiographic hand OA. Subjects with higher maximal grip strength were at increased risk for development of OA in the proximal interphalangeal (PIP) joints, MCP and thumb base joints in men; and in the MCP in women. No association was found between maximal grip strength and incident distal interphalangeal (DIP) joints OA in men or women. The conclusion is that increased grip strength, which is the major force of loading across proximal hand joints, increases the risk of OA in those joints.