PTS is usually caused by repetitive physical activity involving quick pronation and grasping movements:
- Manual labor – mechanics, chopping wood, carpentry
- Physical activity – weight lifting, playing racquet sports, throwing balls, rowing, skiing, holding the handlebars of a bicycle
- Activities of daily living – carrying books, pouring drinks, cleaning dishes, raking leaves, shoveling snow
- Compressive tumors
- Hypertrophy of bicipital aponeurosis
Because it can be mistaken for more common conditions such as CTS, the incidence of pronator syndrome is rare, occurring in less than 1 in 100 000 people annually.
Impingement of the median nerve can occur at several locations in pronator syndrome: elbow joint (most common cause), distal humerus, proximal elbow, proximal forearm, or due to the Gantzer muscle (accessory head of the flexor pollicis longus muscle).