There are many ring-shaped fitness equipment called upper limb tractors in the park. The upper limb tractor mainly uses its own strength to fight against it and improve the mobility of the affected limb of scapulohumeral periarthritis. For ordinary bodybuilders, it can exercise the muscles of shoulders, wrists and arms, improve the flexibility of upper limbs, enhance the flexibility of muscles and ligaments around shoulder joints, and have a positive rehabilitation effect on shoulder joint dysfunction and old injuries.