Chishi (rod with heavy stone, Stone of power)
The chishi is used mainly to strengthen your grip and wrists. The exercises with the chishi also help strengthen your elbow, shoulder and wrist joints. Exercising with the chishi also improves your reaction times through tsuki (push or punch), shuto uke (knife and block), nagashi uke (fluid block) and hiki uke (grip block). Furthermore, exercising with the chishi develops the muchimi (heavy hand and hit) and the intensity of your movement.
The chishi is said to have come from China according to popular theory, however, similar implements in both use and design can also be found in India. The chishi develops good grip strength, particularly in the thumb and little finger. It also builds strong tendons in the wrist, elbows, and shoulder, whilst developing the bicep, triceps, latissimus dorsi and trapezius muscles. Regular practice with the chishi ensures that the practitioner is able to lock their techniques into the tanden, learning to use the large muscles of the back and the core for punching and blocking, rather than the weaker muscles of the arms.