Arm wrestling is a compound movement that involves multiple muscle groups of the upper body at different stages. The muscles used in arm wrestling are primarily in the upper body, including the arms, shoulders, and back. The primary muscles used in arm wrestling are:

• Forearms: The muscles in the forearms, including the flexors and extensors, are responsible for flexing and extending the wrist and fingers. The wrist flexors and extensors are heavily used in arm wrestling.

• Biceps: The biceps, located in the front of the upper arm, are responsible for flexing the elbow and rotating the arm. The biceps are also heavily used in arm wrestling.

• Triceps: The triceps, located in the back of the upper arm, are responsible for extending the elbow. The triceps are also heavily used in arm wrestling.

• Shoulder muscles: The shoulder muscles, including the lats, pecs, and subscapularis, come into play when rotating the opponents arm and creating a strong pulling motion towards you.

• Back muscles: The back muscles, including the latissimus dorsi and the trapezius, also play a role in arm wrestling. These muscles help to provide stability and control during the arm-wrestling match.

• Pronator teres: This muscle is located in the forearm and is responsible for rotating the forearm inward. It is one of the primary muscles used in arm wrestling.

• Flexor carpi ulnaris: This muscle is located in the forearm and is responsible for flexing the wrist. It is also one of the primary muscles used in arm wrestling.

It should be noted that depending on the technique and where you are in the range of motion, the muscles youre actively engaging will differ.