Arm Wrestler: The Seated Internal Pivot for Pecs and Subscapularis

Internal rotation means turning your arm inward, toward your body. You use it when you reach across your chest or put on a jacket.

The pectoralis major is the large chest muscle that helps bring the arm in front of you and toward your body. The subscapularis is a rotator cuff muscle on the front of the shoulder blade. It helps turn the arm inward and keeps the ball of the joint steady.

In Arm Wrestler, your elbow stays close to your side and acts as a hinge. Your forearm pivots inward, and the chest and front shoulder muscles control the turn.

• Training that challenges your sense of joint position, called proprioception, improved control in the trained wrist and also in the opposite, untrained wrist. The two sides of the body seem to learn from each other [R15]. This was a wrist study, not a shoulder study.
• In stroke rehabilitation, training both arms together produced greater shoulder-movement gains than single-arm training. This comes from stroke patients, so it is a reason to be curious, not proof for healthy adults [R14].
• Programs that focus on control and coordination may reduce shoulder disability a little more than generic exercise, though the pain effect is uncertain [R02].

1. Sit tall in a stable chair with your back supported.
2. Bend your elbow to about a right angle. Keep the elbow close to your side. Let it act as a hinge rather than a lever you swing.
3. Turn the forearm inward, slowly. Move the trainer or your forearm toward your belly. Stop before you feel any pinch or strain.
4. Return with control. Let the forearm come back to the start without letting it drop. Smooth is better than fast.
5. Repeat a few times, then rest. Build up across weeks.