Shoulder internal rotation is the inward rotation of the upper arm, a function of the glenohumeral joint that allows for a wide range of motion. Adequate internal rotation is fundamental for many daily tasks, including reaching behind your back for dressing or personal hygiene. It is also necessary for specific athletic movements, like the follow-through phase of a throw or the stroke mechanics in swimming. When this inward rotation is limited, the body must compensate, which can lead to pain or injury in the shoulder, neck, or upper back.
Assessing Your Current Range of Motion
A simple, effective way to check your shoulder’s mobility at home is the Apley Scratch Test, which evaluates a combination of shoulder movements, including internal rotation. To test your internal rotation, reach behind your back with the hand of the arm being tested, attempting to touch the inferior angle of the opposite shoulder blade. The spinal level your thumb reaches provides a quick metric for comparison between your two shoulders. A significant difference in reach between your dominant and non-dominant arm may indicate a restriction.
The most common anatomical cause of limited shoulder internal rotation is tightness in the posterior glenohumeral capsule, a sleeve of connective tissue surrounding the joint. Tightness in large muscles like the latissimus dorsi and teres major, which are powerful internal rotators, can also contribute to restriction. This restricted movement, often termed Glenohumeral Internal Rotation Deficit (GIRD), can cause the humeral head to shift improperly in the socket during overhead movements, potentially leading to impingement and pain. Identifying this posterior tightness is the first step toward selecting the correct mobility techniques.
Targeted Mobility and Stretching Techniques
The Cross-Body Stretch increases flexibility in the posterior deltoid and the back of the shoulder capsule. To perform this, gently pull the arm being stretched across the chest at shoulder height using the opposite hand, ensuring the stretch is felt in the back of the shoulder. Maintain good posture by retracting the shoulder blade slightly and avoiding rolling the shoulder forward or shrugging toward the ear. Holding this stretch for 30 seconds and repeating it several times helps to lengthen the tightened soft tissues.
The Sleeper Stretch specifically targets the posterior joint capsule, often the deepest source of internal rotation limitation. Lie on the side you wish to stretch, with the arm extended forward at a 90-degree angle from the torso and the elbow bent to 90 degrees. Use your opposite hand to gently press the forearm down toward the floor, rotating the arm inward until a comfortable stretch is felt in the back of the shoulder. Ensure the shoulder does not roll forward off the ground during the movement, and stop if you feel any pinching in the front of the joint.
Stabilization and Strengthening for Lasting Improvement
Achieving lasting improvement requires pairing mobility work with strengthening exercises to stabilize the joint and control the newly gained range. The goal is to correct muscular imbalances by strengthening the external rotators, which pull the arm outward and oppose the internal rotators. The infraspinatus and teres minor muscles perform this outward rotation and are key for centering the humeral head within the socket.
Banded external rotation exercises are effective for targeting these muscles for stability and strength. Stand sideways to an anchor point, holding a resistance band with your elbow bent to 90 degrees and kept close to your side. Slowly rotate your forearm outward against the band’s resistance without letting your elbow move away from your body, pausing at the end range before returning to the start. Performing two to three sets of 10 to 15 repetitions focuses on endurance and control, helping the shoulder maintain proper position during dynamic activities.
Stabilizing the shoulder blade, or scapula, is equally important, as the shoulder socket is attached to this bone. Scapular control exercises, such as the prone T and Y movements, help build a stable foundation for the arm to move upon. Lying face down, extend your arms out to form a “T” or “Y” shape, lifting them slightly off the floor by squeezing the shoulder blades together and down. These movements strengthen the mid and lower trapezius muscles, providing the necessary support to prevent excessive scapular movement when attempting to reach or rotate your arm.