Shoulder mobility is the combined ability of the glenohumeral joint and surrounding structures to move through a full, uninhibited range of motion. This complex movement involves the coordinated motion of the scapula, clavicle, and rib cage. Assessing this mobility is an effective way to understand your body’s functional capacity, which directly influences posture and the ease of performing daily tasks like reaching a high shelf. Restrictions in this range can increase the risk of injury by forcing other joints to compensate during movement.
Testing Basic Shoulder Range of Motion
Testing the basic range of motion involves isolating the shoulder’s ability to move in a single plane to determine the maximum distance the arm can travel. These self-tests check the limits of motion in three primary directions. To test shoulder flexion, raise one arm straight out in front of you, moving it directly overhead as far as possible. A healthy range of motion allows the arm to reach a position where the bicep is aligned with or slightly behind your ear, ideally achieving about 180 degrees of movement.
For shoulder abduction, lift one arm directly out to the side in a wide arc, continuing the motion overhead. Be mindful of any shrugging; the motion should originate purely from the shoulder joint, not from hiking the shoulder toward the ear. The goal is to reach the same overhead alignment as with flexion, around 150 to 180 degrees, without the shoulder blade moving excessively early. The final isolated test is external rotation, performed by standing with the elbow bent to 90 degrees and held close to the side of the body.
While keeping the elbow pressed against your torso, rotate the forearm outward, moving the hand away from the body as far as possible. A normal external rotation range is approximately 90 degrees, which is sufficient for most overhead activities. It is important to prevent the elbow from drifting away from the body or the torso from rotating, as these movements can artificially inflate the measurement. Comparing the distance achieved by the left arm against the right arm in all three tests provides the most valuable data.
Functional Mobility Screens for Integrated Movement
Functional screens require the shoulder to perform complex, integrated movements that simulate real-world activities, moving beyond isolated joint arcs. The Apley Scratch Test is a common screen that simultaneously assesses the shoulder’s ability to combine multiple actions, including rotation, flexion, and extension. The test involves two distinct reaches: one hand reaches behind the neck and down the spine (external rotation and abduction). The opposite hand reaches behind the back and up the spine (internal rotation and adduction).
For the overhead reach, aim for the middle finger to touch the superior angle of the opposite shoulder blade or reach a high vertebral level. For the reach behind the back, the objective is to reach the thumb up the spine as high as possible, ideally reaching the level of the seventh thoracic vertebra (T7). The measurement indicating restriction is the distance between the middle fingers of both hands when they attempt to touch. Perform both reaches on each side and avoid arching the lower back or tilting the trunk, which compensates for true shoulder limitations.
The Wall Angel or Wall Slide evaluates both shoulder mobility and scapular control in the overhead position. Stand with your back, head, and hips flat against a wall, placing your arms against the wall with elbows bent at 90 degrees, resembling a goalpost. The screen involves slowly sliding your arms upward, attempting to keep your wrists, forearms, and elbows in constant contact with the wall. An inability to maintain contact or a tendency for the lower back to arch suggests a restriction in combined shoulder flexion and external rotation, often coupled with poor control of the shoulder blades.
Interpreting Results and Identifying Restrictions
The most significant finding from these self-assessments is asymmetry, which occurs when one shoulder demonstrates a noticeably different range of motion than the other. A difference in reach or rotation between the left and right sides is a primary indicator of restriction. A healthy shoulder should exhibit pain-free movement across the full range of motion.
The inability to complete a screen, such as not reaching the ear in overhead flexion or lifting the forearm less than 90 degrees in external rotation, suggests tightness in the joint capsule or surrounding musculature. Pain experienced during any active movement should be noted, as it can be a sign of underlying issues like tendon irritation or joint inflammation. Painful clicking or a grinding sensation, known as crepitus, suggests mechanical irritation within the joint.
If self-testing reveals a substantial loss of range, persistent pain, or a significant difference in mobility between the two shoulders, seek professional advice. A physical therapist or other healthcare provider can perform a detailed evaluation to determine the specific source of the limitation. While these screens identify restrictions, they are not a substitute for a clinical diagnosis, especially when pain is a factor.