The sensation of shoulder pain during a barbell squat often confuses lifters because the movement is primarily for the lower body. This discomfort is not caused by lifting the weight with the arms, but by the awkward mechanical position the shoulders are forced into to hold the bar. The pain typically stems from either an acute setup error or an underlying mobility restriction that places strain on the shoulder joint capsule and surrounding soft tissues. Understanding the specific causes related to bar placement and physical limitations can resolve this common training issue.
How Bar Placement and Grip Cause Pain
The most immediate cause of shoulder discomfort is the mechanical relationship between the bar, the grip, and the lifter’s anatomy. Low bar squats, where the barbell rests lower on the rear deltoids, require significant shoulder external rotation and abduction to create a stable shelf. Lacking this range of motion forces the shoulder joint into a compromised position, potentially pinching soft tissues like the biceps tendon or rotator cuff.
A high bar position, resting on the upper trapezius muscles, is generally more forgiving and requires less shoulder mobility. However, a grip that is too narrow dramatically increases the demand for shoulder extension and external rotation. This narrower grip generates tension in the pectoral muscles and the anterior shoulder capsule, leading to pain if the lifter aggressively forces their elbows back.
The position of the hands and wrists also transfers strain directly to the shoulders. Hyperextending the wrists or allowing the elbows to drop too far down causes unnecessary load absorption by the shoulder tendons. Allowing the shoulders to roll forward while maintaining the grip can cause the bar to shift and lead to instability.
Correct bar placement is paramount, especially in the low bar style where the bar must sit securely on the shelf created by the rear delts. Placing the bar slightly too low stretches the pectoral muscles excessively, pulling the shoulder forward and creating discomfort. Using a wide enough grip to maintain a neutral wrist position and a comfortable elbow angle alleviates much of this setup-related stress.
The Role of Restricted Shoulder and Thoracic Mobility
While bar placement is an acute factor, the underlying reason many lifters struggle is a chronic lack of mobility, specifically in the thoracic spine (T-spine). The T-spine’s ability to extend is directly linked to shoulder positioning. Limited T-spine extension often forces the shoulders to compensate by shrugging or internally rotating, which is the opposite of the stable, retracted position needed for a squat.
This rounded posture prevents the scapulae from pulling back and down effectively to create a solid foundation for the bar. When the upper back is stiff, the body attempts to achieve the necessary bar position by jamming the shoulder joint, leading to impingement against the acromion process. Prolonged sitting often encourages this flexed posture, contributing to the restriction.
A lack of specific shoulder mobility, particularly external rotation, compounds the problem. The back squat requires the shoulder to move into a mix of extension, adduction, and internal rotation to secure the bar. If external rotation is limited, the lifter must resort to pushing the elbows back too hard. This translates into an anterior sheer force on the humeral head, stressing the front of the joint capsule.
Improving T-spine mobility is the foundational fix because it restores the proper platform for the bar. When the mid-back can extend, the shoulder blades naturally retract, reducing strain on the glenohumeral joint. Without addressing this stiffness, adjustments to grip or bar placement will only be temporary fixes.
Immediate Adjustments and LongTerm Corrections
For immediate relief during a training session, several adjustments can mitigate shoulder pain and allow the workout to continue.
Immediate Adjustments
- Widening the grip on the barbell decreases the required amount of shoulder external rotation and adduction.
- Switching to a thumbless grip promotes a more neutral wrist position and reduces the tendency to grip the bar too tightly.
- Using lifting straps to hold the bar bypasses the mobility issue, allowing the lifter to maintain bar position without forcing the hands.
- Switching to a high bar placement, if currently using low bar, instantly reduces mechanical strain on the shoulder joint.
- When pain is acute, use non-barbell variations like the Goblet Squat or the Safety Squat Bar (SSB).
For a permanent solution, a consistent routine of mobility and stability work is necessary to address the underlying restrictions.
Long-Term Mobility Work
Targeting T-spine extension can be done using a foam roller, where the lifter lies supine with the roller positioned across the mid-back and gently extends over it. A pair of lacrosse balls taped together, often called a “peanut,” can also be used to mobilize the small joints along the thoracic spine.
Shoulder mobility can be enhanced through exercises like “shoulder dislocations,” performed by passing a PVC pipe or resistance band over the head while maintaining straight elbows. This movement improves the range of motion for external rotation and shoulder girdle control. Strengthening the small muscles of the rotator cuff, such as with external rotation presses using a light resistance band, will increase shoulder stability under load.
If the pain is sharp, shooting, or persists long after the squatting session, seek guidance from a qualified physical therapist or sports medicine professional. They can provide a thorough evaluation to rule out a more significant injury, such as a rotator cuff tear or severe impingement. Continuing to push through sharp pain can lead to long-term joint damage or chronic inflammation.