Shoulder impingement is one of the most frequently reported causes of discomfort. This condition arises when certain motions cause irritation and compression within the shoulder joint’s limited space, leading to pain and reduced function. Understanding which activities provoke this irritation is paramount for managing symptoms and preventing the progression of the condition. Identifying and eliminating high-risk movement patterns allows individuals to protect the shoulder structures and focus on pain-free rehabilitation.
The Mechanism of Shoulder Impingement Pain
The pain associated with this condition originates from a mechanical restriction within a narrow corridor of the shoulder called the subacromial space. This space is situated beneath the acromion (a bony projection of the shoulder blade) and above the head of the humerus. Within this confined area reside the tendons of the rotator cuff muscles and the subacromial bursa. During certain arm movements, the humerus moves upward, causing the soft tissues to be pressed against the underside of the acromion. This repetitive compression irritates the tendons and bursa, leading to inflammation that further reduces the available space and causes the characteristic sharp pain when the arm is lifted.
High-Risk Biomechanical Movement Patterns
Movements that elevate the arm while simultaneously rotating it internally are the most problematic, as this combination significantly reduces the subacromial space. When the arm is raised above the shoulder, especially past 90 degrees of abduction, the head of the humerus moves closer to the acromion, and applying an external load dramatically increases the compressive force. Another problematic pattern involves deep internal rotation of the humerus, particularly when the arm is moved away from the body. This position can cause the rotator cuff tendons to roll and become compressed against the bony structures. Moving the arm across the body, known as horizontal adduction, can also induce a painful pinch.
Specific Weight Training Exercises to Eliminate
Overhead Press and Upright Rows
The Overhead Press is a primary offender because it involves lifting a load while the arm is in the high-compression overhead position. This movement drives the head of the humerus upward into the narrow subacromial space, applying maximum pressure to the tendons and bursa. Pressing a bar behind the neck is even more hazardous, forcing the shoulder into a strained position of maximal external rotation combined with abduction. Upright Rows are also discouraged due to the extreme internal rotation they impose on the shoulder joint. As the weight is pulled upward, the humerus rotates internally, funneling the rotator cuff into the impingement zone.
Lat Pulldowns and Bench Dips
Certain variations of Lat Pulldowns and Bench Dips should also be avoided. The behind-the-neck pulldown requires an excessive degree of abduction and external rotation, placing the joint capsule under extreme stress. This compromised position can lead to instability and increased friction. Bench dips force the shoulder into a combination of deep extension and internal rotation, translating the humeral head forward and placing significant strain on the anterior shoulder capsule.
Deep Horizontal Extension
Exercises that involve deep horizontal extension, such as Pec Deck Flys or a very deep Barbell Bench Press, can exacerbate symptoms. Allowing the elbows to drop far below the line of the body stretches the anterior shoulder structures while forcing the humeral head forward. This anterior glide can cause the painful pinch, especially under a heavy load. The depth of the movement should be carefully limited to a pain-free range.
Modifying Everyday Movements
The principles of minimizing compression must extend beyond the gym to everyday activities that frequently trigger shoulder pain. One common aggravator is sleeping position, as lying directly on the affected shoulder compresses the subacromial space overnight, and sleeping with the arm overhead disrupts the healing process. Reaching mechanics require careful attention to avoid the painful combination of elevation and rotation. Individuals should modify the way they reach for high shelves by using a step stool to keep the arm below shoulder height, or by utilizing the unaffected arm. Reaching across the body (horizontal adduction) should also be minimized, and maintaining proper posture helps ensure the shoulder blade is positioned correctly.