Physical Therapy for an AC Joint Sprain
Mangiarelli Rehabilitation physical therapist Bobby demonstrates 3 exercises you can do to prevent stiffness and regain mobility after an AC joint sprain. An AC joint sprain typically occurs due to a sudden fall on the shoulder that can push the shoulder blade away from the collarbone, straining or tearing the ligaments of the AC joint. Physical therapy is the first line of treatment for AC joint sprains and is highly effective in restoring shoulder mobility, strength, and function following an AC injury.
Anatomy of the AC Joint
The AC joint, or acromioclavicular joint, is a joint in the shoulder where the clavicle (collarbone) and the acromion of the scapula (shoulder blade) meet. The AC joint is held in place by four ligaments: the acromioclavicular ligament which provides primary stabilization to the joint; the coracoclavicular ligaments (the trapezoid and conoid ligaments), which provide vertical stability; and the coracoacromial ligament.
The AC joint plays a key role in stabilizing the shoulder, maintaining the position of the shoulder, and allowing for efficient upper limb mechanics, scapular movement, and shoulder control, motion, and strength.
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AC Joint Sprains
An AC joint sprain can occur when a strain or tear occurs in the ligaments of the AC joint, where the shoulder blade attaches to the collarbone. An AC joint sprain, or shoulder separation, typically occurs due to a sudden fall on the shoulder that can push the shoulder blade away from the collarbone due to landing on the outside of the shoulder or onto an outstretched hand. This can result from a tackle while playing football, a bicyclist crashing over the handlebars, injury in a car accident, or from an individual tripping and falling from a ladder or on the stairs.
When a traumatic AC injury occurs, the AC ligaments can be strained or torn from their attachment to the collarbone, creating horizontal and rotational laxity. Disruption can extend to the CC ligaments, which creates vertical instability and loss of optimal force and motion transfer between the shoulder blade and the collarbone. The visible bump over the top of the shoulder can result from this dissociation of the shoulder blade from the supporting strut of the collarbone. This displacement of the shoulder blade has significant functional consequences for the biomechanics of the shoulder, causing incorrect positioning of the scapulohumeral complex and the shoulder blade itself and loss of rotator cuff strength and function.
AC joint injuries account for 40% of all shoulder injuries and 10% of all injuries in collision sports like lacrosse, ice hockey, rugby, and football. Men are five times more likely to suffer a traumatic AC injury due to participation in high-risk collision sports.
Common symptoms of an AC joint sprain include:
Shoulder pain and swelling over the AC joint
Pain that radiates into the neck and shoulder
Loss of shoulder strength and mobility
Visible bump above the shoulder
Pain when lying on the involved side
Popping sound or catching sensation with movement of the shoulder
Discomfort with daily activities that stress the AC joint like lifting objects overhead, reaching across the body, or carrying heavy objects by your side
Elevation of the collarbone depending on severity of injury
AC joint injuries are classified into six different categories based on the severity of the injury:
Grade 1: A partial tear of the AC ligament but no CC ligament or shoulder muscle damage.
Grade 2: A complete tear of the AC ligament and a partial tear of the CC ligaments, but no muscular damage.
Grade 3: A complete tear of the AC and CC ligaments, but no muscular damage.
Grade 4: A complete tear of the AC and CC ligaments and muscular damage causing the collarbone to be displaced posteriorly into or through the trapezius muscle.
Grade 5: A complete tear of the AC and CC ligaments as well as detachment of the deltoid or trapezius muscle from the collarbone.
Grade 6: A complete tear of the AC and CC ligaments as well as inferior displacement of the collarbone with significant muscular damage.
Physical therapy can effectively treat Grade 1-3 AC joint injuries. Due to the severity of Grade 4-6 injuries, surgery and post-surgical rehabilitation is most likely necessary to achieve full function and strength in the shoulder joint.
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Physical Therapy for an AC Joint Sprain
Physical therapy is the first line of treatment for AC Joint sprains and is highly effective in restoring shoulder mobility, strength, and function following an AC injury. During the initial evaluation, the physical therapist assesses shoulder sensation, motion, strength, flexibility, and pain and swelling as well as neck and upper back function to determine the severity of the injury. From there, the therapist designs a customized rehabilitation program.
Physical therapy for an AC joint sprain can include:
Pain and swelling management using ice and heat
Range of motion exercises to gently restore normal movement in the shoulder joint. A physical therapist guides the patient through passive and active ROM exercises, balancing joint protection and optimal motion restoration.
Manual therapy involving hands-on joint mobilizations to gently move the shoulder joint and surrounding muscles to improve flexibility and mobility.
Strength training of the muscles of the shoulder, elbow, and upper back, all of which work together to coordinate upper-body movement. The physical therapist focuses on balancing the strength of all upper-body muscles to ensure efficient movement of the shoulder with a particular focus on scapular stabilizing muscles to ensure proper positioning of the scapulohumeral complex.
Functional training, particularly engaging in overhead lifting and moving the arm across the body, which are activities that place significant stress on the AC joint.
Mangiarelli Rehabilitation physical therapist Bobby demonstrates 3 exercises you can do to safely regain range of motion and strength in the shoulder joint and reduce shoulder stiffness after an AC joint sprain:
