Shoulder Instability Among Athletes
Introduction:
Did you know that the shoulder is the most flexible joint in the body? It helps you perform your everyday tasks, exercises, or sports by enabling arm movement, such as reaching for a ball and throwing it. Although the shoulder has a greater range of motion, instability is common– especially in sports that require strong overhead arm positions like baseball, softball, volleyball, swimming, and water polo. An unstable shoulder can heavily affect an athlete’s performance and potential career. Here is what you need to know about shoulder instability, its symptoms, treatment, and more.
What is Shoulder Instability?
Anatomy of the shoulder
Shoulder instability is when the head of the upper arm bone (humeral head) is forced out of the shoulder socket (glenoid fossa). There are three types of shoulder instability: Anterior, Posterior, and Multidirectional.
Types of Instability:
Athletes have a 95% chance of obtaining Anterior Instability, making it the most common type of shoulder instability. In an anterior unstable shoulder, the humeral head is forced to the front side of the body (anterior side). This is caused by excessively moving your arm laterally (abduction) and rotating your elbows forward (external rotation). An example is throwing a ball.
There is a 30-40% chance of getting the bankart lesion and/or the hill sachs lesion when experiencing an anterior unstable shoulder. Both lesions are complementary, as one causes the other to happen. A Bankart lesion happens when the connective tissues (on the anterior side) that hold the ball and socket together are damaged. The Hill-Sachs Lesion is when the ball of the humeral head gets fractured/ slight indentation caused by the compression of the anterior side of the socket.
Shoulder Abduction
External and Internal Rotation of the Shoulder
Posterior Instability:
With a 2-4% chance of happening, getting a Posterior Shoulder Instability is a lot more rare. The humeral head would be dislocated or subluxed in the posterior side (to the back). This instability is caused by muscle contractions such as through seizures or severe electric shock.
Posterior dislocation of the shoulder
Multidirectional instability is caused by genetical hyperlaxity (double-jointed) or looseness in the joint (laxity) from repetitive overhead motions in sports.
Degrees of Shoulder Instability:
Within each type of shoulder instability are degrees, or how serious the dislocation is. There are three types: Dislocation, Subluxation, and Laxity.
Dislocation – When the ball of the humeral head is completely popped out of the socket.
Subluxation – When the ball of the humeral head is partially popped out of the socket.
Laxity – When the ball of the humeral head is partially popped out of the socket but patients show little to no symptoms (asymptomatic). This is usually genetically affected.
Symptoms:
Regular Shoulder Instability:
Looseness: Athletes can feel the dislocation/ or “pop” in the shoulder
Temporary decreased range of shoulder motion
Pain and discomfort when performing certain activities or arm positions (EX: Reaching behind the body).
Swelling and bruising
Weakness in shoulder joint
Chronic Shoulder Instability symptoms:
Repeated instances of shoulder “popping” or getting “stuck”
Ongoing sensation of slipping in and out of the socket or feeling loose.
Diagnosis:
Diagnosis of shoulder instability usually starts with a physical exam by your doctor. They will check for symptoms and ask about your shoulder injury or instability history. Other ways of diagnosis your doctor might use are:
X-Rays:
MRI Scan (Magnetic resonance imaging):
Computed tomography (CT) scan
Dye test (arthrogram) following with an MRI or CT scan (arthro-MRI or arthro-CT)
Examination under anesthesia, following arthroscopy.
**Check with your physician for a physical examination or consult an orthopedic shoulder specialist for the most accurate diagnosis.
Treatment:
Before surgery, your doctor might advise non-surgical methods for you to explore:
Activity Modification/Restriction: Rest and avoid extreme physical activities in order to reduce stress on the shoulder.
Sling for temporary stabilization (also likely used after surgery)
Ice packs to reduce pain and swelling
Physical therapy
Shoulder instability directed exercises designed to strengthen shoulder muscles
NSAIDs (nonsteroidal anti-inflammatory drugs) to reduce pain and swelling:
Aspirin
Ibuprofen (Motrin, Advil, Nuprin, etc)
Aleve
Surgical Treatment:
Surgery is considered when sports or physical activities are seen as a necessity. For instance, an athlete whose career is based on their athletic ability is more likely to obtain surgical treatment compared to patients who have instability interfering heavily on their daily lives. One common surgical method is the Bankart Repair.
The Bankart Repair is used to reattach the ball to the socket/glenoid rim. This method is often successful, with 97% of the surgery going well. However, like with other surgeries, the healing process takes months.
If the joint capsule is found to be torn away from bone, three holes would be made in the socket with stitches being passed through to connect the ball and socket together. The capsule will heal naturally and prevent re-dislocations.
HOWEVER, if there is a bankart lesion and a hill-sachs lesion, there is an increased risk of instability after surgery. Infection (less than 0.5%) and loss of motion after surgery are potential risks.
Arthroscopy - Doctors would use the arthroscope without opening the shoulder. If the size of the tear is small and more stable, this is a good alternative than open surgery.
Prevention:
Although shoulder instability isn’t completely preventable when playing sports, there are methods to prevent it from happening more likely.
Rotator cuff and shoulder blade exercises:
Side Lying External Rotation
Half Push-up
Bent Over Rows
During sports or other physical activities:
Wear protective equipment
Stop if your shoulder hurts during or after activity
Recovery time for your body to rest
Stretch and warm up before playing sports or working out
Cool down and stretch after activity
Conclusion:
Shoulders are a vital part of the athlete. In fact, shoulders are a vital part to us all. Despite this, it is much too easy to forget about proper care and treatment for these essential muscles. Before mindlessly throwing a ball or swimming for hours on end, make sure to go through the proper exercises to strengthen your shoulders to avoid painful injuries and long recoveries.
Lateral view of the glenohumeral (socket-to-ball) joint; right shoulder
Sources:
“Dislocated Shoulder: Causes, Treatment & Prevention.” Cleveland Clinic, https://my.clevelandclinic.org/health/diseases/17746-dislocated-shoulder#prevention. Accessed 6 July 2024.
Mahaffey, Brain L., and Patrick A. Smith. “Instability in Young Athletes.” American Family Physician, 1999, https://www.aafp.org/pubs/afp/issues/1999/0515/p2773.html.
Salsbery, Mitch. “3 easy exercises to prevent shoulder instability| Ohio State Medical Center.” The Ohio State University Wexner Medical Center, 28 February 2019, https://wexnermedical.osu.edu/blog/exercises-to-prevent-shoulder-instability. Accessed 6 July 2024.
“Shoulder Instability.” Johns Hopkins Medicine, https://www.hopkinsmedicine.org/health/conditions-and-diseases/shoulder-instability. Accessed 6 July 2024.
“Shoulder Instability: Treatment, Diagnosis, & Causes.” Massachusetts General Hospital, https://www.massgeneral.org/orthopaedics/sports-medicine/conditions-and-treatments/shoulder-instability. Accessed 6 July 2024.
“Sports Injuries - Acute, Chronic & Common Injuries | NIAMS.” National Institute of Arthritis and Musculoskeletal and Skin Diseases, 1 September 2021, https://www.niams.nih.gov/health-topics/sports-injuries. Accessed 6 July 2024.
“Types of Shoulder Instability: Symptoms, Tests & Treatments.” Heiden Orthopedics, 28 September 2021, https://heidenortho.com/shoulder-instability/. Accessed 6 July 2024.