A shoulder that slips, pops or feels like it might give out isn’t just annoying. It could be a sign that something deeper is going on inside the joint.
Shoulder instability happens when the upper arm bone doesn’t stay in place in the shoulder joint. It can affect athletes and non-athletes alike and lead to pain, weakness or repeated injuries.
“Your shoulder is the most mobile joint in your body,” said Rafael Buerba, MD, an orthopedic surgeon with Banner - University Medicine. “Because it can move in so many directions, it’s more likely than other joints to become unstable, especially after an injury.”
Here’s what to know about shoulder instability, its causes and how to treat it.
What is shoulder instability?
Your shoulder is a ball-and-socket joint made up of the upper arm bone (humeral head) and the socket (glenoid), which is part of the shoulder blade. Shoulder instability happens when the upper arm bone doesn’t stay in the socket like it should.
You might feel this instability as:
- A loose or “slipping” feeling in your shoulder
- Shoulder pain during activity
- Weakness or difficulty lifting the arm overhead (limited range of motion)
- Clicking or catching with daily activities
- A full or partial dislocation
“A fully dislocated shoulder is when the humeral head comes completely out of the socket,” Dr. Buerba said. “A partial dislocation, called a shoulder subluxation, means it comes partially out of the socket and then slides back in. Both can cause long-term damage if not treated.”
Without treatment, shoulder instability can lead to more serious shoulder injuries like rotator cuff tears, Bankart lesions or long-term joint damage.
What causes shoulder instability?
Instability can happen for a few different reasons:
1. Injury
A fall, car accident or sports injury can force the shoulder out of place. When the shoulder is forced out of place, it can stretch or tear the tissue that holds the joint together, like the labrum, ligaments or tendons. In older adults, instability events can lead to rotator cuff tears.
“The labrum is like a bumper that helps hold the shoulder in place,” Dr. Buerba said. “A Bankart lesion, which is a tear in the labrum, can lead to repeated dislocations, especially in younger patients.”
2. Repetitive motion
People who use their arms a lot in sports like swimming, tennis, volleyball and baseball may stretch shoulder ligaments over time. This can make the joint less stable and increase the chance of dislocation or shoulder pain.
3. Loose joints
Some people are born with hypermobility, or extra flexibility in their joints. This can be helpful in some activities but also increases the risk of an unstable shoulder. People with conditions like Ehlers-Danlos syndrome tend to have loose ligaments that make shoulder stability harder to maintain.
When to see a health care specialist
If your shoulder has dislocated or feels like it might, see your health care provider.
“Even if the shoulder seems to go back into place on its own, there could still be damage inside the joint,” Dr. Buerba said. “We want to make sure there’s not a labral tear, fracture or nerve injury that needs attention.”
You should talk to your provider if:
- You’ve had more than one shoulder dislocation or subluxation
- You feel ongoing pain or weakness
- Your shoulder feels unstable or unpredictable
- You’ve stopped doing things you enjoy because of shoulder problems
How is shoulder instability diagnosed?
If your shoulder feels loose, painful or unstable, see a health care provider. Even if it pops back into place on its own, damage could still be inside the joint.
To find out what’s going on, your provider will:
- Ask about your symptoms and shoulder injuries
- Do a physical exam to check strength and range of motion
- Order imaging tests like an X-ray or magnetic resonance imaging (MRI) to check for rotator cuff tears, a Bankart lesion or bone damage
Treatment options for shoulder instability
Treatment for shoulder instability depends on how serious it is and what caused it.
Nonsurgical treatment
For most people, especially after a first-time dislocation, treatment starts with:
- Rest and avoiding activities that stress the joint
- Ice and anti-inflammatory drugs to manage pain and swelling
- Physical therapy to strengthen the muscles that support the shoulder
“Rehabilitation is key,” Dr. Buerba said. “We focus on building strength in the rotator cuff and the muscles that control the shoulder blade. That helps keep the shoulder stable.”
A custom exercise program can improve shoulder strength, movement and control. This can often prevent the need for surgery, especially in older adults or people with mild symptoms.
Surgery
If shoulder subluxation occurs often or there’s serious damage, surgery may be needed. Surgical treatment usually involves arthroscopic (minimally invasive) techniques to:
- Repair the labrum or fix a Bankart lesion
- Tighten the loose tissue in the joint
- Add bone to the socket in rare cases
“Surgery is often successful, especially in young athletes or people with repeated dislocations,” Dr. Buerba said. “The goal is to return the shoulder to normal and prevent future problems.”
What recovery looks like
Recovery time depends on the treatment. With physical therapy, you may feel better within a few weeks. After surgery, full recovery usually takes several months.
You may need to:
- Wear a sling for a short time
- Avoid heavy lifting or reaching overhead at first
- Stick with a full physical therapy plan
“Following through with rehab is the best way to protect your shoulder and get back to the activities you love,” Dr. Buerba said.
Can you prevent shoulder instability?
You may not be able to prevent every injury, but you can lower your risk by:
- Warming up before exercise
- Strengthening your shoulders and upper back muscles
- Using good form in sports and workouts
- Avoiding motions that feel painful or unstable
If you’ve had shoulder instability in the past, it’s a good idea to follow a regular exercise program and avoid reinjury.
Bottom line
If your shoulder feels loose, weak or like it could pop out of place, talk to your health care provider or an orthopedic specialist at Banner Health. Shoulder instability can lead to long-term damage if left untreated. There are effective treatments that can help you get back to your active life.
At Banner Health, our orthopedic experts specialize in diagnosing and treating shoulder instability. From physical therapy to advanced surgical care, we’re here to help you feel strong, stable and pain-free. Schedule an appointment today.
