Shoulder sprains and strains are both injuries that can happen due to overuse of or trauma to the shoulder. While the symptoms of the two are similar, they involve different types of tissue within your body. Damage to these tissues can make it hard to move and use your shoulder.
What Is a Shoulder Sprain?
Shoulder sprains happen when a ligament in the shoulder tears or is stretched beyond its limitations. Ligaments are bands of connective tissue that connect bones, joints, and organs and hold them in place within your body. The human body has over 900 ligaments.
The ligaments in your shoulder hold together the bones in your shoulder and surrounding areas. The three bones that are most important to your shoulders’ function are:
- Clavicle. The clavicle is also commonly called the collarbone. You have one on each side of your body. Your clavicles connect your sternum, or chest bone, to your scapulas, or shoulder blades.
- Scapula. Your scapula is the triangle-shaped bone that makes up your shoulder blade. This bone connects the clavicle to your upper arm bone, called the humerus. There’s a bony knob at the top of your scapula called the acromion.
- Sternum. The sternum is also called the breast bone. It starts between your clavicles and runs down the center of your rib cage.
Your shoulder is made up of several small joints that allow your shoulder to move. Joints are a point where two bones meet. Tears in the shoulder ligaments happen most often around the acromioclavicular joint, the joint that connects the acromion of the scapula and the clavicle. Injury in this joint is sometimes called a shoulder separation.
Shoulder sprains are caused by some type of trauma. Common causes of shoulder sprains include:
- Falling on your outstretched arm
- Forceful twisting of your arm
- Getting hit hard on your shoulder
- Overuse or repetitive movement of your shoulder, such as in sports like swimming or tennis
Shoulder Sprain vs. Strain
Shoulder sprains and strains are both injuries to the shoulder, but the difference is what tissues are damaged. While a shoulder sprain is tearing or stretching of the ligaments, a shoulder strain happens when a tendon or muscle is overstretched.
Like ligaments, tendons are bands of connective tissue. Tendons connect muscles to bones. Many of the muscles and tendons in your shoulder are part of your rotator cuff. Your rotator cuff is the group of muscles and tendons that stabilize the ball-and-socket joint that connects your humerus to your scapula.
Your rotator cuff has four muscles. These are:
- Infraspinatus. The infraspinatus muscle connects the side of your scapula to the side of your humerus. It allows you to rotate your arm to the outside.
- Subscapularis. The subscapularis stretches from the middle of your scapula to the base of your humerus. This allows you to hold your arm out straight and away from your body.
- Supraspinatus. The supraspinatus muscle reaches from the top of your scapula to the top of your humerus at your shoulder joint. It allows you to lift your arm inward and rotate your arm.
- Teres minor. The teres minor is a small muscle that attaches the side of your scapula to the humerus below the infraspinatus. This muscle helps you rotate your arm.
There are three other muscles that help your shoulder move properly. These muscles are:
- Deltoid. Your deltoid muscles cover the tops of your shoulders. They allow you to move your arms forward, backward, and out to the sides.
- Rhomboid. Your rhomboid muscles stretch from the base of your neck across to your scapulas. They let you lift your shoulder blade.
- Trapezius. Your trapezius is a diamond-shaped muscle in your back. It starts at the base of your skull and reaches across your shoulder blades and down to the middle of your spine. It helps you raise and lower your shoulders.
Shoulder strains are most commonly due to overstressing or overusing your shoulder. Lifting heavy objects or playing sports that involve repetitive arm movement can strain your shoulder, but a forceful impact or fall can also cause a strain.
Shoulder Sprain Symptoms and Shoulder Strain Symptoms
The symptoms of shoulder sprains and shoulder strains often overlap. Shoulder sprains and strains can both have symptoms like:
- Limited ability to move your shoulder
If you hear a pop in the joint at the moment of injury, that usually indicates a sprain. Symptoms that are more likely to indicate a strain include muscle spasms, muscle weakness, and redness.
Diagnosing Shoulder Sprains and Strains
To diagnose a shoulder injury, your doctor will start with a physical exam. They’ll check the location of your swelling and pain to get an idea of how severe the damage is.
In some situations, your doctor may want you to have imaging tests done so they can get a more complete picture of your injury. These imaging tests may include:
- MRI. Magnetic resonance imaging, or MRI, is done in a large machine. This machine uses computer-generated radio waves and a large magnet to take images of bones, organs, and tissues.
- X-ray. X-rays create images by sending energy beams through your body. Your doctor can use an X-ray to rule out a fracture or check to see if the joint has dislocated during your injury.
- Ultrasound. Ultrasounds use sound waves to create images. Your doctor can use an ultrasound to differentiate between a sprain, strain, or muscle tear.
Shoulder Sprain Treatment and Shoulder Strain Treatment
Most shoulder sprains and strains can be treated at home with the RICE method: rest, ice, compression, and elevation.
- Rest. Don’t stop moving your shoulder completely, but stay away from activities that cause pain or discomfort, like lifting heavy objects.
- Ice. Use an ice pack every two or three hours when you’re awake for 15 to 20 minutes during the first few days after the injury. This helps reduce pain and swelling.
- Compression. If possible, apply compression to your shoulder with an elastic bandage to minimize swelling. If the pain gets worse, the area starts to feel numb, or you notice swelling below the bandage, these are signs that the bandage is too tight and needs to be loosened.
- Elevation. Another way to reduce swelling is to elevate the injury above your heart, especially while you’re sleeping.
Over-the-counter NSAID medication, like ibuprofen or aspirin, can help relieve pain and swelling. If your muscle is strained, your doctor may recommend using a pain reliever like acetaminophen instead, as NSAIDs can increase your risk of bleeding.
In cases of severe damage, your doctor may recommend surgery.
Shoulder Sprain Recovery Time and Shoulder Strain Recovery Time
The recovery time for shoulder sprains and strains will depend on the severity of your injury. You may feel better after a few days, or it may take a few months. Your doctor may recommend physical therapy to help you regain full use of your shoulder.