A shoulder contusion is a common soft tissue injury, medically defined as a bruise. This injury occurs when blunt force damages small blood vessels beneath the skin and within the underlying muscle. The resulting leakage of blood into the surrounding tissue causes characteristic discoloration and swelling. Contusions are prevalent in physically active populations, especially those who participate in contact sports or experience accidental trauma.
Mechanism of Injury
A shoulder contusion results directly from blunt-force trauma or a direct impact to the area. This mechanical force crushes the soft tissues—skin, subcutaneous tissue, and muscle fibers—against the underlying bone. The impact disrupts microscopic blood vessels (capillaries), allowing blood to pool locally, a process called microvascular disruption.
The severity depends on the force of the impact and the specific tissues involved. The most common type is a muscle contusion, concentrated in superficial muscles like the deltoid. A greater impact can cause a bone contusion (bone bruise), where force is transmitted deeper, causing microscopic damage and bleeding within the bone marrow.
Both muscle and bone contusions cause localized internal bleeding, which may collect into a palpable lump known as a hematoma. The injury initiates the body’s inflammatory response, which is responsible for the immediate swelling and tenderness that follows.
Distinguishing Signs and Symptoms
Patients typically experience immediate, localized pain and tenderness directly over the site of impact. This discomfort intensifies when attempting to move the arm or when pressure is applied to the bruised area. Within hours to days, visible discoloration of the skin, known as ecchymosis, appears as blood from the damaged vessels spreads and breaks down.
The bruising may initially appear reddish or blue-black and gradually changes color (green, yellow, and brown) as the body reabsorbs the blood products. Swelling is also a common sign and contributes to stiffness and a reduced range of motion in the shoulder joint. This limited movement occurs as the body attempts to protect the injured soft tissues.
Any injury involving trauma to the shoulder should be evaluated by a medical professional for a proper differential diagnosis. It is important to rule out more serious injuries that mimic a simple bruise, such as a fracture, ligament sprain, or rotator cuff tear. Severe, unrelenting pain, noticeable deformity, or a complete inability to move the arm necessitate immediate medical attention.
Treatment and Recovery Expectations
Immediate care for a shoulder contusion generally follows the R.I.C.E. protocol: Rest, Ice, Compression, and Elevation.
- Resting the shoulder involves avoiding activities that cause pain to prevent further trauma to the damaged tissue.
- Applying ice for 15 to 20 minutes several times a day during the first 48 hours helps restrict blood flow, limiting swelling and providing temporary pain relief.
- Compression using an elastic bandage or wrap helps control swelling; it must be applied snugly without causing numbness or tingling.
- Elevation of the injured shoulder above the level of the heart, whenever possible, uses gravity to assist in draining excess fluid from the area.
Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) can manage pain and inflammation, though alternative pain relievers like acetaminophen may be recommended after the initial inflammatory phase.
Most uncomplicated muscle contusions heal with conservative management, typically recovering within two to four weeks. More severe contusions, especially those involving deeper muscle layers or a significant hematoma, may take four to six weeks or longer to fully resolve.
In rare cases, a large hematoma may require medical drainage, or persistent stiffness might necessitate physical therapy to restore full range of motion. The final stage of recovery is a gradual and pain-free return to activity, ensuring the injured tissue has fully healed before resuming high-impact movements.