Shoulder pain in a child can cause worry, but the reasons range from minor muscle strains to complex orthopedic issues. The shoulder is the body’s most mobile joint, achieved by a shallow socket and a complex network of muscles, tendons, and ligaments. This high degree of mobility makes it susceptible to injury and instability. Understanding whether the pain developed gradually or began with a sudden event is the first step in determining the likely cause.
Overuse Injuries in Young Athletes
The most common source of shoulder pain in children and adolescents is the repetitive stress of athletic activity. These overuse injuries develop gradually when the body’s repair mechanisms cannot keep up with the microscopic damage caused by repeated throwing or overhead movements. Sports like baseball, swimming, tennis, and volleyball place cyclical strain on the shoulder joint structure.
A common example is tendinitis, which involves inflammation of the tendons, particularly the rotator cuff or the long head of the biceps. The rotator cuff stabilizes the shoulder, and chronic fatigue or poor throwing mechanics can lead to painful microscopic tearing in these tissues. Tendinitis pain usually increases during and immediately after the activity, often described as a burning sensation.
A more serious issue unique to skeletally immature athletes is “Little League Shoulder,” medically termed proximal humeral epiphysiolysis. This is a stress fracture of the growth plate (physis) at the top of the upper arm bone (humerus), not a soft tissue injury. Repetitive, forceful rotation, such as in pitching, stresses this vulnerable area before the growth plate has fused into solid bone. The pain is a gradual onset, presenting as a deep ache that worsens with throwing and can lead to a decrease in throwing speed or control.
Another chronic condition is shoulder impingement syndrome, where rotator cuff tendons or the bursa are pinched beneath the acromion. This irritation often results from underlying instability or muscle imbalance that causes the humeral head to move improperly during overhead motion. The condition is characterized by dull pain and difficulty lifting the arm above shoulder height. Limiting pitch counts and ensuring proper sports technique are important to prevent these chronic issues.
Acute Traumatic Injuries
Pain that begins abruptly following a specific incident, like a fall or collision, is categorized as an acute traumatic injury. This injury is characterized by immediate, severe pain and may include a visible change in the shoulder’s appearance. The force of the trauma causes mechanical failure of the bone, joint, or surrounding soft tissues.
A shoulder dislocation occurs when the ball of the upper arm bone completely separates from the socket, which is a visibly obvious and painful event. A less severe form is a subluxation, where the ball partially slips out before spontaneously relocating back into place. These events often happen when the arm is forced into an abducted, externally rotated position, and may cause numbness or tingling if nerves are stretched.
Clavicle (collarbone) fractures are frequent traumatic injuries, often resulting from a direct fall onto the shoulder or a fall onto an outstretched hand (FOOSH). The fracture presents as immediate pain, swelling, and an unwillingness to move the arm, sometimes with a bump over the fracture site. A proximal humeral fracture, a break in the upper arm bone near the shoulder, is also common from a FOOSH mechanism. Most of these fractures are managed non-surgically with immobilization due to children’s rapid bone healing potential.
An AC (acromioclavicular) joint separation occurs where the collarbone meets the highest point of the shoulder blade. This injury results from a blow to the top of the shoulder, tearing the ligaments and often resulting in a noticeable step-off or bump. These traumatic injuries require immediate medical evaluation to determine the extent of the damage and ensure proper alignment and healing.
Developmental and Systemic Causes
While mechanical injury is the most frequent source of shoulder pain, less common, non-traumatic causes may indicate a systemic or developmental issue. The shoulder can be the site of referred pain, where the pain originates elsewhere but is perceived in the joint. For instance, irritation of the diaphragm or conditions in the neck and upper spine can send pain signals interpreted as originating in the shoulder.
A rare but significant condition is Slipped Proximal Humeral Epiphysis (SPHE). This involves the true displacement of the growth plate at the head of the humerus. It typically occurs in obese adolescents or those with underlying endocrine issues, and is distinct from Little League Shoulder. The condition involves the growth plate weakening and the humeral head slipping out of its normal alignment.
Nerve entrapment conditions, such as Thoracic Outlet Syndrome (TOS), occur when nerves or blood vessels are compressed between the first rib and the collarbone. This syndrome is sometimes seen in overhead athletes due to muscle hypertrophy or repetitive motion. It can cause shoulder pain accompanied by numbness, tingling, or swelling and discoloration of the hand and arm.
Infection in the joint (septic arthritis) or the bone (osteomyelitis) is a rare but severe cause of shoulder pain. This condition is often accompanied by systemic symptoms, such as a high fever, chills, and an inability to move the arm due to severe pain. Infection requires immediate medical investigation and treatment, as delayed care can lead to rapid destruction of the joint cartilage.
Recognizing Red Flags and Seeking Medical Care
The decision of when to seek professional medical attention depends on the severity and nature of the pain and associated symptoms. Immediate medical care, such as an urgent care or emergency room visit, is necessary if certain red flags are present. These signs include a visibly deformed shoulder, such as a pronounced bump or an arm that hangs abnormally, suggesting a fracture or dislocation.
Prompt evaluation is necessary if your child reports an inability to move the arm or if the pain cannot be controlled with over-the-counter medication. Immediate assessment is also warranted if the child exhibits signs of nerve involvement. Pain accompanied by systemic symptoms suggests a possible infection that requires urgent diagnosis.
Immediate medical attention is required for the following red flags:
- A visibly deformed shoulder, suggesting a fracture or dislocation.
- Inability to move the arm at all.
- Pain so intense it cannot be controlled with over-the-counter medication.
- Signs of nerve involvement, such as numbness, tingling, or weakness in the arm or hand.
- Pain accompanied by a fever, chills, or localized warmth and redness.
For less acute situations, initial home treatment involves relative rest and the application of ice to manage pain and swelling. If the pain persists without improvement after one to two weeks of rest, or if it consistently wakes your child from sleep, a scheduled visit with a healthcare provider is appropriate. A professional evaluation, often including imaging, is necessary to accurately diagnose the underlying cause and develop a tailored treatment plan.