Shoulder pain in children and adolescents can be a source of worry for parents. The causes of this pain vary widely, ranging from obvious injuries sustained during play to more subtle issues related to growth and repetitive motion. While most instances of shoulder discomfort are manageable with rest, understanding the different origins of the pain is the first step toward appropriate care.
Sudden Injuries and Acute Causes
Pain that begins immediately following a specific event often indicates an acute injury to the bone or joint structure. One of the most common bony injuries is a fracture of the clavicle, or collarbone, frequently resulting from a fall directly onto the shoulder or an outstretched hand. The break, most often in the midshaft, can cause visible deformity and intense pain, with the child typically holding the arm close to the body for relief.
Acute shoulder dislocation occurs when the ball of the upper arm bone (humerus) completely pops out of the shoulder socket. This traumatic event, more common in teenagers, is typically caused by a sudden, forceful transmission up the arm during a fall or collision. Another acute possibility is an acromioclavicular (AC) joint separation, which involves ligament damage where the clavicle meets the shoulder blade. This injury results from a direct blow to the side of the shoulder, often causing a noticeable bump above the joint.
Overuse and Growth Plate Conditions
Shoulder pain that develops gradually over weeks or months, especially in young athletes, is often classified as an overuse injury. The unique vulnerability in this age group stems from the presence of growth plates, which are areas of soft, developing cartilage near the ends of long bones. These plates are structurally weaker than surrounding tendons and ligaments, making them highly susceptible to repetitive stress.
The most recognized overuse injury is Little League Shoulder, or proximal humeral epiphysiolysis, which affects the growth plate at the top of the humerus. This condition is caused by the torsional stress of repeated overhand motions, such as pitching, swimming, or serving a tennis ball, leading to inflammation and widening of the growth plate. Symptoms typically include pain during throwing, decreased velocity or control, and soreness lasting for days after activity.
Repetitive overhead motion can also lead to shoulder instability, where structures holding the joint in place become stretched or damaged, causing the joint to shift excessively. Tendonitis and muscle strains are common, with the rotator cuff and biceps tendon being frequent sites of inflammation. This irritation is often related to a rapid increase in training volume, poor throwing mechanics, or muscle strength imbalance. Rest from the aggravating activity is the initial step in allowing these irritated tissues to heal.
Causes Unrelated to Injury
Not all shoulder pain originates from the shoulder joint; it can be referred from other parts of the body or stem from systemic conditions. Referred pain from the neck (cervical spine) is common, where irritation of the spinal nerves is felt in the shoulder blade or down the arm. Neck stiffness or pain that worsens with head movement can suggest a cervical source for the discomfort.
Inflammatory conditions can also target the joints, such as Juvenile Idiopathic Arthritis (JIA), a chronic autoimmune disease in children. While JIA often presents with pain, swelling, warmth, and stiffness, it can sometimes affect the shoulder. Systemic JIA may also include non-joint symptoms like high fever, fatigue, and rash.
Bone or joint infections, such as osteomyelitis or septic arthritis, are less common but serious causes. These conditions can cause deep, throbbing bone pain in the shoulder, often accompanied by systemic symptoms like fever. Non-mechanical pain—pain that is constant, not relieved by rest, or present at night—can be a sign of a systemic or infectious process.
When Immediate Medical Evaluation is Necessary
While many causes of shoulder pain can wait for an appointment with a primary care physician, certain signs require immediate medical evaluation. Visible deformity is a strong indicator of a severe acute injury, such as a fracture or a complete joint dislocation. This includes a noticeable misalignment, a prominent bump above the joint, or skin that appears “tented” over a broken bone.
Inability to move the arm at all, or a sudden, complete loss of function, should also prompt urgent attention. Any pain accompanied by neurological symptoms, such as numbness, tingling, or weakness radiating into the arm or hand, may signal nerve compression that requires prompt assessment. If the shoulder pain is combined with high fever, chills, or if the pain is so severe it wakes the child from sleep, an infectious or systemic cause must be ruled out immediately.