The thoracic outlet is a crucial anatomical passageway for nerves like the brachial plexus, as well as the subclavian artery and vein. When these structures are compressed, symptoms vary depending on which component—nerve or vessel—is most affected. For athletes, especially those in sports requiring vigorous arm motions such as swimming, baseball, or tennis, TOS can present as pain, numbness, tingling, or weakness in the shoulder, arm, or hand. Notably, neurogenic thoracic outlet syndrome, resulting from brachial plexus compression, is the most common form, accounting for over 90% of cases according to StatPearls.
The clinical presentation of TOS can be vague, often mimicking other conditions and complicating diagnosis. Symptoms may include neck, shoulder, or chest pain, arm fatigue, a weakened grip, or sensory changes such as tingling and numbness in the fingers. Vascular forms of TOS, less common but potentially more severe, can cause swelling, discoloration, or even blood clots in the affected limb. In extreme cases, arterial compromise may manifest as a pulsating lump near the collarbone or diminished pulses in the arm.
Several factors can predispose an individual to develop TOS. Anatomical variations—such as having an extra cervical rib—trauma, repetitive overuse, and poor posture are recognized risk factors. According to Cleveland Clinic, congenital predispositions may remain asymptomatic until triggered by injury or chronic overuse, a scenario not uncommon in professional sports. The estimated incidence of TOS varies widely, from 3 to 80 cases per 1,000 people, in part due to the challenge of establishing a definitive diagnosis.
Diagnosis typically involves a thorough physical examination and specific movement-based tests, such as the Adson maneuver or Roos stress test, which aim to reproduce symptoms by narrowing the thoracic outlet. Imaging—like chest or cervical spine X-rays—and electrodiagnostic studies may be employed to rule out other causes and confirm the diagnosis.
Management of TOS prioritizes conservative treatment. Physical therapy is the cornerstone, focusing on postural correction and strengthening the muscles around the thoracic outlet to relieve pressure. Most patients, including athletes, respond well to this approach, with symptom resolution rates approaching 90% in some studies referenced by StatPearls. Lifestyle modifications, such as avoiding overhead arm positions and repetitive activities, are recommended to prevent recurrence. In rare cases where conservative measures fail or complications like blood clots arise, surgical intervention may be considered, though this remains controversial due to mixed long-term outcomes and potential risks.
For sports medicine professionals, early recognition of TOS is critical to prevent long-term disability and allow athletes to return to peak performance. The prognosis is generally excellent with appropriate management. As highlighted by the Mayo Clinic, most individuals see significant improvement with physical therapy and pain relief, underscoring the importance of a multidisciplinary approach in both diagnosis and ongoing care.