Immediate brachial plexus injury following freestyle swimming: a rare case report

Background. Brachial plexus injury (BPI) is a serious condition affecting the motor and sensory functions of the upper extremity. While most BPIs are caused by high-energy trauma, this case highlights a rare instance of swimming-induced BPI, emphasizing its clinical presentation, diagnostic challenges, and treatment considerations to raise awareness of this uncommon etiology. Case reports. A 60-year-old female presented with acute right upper extremity weakness after a freestyle swimming session. Examination revealed flaccid paralysis, diminished reflexes, and sensory deficits in the C5-C6 dermatome. Motor testing showed dysfunction in the supraspinatus and infraspinatus muscles. Electromyography, nerve conduction studies, and MRI confirmed an upper trunk BPI with denervation and nerve injury signs. Conclusions. Although BPIs are commonly associated with high-energy trauma, repetitive motions in freestyle swimming, such as shoulder abduction and external rotation, can overstretch the brachial plexus, leading to inflammation and upper trunk injury. Early diagnosis and a multidisciplinary approach are essential for optimal recovery.