Background <p>Despite significant advances in primary nerve reconstruction, many patients with peripheral nerve injuries fail to achieve sufficient functional reinnervation. This is particularly true in cases of delayed presentation, extensive lesions, or advanced denervation atrophy. In such situations, tendon or muscle transfer procedures are of high clinical relevance.</p> Objectives <p>The aim of this study is to describe the functional anatomy of the shoulder, analyze common causes of clinically relevant functional deficits, and systematically review established motor reconstructive procedures for selected injury patterns. The focus is on C5/6 brachial plexus injuries, different forms of scapular winging, lesions of the musculocutaneous nerve, and proximal radial nerve injuries with loss of elbow extension in the context of complex conditions, including spinal cord injury.</p> Methods <p>This is a&#xa0;narrative review based on current literature and clinical experience.</p> Results <p>Tendon or muscle transfer procedures can provide meaningful functional improvement even in cases of irreversible nerve injury. Established techniques include trapezius, pectoralis major, and latissimus dorsi transfers to restore elbow function in shoulder function and elbow flexion. Elbow extension can be reconstructed using either a&#xa0;posterior deltoid or a&#xa0;biceps transfer, depending on the individual clinical situation.</p> Conclusion <p>Tendon or muscle transfer procedures represent an essential component in the treatment of complex upper extremity dysfunction and can significantly improve functional outcomes when carefully indicated.</p>