Shoulder pain or paresis should be assessed carefully, as there are many possible causes, which can be osteoarticular, degenerative, inflammatory, or neurological. Weakness or pain can be related to cervicobrachialgia, plexitis, or focal mononeuropathy. The clinical picture should identify any muscular or mechanical origin of paresis responsible for pseudo-paretic functional limitation. Neurogenic scapulalgia with functional deficit implies the compression or entrapment of a nerve trunk including the axillary, long thoracic, accessory, suprascapular, or dorsal scapular nerves. Nerve conduction study and myography together with medical imaging help to identify the relevant etiology. Treatment mostly includes pain relief and physiotherapy, but surgery is rarely necessary.