Neurological Pathologies of the Shoulder

NEUROLOGICAL PATHOLOGIES OF THE SHOULDER In sports medicine, neurological pathologies originate either from the iterative stretching of a nerve during specific movements or from the compression of a nerve at the level of a canal due to hypertrophy of a sheath, a muscular structure, or even a bone. ➢Among the numerous nerves responsible for the innervation of the muscles of the shoulder girdle, only two are likely to be injured by sports practice due to their route, the suprascapular nerve responsible for the innervation of the supraspinatus and infraspinatus, and the serratus major nerve or nerve of Charles Bell. The circumflex nerve injured during shoulder dislocations does not present any specificity specific to a sport or activity will not be treated in this work. ➢ Paralysis of the serratus major The serratus nerve, or respiratory nerve of Charles-Bell, arises from two distinct cervical roots on the dorsal surface of the fifth and sixth branches. This nerve descends vertically behind the brachial plexus, then on the lateral wall of the thorax, behind the external mammary artery and the lateral perforators of the intercostal nerves, on the posterior surface of the serratus major. It gives a branch to each of the digitations of the greater serratus. It can be stretched iteratively by various sports movements at the level of the second rib (region of inflection of the nerve). This results in peripheral neurological damage affecting the serratus major muscle . ❉ Etiology These are the throwing activities (javelin, discus, shot put, tennis serve, handball shooting, etc.) which are most frequently affected by this pathology. The mechanism involved in the tennis player during the serve is an inflexion rotation of the humeral head. The repetition of serves in first round players makes this irritant pathology particularly common in these athletes. This mechanism can also be encountered in weightlifters due to movements combining lowering and retropulsion of the shoulder stump (fight against the lowering of the shoulder stump caused by the load) and the subject practicing bodybuilding during the press. lying down and working on the pectorals and trapezius. ❉ Diagnosis . Physical examination The athlete consults: - or for painful discomfort in the posterior part of the shoulder. It is in this case of diffuse pain extending from the dorsal spine (upper region) to the outer edge of the thorax, which may suggest Scheuermann's disease or scoliotic pain, and radiating into the arm, sometimes as far as the elbow. Its often quite low intensity contrasts with its practically permanent nature with nocturnal reinforcement, - either for a clear sensation of reduction in muscular strength or an abnormal fatigability with difficulty breaking the descent of the arm and reduction in strength during elevation. - or, more rarely for an asymmetrical aspect of the scapular region discovered fortuitously by the athlete or reported by a loved one. The clinical examination, carried out from behind and comparatively, shows a characteristic deformation of the upper lateral ❉dorsal region. There is amyotrophy of the serratus major muscle, the spinal edge of the scapula is detached from the coastal grill and tends to move closer to the spinal axis *. This phenomenon can be potentiated if the athlete is asked to perform an antepulsion movement, or better if he is made to carry a load with his arms outstretched. A simple test consists of asking the athlete to lean with their arms outstretched against a wall while observing the movement of the shoulder blades. In severe forms, there is marked functional discomfort during anterior and/or lateral elevation movements of the arm, as well as a reduction in overall shoulder muscle strength. ❉This phenomenon can be observed during fashion shows among slender and skinny models. From the back, there is a real “dance” of the shoulder blades accentuated by the swaying of the hips when walking. Radiological examination (x ❉ray, ultrasound, CT scan) of the region is unnecessary. . Complementary exam The electromyogram confirms the clinical diagnosis in the form of a reduction in muscular responses to electrical excitations. The peripheral neurogenic nature of the damage to the CharlesBell nerve can only be demonstrated with great difficulty due to the impossibility of positioning the electrodes at the nerve ends of the nerve, hidden by the scapula. ❉ Treatment Temporary cessation of the sports practice in question, or adjustment of training for a few weeks (modification of a gesture, stopping of a gesture sequence). Prescription of vitamin complex B1-B6 (4 to 6 tabs/day) for 1 to 2 months to help nerve regeneration. Physiotherapeutic maintenance of the other shoulder muscles through static and dynamic work, and joint mobility. Daily application (at least 4 to 5 times/week) of exito-motor currents to prevent the continuation of the amyotrophic process. A new electromyogram will be performed every month and a half until complete recovery. ❉The clinical examination will ensure improvement in muscular strength and good physiology of the scapula. Resumption of sport (very variable depending on the severity of the damage and the type of activity) will only be authorized when signs of nerve regeneration appear, and with the advice of a qualified trainer to correct the gesture. responsible for the injury. ➢ Damage to the suprascapular nerve The supraspinatus nerve is a branch of the suprascapular nerve. The latter comes from the first primary trunk. It runs along the posterior surface of the omohyoid and passes through the coracoid notch (below the coracoid ligament) to reach the supraspinous fossa. At this level it gives off the supraspinous branch and extends into the infraspinous fossa where it ends.