NEUROLOGICAL PATHOLOGIES OF THE SHOULDER In sports medicine, neurological pathologies originate either from the iterative stretching of anerve during specific movements or from the compression of a nerve at the level of a canaldue 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, thesuprascapular nerve responsible for the innervation of the supraspinatus and infraspinatus,and the serratus major nerve or nerve of Charles Bell. The circumflex nerve injured duringshoulder dislocations does not present any specificity specific to a sport or activity will not betreated in this work. ➢ Paralysis of the serratus major The serratus nerve, or respiratory nerve of Charles-Bell, arises from two distinct cervicalroots on the dorsal surface of the fifth and sixth branches. This nerve descends verticallybehind the brachial plexus, then on the lateral wall of the thorax, behind the externalmammary artery and the lateral perforators of the intercostal nerves, on the posterior surfaceof the serratus major. It gives a branch to each of the digitations of the greater serratus. Itcan 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 affectingthe 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 thetennis player during the serve is an inflexion rotation of the humeral head. The repetition ofserves in first round players makes this irritant pathology particularly common in theseathletes. This mechanism can also be encountered in weightlifters due to movementscombining lowering and retropulsion of the shoulder stump (fight against the lowering of theshoulder stump caused by the load) and the subject practicing bodybuilding during thepress. lying down and working on the pectorals and trapezius. ❉ Diagnosis . Physical examination The athlete consults: - or for painful discomfort in the posterior part ofthe 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 intensitycontrasts with its practically permanent nature with nocturnal reinforcement, - either for aclear sensation of reduction in muscular strength or an abnormal fatigability with difficultybreaking the descent of the arm and reduction in strength during elevation. - or, more rarelyfor an asymmetrical aspect of the scapular region discovered fortuitously by the athlete orreported by a loved one. The clinical examination, carried out from behind andcomparatively, 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 *. Thisphenomenon 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 ofasking the athlete to lean with their arms outstretched against a wall while observing themovement of the shoulder blades. In severe forms, there is marked functional discomfortduring anterior and/or lateral elevation movements of the arm, as well as a reduction inoverall 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 theswaying 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 areduction in muscular responses to electrical excitations. The peripheral neurogenic natureof the damage to the CharlesBell nerve can only be demonstrated with great difficulty due tothe impossibility of positioning the electrodes at the nerve ends of the nerve, hidden by thescapula. ❉ 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 nerveregeneration. Physiotherapeutic maintenance of the other shoulder muscles through staticand dynamic work, and joint mobility. Daily application (at least 4 to 5 times/week) ofexito-motor currents to prevent the continuation of the amyotrophic process. A newelectromyogram 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 ofthe damage and the type of activity) will only be authorized when signs of nerve regenerationappear, and with the advice of a qualified trainer to correct the gesture. responsible for theinjury. ➢ Damage to the suprascapular nerve The supraspinatus nerve is a branch of the suprascapular nerve. The latter comes from thefirst primary trunk. It runs along the posterior surface of the omohyoid and passes throughthe coracoid notch (below the coracoid ligament) to reach the supraspinous fossa. At thislevel it gives off the supraspinous branch and extends into the infraspinous fossa where itends.