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The four names identify distinct pathways: chorda tympani, the sensory buccal nerve, the radial nerve formerly called musculospiral, and the obturator nerve. Origin must include the parent nerve or nerve plexus, while the function must follow the actual fibre supply rather than the name of a structure crossed.

Chorda tympani. This branch leaves the facial nerve in its descending facial canal before the stylomastoid foramen. It enters the tympanic cavity from behind, passes forwards between the malleus and incus close to the inner surface of the tympanic membrane, and leaves through the petrotympanic fissure. In the infratemporal fossa it joins the lingual nerve, a branch of the mandibular division of the trigeminal nerve. It then travels with that carrier towards the tongue and submandibular ganglion.

The chorda tympani carries taste from the anterior two thirds of the tongue, with sensory cell bodies in the geniculate ganglion and central connections to the nucleus of the solitary tract. It also carries preganglionic parasympathetic fibres from the superior salivatory nucleus towards the submandibular ganglion; postganglionic fibres supply the submandibular gland and sublingual gland. It does not provide the general touch supply of that part of the tongue; that travels through the lingual nerve's trigeminal nerve pathway. Taste and tactile testing can consequently distinguish two functions that briefly share one peripheral trunk.^[ref]

Buccal nerve. In the usual anatomical meaning intended by this list, this is the long buccal nerve from the anterior division of the mandibular trigeminal nerve. It commonly emerges between the heads of the lateral pterygoid muscle, descends near the anterior border of the mandibular ramus and the temporalis muscle insertion, and passes towards the cheek. Its branches reach cheek skin, the buccal mucosa, and the buccal gingiva beside the lower molars. It is principally sensory. The motor supply of the buccinator muscle comes from the facial nerve, whose buccal branches are a different set of nerves. Thus the ability to hold the cheek against the teeth and sensation in the cheek are not tests of the same efferent pathway.^[ref]

Radial nerve, historically musculospiral. This is the major continuation of the posterior cord of the brachial plexus, usually containing fibres from C5–T1. It passes from the axilla into the posterior arm, accompanying the profunda brachii artery in the radial groove of the humerus. It pierces the lateral intermuscular septum and reaches the anterior compartment between brachialis and brachioradialis. Near the lateral elbow it divides into a superficial sensory branch and a deep motor branch. The latter passes through the supinator muscle and continues as the posterior interosseous nerve.

The radial nerve supplies triceps brachii and anconeus, then brachioradialis, the radial wrist extensors and, through its deep continuation, the principal finger and thumb extensors and associated posterior forearm muscles. Its sensory branches supply posterior arm and forearm regions and part of the dorsolateral hand. A lesion's level matters: an arm lesion can impair wrist and finger extension, while an isolated superficial branch lesion is sensory and does not itself cause a wrist drop. Conversely, a posterior interosseous nerve lesion chiefly affects motor function. The fingertip pads are not the characteristic autonomous sensory territory of the superficial radial nerve.^[ref]

Obturator nerve. It arises from the anterior divisions of the anterior rami of L2–L4 in the lumbar plexus. It emerges from the medial border of psoas major, crosses the pelvic side wall and leaves through the obturator canal with the obturator vessels. Its anterior and posterior divisions characteristically run on opposite sides of adductor brevis, although the level of division varies. The anterior division supplies adductor longus, gracilis and commonly adductor brevis; the posterior division supplies obturator externus and the adductor portion of adductor magnus, with variable additional contributions. The hamstring portion of adductor magnus has a different supply. Cutaneous supply to a variable medial-thigh patch and articular branches to the hip and knee supplement its principal motor role in thigh adduction. Obturator internus is supplied by its own sacral-plexus nerve, not by the obturator nerve merely because the names resemble one another.^[ref][ref]

The glenohumeral joint combines a large humeral head with a shallow glenoid cavity. Its range of movement depends on the comparatively loose joint capsule; the glenoid labrum, rotator cuff and surrounding muscles provide stability. An injury can therefore lever the humeral head out of the glenoid cavity while tearing the joint capsule and sometimes the glenoid labrum or adjacent bone.

The historical names describe where the humeral head is found relative to the scapula and clavicle:

An 1867 answer would stress early recognition, relaxation of the muscles, and controlled traction with suitable countertraction or gentle leverage to guide the humeral head through the torn joint capsule. Anaesthesia made relaxation practicable. These are principles, not a reason to reproduce old forceful manoeuvres or indiscriminate pulley traction: force can produce a fracture or damage the axillary artery and brachial plexus.

Current assessment establishes the direction and associated fracture, usually with radiography in appropriate views. Before and after joint reduction, record pulse, perfusion, distal movement and sensation, including sensation over the lateral deltoid muscle supplied by the axillary nerve. A nerve injury accompanying joint dislocation makes prompt restoration of alignment especially important.^[ref] Joint reduction is performed by trained clinicians with suitable analgesia and, when needed, sedation or anaesthesia. Repeated forceful attempts are inappropriate; irreducibility or associated complex fracture requires specialist management.^[ref]

After joint reduction, reassess the axillary nerve and circulation and confirm alignment and relevant fractures with radiography. A temporary sling relieves pain, followed by progressive physiotherapy to restore movement and rotator cuff function. The balance is between recurrent instability and stiffness: prolonged immobilisation is not a universal solution. Recurrent instability, significant structural injury and persistent weakness require further assessment.^[ref]