Question

a young cyclist is involved in a road traffic collision he is complaining of pain in his right shoulder region he is unable to abduct his right arm and lateral rotation is weekend he has decreased sensation over the upper outer deltoid which nerve has he damaged

Answer 1

Axillary nerve

• It originate from brachial plexus
• It supplies deltoid muscle, teres minor and triceps brachii.
• Damage to this nerve causes paralysis of these muscle, which lead to loss of abduction, lateral rotation.
• It also carries sensory fibers to skin over deltoid. Therefore its its injury causes loss of sensation over that area (called as regimental patch sign)

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