Study note

Injury to the nerve supplying serratus anterior

THE CONTEXT

Injury to the nerve to serratus anterior, also called the nerve of Bell in the passage, causes scapular winging and impaired shoulder function.

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Sudden pressure on the shoulder from above can injure the nerve.

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Carrying heavy loads on the shoulder is another stated cause.

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Winging is excessive prominence of the medial border of the scapula.

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Normally, the pull of serratus anterior keeps the medial border against the thoracic wall.

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Winging appears during attempts at pushing.

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Pushing and punching actions are lost.

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The arm cannot be raised beyond 90° because overhead abduction requires serratus anterior.

NEETx

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