Boxer's muscle is a/an?

Appeared in: AIIMS Bhuvneshwar NO- 2018

Explanation

The Serratus anterior is widely known by the nickname "boxer's muscle" or "swimmer's muscle.".
Its primary function is to protract the scapula, which means pulling the shoulder blade forward and around the rib cage.
This protraction is the fundamental biomechanical movement involved in pushing or throwing a punch, hence the nickname.
The muscle arises from the upper eight or nine ribs and inserts on the medial border of the scapula.

Option A: Brachioradialis is a muscle of the forearm. Its main function is flexion of the elbow, particularly when the forearm is in a neutral (thumb-up) position. It does not contribute to the punching motion from the scapula.
Option C: Biceps brachii is a large muscle on the front of the upper arm. It is a powerful flexor of the elbow and the main supinator of the forearm (turning the palm upwards). It does not protract the scapula.
Option D: The Deltoid is the large, triangular muscle that forms the rounded contour of the shoulder. Its primary role is abduction of the arm (lifting it out to the side). While it's involved in shoulder movements, it is not the primary muscle for the forward punching thrust.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy and function of upper limb and shoulder girdle muscles as background academic context rather than a clinical decision trigger.
Nurses should be aware that the long thoracic nerve is vulnerable to injury during certain surgical procedures like mastectomy or axillary lymph node dissection, as well as from direct trauma to the chest wall.
Assessment for scapular winging is a key part of the neurological examination of the upper limb. Ask the patient to push against a wall with outstretched arms and observe for any prominence of the scapulae.
A patient with serratus anterior weakness will have significant difficulty with activities of daily living that involve pushing, reaching, or lifting objects overhead.

How to Approach the Question

First, identify the key phrase in the question: "Boxer's muscle". This is a specific anatomical nickname.
This is primarily a factual recall question. Access your knowledge of muscle anatomy and their common names or functions.
Recall that the motion of a boxer's punch involves protracting the scapula (moving it forward).
Evaluate the options based on this action. The Serratus anterior is the prime mover for scapular protraction.
Eliminate the other options by recalling their primary functions: Brachioradialis (elbow flexion), Biceps brachii (elbow flexion/supination), and Deltoid (shoulder abduction). This confirms that Serratus anterior is the only logical answer.

Concept Tested & Keywords

QR2Te4vyisgLrV6apOhNTm

E6 Anatomy BDChaurasia V1 10e p. 53-55

E6 Anatomy Grays 43e Vol 2 Part 2 pp. 100-102, 72-74

Practise the full AIIMS Bhuvneshwar NO- 2018

Attempt every question from this paper in a timed mock, then review the full solution for each one.