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HMS, BM EQ-Bank 23 MC

During a biceps curl, what occurs at the elbow joint?

  1. The biceps contracts concentrically as the primary agonist
  2. The triceps contracts concentrically as the primary agonist
  3. The biceps and triceps contract simultaneously
  4. The triceps relaxes while the biceps stabilises
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Consider Option A:

  • During the lifting phase of a biceps curl, the biceps muscle shortens (contracts concentrically) while generating force to lift the weight
  • The biceps is the primary agonist (prime mover) in elbow flexion
  • As the agonist, it is responsible for producing the desired movement against gravity
  • The triceps (antagonist) relaxes during this phase through reciprocal inhibition.

The other options are incorrect because:
B: The triceps extends the elbow – it is not the agonist during a curl
C: The biceps and triceps don’t contract simultaneously due to reciprocal inhibition
D: This reverses the roles – the triceps relaxes but the biceps contracts rather than stabilises