During a tennis serve, list the main sequence of muscle contractions and relaxations in the upper limb, starting from the shoulder, arm, forearm, wrist, to the hand, and name the key muscles involved.
Answer
Deltoid – biceps brachii – triceps brachii – wrist extensors – flexor digitorum superficialis, with contraction in that order and relaxation during follow‑through.
Step-by-step solution
- Start with the shoulder: deltoid contracts to lift the arm forward.
- At the same time, biceps brachii contracts to flex the elbow for forward motion.
- Just before ball release, triceps brachii contracts to extend the elbow, adding power.
- Wrist extensors contract to straighten the wrist at impact.
- After release, flexor digitorum superficialis and hand muscles relax, allowing follow‑through.
- During the follow‑through, stabilising muscles contract while previously active muscles begin to relax.
Common mistake: Mixing up order of contraction and relaxation
Concept tested: Sequential muscle action in throwing
Published · How this solution was prepared and checked
← All Body Movements questions