Muscles act in antagonistic pairs against an incompressible skeleton
Muscles can only pull — they cannot push. So two muscles work as a pair: one contracts to create movement, and the other contracts to reverse it.
Real World
When sprinter Dina Asher-Smith drives off the blocks, her quadriceps contract to extend the knee while the antagonistic hamstrings relax — the reverse happens during the swing phase of her stride.
Exam Focus
Always name both muscles in the pair and state which contracts and which relaxes for the described movement.
Evaluation Scaffold
A four-step framework for high-quality evaluation. Use this for 'assess', 'evaluate', and 'to what extent' questions.
How well did you know this?