AQA GCSE · Question 09.3 · The Human Body and Movement in Physical Activity and Sport
Identify the type of muscle contraction that is taking place at the elbow as the arm moves from A to B.
How to approach this question
Consider what is happening to the agonist muscle (the bicep) during the movement. The muscle is contracting and shortening to lift the weight. Identify the term for this type of contraction.
Full Answer
When the arm moves from A to B, the bicep muscle contracts and shortens to lift the dumbbell. A muscle contraction that results in a change in muscle length and causes movement is called an isotonic contraction. Specifically, when the muscle shortens under tension, it is a concentric contraction. 'Isotonic' is also a correct answer as concentric is a type of isotonic contraction.
Common mistakes
Confusing concentric with eccentric (muscle lengthening under tension) or isometric (no change in length).
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