Your muscles can only pull, so your upper arm muscles cannot simply push your lower arm away Instead, you need a different set of muscles to pull your arm in the other direction Try flexing your arm a few times and see if you can find the muscle that straightens your arm Try tensing your arm to hold it very straight. Muscles are only able to pull They work in opposing pairs where one muscle contracts to pull, while the other relaxes and elongates to allow movement.
The muscles can only pull, not push So, to move a limb, one muscle relaxes while the other muscle pulls The muscles that allow you to tighten your fingers are primarily located in the forearm. Muscles work by contraction, which means they shorten in length When a muscle contracts, it pulls on the bones it's attached to, causing movement Muscles can't push because they can't extend or lengthen by themselves
A string can contract and shorten when pulled, but it can't push or bulge This fundamental truth applies to muscle fibers as well Muscles can only pull because they are designed to contract, drawing two ends of the muscle fiber toward each other When multiple muscle fibers contract simultaneously, it results in a range of movements. Study with quizlet and memorize flashcards containing terms like muscles are only able to pull, they never push, regardless of type, all levers follow the same basic principle Effort farther than load from fulcrum = mechanical advantage
Effort nearer than load to fulcrum = mechanical disadvantage., movements of the thigh are accomplished by muscles anchored to the pelvic girdle
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