Hamstring
to make it tight
You can flex skeletal muscles voluntary. These are the muscles you can control and move consciously. Smooth muscles and cardiac muscles, which work involuntarily, cannot be consciously flexed.
Your hamstring muscles.
The sternocleidomastoid muscles are the ones that flex when the intercostals are flexed. This will also cause the scalene muscles to flex.
To flex your chest, you tighten the muscles that are in that area. This might include your arms or back as well, but you tighten the muscles in your chest and abs.
Muscles can contract and shorten
i done no
You flex your muscles to do this and these pull on the tendons which link the muscles to the bones.
yes.. everyone has muscles in their legs
There are fast twitch muscles fibers in all of your muscles, especially in your legs.
brechioradialis
Biceps Brachii flexes the forearm and the Triceps Brachii extends the forearm.