The bicep muscle relaxes. It is vice-versa when the bicep muscle contracts.
... Is when you pull the bar/handlebar up, towards your body.
The Circuit Program: 5 Minutes Biceps Workout For Perfect Body
Flexion takes place.
The muscles in your arm never expand; so when you bend your arm, your biceps contract as your triceps return to their regular form. When you extend your arm, you triceps contract as your biceps return to their regular form.
When you flex your arm your biceps contract, and your triceps extend. And when you unflex your arm the triceps contract and you biceps extend. The muscles work together to allow you to move your body.
biceps and triceps respectively
The triceps be retact and contract
The biceps and triceps. When the biceps contract, the triceps relax. If you can flex it, there's an opposite action happening somewhere.
Contraction of the biceps and the relaxation of the triceps bend the arm .In straightening the arm the triceps contract and the biceps relax
The Triceps extend (Stretch out) as the biceps contract.
The Triceps brachii
The triceps contract when the biceps relax.And, vice versa. The triceps relax when the biceps contract.
There are many arm muscles. The triceps (on the back of your upper-arm) contract when you straighten your arm, and the biceps (the front of the upper-arm) relaxes.
The primary antagonist muscles in a seated row are the pectoralis major, anterior deltoid, and biceps brachii. These muscles lengthen as the back muscles contract during the rowing motion.
The biceps and triceps muscles work synergistically; the biceps muscles contracting concentrically and the triceps muscles contracting eccentrically when the forearm lifts, and it's the exact reverse when the forearm lowers.