I read a Frederic Delavier’s book « Strength Training Anatomy » and there is good stuff.
Sitting and you take th dumbbell your your two hands behind your neck :
Inhale and make an extension with your arms
Exhale at the end of the movement
The vertical position of the arm streches the long head of the triceps to have a good contraction during work.
Note : The three head’s fiber of triceps muscles fit into a tendinous plate which is attached by a tendo to the olecranon. When triceps contract, the tendinous plate into the head’s fibers like a wooden plate sinking into butter. Contracted muscle protrudes from the tendon plate creating this « horseshoe » form.
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