Human (Homo sapiens sapiens)
The shoulder joint is a 3rd Order lever: the clavicle and humerus form the fulcrum; the deltoid muscle is contracting, abducting the humerus; the arm is moving out and upward.
The shoulder joint is a 3rd Order lever: the clavicle and humerus form the fulcrum; the deltoid muscle is contracting, abducting the humerus; the arm is moving out and upward.
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This shows the arm after the deltoid muscle has partially contracted; the lever arms have different positions after the in-force (muscle) has begun to exert force on the lever.
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The VR of this lever is around 3/1; this lever does not move very quickly but, as one can see from the muscle mass surrounding the joint, has a powerful movement.