Introduction:
A lever is a rigid beam that rotates around a fixed point, the fulcrum. The lever has three parts fulcrum, effort, and resistance. Fulcrum (joints) is a fixed point where movements can happen. Effort (muscles) is a force used for producing a movement. Resistance (bones) is the weight of the object that is being moved.
Levers produce mechanical advantage. Mechanical advantage (MA) is determined by the ratio of the length of the effort arm to the length of the resistance arm.
The MA value can vary with different arm lengths which can either favor strength or speed.
If the MA value is less than 1, the lever produces more speed than the input effort and if the MA value is more than 1, the lever produces less speed than the input effort. If the value is 1, there is no mechanical advantage.
Dorsiflexion is the backward flexion of the hand or foot. The raising of the palm or toe movement occurs with the help of wrist or ankle joint.
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