Muscle and systems combine to allow us to move.
Muscles have their insertions and origins most often on bones.
This forms a system of levers which when the muscles contract transfer their energy into movement. This investigation tests the variation in efficiencies by which this transfer takes place. Use a physics book to find the formula for calculating the forces involved with a lever system. The distance form the fulcrum of the elbow to the insertion of the bicep on the ulna.