Resources for Educators
Kris Bour, instructor at Georgia Career College, shares this analogy to describe how muscles work:
When the Amish are going to build a barn, it is a community event. The women busy themselves with preparing a meal for all while the men work in teams, much like muscles, to raise the barn. Ropes are attached to specific areas on the barn wall for an optimal, smooth rising. The man in the middle is in the best position for leverage in raising the wall; a muscle that is in the best position to do the primary action is the Agonist or Prime Mover. The man in the middle cannot alone raise the wall; he needs the assistance of the men on either side of the wall. These men use their ropes to stabilize the wall from any unnecessary movement such as wobbling, and help pull up the wall; the muscles that act as assistants in the movement, and prevent unnecessary movement from occurring are called Synergists. They are not in the best position to make the action occur and can substitute if the Prime Mover is injured, but they cannot do the job as efficiently as the PM. The man on the opposite side of everyone else is there to stabilize the wall from going too far. He works in opposition to everyone; muscles that work in opposition to the Agonist/Prime Mover are called Antagonists.
This can be made an interactive project with some ropes and an old pallet. Fixators can also be placed at the origin of the PM at the bottom of the wall.