One of the core concepts of kinesiology, a foundation of physical therapy, is understanding lever systems. A lever system is described when using muscles to move joints as the relation between 3 components: load, fulcrum, and effort. There are 3 ways that these components are organized in order to create force and move a load. This should serve as a good review for anyone studying kinesiology or to better understand how our muscles are affecting our joints.
Hopefully this will serve as a good review for some of you in school or in the clinic. Often these foundational concepts are overlooked, but can play a role in standard rehabilitation programs. Not only does it help us in knowing how to properly load each joint/muscle, but it also can tell us what those muscles are to do.
-Dr. Chris Fox, PT, DPT, OCS