Effective coaching requires efficient communication. This communication is greatly aided by coach and athlete sharing a terminology for both human movement and body parts.
We've developed an exceedingly simple lesson in anatomy and physiology that we believe has improved our ability to accurately and precisely motivate desired behaviors and enhanced our athletes' understanding of both movement and posture.
Basically, we ask that our athletes learn four body parts, three joints (not including the spine), and two general directions for joint movement. We cap our A&P lesson with the essence of sports biomechanics distilled to three simple rules.
We use a simple iconography to depict the spine, pelvis, femur, and tibia. We show that the spine has a normal "S" shape and where it is on the athlete's body. We similarly demonstrate the pelvis, femur, and tibia.
We next demonstrate the motion of three joints. First, the knee is the joint connecting tibia and femur. Second, working our way up, is the hip. The hip is the joint that connects the femur to the pelvis. Third, is the sacroiliac joint (SI joint), which connects the pelvis to the spine. (We additionally make the point that the spine is really a whole bunch of joints.)
We explain that the femur and tibia constitute "the leg" and that the pelvis and spine constitute "the trunk." That completes our anatomy lesson - now for the physiology. We demonstrate that "flexion" is reducing the angle of a joint and that "extension" is increasing the angle of a joint.