👉 Sedentary (or "sensible") humans have three main skeletal systems: pelvis, hip, and lower back. These are called the femur, ilium, and scapula respectively. The third skeleton is a bone in the human body called the tibia, which connects to the femur at the knee joint and provides stability for the leg. Sedentary humans have more bones than active individuals. This means they require less energy to maintain their bodies, and therefore