Life is movement, movement is life !
Joints join bones
The human skeleton is joined together by 96 primary joints.
Nerves control the movement of joints, enabling many complex but coordinated movements that enrich human lives.
Three major categories of human joints：
Synarthroses, Immovable Joint
Perfect combinations－the structure of the knee joint
Cartilage in a joint
Covers smoothly over the surface of the ends of bones. Cartilage is smooth, glossy, and elastic. It enables the joint to move agilely and absorb external shocks.
The quadriceps at the front and the hamstrings in the back not only increase stability but also make the knee more agile.