How Joints Help Your Body Move
Think of the song: “The leg bone is connected to the / Knee bone.”
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Transcript
Your body enjoys movement thanks to the interaction between muscles, bones, and joints! Strong tissues called tendons connect muscles to bones. When you contract and relax your muscles, the tendons pull on the bones, forcing them to move at the place where they meet-the joint.
Although a few joints in your body are immovable or only slightly movable, most are fully movable.
Movable joints, known as synovial joints, connect bones within a cushioned capsule. These joints can rotate like a ball and socket; slide like a glide; turn like a pivot; or bend like a hinge.
Take a closer look at that knee to see how synovial joints let you move.
The knee is a hinge joint that allows extension of the lower leg. Ligaments connect the upper and lower leg bones, while a tough fibrous capsule surrounds their ends and holds the entire joint together.
Lining the capsule is the synovial membrane which secretes synovial fluid that fills the joint cavity. This fluid lubricates the joint and prevents the bones from grinding against each other as the joint flexes. A layer of cartilage covers the end of each bone, providing plenty of cushion to help your knees withstand the pounding when you run and jump.
Although a few joints in your body are immovable or only slightly movable, most are fully movable.
Movable joints, known as synovial joints, connect bones within a cushioned capsule. These joints can rotate like a ball and socket; slide like a glide; turn like a pivot; or bend like a hinge.
Take a closer look at that knee to see how synovial joints let you move.
The knee is a hinge joint that allows extension of the lower leg. Ligaments connect the upper and lower leg bones, while a tough fibrous capsule surrounds their ends and holds the entire joint together.
Lining the capsule is the synovial membrane which secretes synovial fluid that fills the joint cavity. This fluid lubricates the joint and prevents the bones from grinding against each other as the joint flexes. A layer of cartilage covers the end of each bone, providing plenty of cushion to help your knees withstand the pounding when you run and jump.