Health Essentials: Joints Made Simple

What is a joint?
A joint is the point of connection between two or more bones, mainly to allow movements. Major classification of joints includes: 
· Fibrous, bones united by fibrous and rubbery tissue presenting little movement;
· Cartilaginous, bones united by hyaline cartilage or fibrocartilage. Hyaline cartilages are tough and elastic fibrous tissues, while fibrocartilages are tissues with greater flexible movement; and
· Synovial, contains synovial fluids which allows for the greatest movement between bones

Typically, the more movement allowed for a joint, the more it is able to reduce friction. The first two classifications (fibrous and cartilaginous) are mainly to support the skeletal system and are connectors of growth, while synovial joints are mainly designed for movement. These synovial joints reduce friction while managing applied force.

How are synovial joints structured to help support forces? 
The answer is a series of support systems. Structural support to the joints includes:
· Hyaline cartilage, which provides a smooth surface to the bones;
· Fibrocartilage forms articular disks, is a plate that is attached to the joint capsule which help separates the bones from touching;
· Fat pads to provide protection for the cartilage;
· Synovial Membrane, a layer of connective tissue which secretes a thin lubricate of synovial fluid; and Ligaments and Tendons. Ligaments are tough fibrous bands of tissue to support organs while holding bones together. Tendons are tough bands of fibrous tissue that connects muscles with bones.

Are all Synovial Joints made the same? 
Well, the simple answer is no. And that is a good thing. Imagine your body as a building. The same way different hinges help support forces of a building (through flexible movement), the same applies to your body. Different types of synovial joints include: 
· Plane, allows bones to slide past each other;
· Pivot, allows rotation around an axis (i.e. the neck);
· Hinge, allows extension and retraction of a limb (i.e. knees and fingers);
· Ball and socket, allows for radial movement in all directions (i.e. hip)
· Saddle, allows movement back and forth (i.e. thumb);
· Condyloid, similar to ball and socket with less movement (i.e. wrist)

How do joints exactly work?
When forces are applied to the skeleton, joints move. In one end of the tendon, muscles connect to bones where connective tissues are secured to collagen fibers. On the other end, connective tissues are structured to manage force efficiently. Ultimately, the skeletal muscle pulls on tendons attached to the skeleton for movement, as well as, producing tension to sustain posture. Layers of tissues maintain intricate nerve and circulatory networks, which explains when the tissues are trained, new cellular enhancements, allow the body to adjust to new loads of stress.

What are specific layers of the skeletal muscle? 
· Muscle Fascia – Thick connective tissue that encases muscles
· Myofibrils – Made of cylindrical thread-like fibers that make up the part of the contractions of the muscle fiber. They are comprised of myofilaments, a protein which produces the muscle into motion.
· Myosin and Actin – Myosin are thick myofilaments, while actin are the thin filaments. Together, they help create tension inside the muscle tissues.

Final Statement
Knowledge of your joints is significant to understanding the human body. And having extensive knowledge to functional anatomy can help employ new awareness for physical self-sustainment.