A wrong move, and there it is... Joint sprains are one of the most common sports injuries, often with painful consequences. But what is the best way to handle such an injury?
Functions of Joints
A joint represents the mobile connection between two or more bones or cartilage. The human body has 140 "true joints" (articular space between two bones, covered by cartilage) and 72 "false joints" (e.g., intervertebral discs).
True, or discontinuous, joints have an articular space, a discontinuity or gap, between the bones. This gap separates the articular surfaces, which are covered with cartilage. Articular capsules surround the joint externally. The most well-known true joints are the ankle, knee, shoulder, and hip joints. Many of these joints are reinforced by ligaments, membranes, or synovial bursae.
False joints differ from true joints because they lack gaps or articular spaces. In these cases, two bones are connected by connective tissue, for example. As a result, they have limited range of motion. Cartilaginous joints include intervertebral discs.
What Types of Joints Are There?
There are different types of joints, which vary in structure and axes of movement:
- Rotary Joint: Rotary joints are typically recognized by their pin-shaped bone end on one side. On the other side of the bone is a groove-shaped articular cavity. Rotary joints have one axis of movement and can perform rotation. Well-known examples include the knee and ulna joints.
- Condyloid Joint: A key feature of condyloid joints, like the wrist, is their concave inward-curved surface and convex outward-curved surface. These allow lateral movements, flexion, and extension.
- Hinge Joint: Hinge joints, such as the elbow, consist of a cavity and a condyle. Unlike ball-and-socket joints, hinge joints have only one plane of motion. They allow flexion and extension.
- Saddle Joint: Saddle joints have two axes of motion, allowing movement in four directions. The thumb's carpometacarpal joint is a good example.
- Ball-and-Socket Joint: Ball-and-socket joints are composed of a cavity and a ball-shaped joint head. The shoulder joint is an important ball-and-socket joint, capable of internal and external rotations in addition to flexion and extension.
What Happens During a Joint Sprain?
“A sprain is a closed injury to one or more joints that occurs when the physiological range of motion of the joint is exceeded by an external force. The ligament structures of the joint become injured.”
In many cases, the ankle, knee, or wrist joint is affected. However, the cervical spine can also suffer from a sprain.
It is not uncommon for a sprain to be accompanied by rapid swelling. Additionally, bruising (blue discoloration) or localized pain often indicates a sprain.