Liigend

Liigend is the Estonian term for a joint, the connection between two or more skeletal elements that enables movement and provides stability. In anatomy, a liigend allows bones to move relative to each other while distributing loads and maintaining alignment.

Anatomy and components: A typical joint includes articular surfaces covered by cartilage, a joint capsule, a synovial membrane, and synovial fluid that lubricates the space between bones. Ligaments strengthen the joint and guide motion, while surrounding muscles and tendons control movement and protect the joint from dislocation.

Classification: joints are commonly categorized by movement into synarthroses (immovable), amphiarthroses (slightly movable), and diarthroses (freely movable). By tissue organization, they are fibrous joints (tightly joined by fibrous tissue), cartilaginous joints (bone ends joined by cartilage), and synovial joints (with a fluid-filled cavity). Synovial joints are the most common and include specialized forms such as ball-and-socket, hinge, pivot, saddle, condyloid, and plane joints.

Examples: the knee and hip are diarthrodial, synovial joints that permit multiple movements; the elbow is a hinge joint; the wrist contains condyloid and plane joints; the shoulder exemplifies a ball-and-socket joint.

Clinical relevance: joint disorders can cause pain, swelling, and reduced mobility. Common conditions include osteoarthritis, rheumatoid arthritis, gout, and injuries such as sprains and dislocations. Diagnosis combines clinical examination with imaging and, when needed, laboratory tests. Treatments focus on pain relief, preserving function, physical therapy, medications, and, in some cases, surgery such as arthroplasty.