Range of motion in the context of "Pivot joint"

Flexibility is the anatomical range of movement in a joint or series of joints, and length in muscles that cross the joints to induce a bending movement or motion. Flexibility varies between individuals, particularly in terms of differences in muscle length of multi-joint muscles. Flexibility in some joints can be increased to a certain degree by exercising, with stretching being a common exercise component to maintain or improve flexibility.

Limberness is the condition of having flexibility to a positive or superior degree, which is also spoken of as a person having flexibility or being flexible.

Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibious stem tetrapod ancestors during the Carboniferous period. Amniota is defined as the smallest crown clade (the group including all descendants of the last common ancestor) containing humans, the Greek tortoise, and the Nile crocodile.Amniotes represent a crucial evolutionary step in vertebrate history, marking the transition from aquatic to fully terrestrial life.

Amniotes are distinguished from the other living tetrapod clade — the non-amniote lissamphibians (frogs/toads, salamanders/newts and caecilians) — by: the development of three extraembryonic membranes (amnion for embryonic protection, chorion for gas exchange, and allantois for metabolic waste disposal or storage); internal fertilization; thicker and keratinized skin; costal respiration (breathing by expanding/constricting the rib cage); the presence of adrenocortical and chromaffin tissues as a discrete pair of glands near their kidneys; more complex kidneys; the presence of an astragalus for better extremity range of motion; the diminished role of skin breathing; and the complete loss of metamorphosis, gills, and lateral lines.

Osteoarthritis is a type of degenerative joint disease that results from breakdown of joint cartilage and underlying bone. A form of arthritis, it is believed to be the fourth leading cause of disability in the world, with an estimated 240 million people worldwide having activity-limiting osteoarthritis. The most common symptoms are joint pain and stiffness. Usually the symptoms progress slowly over years. Other symptoms may include joint swelling, decreased range of motion, and, when the back is affected, weakness or numbness of the arms and legs. The most commonly involved joints are the two near the ends of the fingers and the joint at the base of the thumbs, the knee and hip joints, and the joints of the neck and lower back. The symptoms can interfere with work and normal daily activities. Unlike some other types of arthritis, only the joints, not internal organs, are affected.

Possible causes include previous joint injury, abnormal joint or limb development, and inherited factors. Risk is greater in those who are overweight, have legs of different lengths, or have jobs that result in high levels of joint stress. Osteoarthritis is believed to be caused by mechanical stress on the joint and low grade inflammatory processes. It develops as cartilage is lost and the underlying bone becomes affected. As pain may make it difficult to exercise, muscle loss may occur. Diagnosis is typically based on signs and symptoms, with medical imaging and other tests used to support or rule out other problems. In contrast to rheumatoid arthritis, in osteoarthritis the joints do not become hot or red.

Arthritis is a general medical term used to describe a disorder in which the smooth cartilagenous layer that lines a joint is lost, resulting in bone grinding on bone during joint movement. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In certain types of arthritis, other organs such as the skin are also affected. Onset can be gradual or sudden.

There are several types of arthritis. The most common forms are osteoarthritis (most commonly seen in weightbearing joints) and rheumatoid arthritis. Osteoarthritis usually occurs as a person ages and often affects the hips, knees, shoulders, and fingers. Rheumatoid arthritis is an autoimmune disorder that often affects the hands and feet. Other types of arthritis include gout, lupus, and septic arthritis. These are inflammatory based types of rheumatic disease.

Joint stiffness may be either the symptom of pain on moving a joint, the symptom of loss of range of motion or the physical sign of reduced range of motion.

• Pain on movement is commonly caused by osteoarthritis, often in quite minor degrees, and other forms of arthritis. It may also be caused by injury or overuse and rarely by more complex causes of pain such as infection or neoplasm. The range of motion may be normal or limited by pain. "Morning stiffness" pain which eases up after the joint has been used, is characteristic of rheumatoid arthritis.
• Loss of motion (symptom): the patient notices that the joint (or many joints) do not move as far as they used to or need to. Loss of motion is a feature of more advanced stages of arthritis including osteoarthritis, rheumatoid arthritis and ankylosing spondylitis.
• Loss of range of motion (sign): the examining medical professional notes that the range of motion of the joint is less than normal. Routine examination by an orthopaedic surgeon or rheumatologist will often pay particular attention to this. The range of motion may be measured and compared to the other side and to normal ranges. This sign is associated with the same causes as the symptom. The loss of range of motion in the joint may be due to a contracture. In extreme cases when the joint does not move at all it is said to be ankylosed.