ojentamisen

Ojentamisen is a term used in anatomy and physiology to describe the extension of a joint, that is, the action of increasing the angle between two body segments toward a straight line. The noun is derived from the Finnish verb ojentaa, meaning to extend or straighten. It is the counterpart to flexion (koukistus).

In the human body, ojentaminen occurs at many joints, including the elbow, knee, wrist, hip, and spine. A fully extended elbow straightens the forearm relative to the upper arm; knee extension straightens the leg. The movement can be active, produced by muscle contraction, or passive, produced by gravity or external support.

Mechanism-wise, extension is carried out mainly by extensor muscles, such as the triceps brachii at the elbow and the quadriceps group at the knee. The movement is opposed by flexor muscles. Extension can occur as part of ordinary activities, sports, and rehabilitation, and it contributes to standing, walking, and reaching motions.

Clinical and practical relevance of ojentaminen includes the assessment of a joint’s range of motion, which is common in physiotherapy and rehabilitation. Reduced extension can indicate injury, inflammation, contractures, or degenerative conditions, while hyperextension refers to extension beyond the normal range. Therapeutic approaches often aim to improve or restore extension through targeted exercises such as leg extensions, elbow extensions, or spinal extensions, along with stretching and joint mobilization as appropriate.