Semiflexed

Semiflexed is an adjective used to describe a partial degree of flexion in which a joint is bent but not to its full range. The term denotes a position that lies between extension (straight) and full flexion (fully bent), with the exact angle depending on the joint and context.

In anatomical, clinical, and biomechanical usage, semiflexed describes body postures or positions during movement, imaging, or assessment. It is commonly applied to joints such as the knee, elbow, wrist, and hip to indicate a partially bent configuration that affects muscle length, joint loading, and accessibility for examination or procedures. The term is often contrasted with extended or fully flexed positions.

The specific angular threshold for what counts as semiflexed is not universal and varies by discipline and clinical protocol. As such, semiflexed should be interpreted in context, often described qualitatively (e.g., “partially flexed knee”) or with explicit angle measurements in a given study or report. It can also refer to component orientation in orthopedic implants or prosthetics when a partial bend is intentional or necessary.

Examples of usage include a semiflexed knee during certain gait phases, a semiflexed elbow in certain resting or functional positions, or a semiflexed knee radiograph used to visualize particular structures. In imaging, semiflexed positions can optimize visibility of specific anatomy while maintaining patient comfort or safety.

Etymology: from semi- meaning half and flexed meaning bent. See also flexion, extension, range of motion, biomechanics.