In anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal (bones, cartilage, and ligaments) and muscular (muscles and tendons) systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder. The trunk may be flexed toward the legs or the neck to the chest.
The opposite term is extension, or straightening. Flexion decreases the angle between the bones of the limb at a joint, and extension increases it.
Note that specific flexion activities may occur only along the sagittal plane, i.e. from the forward to backward direction, and not side-to-side direction, which is further discussed in abduction.
Additional recommended knowledge
Active range of motion exercises include movements such as flexion and extension. These exercises are used after an injury or surgery. They are done by a physical therapist or nurse initially, and may be continued by the patient.
In the healing process, active range of motion exercises, should avoid forcing the appendage into the extension or flexion position. The stress induced may re-injure the affected appendage (limb).
Muscles of flexion
- of forearm, at elbow
- Anterior compartment of the arm
- Anterior compartment of the forearm
- of thumb
- Flexor pollicis longus
- Flexor pollicis brevis
- of femur/thigh at hip (L1-L2)
- Tensor fasciae latae
- Rectus femoris
- (additional minor contributions from other hip flexors)
- of toes
- Posterior compartment of leg
- Flexor digitorum brevis
- Quadratus plantae
- Flexor hallucis brevis
- Flexor digiti minimi brevis
- of proximal phalanges at metatarsophalangeal joint
- Lumbrical muscle (foot)
- Plantar interossei
- Dorsal interossei
- neck at atlanto-occipital joint
- ^ http://www.exrx.net/Articulations/Shoulder.html#anchor102874
- ^ http://www.exrx.net/Articulations/Elbow.html#anchor764071
- ^ http://www.exrx.net/Articulations/Wrist.html#anchor260949
- ^ http://www.exrx.net/Articulations/Fingers.html#anchor801484
- ^ http://www.exrx.net/Articulations/Fingers.html#anchor783387
- ^ http://www.exrx.net/Articulations/Thumb.html#anchor206196
- ^ http://www.exrx.net/Articulations/Thumb.html#anchor212077
- ^ http://www.exrx.net/Articulations/Hip.html#anchor845056
- ^ http://www.exrx.net/Articulations/Knee.html#anchor22052
- ^ http://www.exrx.net/Articulations/Toes.html#anchor229680
|Types of joints||Amphiarthrosis - Symphysis - Gomphosis - Synovial joint (Hinge joint, Pivot joint, Condyloid joint, Saddle joint, Ball and socket joint, Gliding joint)|
|Terminology||Kinesiology - Anatomical terms of motion - Agonist/Antagonist|
|Motions||Flexion/Extension - Adduction/Abduction - Internal rotation/External rotation - Supination/Pronation - Plantarflexion/Dorsiflexion - Eversion/Inversion - Elevation/Depression - Protraction/Retraction|