In anatomy, flexor is a muscle that contracts to perform flexion (from the Latin verb flectere, to bend), a movement that decreases the angle between the bones converging at a joint. For example, one's elbow joint flexes when one brings their hand closer to the shoulder, thus decreasing the angle between the upper arm and the forearm.
Flexors
Upper limb
- of the humerus bone (the bone in the upper arm) at the shoulder
- Pectoralis major
- Anterior deltoid
- Coracobrachialis
- Biceps brachii
- of the forearm at the elbow
- Brachialis
- Brachioradialis
- Biceps brachii
- of carpus (the carpal bones) at the wrist
- flexor carpi radialis
- flexor carpi ulnaris
- palmaris longus
- of the hand
- flexor pollicis longus muscle
- flexor pollicis brevis muscle
- flexor digitorum profundus muscle
- flexor digitorum superficialis muscle
Lower limb
Hip
thumb|The iliacus and nearby muscles
The hip flexors are (in descending order of importance to the action of flexing the hip joint):
- Collectively known as the iliopsoas or inner hip muscles:
- Psoas major
- Iliacus muscle
- Anterior compartment of thigh
- Rectus femoris (part of the quadriceps muscle group)
- Sartorius
- One of the gluteal muscles:
- Tensor fasciae latae
- Medial compartment of thigh
- Pectineus
- Adductor longus
- Adductor brevis
- Gracilis
Without the iliopsoas muscles, flexion in sitting position is not possible across the horizontal plane.
- Biceps femoris
- Semitendinosus
- Semimembranosus
- Gracilis
- Sartorius
- Gastrocnemius
- Popliteus
- Plantaris (negligible)
- of toes
- Posterior compartment of leg
- Flexor hallucis longus
- Flexor digitorum longus
- 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
Other
- torso/lumbar vertebrae
- Rectus abdominis muscle
- neck at atlanto-occipital joint
- Longus capitis muscle
- Longus colli muscle
See also
- List of extensors of the human body