Wrist Flexors

Other Names

• Forearm (Inner)
• Hand Flexors

Heads

1. Flexor Digitorum Superficialis
2. Flexor Digitorum Profundus
   • 4 Heads
3. Flexor Carpi Radialis
4. Flexor Carpi Ulnaris
5. Palmaris Longus
6. Flexor Pollicis Longus

Movement

Wrist

• Flexion [1, 2, 3, 4, 5, 6]
• Abduction [3]
• Adduction [4]

Fingers

• Flexion [1, 2]
• Adduction [1, 2]

Thumb

• Flexion [6]

Elbow (very weak)

• Flexion [1, 3, 4, 5]

Attachments

Origin

• Humerus (Medial Distal)
  • Medial Epicondyle [1, 3 , 4, 5]
• Ulna
  • Medial Coronoid [1]
  • Proximal 3/4 (Anterior & Medial) [2]
  • Proximal Posterior [4]
• Radius (Middle Anterior) [1, 6]

Insertion

• Fingers (Palmer Surface)
  • Sides of middle phalanges [1]
  • Base of distal phalanges [2]
• Thumb (Palmer Surface)
  • Base of distal phalanx [6]
• Metacarpals (Palmer Surface)
  • Second & Third [3]
  • Fifth [4]
  • Second, Third, Fourth, Fifth
    • Palmer Aponeurosis [5]
• Carpals (Medial) [4]
  • Pisiform
  • Hamate

Comments

The triarticulate [1] and biarticulate [2, 3, 4, 5, 6 ] wrist flexor muscles may independently enter passive insufficiency through the completion of one of 4 eccentric joint movements (opposite movements of the wrist, fingers, thumb, elbow) when an adjacent joint eccentric movement is sustained. The triarticulate and biarticulate wrist flexor muscles [1, 2, 3, 4, 5, 6 ] may independently enter active insufficiency through the completion of one of 4 concentric joint movements (movements of the wrist, fingers, thumb, elbow) when an adjacent joint concentric movement is sustained.

The Palmaris Longus is absent on one or both sides in about 21% of people.