1. Abductor pollicis brevis (APB)

2. Thenar Group
Attachments: Proximal: Tubercles of scaphoid + trapezium + flexor retinaculum Distal: Base of PROXIMAL phalanx of thumb (lateral side) Action: ABduct CM jt of thumb PERIPHERAL NERVE + spinal cord level of origin: Median nerve: C6, 7, 8, T1 Spinal Segments: C6, 7, 8, T1

3. Flexor pollicis brevis (FPB)

4. Thenar Group
Attachments: Proximal: Tubercle of trapezium + flexor retinaculum Distal: Base of PROXIMAL phalanx of thumb (lateral side) Action: Flex MP + CM jts of thumb PERIPHERAL NERVE + spinal cord level of origin: Median nerve: C6, 7, 8, T1 Spinal Segments: C6, 7, 8, T1

5. Opponens pollicis

6. Thenar Group
Attachments: Proximal: Tubercle of trapezium + flexor retinaculum Distal: Body of 1st metacarpal (lateral side) Action: Opposes CM jt of thumb (3 of 4 opposition movements = AB, flex, + MR) PERIPHERAL NERVE + spinal cord level of origin: Median nerve: C6, 7, 8, T1 Spinal Segments: C6, 7, 8, T1

7. Adductor pollicis: Oblique and transverse heads

8. Thenar Group
Attachments: Proximal: Oblique Head: Capitate + base of metacarpals Transverse Head: 3rd metacarpal Distal: Base of PROXIMAL phalanx of thumb (medial side) Action: ADduct CM jt of thumb PERIPHERAL NERVE + spinal cord level of origin: Ulnar nerve: C8, T1 Spinal Segments: C8, T1

9. Abductor Digiti Minimi (ADM)

10. Hypothenar Group
Attachments: Proximal: Pisiform + tendon of FCU Distal: Base of PROXIMAL phalanx of digit 5 Action: ABduct MP jt of 5, assist in flex MP of 5 PERIPHERAL NERVE + spinal cord level of origin: Ulnar nerve: C8, T1 Spinal Segments: C8, T1

11. Flexor digiti minimi (brevis)

12. Hypothenar Group
Attachments: Proximal: Hook of hamate + flexor retinaculum Distal: Base of PROXIMAL phalanx of digit 5 Action: Flex MP jt of 5 PERIPHERAL NERVE + spinal cord level of origin: Ulnar nerve: C8, T1 Spinal Segments: C8, T1

13. Opponens digiti minimi

14. Hypothenar Group
Attachments: Proximal: Hook of hamate + flexor retinaculum Distal: Body of metacarpal 5 Action: Oppose CM jt of 5 (AD, flex, + LR) PERIPHERAL NERVE + spinal cord level of origin: Ulnar nerve: C8, T1 Spinal Segments: C8, T1

15. Lumbricals (4)

16. Palmar Group
Attachments: Proximal: Tendons of FDP (on radial side) Distal: Dorsal apparatus on radial side of 2, 3, 4, 5 Action: Extend IP jts 2-5, flex MP jts 2-5 PERIPHERAL NERVE + spinal cord level of origin: Median n. to I, II; Ulnar n. to III, IV Spinal Segments: C8, T1

17. Palmar interossei (PAD) unipennate form

18. Palmar Group
Attachments: Proximal: Metacarpals 2, 4, 5 on palmar surface Distal: Dorsal apparatus on digits 2, 4, 5 Action: ADduct + flex MP + extend IP jts of 2, 4, 5 PERIPHERAL NERVE + spinal cord level of origin: Ulnar nerve: C8, T1 Spinal Segments: C8, T1

19. Dorsal interossei (DAB) bipennate form

20. Palmar Group
Attachments: Proximal: Adjacent sides of two metacarpals Distal: Dorsal apparatus on digits 2, 3, 4 Action: ABduct MP jt 2, 4. RD + UD MP jt 3. Flex MP jt 2, 3, 4. Extend IP jts 2, 3, 4 PERIPHERAL NERVE + spinal cord level of origin: Ulnar nerve: C8, T1 Spinal Segments: C8, T1

21. Palmaris brevis

22. Palmar Group
Attachments: Proximal: Flexor retinaculum + palmar aponeurosis Distal: Skin on ulnar side of palm Action: Wrinkle palmar fascia – for grip PERIPHERAL NERVE + spinal cord level of origin: Ulnar nerve: C8, T1 Spinal Segments: C8, T1