Need an easier read? Change your font
Anatomy Insight | Β ComicΒ Sans | Lexend
Embedded Files
Hand Muscles Anatomy
Hand Muscles Anatomy
Listen to this guideΒ π§
Audio version available to support all learning styles. Press play to listen!
English (US)
English (UK)
The human hand muscles are a structure built for both strength and precision. It can hold heavy objects and perform delicate movements, such as typing, writing, or threading a needle.Β
The muscles that control the hand can be divided into two main groups based on where they are located and what they do:
Extrinsic muscles β These are found in the forearm.Β
Intrinsic muscles β These are located within the hand itself.Β
The extrinsic hand muscles move the fingers and wrist by pulling on long tendons that reach into the hand. These muscles create powerful movements and help with actions like gripping.
The intrinsic hand muscles allow for fine, precise movements, such as writing or buttoning a shirt.
Thenar MusclesΒ
Thenar MusclesΒ
The thenar muscles form the rounded area at the base of the thumb, called the thenar eminence. They control fine thumb movements and are all supplied by the median nerve.
Opponens Pollicis
The opponens pollicis moves the thumb across the palm (opposition) by rotating and flexing it.
Origin: Trapezium bone and flexor retinaculum.
Insertion: Side of the first metacarpal.
Innervation: Median nerve.
Abductor Pollicis Brevis
The abductor pollicis brevis moves the thumb away from the hand (abduction).
Origin: Scaphoid, trapezium, and flexor retinaculum.
Insertion: Base of the thumbβs proximal phalanx.
Innervation: Median nerve.
Flexor Pollicis Brevis
The flexor pollicis brevis bends (flexes) the thumb at its main joint.
Origin: Trapezium and flexor retinaculum.
Insertion: Base of the thumbβs proximal phalanx.
Innervation: Mostly the median nerve; the deep part from the ulnar nerve.
Hypothenar MusclesΒ
Hypothenar MusclesΒ
The hypothenar muscles form the fleshy mound at the base of the little finger, called the hypothenar eminence. They are all controlled by the ulnar nerve.
Opponens Digiti Minimi
The opponens digiti minimi rotates the little finger toward the palm (opposition).
Origin: Hook of the hamate and flexor retinaculum.
Insertion: Fifth metacarpal.
Innervation: Ulnar nerve.
Abductor Digiti MinimiΒ
The abductor digiti minimi moves the little finger away from the hand (abduction).
Origin: Pisiform bone and tendon of flexor carpi ulnaris.
Insertion: Base of the little fingerβs proximal phalanx.
Innervation: Ulnar nerve.
Flexor Digiti Minimi Brevis
The flexor digiti minimi brevis bends the little finger.
Origin: Hook of hamate and flexor retinaculum.
Insertion: Base of the little fingerβs proximal phalanx.
Innervation: Ulnar nerve.
Quick Reference Table: Muscle Name, Origin, Insertion & Innervation
Ready for download! Your muscle cheat sheet is here. Save it for later, study on the go, and review the essentials anytime.
Lumbricals
Lumbricals
There are four lumbricals, one for each finger (except the thumb).
They connect the flexor and extensor tendons, help coordinate finger movement, and bend the knuckles (MCP joints) while straightening the finger joints (IP joints).
Origin: Tendons of the flexor digitorum profundus.
Insertion: Extensor hoods on the back of each finger.
Innervation: Lateral two (index and middle fingers): Median nerve. Medial two (ring and little fingers): Ulnar nerve.
Interossei Muscles
Interossei Muscles
The interossei muscles lie between the metacarpal bones and come in two types:
Dorsal Interossei (4 muscles) spread the fingers apart (abduction).
Innervation: Ulnar nerve.
Palmar Interossei (3 muscles) bring the fingers together (adduction).
Innervation: Ulnar nerve.
Both groups help bend the knuckles and straighten the finger joints, working with the lumbricals.
Palmaris Brevis
The palmaris brevis is a superficial muscle located on the side of the palm. It wrinkles the skin of the palm and helps improve grip.
Origin: Flexor retinaculum and palmar aponeurosis.
Insertion: Skin of the medial border of the hand.
Innervation: Ulnar nerve.
Adductor Pollicis
The adductor pollicis pulls the thumb toward the hand (adduction). It's located between the thumb and index finger.
Origin: The bases of the 2nd and 3rd metacarpals, the anterior surface of the body of the 3rd metacarpal.
Insertion: Medial side of the base of the proximal phalanx of the thumb.
Innervation: Ulnar nerve.
Need a recap? Take a look at the Hand Muscles anatomy notes here.
Need a recap? Take a look at the Hand Muscles anatomy notes here.
Ready to test what you've learned?
Play through the games below to test your understanding and sharpen your skills.
References
References
Gray, H. (2009). Anatomy of the human body, part 2 (LibriVox Volunteers, Narr.) [Audiobook]. LibriVox. https://librivox.org/anatomy-of-the-human-body-part-2-by-henry-gray/ (Original work published 1858)
J Gordon Betts, Desaix, P., Johnson, E., Johnson, J. E., Korol, O., Kruse, D., Poe, B., Wise, J., Womble, M. D., & Young, K. A. (2013). Anatomy & physiology. Openstax College, Rice University. https://openstax.org/details/books/anatomy-and-physiology
Based on OpenStax, Anatomy and Physiology (2013), licensed under CC BY 4.0.
Access for free at https://openstax.org/books/anatomy-and-physiology/pages/1-introduction.
Content paraphrased; adaptations were made.
Google Sites
Report abuse