Origin and insertion of deltoid , teres minor, biceps, brachialis, muscles of hand and there action
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Searching for anatomy of these upper limb muscles in parallel.
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deltoid teres minor origin insertion action upper limb muscles
Bailey and Love's Short Practice of Surgery 28th Edition
Page 547
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biceps brachii brachialis origin insertion action forearm muscles
Bailey and Love's Short Practice of Surgery 28th Edition
Page 506
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The retrieved results are insufficient for a comprehensive anatomical answer. I'll complete this fully from established anatomical knowledge.
Upper Limb Muscles — Origin, Insertion & Action
1. Deltoid
| Feature | Detail |
|---|---|
| Origin | Anterior 1/3: Lateral 1/3 of clavicle (anterior border) · Middle 1/3: Acromion (lateral border) · Posterior 1/3: Spine of scapula (lower lip) |
| Insertion | Deltoid tuberosity on the lateral surface of the shaft of the humerus |
| Nerve Supply | Axillary nerve (C5, C6) |
Actions:
- Anterior fibers: Flexion, medial rotation, horizontal adduction of the arm
- Middle fibers: Abduction of the arm (main abductor from 15°–90°)
- Posterior fibers: Extension, lateral rotation, horizontal abduction of the arm
- All fibers together: Stabilize the glenohumeral joint
2. Teres Minor
| Feature | Detail |
|---|---|
| Origin | Upper 2/3 of the lateral (axillary) border of the scapula (dorsal surface) |
| Insertion | Lowest (inferior) facet of the greater tubercle of the humerus; also blends into the posterior capsule of the shoulder joint |
| Nerve Supply | Axillary nerve (C5, C6) — inferior branch |
Actions:
- Lateral (external) rotation of the arm at the shoulder
- Weak adduction of the arm
- Part of the rotator cuff — stabilizes the humeral head in the glenoid cavity
3. Biceps Brachii
| Feature | Detail |
|---|---|
| Origin — Long head | Supraglenoid tubercle of the scapula (intra-articular tendon) |
| Origin — Short head | Coracoid process of the scapula (with coracobrachialis) |
| Insertion | Posterior part of the radial tuberosity; via the bicipital aponeurosis (lacertus fibrosus) into the deep fascia of the forearm and ulnar periosteum |
| Nerve Supply | Musculocutaneous nerve (C5, C6) |
Actions:
- Supination of the forearm (most powerful supinator, especially with elbow at 90°)
- Flexion of the elbow (forearm in supination)
- Weak flexion of the shoulder
- Long head helps depress humeral head in abduction
4. Brachialis
| Feature | Detail |
|---|---|
| Origin | Anterior surface of the lower half of the humerus (distal to the deltoid tuberosity), and the medial and lateral intermuscular septa |
| Insertion | Coronoid process and tuberosity of the ulna |
| Nerve Supply | Musculocutaneous nerve (C5, C6); small lateral part by radial nerve (C7) |
Actions:
- Flexion of the forearm at the elbow joint in all positions (pronated, supinated, or neutral)
- Called the "workhorse" of elbow flexion — acts regardless of forearm position (unlike biceps)
5. Muscles of the Hand
The hand muscles are divided into three groups: thenar, hypothenar, and intrinsic (lumbricals + interossei).
A. Thenar Muscles (thumb group)
| Muscle | Origin | Insertion | Action |
|---|---|---|---|
| Abductor Pollicis Brevis | Flexor retinaculum, scaphoid tubercle, trapezium | Lateral side of base of proximal phalanx of thumb | Abducts thumb (anterior) |
| Flexor Pollicis Brevis | Superficial head: Flexor retinaculum, trapezium ridge · Deep head: Trapezoid, capitate | Lateral side of base of proximal phalanx of thumb (with sesamoid) | Flexes metacarpophalangeal (MCP) joint of thumb |
| Opponens Pollicis | Flexor retinaculum, trapezium ridge | Whole length of lateral border of 1st metacarpal | Opposition of thumb (rotation + flexion + medial rotation) |
| Adductor Pollicis | Oblique head: Capitate, bases of 2nd & 3rd metacarpals · Transverse head: Palmar surface of 3rd metacarpal shaft | Medial side of base of proximal phalanx of thumb (with sesamoid) | Adducts thumb toward palm |
Nerve supply: All thenar muscles — Recurrent branch of median nerve (C8, T1), except adductor pollicis — Deep branch of ulnar nerve (C8, T1)
B. Hypothenar Muscles (little finger group)
| Muscle | Origin | Insertion | Action |
|---|---|---|---|
| Abductor Digiti Minimi | Pisiform bone, pisohamate ligament, flexor retinaculum | Medial side of base of proximal phalanx of little finger | Abducts little finger |
| Flexor Digiti Minimi Brevis | Hook of hamate, flexor retinaculum | Medial side of base of proximal phalanx of little finger | Flexes MCP joint of little finger |
| Opponens Digiti Minimi | Hook of hamate, flexor retinaculum | Medial border of 5th metacarpal (whole length) | Draws 5th metacarpal anteriorly; rotates it — opposes little finger to thumb |
| Palmaris Brevis | Palmar aponeurosis (medial border) | Skin of medial palm | Wrinkles skin on medial palm; deepens the hollow of the palm |
Nerve supply: All hypothenar muscles — Deep branch of ulnar nerve (C8, T1)
C. Lumbricals (4 muscles)
| Feature | Detail |
|---|---|
| Origin | From tendons of flexor digitorum profundus (1st & 2nd from lateral side of tendon; 3rd & 4th from adjacent sides of tendons) |
| Insertion | Lateral side of the extensor expansion (dorsal digital expansion) of the 2nd–5th fingers |
| Nerve supply | 1st & 2nd (lateral): Median nerve · 3rd & 4th (medial): Deep branch of ulnar nerve |
| Action | Flex MCP joints + Extend interphalangeal (IP) joints of fingers 2–5 |
D. Dorsal Interossei (4 muscles — DAB: Dorsal ABduct)
| Feature | Detail |
|---|---|
| Origin | Adjacent sides of two metacarpal bones (bipennate) |
| Insertion | Into bases of proximal phalanges and extensor expansions of fingers 2, 3, 4 |
| Nerve supply | Deep branch of ulnar nerve (C8, T1) |
| Action | Abduct fingers from the middle finger (axial line); flex MCP joints; extend IP joints |
E. Palmar Interossei (3 muscles — PAD: Palmar ADduct)
| Feature | Detail |
|---|---|
| Origin | Palmar surfaces of 2nd, 4th, and 5th metacarpals (unipennate) |
| Insertion | Bases of proximal phalanges and extensor expansions of 2nd, 4th, and 5th fingers |
| Nerve supply | Deep branch of ulnar nerve (C8, T1) |
| Action | Adduct fingers toward the middle finger; flex MCP joints; extend IP joints |
Quick Memory Aids
| Muscle | Key Action to Remember |
|---|---|
| Deltoid (middle) | Only abductor of shoulder 15°–90° |
| Teres Minor | Lateral rotator of shoulder (rotator cuff) |
| Biceps | Best supinator; elbow flexion in supination |
| Brachialis | Elbow flexor in ALL positions |
| Lumbricals | "L-shaped" — flex knuckles, extend fingers |
| Dorsal Interossei | DAB — Dorsals ABduct |
| Palmar Interossei | PAD — Palmars ADduct |
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