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76 Cards in this Set
- Front
- Back
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Clavicle
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Paired horizontal elongated bones with 2 joints.
P: Sternoclavicular joint is atypical synovial, ball and socket. Acromioclavicular joint is atypical synovial joint. Acromial end, sternal end and shaft. L: Coracoclavicular ligament arises inferiorly in 2 parts. The trapezoid portion arises from the trapezoid line at lateral inferior margin. Conoid ligament arises from the conoid tubercle just medial and posterior to this. Acromiocavicular ligament which is a thickening of the joint capsule superiorly. Costoclavicular ligament, ant. and post. sternoclavicular ligaments and interclavicular ligaments. O: SCM arises from medial supero-posterior portion of clavicle. Pec major from anteromedial portion. Deltoid anterolaterally. I: Subclavius mid inferior portion, from 1st rib. Trapezius at latero-superior portion, from neck. R: subclavian vessels and trunks of brachial plexus posterior to middle third of clavicle. |
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Scapula
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Paired flat triangular with 3 processes
P: Glenoid process laterally, seperated from the rest of scapula by the neck of scapula Spine (inc. acromion) posteriorly which seperates supraspinous and infraspinous fossae Coracroid process anterolaterally arising from the neck superiorly. Between coracoid process and superior border is the suprascapular notch. Anterior flat portion is subscapular fossa Has a superior and inferior angle, both medially. L: Acromioclavicular ligament in joint capsule. Coracoacromial ligament from lateral coracoid to medial acromion. Coracoclavicular ligament (conoid and trapezoid) from superomedial coracoid to lateroinferior clavicle. Transverse scapular ligament across suprascapular notch, to form suprascapular foramen. O: rotator cuff - on respective fossa -supraspinatus, infraspinatus, subscapularis. Teres minor which arises from upper lateral border posteriorly. Other muscles - Omohyoid to medial edge of suprascapular notch Biceps brachii (long head) provides a small atachment to the superior glenoid. The short head attaches to the coracoid process. Deltoid arises from lateral acromion and inferior spine (as well as clavicle) Triceps brachii from lateral border, superior portion above teres minor. Teres major from lateral border inferior portion (below teres minor) Latissimus dorsi has small atachment to the inferior angle. I: Serratus anterior to medial anterior border of scapula Pectoralis minor to medial coracoid Trapezius along superior spine (along with clavicle) Levator scapulae at superior angle/medial border. Rhomboid minor to medial border (mid portion at base of the spine) Rhomboid major to medial border (inferior potion) |
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Supraspinatus
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Rotator cuff muscle
O: Supraspinous fossa I: superior facet on greater tubercle R: courses underneath the acromion and can be impinged here. Between the tendon and the acromion is the subacromial bursa I: suprascapular nerve (C5/C6) action: abduction (assisting deltoid, main effect past 30 degrees) |
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Subscapularis
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Rotator cuff muscle
O: Subscapular fossa I: lesser tubercle and front of joint capsule R: Seperated from scapula neck by a large bursa, the subscapular bursa (or semitendous bursa of the subscapularis) I: subscapular nerve and inferior subscapular nerve (C5/C6) actions: medial rotation and adduction. |
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Infraspinatus
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Rotator cuff muscle
O: Infraspinous fossa I: middle facet of greater tubercle R: I: suprascapular nerve (C5/C6) action: laterally rotation |
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Teres minor
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Rotator cuff muscle
O: Lateral border mid-superior portion I: inferior facet of greater tubercle R: united with posterior joint capsule I: axillary nerve (C5/C6) action: laterally rotation |
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Serratus anterior
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O: Upper 8-9 ribs
I: Anterior medial border of scapula Action: "Boxer's muscle", protracts the scapula around the ribs during big swing Neuro: long thoracic nerve (C5,6,7). Damage causes winging of scapula |
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Rhomboids
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O: Major - Spinous processes T2-T5
Minor - Spinous processes and nuchal ligaments C7-T1 I: Major - Inferior medial border of scapula. Minor - mid medial border of scapula (above major attachment) Action: holds scapula (and therefore limb) against ribcage). Retracts scapula towards vertebral column (adduction and lateral rotation). Aids levator scapulae in lifting medial border pf scapula. Neuro - Dorsal scapular nerve (C4, C5) |
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Levator scapulae
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O: Posterior tubercle of transverse processes of C1-C4
I: upper medial posterior border of scapula. Action: elevates scapula, medially rotates inferior angle. Neuro: Cervical nerve (C3, C4) and dorsal scapular nerve (C5) |
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Latissimus dorsi
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O: Spinous processes T7-L5, upper 2 sacral segments, iliac crest and lower 3-4 ribs.
I: Inferior angle of scapula. Lateral edge of intertubercular groove of humerus. Action: adduction, extension and internal rotation Neuro: thoracodorsal nerve (C6-C8) |
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Teres major
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O: Lower lateral border of scapula
I: Medial portion of intertubercular groove/ crest of lesser tubercle Action: internal rotation Neuro: lower sabscapular nerve (C5 C6) |
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Trapezius
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O: Occipital protuberance, nuchal ligaments, Spinous processes C7-T12
I: Superior fibres: Lateral clavicle Middle fibres: acromion, lateral spine of scapula Inferior fibres: Form an aponeurosis which inserts into tubercle on medial apex of spine of scapula Action: Retracting, elevating and depressing scapula Neuro: Motor - accessory nerve (XI) and ventral rami C3,C4 Sensation Ventral rami C3, C4 |
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Omohyoid
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O: Medial border of suprascapular notch
I: Hyoid bone - has 2 bellies in series. The 1st from the origin runs medialward and cranial, as it passes behind the SCM (as a fibrous tendon) it hooks around and turns upward. The second belly ascends to the hyoid. action: depresses larynx and hyoid bone Neuro: C1-C3 |
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Sternocleidomastoid
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O: Medial head - Sternum
Lateral head - medial 1/3 clavicle. I: Broadly across the lateral mastoidprocess, with a small attachment to the superior nuchal line of the occipital bone Action: tilts head ipsilaterally, rotates head contralaterally. Together with other SCM, lifts sternum, flexes head, acts as accessory inspiration muscle. Neuro: Motor - accessory nerve (as with trapezius, as both are in the 'investing fascia of the neck') R: Anterior is the anterior triangle, post. is the post. triangle. Covers the CCA, brachial plexus and accessory nerve. V: sometimes the SCM and trapezius are in contact and thus there is no posterior triangle |
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Deltoid
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O: Ant.head - Lateral/superior 1/3rd of calvicle
Med. head - superior acromion. Post. head - post/inf. spine of scapula I: Deltoid tuberosity on humerus. Action: Abduction, flexion, extension Neuro: Axillary (C5-C6) via superior trunk |
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Subclavius
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O: Medial 1st rib/1st costal cartilege
I: groove on the underside of clavicle past the midpoint, prior to the conoid ligament A: depresses shoulder. Protects subclavian artery, vein and brachial plexus. Neuro: nerve to subclavius from C5/C6 roots. |
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Biceps brachii
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O: Short head - coracoid process
Long head. Superior glenoid (varies, sometimes bony, sometimes cartilagenous, sometimes mixed). I: Combined tendon into radial tuberosity A: supinates forearm. Flexes elbow (moderately) Neuro: Musculocutaneous nerve (C5-C7) |
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Biceps brachii
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O: Short head - coracoid process
Long head. Superior glenoid (varies, sometimes bony, sometimes cartilagenous, sometimes mixed). A: supinates forearm. Flexes elbow (moderately) Neuro: Musculocutaneous nerve (C5-C7) |
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Triceps brachii
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O: long head - infraglenoid tubercle of scapula (sup. lateral border)
Medial head - posterior humerus in groove of radial nerve, and medial and lateral intermuscular septa Lateral head - posterior humerus lateral to the groove for radial nerve, from greater tubercle down to lateral intermuscular septum I: Olecranon Action: Extends elbow, the long head adducts the shoulder Neuro: Radial nerve. Long head usually by axillary (makes sense, acts on shoulder) |
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Brachialis
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O: Lower half of anterior humerus, just below deltoid tuberosity
I: tuberosity and coronoid process of the ulna action: flexes elbow Neuro: Musculocutaneous (C5/C6). Proprioception is via radial nerve posterior to deltoid insertion. |
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Anconeus
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Some say this is extension of triceps
O: Lateral epicondyle of humerus (posterior) I: Lateral olecranon process, posterior ulna just past olecranon A: extends elbow. Stabilises forearm during pronation/supination. Neuro: radial nerve (C7,8, T1) |
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Humerus
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Long bone of the upper arm, 2 synovial joints, the glenohumeral and elbow joints - radiocapitellar and trochlea-olecranon.
Landmarks: The rounded head which articulates with the glenohumeral joint. The greater tuberosity (lateral) and lesser tuberosity (anterior) of the proximal neck. The supraspinatus, infraspinatus and teres minor insert into the greater tuberosity in that order, top to bottom. The subscapularis passes in front of the humerus to attach into the superior lesser tubercle. The intertubercular groove (or bicipetal groove) runs between the tubercles! It transmits the tendon of long head of biceps. The latissimus dorsi and teres major (sup. and inf.) attach to the medial surface, and the pectoralis major attaches to the lateral surface. The deltoid tuberosity is a prominence antero-laterally on the mid humerus. The deltoid attaches here. The coracobrachialis inserts into an impression on the medial side of the humerus, roughly at the mid-point. The attachment lies between the attachments for triceps and brachialis. The brachialis originates broadly over the anterior lower 1/3rd of humerus. Over the lateral distal third are the insertions of the brachioradialis, the extensor carpi radialis longus and the common extensor origin over the lateral epicondyle. The pronator teres atatches to the superior medial epicondyle, along with the common flexor origin distal to this. Posteriorly on the humerus, the only attachments are the lateral and medial heads of the triceps which originate in the superior 1/3rd and distal 2/3rds respectively. The anconeus originates very low down, on the posterior aspect of the lateral epicondyle. Between the lateral and medial heads of the triceps is the spiral groove, or groove for the radial nerve. This runs medial to lateral, and eventually curls around anteriorly (below the deltoid tuberosity). Distally and centrally there is the trochlea (ulna articulation) and capitulum (radial articulation). Immediately superior to these anteriorly are the coronoid fossa and radial fossa respectively. Posteriorly, above the trochlea is the olecranon fossa. Important relations: Axillary nerve passes through the quadrangular space (with the posterior circumflex humeral artery), which is just medial to the surgical neck of the humerus (lat. axillary wall). These structures can be damaged here in trauma. Boundaries are the Subscapularis and teres minor superiorly, the Teres major inferiorly, the long head of triceps medially and the humerus laterally. The radial nerve sits in the spiral groove, and a humerus fracture can damage it. It passes anteriorly, to cross the elbow in front of the lateral epicondyle. The ulnar nerve runs on the posteromedial aspect of the humerus, and is superficial overlying the posterior part of the medial epicondyle (funny bone). |
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Quadrangular space
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A space in the medial wall of the axilla that carries the axillary nerve and posterior circumflex humeral artery.
Bounded by: Superior: subscapularis and teres minor Inferior: teres major lateral: surgical neck of the humerus medial: long head of triceps |
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Coracobrachialis
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O: coracoid process
I: small attachment medial anterior humerus at around mid point between the origins of triceps brachii and brachialis. |
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Pectoralis minor
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O: 3-5th ribs, near the costal cartilages.
I: The medial and superior surface of the coracoid process of the scapula Action: holds the scapula in against the chest, stabilises. Draws the scapula inferomedially. Neuro: Medial pectoral nerve (C8-T1) |
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Glenohumeral joint
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Multiaxial synovial ball and socket joint of the shoulder, which has a large range of movement but is relatively unstable. It is a muscle dependent joint as it lacks strong ligaments.
Parts - The humeral head is covered with articular cartilege across the articular surface. The glenoid fossa of the scapula is a shallow depression, which is deepened by the fibro-cartilagenous glenoid labrum. The joint capusle, which is stronger posteriorly as it is re-inforced by teres minor. The anterior of the joint capsule is relatively weak. Bursae: synovial sacs that reduce friction between joint components Subdeltoid bursa between deltoid and joint superiorly. Coracobrachial bursa between subscapularis and tendon of coracobrachialis Subacromial bursa between joint capsule/supraspinatus muscle and the acromion. Subcapsular bursa between joint capsule/neck of scapula and subscapularis. Subcoracoid bursa between joint capsule and coracoid is a continuation of the subscapular bursa. Ligaments: Coracohumeral ligament which passes from coracoid to superior greater tuberosity, blended with supraspinatus tendon. Transverse humeral ligament - covers the bicipital groove (lesser to greater tuberosity) to hold the long head tendon of biceps in place. The sup, mid and inf glenohumeral ligaments pass from above, medial and inferior glenoid to the upper lesser tubercle, lower lesser tubercle and medial anatomical neck of humerus. Neuro: Suprascapular, axillary and lateral pectoral nerve |
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Humeroulnar joint (trochlea/olecranon)
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The trochlea of the humerus articulates with the trochlea notch of the olecranon process of the ulna bone.
Parts: Trochlea - latin for pulley. Anterolaterally tilted saddle shaped convex surface on the distal humerus. Trochlea notch - The notch is formed by the olecranon posteriorly and the coronoid process inferiorly. There is a bare area covered in fibrous cartilage at roughly the midpoint, called the non-articular portion. This divides the notch into olecranon and coronoid portions. Ligaments: The ulna collateral ligament stengthens the joint capsule medially. The ligament has 3 parts that form a triangle - anterior band from coronoid to medial epicondyle posterior band from medial epicondyle to medial olecranon (weak) the oblique band from coronoid to olecranon Joint capsule- runs from trochlea to coronoid anteriorly, and from medial epicondyle to olecranon posteriorly. On the humeroulna side there are 2 fossae, the olecranon fossa posteriorly and the coronoid fossa anteromedially |
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Humeroradial joint (radiocapitellar)
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The radius articules with the humerus at the capitellum.
Parts - Capitellum and radial head. No real insights about these, simple articulation. Ligaments: The radial collateral ligament has 2 parts - The anterior band from the lateral epicondyle to radial head. It is continuous distally with the annular ligament The posterior band from the lateral epicondyle to the ulna supinator crest (wraps around the back) Joint caspule - runs from the capitellum to annular ligament anteriorly and from the lateral epicondyle to the olecranon posteriorly. 1 space anteriorly, the radial fossa proximal to the capitellum |
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Superior radioulnar joint
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The radius articulates with the ulnar at the elbow in the radial notch of the lateral surface of the ulna.
Ligaments: The annular ligament runs from the anterior portion of the radial notch on the ulna, around the radius (where it is continuous with the radial collateral) to insert into the posterior aspect of the radial notch of the ulna. It forms a sling around the radial head, holding it into the notch. |
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Common flexor origin
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Arises from the medial epicondyle, and is the origin of a number of forearm flexors
Medial to lateral - Flexor carpi ulnaris - Flexor digitorum superficialis - Palmaris Longus - Flexor carpi radialis - Pronator teres |
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Common extensor origin
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Arises from the lateral epicondyle, and is the origin of a number of forearm extensors
From lateral to medial - Extensor carpi radialis brevis - Extensor digitorum - Extensor digiti minimi - Extensor carpi ulnaris |
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Carpal tunnel
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Formed by flexor retinaculum over carpal bones. The palmaris longus inserts into the retinaculum as well as the palmar aponeurosis.
The flexor retinaculum attaches from the tubercle of the scaphoid and ridge of trapezium to the pisiform and hook of the hamate. Deep to the retinaculum is the median nerve. Beneath this are the 2 rows of the flexor digitorum tendons, deep is the profunda row, and superficial is the superficial row. The superficial row forms a double row, with the 3rd and 4th tendons above the 2nd and 5th. Lateral to these is the flexor pollicis longus tendon, and further medial (outside the carpal tunnel but deep to the retinaculum) is the flexor carpi radialis tendon. The palmar cutaneous branch of the median nerve, supplying the thenar emminence, branches prior to the carpal tunnel, and is superficial to it. |
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Posterior compartment of the forearm
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4 superficial muscles arise from the common extensor origin
- extensor carpi radialis brevis - extensor digitorum - extensor digiti minimi - extensor carpi ulnaris The other superficial muscle - the extensor carpi radialis longus runs from the lateral epicondyle and lateral supracondylar ridge of the humerus to the dorsal base of the 2nd metacarpal. The brachioradialis is often included as part of the posterior compartment, although is is in the lateral part of the anterior compartment, running from the lateral supracondylar ridge to the distal radial styloid process The deep muscles arising from the posterior forearm are the: - extensor pollicis longus - extensor pollicis brevis - abductor pollicis longus - extensor indicis - supinator the anconeus inserts into the forearm/posterior compartment at posterolateral proximal ulna/olecranon. |
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Anterior compartment of the forearm
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5 superficial muscles arise from the common flexor origin
- Flexor carpi ulnaris - Flexor digitorum superficialis - Palmaris Longus - Flexor carpi radialis - Pronator teres There are 3 deeper muscles that arise further down the forearm - The flexor pollicis longus arising from the anterior radius for most of its length until the - pronator quadratus, arising from the distal 1/4 anterior radius, to the distal 1/4 of ulna - the flexor digitorum profundus arises from the proximal 3/4 of the anteromedial ulna All muscles in the anterior compatment are supplied by the median nerve, other than flexor carpi ulnaris and part of the f.digitorum profundus, both supplied by the ulnar nerve |
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Brachioradialis
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O: Lateral supracondylar ridge
I: Distal radial styloid Actions: Flexes forearm (weakly) Some supination and pronation Neuro: radial nerve All 3 lateral posterior muscles (BR, ECRL, ECRB) pass under the abductor pollicis longus, extensor pollicis brevis and extensor pollicis brevis in the proximal wrist |
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Extensor carpi radialis longus
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O: lateral supracondylar ridge and epicondyle
I: dorsal portion of 2nd metacarpal A: extension and lateral/radial abduction Neuro: radial nerve C6/C7 All 3 lateral posterior muscles (BR, ECRL, ECRB) pass under the abductor pollicis longus, extensor pollicis brevis and extensor pollicis brevis in the proximal wrist |
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Extensor carpi radialis brevis
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O: Common extensor tendon, lateral epicondyle
I: Base of the 3rd metacarpal A: Extension and abduction (radial) N: Radial nerve R: Under dorsal carpal ligament. 2nd extensor compartment of the wrist. All 3 lateral posterior muscles (BR, ECRL, ECRB) pass under the abductor pollicis longus, extensor pollicis brevis and extensor pollicis brevis in the proximal wrist |
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Extensor digitorum
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O: common extensor origin (lateral epicondyle)
I: Divides into four tendons which pass through the dorsal carpal ligament, and then diverge to insert into the middle and distal phalanges of the medial 4 fingers. They are bound to the collateral ligaments at the MCPJ to act as the dorsal ligaments of these joints. At the proximal phalanx they are joined by the interossei and lumbrical tendons to form strong attachments. This common attachment splits again over the PIPJ and the central (intermediate) slip inserts to the base of the 2nd phalanx, while the 2 collaterals extend across the DIPJ and join dorsally to insert into the base of the distal phalanx. A: Extends fingers (MCP, PIP, DIP), wrist and elbow. There are oblique bands between adjacent divisions to keep the tendons over the metacarpal heads, resulting in optimal leverage. N: posterior interosseus nerve (C7, C8 from radial nerve) |
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Extensor digiti minimi
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O: common extensor origin
I: Runs under the dorsal carpal ligament to combine with the ex. digitorum to insert into the proximal and distal phalanges of the little finger. A: Extends little finger at MCP, PIP, DIPJs N: posterior interosseus nerve (C7, C8 of radial nerve) V: Occasionally supplies tendon to ring finger. Not uncommonly fused with ex. digitorum. |
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Extensor carpi ulnaris
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O: common extensor origin
I: Base of 5th metacarpal A: extends the wrist, ulnar deviation (adduction) N: posterior interosseus (C7, C8 of radial) |
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Extensor indices
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O: Dorsal ulna very distally (around 5/6ths down)
I: Passes through the dorsal carpal ligament to insert along the index finger bones. It runs along the ulnar side of the extensor digitorum tendon to the index finger. A: Extends index fingerm as well as assisting in wrist and carpal extension. N: Post. interosseus (C7, C8 of radial) |
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Extensor pollicis longus
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O: latero-dorsal ulna over long area of mid-third, between Abd. pollicis longus and Ex. indices.
I: Passes through the third tendon compartment, in the narrow groove on the distal dorsal radius to insert in the base of the distal phalanx of the thumb. A: Extends the terminal phalanx and helps abduct the wrist. Uses the dorsal radial tubercle as a fulcrum for action. N: Post. interosseus (C7, C8 of radial) R: Crosses over the tendons on Ex. Carpi radialis longus and brevis obliquely. Together with the more radial Ex. pollicis brevis forms the anatomic snuff box, which contains the radial artery. |
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Extensor pollicis brevis
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O: Medio-dorsal surface of radius distal to the APL origin, in the distal mid third.
I: It passes along with abductor pollicis longus in a groove on the lateral radius to insert into the base of the first phalanx of the thumb. A: Extends and abducts the thumb at CMCJ and MCPJs. N: Post. interosseus (C7, C8 of radial) V: absence or fusion with Ex. pollicis longus R: Together with the more posterior Ex. pollicis longus (from the posterior lateral ulna) forms the anatomic snuff box, which contains the radial artery. |
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Abductor pollicis longus
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O: Arises from the laterodorsal ulna and mediodorsal radius in the middle thirds, below anconeus on ulna and supinator on radius.
I: It passes along with extensor pollicis brevis in a groove on the lateral radius, to insert in the radial side of the base of the first metacarpal A: Abduct CMCJ of thumb, moving the thumb anteriorly. Assists in wrist abduction. N: Post. interosseus (C7, C8 of radial) |
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Dorsal carpal ligament
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Also called the extensor retinaculum
O: Triquetrum and pisiform I: Lateral margin of radius A: Holds extensor tendons in place R: Continuous with palmar carpal ligament (NOT flexor retinaculum) |
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Supinator
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O: Made up of 2 planes of muscle (superficial and deep) both arising from the lateral epicondyle of humerus, radial collateral ligament and the ridge of the ulna.
I: Curls around proximal radius, inserting into the radial tuberosity, oblique line of radius, the lateral border and around to the dorsal medial surface. A: Supinates forearm N: deep branch of radial nerve R: The deep branch of the radial nerve runs between the deep and superficial planes of the supinator. |
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Flexor carpi ulnaris
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O: 2 heads - The humeral head arises from the common flexor origin (medial humeral epicondyle)
The ulnar head arises from the medial olecranon and proximal 2/3rd of dorsal ulna. I: Pisiform bone. Ligamentous attachments to the hamate and 5th metacarpal. A: Flexion, adduction of wrist. N: Muscular branches of ulnar nerve C8, T1 (only this muscle and 1/2 of flexor digitorum profundus are supplied by ulnar in anterior compartment). R: The ulnar nerve and artery run between the humeral and ulnar heads. |
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Flexor digitorum superficialis
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O: 2 heads -
The humero-ulnar head from the common flexor origin on the medial epicondyle, and the coronoid process of ulna. The radial head from the anterior radius just below the tuberosity. I: Anterior bases of the 4 middle phalanges. A: Flexes fingers, primarily PIPJs. N: Median nerve R: The median nerve and ulnar artery pass between the 2 heads of the muscle. |
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Palmaris longus
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O: Common flexor origin (medial humeral epicondyle)
I: Anterior flexor retinaculum/palmar aponeurosis. A: wrist flexor. exposes claws in animals like cats. N: median nerve. V: absent in 16% of caucasians. Less commonly absent in other groups. |
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Flexor carpi radialis
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O: Common flexor origin (medial humeral epicondyle)
I: Base of 2nd metacarpal. Small slips to base of 3rd metacarpal and trapezial tuberosity. A: Flexes wrist, some abduction. N: Median nerve |
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Palmar carpal ligament
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Another name for the expansion of the antebrachial fascia over the wrist. This lies superficial (and proximal, wrist rather than carpals) to the flexor retinaculum.
R: The ulnar canal, containing the ulnar nerve and artery is deep to the palmar carpal ligament, but superficial to the flexor retinaculum. The palmar carpal is continuous with the extensor retinaculum. |
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Pronator teres
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Superficial forearm muscle of anterior compartment
O: 2 heads - Humeral head arises from the medial supracondylar ridge and the common flexor tendon Ulnar head is small, arising from medial coronoid process I: Pass obliquely across the forearm (to the ulnar side) inserting into the lateral surface of the mid-radius, just distal to the insertion of supinator. A: Pronates forearm, weakly flexes elbow. R: The median nerve enters the forearm between the 2 heads, and is seperated from the ulnar artery by the ulnar head. The lateral border of the muscle forms the medial border of the cubital fossa. V: Absent ulnar head occasionally |
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Flexor pollicis longus
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Deep muscle of anterior compartment
O: anterior radius from just below tuberosity to origin of pronator quadratus at distal 1/4. I: Passes beneath flexor retinaculum (through carpal tunnel) to base of distal phalanx of thumb. A: Flexes thumb (MCP and IPJ) N: Anterior interosseus nerve (C8 T1 of median nerve). V: Also originates at medial epicondyle in 40%. |
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Pronator quadratus
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Deep muscle of anterior compartment
O: Distal 1/4 of ulna anteriorly I: Distal 1/4 of radius anteriorly. A: Pronates hand, stabilises distal radioulnar joint. Aids in wrist extension. N: Ant. interosseus (C8, T1 of median). |
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Flexor digitorum profundus
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Deep muscle of anterior compartment
O: upper 3/4 of anterior and medial ulna I: Passes through the deep carpal tunnel as four in line tendons. Spreads out across the hand to insert in the base of the distal phalanges. Passing over the anterior fingers, it passes through the split in the tendons of FDS at the insertions at base of proximal phalanges. A: Flexes wrist, midcarpals, MCPJs and IPJs. N. Ulnar aspect is supplied by muscular branch of ulnar nerve (C8, T1). Radial aspect is supplied by Ant. interosseus branch of median nerve (C8, T1). V: The tendon of the index finger often has a seperate muscle belly. |
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Radius
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One of the two paired long bones of the forearm. Prismatic in shape, heavier at the distal end. 4 joints (elbow, wrist, prox and distal radioulnar)
P: Radial head which articulates with the capitellum of the humerus, as well as the radial notch of the ulna Radial tuberosity which is the site of insertion of the biceps tendon. The supinator inserts along the lateral edge of the tuberosity, and continues down the oblique line. Interosseus crest medially which attaches the interosseus membrane, and delineates dorsal from palmar surfaces. Rough patch mid-shaft laterally for pronator teres insertion. Styloid process laterally at the distal tip, for the brachioradialis insertion, and the radial collateral ligament of the wrist. The distal tubercles, 1 posterior and one medial, which the extensor tendons pass between. The posterior tubercle is called Lister's tubercle. The ulnar notch on the distal medial surface contains the head of the ulna, fortified by the radioulnar ligaments. L: Radial collaterals of the elbow - 2 bands (anterior and posterior) The annular ligament around the radial head. The oblique band to the ulna ~1/3rd down, medially The interosseus membrane, from the interosseus crest The radial collateral ligament of the wrist from the radial styloid to the lateral portion of the scaphoi, and the trapezium. It is seperated from the pollicis tendons (snuff box) by the radial artery. Palmar/dorsal radioulnar ligaments around the ulna notch. The palmar/dorsal radiocarpal ligaments attaching the distal radius to the scaphoid, lunate, trapezoid, trapezium and capitate bones. O: Flexor digitorum superficialis - Prox radius just below tuberosity Flexor pollicis longus - across most of mid 1/3rd anteriorly Abductor pollicis longus - Mid posterior radius Extensor pollicis brevis - Medio-posterior lower 1/3rd I: Biceps brachii - Radial tuberosity Supinator - lateral tuberosity and oblique line distal to this. Pronator teres - Mid lateral radius Pronator quadratus - Anteromedial lower 1/4 Brachioradialis - radial styloid |
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Ulna
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One of the two paired long bones of the forearm. Prismatic in shape, heavier at the proximal end. 4 joints (elbow, wrist, prox and distal radioulnar)
P: Olecranon proximally, with the coronoid process anterior to it across the trochlea notch. This articulates with the trochlea. The radial notch on the lateral proximal edge, which the radial head sits in, held by the annular ligament. This forms the pivot-type proximal radioulnar joint. Ulnar tuberosity just distal to the coronoid process is a bony prominence which is the origin of the oblique cord between the ulna and radius (just below the radial tuberosity). The oblique cord is a ligament that supports the radioulnar joint. The ulnar tuberosity also is the site of insertion for the brachialis. The supinator crest extends from the lateral side of the ulnar tuberosity distally, and is the attachment for the supinator. From the supinator crest arises the interosseus crest, which provides attachment for the interosseus membrane down the length of the bone. Ulnar styloid projects from the medial posterior portion of the ulna at the distal end. The ulnar collateral ligament of the wrist attaches here. The ulnar styloid is seperated from the ulnar head proper by a depression that houses the attachment for the triangular articular disk (or triangular fibrocartilagenous complex, TFCC) Between the styloid process and the head is the groove for the extensor carpi ulnaris. The head articulates with the wrist via the TFCC. L: Ulnar collateral ligaments (3 bands, the anterior, posterior and oblique) Annular ligament around radial head Oblique band Interosseus membrane Ulnar collateral ligament from the ulnar styloid, with 2 bundles, to pisiform/transverse carpal ligament and the triquetral bone The dorsal/palmar radioulnar ligaments across the DRUJ ant and post. The dorsal/palmar ulnocarpal ligaments, from ulnar styloid to various carpal bones of both rows. The triangular cartilage between the ulnar head and the triquetral/pisiform bones. O: Pronator teres - common flexor origin + coronoid process Flexor carpi ulnaris - common flexor origin + olecranon/posterior ulna Flexor digitorum superficialis - common flexor origin + coronoid process Flexor digitorum profundus - coronoid and anteromedial ulna Pronator quadratus - Distal 1/4 anterior ulna shaft Extensor carpi ulnaris - common extensor origin + posterior ulna border Supinator - common extensor origin + supinator crest Abductor pollicis longus - laterodorsal mid third of ulna Extensor pollicis longus - dorsal shaft of ulna Extensor pollicis brevis - dorsal shaft of ulna Extensor indicis - Posterior distal ulna I: Triceps brachii - olecranon Anconeus - lateral olecranon Brachialis - coronoid |
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Scaphoid
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A cashew shaped carpal bone of the first row
P: Dorsal groove which is the attachment for ligaments. Tubercle on the latero-proximal portion, attachment for the transverse carpal ligament. 2 articular facets medially - proximal smaller one for the lunate, larger distal one for the head of the capitate. Distal convex surface articulates with trapezium and trapezoid. Proximal surface articulaes with radius. L: Radiocarpals Ulnocarpals Scapholunate - 3 parts, dorsal (strongest), palmar and proximal. Radial collateral ligament Radiate carpal ligaments - a series of bands that radiate out from the head of the capitate to other carpals on the palmar aspect Palmar and dorsal carpal ligaments O: Abductor pollicis brevis from the tubercle Vasc: lateral radial branches supply it from the distal pole. The backwards supply means a fracture can cause necrosis of the proximal pole. |
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Lunate
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A semilunar carpal bone of the first row
P: The concave surface faces distally, with a large articulation for the capitate, and seperated from this by a ridge, a smaller articulation for the hamate. The proximal convex surface articulates with the radius. The lateral surface is also concave, like the side of a banana, and holds the facet for the scaphoid articulation. The medial surface is largely convex, but holds a shallow concave facet for the trapezium. L: Radiocarpals Ulnocarpals Scapholunate - 3 parts, dorsal (strongest), palmar and proximal Radiate carpal ligaments - a series of bands that radiate out from the head of the capitate to other carpals on the palmar aspect Palmar and dorsal carpal ligaments |
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Triquetral
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A triangular pyramidal carpal bone of the first row situated on the ulnar side of the carpus
P: The apex faces medial, and holds the insertion of the ulnar carpal ligament. The base faces lateral, and articulates with the lunate. There are 3 other surfaces - The distal surface is a broad articulation for the hamate, and is rough on the dorsal aspect for ligamentous attachments. The proximal surface has a medial non-articular portion and a lateral portion that articulates with the triangular articular disk. It does not articulate with the ulna. The remaining surface faces somewhat palmar. Laterally it is rough, holding ligamentous attachments. Medially it holds a oval facet for the pisiform bone. L: Radiocarpals Ulnocarpals Radiate carpal ligaments - a series of bands that radiate out from the head of the capitate to other carpals on the palmar aspect Palmar and dorsal carpal ligaments |
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Pisiform
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A split-pea shaped bone of the first carpal row. This is a sesamoid bone contained within the flexor carpi ulnaris tendon.
R: The pisiform is situated palmar to all the other carpals P: The palmar surface (anterior to the other carpals) holds attachments for the flexor carpi ulnaris, the transverse carpal ligament and the abductor digiti minimi. The dorsal surface holds a smooth oval facet that articulates with the proximal-medial portion of the triquetral. The remaining surfaces (rounded lateral and medial) hold no articulations or insertions. L: Radiate carpal ligaments - a series of bands that radiate out from the head of the capitate to other carpals on the palmar aspect Ulnar collateral ligament 2 volar ligaments. Pisohamate and pisometacarpal ligaments (to the 5th MC). TThese are extensions of the FCU tendon. O: Abductor digiti minimi O/I: Exists in the Flexor carpi ulnaris tendon as a sesamoid bone |
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Trapezium
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An irregular quadrilateral carpal bone of the second row
Also called greater multangular P: The proximal surface articulates with the scaphoid medially. The distal surface has a saddle shaped articulation with the 1st metacarpal. Medially there is a large proximal facet that articulates with the trapezoid, and a small distal facet that articulates with the 2nd metacarpal On the palmar surface there is a deep groove, and strong lateral ridge. This groove transmits the flexor carpi radialis tendon. The ridge holds the origins of opponens pollicis, abductor and flexor pollicis brevis, and the attachment of the transverse carpal ligament. There is a tubercle of the trapezium, just anterior to the 1st metacarpal facet. L: Radiate carpal ligaments - a series of bands that radiate out from the head of the capitate to other carpals on the palmar aspect Dorsal ligament to trapezoid Volar ligament to trapezoid Interosseus ligament to trapezoid |
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Trapezoid
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The smallest carpal bone in the distal row, wedge shaped quadrilateral prism, broad dorsally.
Also called lesser multangular. P: 4 articular facets, all roughly same size. Proximal surface articulates with scaphoid. Distal surface articulates with 2nd metacarpal Lateral surface articulates with trapezium Medial surface articulates with capitate The dorsal and palmar surfaces hold ligamentous attachments L: Dorsal, volar and interosseus ligaments to trapezium laterally and capitate medially. |
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Capitate
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The largest carpal bone. Roughly quadrilateral with a domed head proximally.
P: The proximal head (direxted slightly laterally) articulates with the scaphoid and lunate. Distal to this is the neck, which has no articulations, but a deep groove for ligamentous attachments. Distal to this is the body of the capitate. Laterally the body articulates with the trapezoid. Medially the body articulates with the hamate with a long facet. Distally the base of the body is divided into 3 facets, for the 2nd, 3rd and 4th metacarpals. The first facet is the smallest, the 3rd the largest. Volar there is an attachment for ligaments and the adductor pollicis. L: Radiate carpal ligaments radiate out from the head to the surrounding carpals on the palmar aspect. The dorsal and interosseus ligaments to the trapezium, scaphoid, lunate and hamate. O: Adductor pollicis |
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Hamate
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A wedge shaped carpal bone of the second row, broad distally, with a hook like process from the palmar surface.
P: The proximal narrow (apex) articulates with the lunate. The medial surface has a long oblong facet to articulate with the triquetral bone. The lateral border has a large facet in the upper/posterior portion to articulate with the capitate. Distally the broad base of the wedge has 2 facets to articulate with 4th and 5th metacarpals. The palmar surface projects the hamulus, a hook like process which has attachments to the transverse carpal ligament and flexor carpi ulnaris at the apex, the flexor digiti minimi brevis and opponens digiti minimi medially, and the lateral side (the hook) holds the flexor tendons into the palm of the hand. L: Dorsal, palmar and interosseus ligaments to capitate, triquetrum and lunate. O: flexor digiti minimi brevis, opponens digiti minimi into hamulus. I: Flexor carpi ulnaris |
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Metacarpals
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Elongated bones that are located between the carpals and phalanges in the hand.
P: The body is prismoid in form, curved to be concave anteriorly. Has 3 surfaces - medial, lateral and dorsal. The medial and lateral surfaces hold attachments for the lumbricals. The dorsal surface has a ridge in the midline. Either side of the ridge are attachments for the dorsal interossei muscles. From the midpoint, the ridge diverges into 2 lines, forming a flat triangular surface distally. The surface is covered by the extensor tendons. The diverging lines end in tubercles, which attach the collateral ligaments of the MCP joints. The base is cuboidal, articulating with the carpus and adjacent metacarpals. The dorsal and palmar surfaces hold ligamentous attachments. The head is domed, articulating with the proximal phalanx. On either side there is a tubercle for the collateral ligaments (see description of body). The palmar surface is grooved in the midline for the flexor tendons. The extensor tendons run broadly across the flat dorsal aspect. Proximal articulations: 1st with trapezium 2nd with trapezium, trapezoid, capitate and 3rd metacarpal 3rd with capitate, 2nd and 4th metacarpals 4th with capitate, hamate, 3rd and 5th metacarpals 5th with hamate and 4th metacarpal I: ECRL/B into MC2 ECU into MC5 APL into MC1 OP into MC1 OPM into MC5 |
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Phalanges (hand)
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14 in each hand, elongates bones concave anteriorly.
P: Body - rough sides for flexor tendon insertions. Base - proximal broad portion Head - the distal portions have 2 condyles laterally with a central groove Dorsally - MCPJ: The capsule and extensor tendons are lax dorsally allowing phalanx bones to flex more than 100 degrees, limited by the condylar notch of the proximal phalanx anteriorly. PIPJ: The extensor mechanism (complex arrangement of Extensor digitorum/inidices/minimi, lumbrical and interosseus tendons) splits into 3 bands, the central slip attaches to the dorsal tubercle of the middle phalanx. The lateral bands continue come together to insert into the midline of distal phalanx. The oblique retinacular ligament runs from the proximal phalanx annular ligament/pulley to the terminal extensor tendon laterally. It prevents DIP flexion during extension, and PIP hyperextension. Palmar- The flexor tendons run through annular ligaments that act as pulleys, stabilising the tendons in the midline, 5 in each finger, 3 in the thumb. The flexor dig. superficialis splits into 2 slips which attach to the sides of the middle phalanx, while the flexor dig. profundus attaches to the distal phalanx in the midline. The vincula are ligaments that attach the FDS to the proximal phalanx as it passes over, and the FDP to the middle phalanx as it passes over, essentially meaning these tendons can each act on 2 phalanges each. L: The interphalangeal joints are largely supported by the palmar ligaments and collateral ligaments |
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CMC joints
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Bounded by palmar and dorsal carpometacarpal ligaments. These are strong transversly, but weak longitudinaly.
The thumb CMCJ is more complex, and has 5 ligaments, 3 intracapsular and 2 extrascapsular. Extracapsular - anterior oblique ligament from the palmar tubercle of trapezium to palmar tubercle of MC1. ulnar collateral ligament Intracapsular - Intermetacarpal ligament from MC1 base to MC2 base posterior oblique ligament from dorsoulnar trapezium to ulnopalmar tubercle of MC1. dorsoradial ligament from dorsal trapeqium to dorsal MC1 |
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MCP joints
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Bounded by the collateral and palmar ligaments.
The palmar ligaments actually have fibrocartilagenous components (the palmar plate), that fortify this area to prevent hyperextension. The metacarpal heads are bound together by the deep transverse metacarpal ligament, interconnecting the palmar plates. |
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Lumbricals
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Intrinsic muscles of the hand on the palmar surface. There are 4 muscles, each associated with a non-thumb digit.
1st: unipennate. O: Lateral side of lateral flexor digitorum profundus tendon I: Extensor expansion on lateral side of MCPJ of index finger 2nd: unipennate O: Lateral side of 2nd flexor digitorum profundus tendon I: Extensor expansion on lateral side of MCPJ of middle finger 3rd: bipennate O: Lateral side of 3rd flexor digitorum profundus tendon I: Extensor expansion on lateral side of MCPJ of ring finger 4th: bipennate O: Lateral side of 4th flexor digitorum profundus tendon I: Extensor expansion on lateral side of MCPJ of little finger Action: Flex MCP joints and extend IP joints via the extensor expansion. Neuro: 1 + 2 median nerve 3 +4 ulnar nerve |
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Dorsal interossei
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Intrinsic muscles of the dorsal hand. There are 4 muscles, inserting into the index, 2 to the middle, and ring fingers. All are bipennate.
1st: O: Mainly radial side of MC2. Some fibres arise on ulnar side of MC1. I: Radial side of base of 2nd proximal phalanx and extensor expansion 2nd: O: Mainly radial side of MC3. Some fibres arise on ulnar side of MC2. I: Radial side of base of 3rd proximal phalanx and extensor expansion 3rd: O: Mainly radial side of MC4. Some fibres arise on ulnar side of MC3. I: Radial side of base of 3rd proximal phalanx and extensor expansion 4th: O: Mainly radial side of MC5. Some fibres arise on ulnar side of MC4. I: Ulnar side of base of 4th proximal phalanx and extensor expansion Actions: abduct fingers, assist lumbricals in flex MCPJs and extends IPJs. Mnemonic: DAB PAD (dorsal abduct, palmar adduct) Neuro: ulnar nerve R: The radial artery passes between the 2 heads of the 1st dorsal interosseus as it moves from the dorsum of the hand to the palm. |
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Palmar interossei
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Intrinsic muscles of the palmar aspect, overlying the metacarpals anteriorly. There are 3 muscles, all unipennate.
1st: O: Ulnar side of MC2 I: Ulnar side of proximal phalanx of index finger. 2nd: O: Radial side of MC4 I: Radial side of proximal phalanx of ring finger. 3rd: O: Radial side of MC5 I: Radial side of proximal phalanx of little finger. There is no palmar interosseus associated with the middle finger. Action: Adduct fingers. Also assist lumbricals in flexing MCPJs and extending IPJs Mnemonic: DAB PAD (dorsal abduct, palmar adduct) Neuro: ulnar nerve V: >80% of people has a pollical palmar interosseus muscle (PPIM), a palmar interosseus muscle to the thumb. |
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Adductor pollicis
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A triangular muscle with 2 heads in the palm.
O: 2 heads Oblique head - from the capitate bone, bases of the 2nd and 3rd metacarpals and the tendon of flexor carpi radialis Transverse head - arises from a broad base on the lower 2/3 of the 3rd metacarpal I: The two heads and the medial portion of flexor pollicis brevis unite to insert into the ulnar side of the base of the proximal phalanx of the thumb. Actions: adducts thumb at CMCJ Neuro: ulnar nerve R: The radial artery runs between the 2 heads on its path from the dorsum of the hand to the palm to form the palmar arch. V: The ulnar sesamoid is usually present in the tendon. |
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Hypothenar muscles
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A group of three muscles related to the little finger and ulnar side of the hand. These are (medial to lateral):
Abductor digiti minimi O: pisiform bone and flexor retinaculum I: ulnopalmar margin of the base of the proximal phalanx of the little finger. Small insertion into the extensor expansion A: abducts little finger at CMCJ. May flex MCPJ and extend IPJ via extensor apparatus. N: ulnar nerve V: Inserts into the sesamoid when present. Flexor digiti minimi brevis O: Convexity of hamulus of hamate I: ulnar side of base of 1st phalanx thumb A: flexes little finger N: ulnar nerve R: seperated from abductor digiti minimi by the ulnar nerve and artery V: sometimes absent Note there is no flexor digit minimi longus in humans, except in rare variations. Opponens digiti minimi O: Convexity of hamulus of hamate and transverse carpal ligament I: The length of the ulnar margin of MC5. Action: flexes and laterally rotates CMCJ N: ulnar |
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Palmaris brevis
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A short quadrilateral muscle in the ulnar side of the palm.
O: Transverse carpal ligament and palmar aponeurosis I: The skin of the palm medially, over the hypothenar emminence. Action: Pulls the skin over the hypothenar emminence, deepening the cup of the hand. Neuro: Ulnar nerve |
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Thenar muscles
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3 muscles of the palmar hand that supply the thumb and form the thenar eminence. These are (from lateral to medial):
Abductor pollicis brevis O: Flexor retinaculum, tubercle of the scaphoid and sometimes tubercle of trapezium I: lateral side of base of 1st phalanx of thumb and capsule of CMCJ A: Abducts thumb. Assists in opposition and extension N: recurrent branch of median nerve (C8, T1) Flexor pollicis brevis O: Flexor retinaculum, tubercle of trapezium. I: Lateral side of the proximal phalanx of the thumb (there is a sesamoid bone contained in the tendon) There is a small deep head that runs from ulnar side of MC1 to ulnar side of 1st phalanx. A: Flexes thumb at MCPJ N: recurrent median nerve (C8, T1). Small deep head is often supplied by deep ulnar nerve Opponens pollicis O: Flexor retinaculum, tubercle of trapezium. I: Full length of radial surface of metacarpal of thumb A: opposition via flexion of CMCJ N: recurrent median (C8, T1) |
