What bones make up the wrist
Distal radius and ulna, carpal bones, and metacarpal bones
What is the distal radio-ulnar joint
A pivot joint formed by the distal radius which fits into the ulnar notch at the head of the ulna
What is the location of the triangular articular disc
connects the base of the radius to ulnar styloid process
what does the triangular articular disc articulate with
Its proximal surface articulates with the head of the ulna while its distal surface articulates with the triquetral and lunate bones
What are the two main roles of the triangular articular disc
stabilize the distal radioulnar joint, and allow rotational movement around the styloid process during pronation and supination
What are the proximal carpal bones
Scaphoid, lunate, triquetrum, pisiform
What are the distal carpal bones
trapezium, trapezoid, capitate, hamate
What carpals does the base of the radius articulate with
scaphoid, lunate, triquetrum
what is the midcarpal joint
complex joints between distal and proximal rows of carpal bones (except the pisiform)
what are the movements of the wrist and carpal joints
- flexion mostly at the midcarpal joint 2. extension mostly at the radio carpal joint 3. abduction (radial deviation) limited by the radial styloid process 4. adduction (ulnar deviation) has great excursion
Where is the radial collateral ligament and what does it do
It stretches from the styloid process of radius to the scaphoid and it limits ulnar deviation
Where is the ulnar collateral ligament and what does it do
It stretches from the ulnar styloid to the triquetrum and pisiform. Its role is to limit abduction, or radial deviation.
Where do the superficial muscles of the anterior forearm originate
CFO - Common flexor origin aka medial epicondyle
What is the insertion and action of the palmaris longus
Insertion: palmar aponeurosis
Action: wrist flexion
What is the insertion and action of the pronator teres
Insertion: radius
Action: pronate forearm
What is the insertion and action of the flexor carpi radialis
Insertion: MC 2,3
Action: flex and radially deviate wrist
What is the insertion and action of the flexor carpi ulnaris
Insertion: MC 5
Action: flex and ulnarly deviates the wrist
Where does the pisiform bone develop
Within the tendon of the flexor carpi ulnaris. This is called a sesamoid bone
What is the origin, insertion and action of the flexor digitorum superficialis
Origin: CFO, Radius, and ulna
Insertion: middle phalanges of 2-5
action: flexes fingers
what is the origin, insertion, and action of the flexor digitorum profundus
origin: Ulna
insertion: distal phalanges of 2-5
action: flexes fingers
What is the innervation of the flexor digitorum profundus
median n. to the radial half, ulnar n. to the ulnar half
What is the origin and insertion of the flexor pollicis longus
origin: radius
insertion: distal phalanx of thumb
What is the origin, insertion, and action of the pronator quadratus
Origin: ulna
insertion: radius
action: pronate forearm
How are the finger insertions of the long flexors positioned relative to one another
The flexor digitorum S. splits its tendons and insert distally to the PIP. The FDP passes through the FDS to insert distally to the DIP
What does the median nerve innnervate
Pronator teres, flexor carpi radialis, palmaris longus, half of the flexor digitorum profundus, flexor pollicis longus, pronator quadratus
What is the location of the median nerve
Deep to the bicipital aponeurosis through the pronator trees down the center of the forearm deep to the flexor digitorum superficialis
What does the ulnar nerve innervate
Flexor carpi ulnaris, half of the flexor digitorum profundus
what is the location of the ulnar nerve
posterior to the medial epicondyle, through the flexor carpi ulnaris down the side of the forearm deep to the flexor carpi ulnaris
Where are the common locations of ulnar nerve compression
When it’s near the arcade of Struthers, in the cubital tunnel, or near the heads of the flexor carpi ulnaris
What is the origin of the brachiolradialis, extensors carpi radialis longus and brevis, extensors digitorum and digit minima, and extensor carpis ulnaris
Origin: CEO aka supracondylar ridge
What is the insertion and action of the brachioradialis
insertion: radius
action: flexes elbow ad maintains half pronated position
What is the insertion and action of extensors carpi radialis longus and brevis
insertion: MC 2,3
Action: extend and radially deviate wrist
What is the insertion and action of the extensors digitorum and digiti minimi
Insertion: into extensor expansions over middle and distal phalanges
Action: extend fingers
What is the insertion and action of the carpi ulnaris
Insertion: MC 5
Action: extend wrist and ulnarly deviate
What is the origin and insertion of the supinator
Origin: crest of the ulna, lateral epicondyle of humerus, radial collateral and annular ligaments
insertion: Lateral surface of proximal radius
What is the origin and insertion of the abductor pollicis longus
Origin: Posterior surface of middle third of ulna, radius and interosseous membrane
Insertion: Base of first MC
What is the origin and insertion of the extensor pollicis longis
Origin: Proximal surface of middle third of ulna and interosseous membrane
Insertion: Base of distal phalanx of thumb
What is the origin and insertion of the extensor pollicis brevis
Origin: Posterior surface of radius and interosseous membrane
Insertion: base of proximal phalanx of thumb
What is the origin and insertion or the extensor digiti indici
Origin: proximal surface of ulna and interosseous membrane
Insertion: extensor expansion of second digit
What does the radial nerve innnervate
All the nerves of the posterior forearm
What is the extensor retinaculum
A CT sheet that holds down the extensor tendons
What is a ganglion cyst
Fluid filled vesicle in the synovial sheath of extensor tendons
What are extensor dorsal expansions
The extensor tendons broaden out over MCP joints, divide into 3 slips and insert onto middle and distal phalanges
What is the function of CT slips
interconnects tendons to coordinate their actions
What is the location of the radial nerve
Anterior to lateral epicondyle, deep to brachioradialis, it then branches and the deep branch goes to the posterior compartment while the superficial radial nerve goes to the dorsal skin, superficial to snuffbox tendons
What tendons make up the anatomical snuffbox
Extensors pollicis longus and brevis, abductor pollicis longus
What bones is the anatomical snuffbox a landmark for
Scaphoid, trapezium, and radial styloid process
Where does the radial artery enter the hand
It crosses the floor of the anatomical snuffbox and passes between the first two metacarpal bones to enter the palm of the hand
What moves during forearm pronation and supination
The radius rotates around the ulna within the annular ligament. The ulna shifts laterally via anconeus
What is a common injury to the elbow joint
Nursemaids elbow: dislocation of the radial head from the annular ligament.
