Week 2 - Elbow, arm and forearm Flashcards
Which muscles are in the anterior compartment of the arm, and where to they attach in the forearm?
Biceps - attaches to radial tuberosity
Brachialis - attaches to the tuberosity of the ulna
Describe the brachioradialis and why its layout is unusual
Comes from the humerus close to the elbow joint. Then goes all the way along the radius to attach to the distal end. This is unusual as the other muscles have an origin far away and attachment close
What is the major muscle on the posterior side of the arm, and where does it attach at the elbow?
Triceps
Attaches to a point on the elbow called the olecranon of the ulna
What is required from the shoulder for distal movements?
Shoulder stability
How do the triceps and biceps help with shoulder stability?
Triceps holds scapula and humerus together, while the biceps originates from the scapula. These attachments hold the shoulder steady
When does the biceps act as a supinator?
When the forearm is in a prone position - its able to drop the hand into the supine position
What actions to anterior muscles of the forearm perform?
Flexing of the wrist and joints of the hand, as well as protonation
What actions do posterior muscles of the forearm perform?
Extension of the wrist and joints of the hand, and one supinatory action
What are the common origins for superficial flexors and extensors of the forearm?
Flexors - medial epicondyle
Extensors - lateral epicondyle
What are the superficial muscles of the forearm?
Palmaris longus Pronator teres Flexor carpi radialis Flexor carpi ulnaris Flexor digitorum superficialis
What does palmaris longus do?
This tiny muscle has four tendons that are sent through the hand and flex the fingers
What does the pronator teres do?
Moves the radius relative to the ulna. PT is a round muscle attached to the radius
What are the two wrist/hand flexor muscles in the forearm?
Flexor carpi ulnaris (along ulnar side)
Flexor capri radialis
Where would you find the flexor digitorum superficialis and what does it do?
Flexes fingers, found between the two flexor carpi muscles, in a slightly more posterior plane
What are the deep anterior muscles of the forearm?
Flexor pollicis longus Flexor digitorum profundus Pronator quadratus (the deep pronator of the forearm)
What are the deep anterior muscles of the forearm attached to?
radius, ulna and interossesous membrane
What does the flexor pollicis longus do and where would you find it?
It’s a flexor of the thumb
Short flexor in the hand
It’s a lateral muscle and runs from the radius and the interossesous membrane
What is the flexor digitorum profundus?
The large anterior mass of the forearm
Deep flexor of the fingers
medial muscle running from the ulna and the IO membrane. Almost reaches posterior side of ulna
What are the two extensor muscles of the forearm in the posterior compartment?
Extensor carpi radialis
Extensor carpi ulnaris
How is the extensor on the radial side of the forearm different to that of the ulnar side?
It’s a combination of two muscles, with two tendons - extensor carpi radialis longus and radialis brevis
What is the common extensor of the fingers and where is it?
Extensor digitorum communis - does all the fingers, found in the posterior compartment of the forearm
What do the muscles extensor indicis and extensor digiti minimi do?
These are extra extensors of the little finger and the index finger
What are the two extensors of the thumb?
Extensor pollicis longus
Extensor pollicis brevis
What is the abductor of the thumb?
Abductor pollicis brevis
