MSK 3 - Upper Limbs Flashcards
anterior compartment of the forearm:
These muscles are _______ of the wrist and digits and facilitate _________ of the forearm at the radio-ulnar joint
They are arranged into a …………
flexors
pronation
superficial, intermediate and deep group
a
Pronator teres
b
Brachioradialis
c
Flexor carpi radialis
d
Flexor digitorum superficialis
e
Flexor carpi ulnaris
The _______ epicodyle of the humerus acts as the common flexor origin for the superficial and intermediate flexors. A common ______ arises from here, providing the proximal insertion point for these 4 muscles
Any overuse injury (such as ______ elbow) is reflected by pain here
medial
tendon
golfers
what is a muscle that everyone may not have?
The palmaris longus (not shown above) is a muscle which is absent in about 20% of people! It is a long thin muscle and is one of the most superficial structures found at the wrist joint – see if you have one by flexing the wrist joint
Simply put, the superficial flexors of the forearm can be drawn as below, with the 4 muscles fanning out from the common flexor origin
what are each of the muscles?
PT – Pronator Teres
FCR – Flexor Carpi Radialis
PL – Palmaris Longus
FCU – Flexor Carpi Ulnaris
What is the action of pronator teres?
Pronation of the forearm and weak elbow flextion
Apart from flexing the wrist, which superficial muscle is involved in adduction (ulnar deviation) of the wrist joint?
Flexor carpi ulnaris
Apart from flexing the wrist, which superficial muscle is involved in abduction (radial deviation) of the wrist joint?
Flexor carip radialis
Three superficial muscles are supplied by ______ nerve with the ulnar nerve suppling the _____________ muscle
median
flexor carpi ulnaris
what and where is the Flexor Digitorum Superficialis (FDS)?
Lies immediately deep to the superficial group of flexors in the forearm and is seen as the only muscle on the intermediate group of the forearm
The flashy mass of muscle has an extensive origin in the forearm, and passes distally down the arm giving rise to 4 tendons.
where and how does the FDS attach?
The distal tendon of FDS is interesting, as when approaching its insertion point it splits into two loops passing around the back of the phalanx. This provides a tunnel in which the flexor digitorum profundus tendon can pass through attaching onto the distal phalanx.
To which digits (fingers) are the 4 tendons of FDS attached?
2-5 - index, long, ring, pinky
On which phalanx are they inserted?
middle
what is the FDS function?
The FDS flexes the wrist, metacarpophalangeal and proximal interphalangeal joints
Can this muscle act on the distal interphalangeal joint? (FDS)
no
What nerve innervates FDS?
Median nevre (C7, C8 and T1)
Brachioradialis:
Although seen as a muscle that lies in the posterior (extensor) compartment of the forearm the brachioradialis acts on the elbow joint with the other anterior muscles.
What is the main action of this muscle?
Flexes elbow when the forearm is in neutral and acts to stabilize the elbow during rapid flexion or extension
which nerve innervates the brachioradialis?
Radial nerve
what rule is the brachioradialis an exception of?
Brachioradialis is the exception to the rule that all flexors lie in the anterior compartment, and that the radial nerve only innervates extensor muscles
whata re the deep groups of msucles related to?
The deep group of muscles are in contact with the bones and interosseous membrane.
The flexor digitorum profundus (FDP) is in relation to the ulna, the flexor pollicis longus in in relation to the radius, and the pronator quadratus which is closely related to the distal parts of both bones.
a
Flexor pollicis longus
b
Flexor digitorum profundus
c
Pronator quadratus
where is the Flexor Digitorum Profundus (FDP)?
FDP is a long, thick muscle that lies deeply in the front of the forearm. It also lies more superficially on the medial border and back of the forearm
What is its main action of FDP on the wrist and finger joints?
flexion
The FDP has a dual nerve supply
Which part of the FDP is supplied by ulnar nerve?
Which part of the FDP is supplied by median nerve?
Ulnar half/Medial half
Radial half/Lateral half
Pollicis – _______
Brevis – ______
Profundus – _____
Quadratus – __________
Thumb
Short (If there’s a brevis muscle, then they’ll likely be a longus!)
Deep (if there’s a profundus, then they’ll likely be a superficialis!)
Square/Rectangular
FPL Is the long flexor of the thumb – which nerve innervates this muscle?
Anterior interosseous branch of the median nerve
where is the Pronator Quadratus?
Lies deeply in the distal part of the forearm, taking origin from the front of the ulna, and passing across to be inserted into the radius
What is the innervation of this muscle? (pronator quadratus)
Anterior interosseous branch of the median nerve
Pronator Quadratus works in synergy with the pronator _____ muscle and form a powerful pair of _______ at both the proximal and distal radioulnar joints
teres
pronators
a
Radial nerve
b
Radial artery
c
Brachial artery
d
Ulnar nerve
e
Ulnar artery
The median nerve enters the forearm _____ to the brachial artery. It then heads under the _______ ___ muscle and passes down the forearm between the FDS and FDP.
It enters the carpal tunnel ____ to the flexor retinaculum
medial
pronator teres
deep
Which muscle(s) does the median nerve not supply in the anterior forearm?
Flexor carpi ulnaris and medial half of flexor digitorum profundus
what is the course/location of the ulnar nevre in the forearm?
After passing posterior to the median epicondyle of the humerus the ulnar nerve enters the forearm by passing between the heads of flexor carpi ulnaris muscle.
Both the ulnar nerve and ulnar artery descend close to each other down the medial aspect of the forearm
The ulnar nerve lies ulnarly/medial to the ulnar artery at the level of the wrist