Arm and Elbow Flashcards
Condyles
articulating surfaces
capitulum
condyle - articulating with the radius
trochlea
condyle articulating with the ulna
two epicondyles
medial and lateral and primarily sites of muscle attachment
three fossa
radial coronoid olecranoin
what side is the radial groove predominately seen on?
the posterior aspect - for the radial nerve
humeroulnar articulation
hinge with flexion and extension - ONLY MOVING IN ONE PLANE - saggital plane
humeroradial articulation
modified hinge joint
can move in two planes extension and flexion and supination and pronation
proximal radioulnar articulation
pivot with supination and pronation
sharing the same joint capsule as the humeroradial and humeroulnar articulations
so single fibrous capsule for these three joints
distal radioulnar articulation
also a pivot joint with supination and pronation
annular ligament
holds the head of the radius to the ulna and also holds it to the humerus - encircling it
prevents distal dislocation of the radius = annular ligament
lateral collateral ligament
lateral epicondyle to annular ligament of the radius
protects against medial deviation of forearm
taut in full extension
on the sides - medial and lateral
checking against too much movement in the opposite direction
-on thumb side
medial collateral ligament
medial epicondyle of humerus to coronoid process and olecranon process
protecting against lateral deviation of forearm - pinky side
makes sense medial is protecting against lateral deviation
what does tommy john surgery fix?
ulnar collateral ligaemnt (UCL) reconstruction
extension and flexion position of the radius/ulna and humerus articulations
olecranon process of ulna and olecranon fossa of the humerus in close proximity during extension
Flexion - the olecranon process moves distal from the humerus and the radius articulates with the capitulum and the ulna articulates with the trochlea and the coronoid fossa
what is moving in supination and pronation
humeroradial joint and proximal and distal radioulnar joints - THE RADIUS ROTATES OVER THE ULNA
supination occurs when the radius head SPINS over the capitulum and is the only bone moving - NOT THE ULNA - radius is spinning around the ulna
Anterior compartment muscles acting on the elbow
biceps brachii and brachialis
- innervated by the musculocutaneous nerve
Posterior compartment muscles acting on the elbow
triceps brachii
anconeus
brachioradialis
all innervated by the radial nerve
Biceps Brachii
Attachment
Action
Innervation
Attachment :
Long head - supraglenoid tubercle
Short head - coracoid process of the scapula
Action - elbow flexion and weak shoulder flexion
Forearm supination
Innervation - musculocutaneous
brachialis
Attachment
Action
Innervation
Attachment - distal/ anterior humerus to the coronoid process of the ulna
Action - flexes the forearm
Innervation
Triceps Brachii
Attachment
Action
Innervation
Attachment
Long head - infraglenoid tubercle
Lateral Head - posterior/ superior humerus
Medial Head- posterior inferior humerus
ALL HEADS THEN ATTACHING TO THE OLECRANON PROCESS OF ULNA
Action - extend elbow ( long head can also extend the shoulder)
Innervation - radial nerve
heads of the triceps
long head
lateral head
medial head
Anoconeus
Attachment
Action
Innervation
Attachment - lateral epicondyle of the humerus to the olecranon of the ulna
Action - extends the FOREARM
Innervation - radial nerve
Brachioradialis
Attachment
Action
Innervation
Attachment - lateral distal humerus to lateral distal radius
Action - FLEXION of arm - due to developmental process
Innervation - RADIAL nerve to developmental origin
muscles acting on the radioulnar joints
supinator
biceps brachii
pronator teres
pronator quadratus
where does the radius go when you pronate?
towards the THUMB
supinator
Attachment
Action
Innervation
Attachment - lateral epicondyle of humerus and proximal ulna to proximal radius
Action - supinates forearm
Innervation - radial nerve - because posterior muscle in anatomical position
pronator teres
Attachment
Action
Innervation
Attachment - medial epicondyle and the coronoid process of ulna to the lateral aspect of the radius
Action - pronation of the forearm
Innervation - median nerve
pronator quadratus
Attachment
Action
Innervation
Attachment - distal anterior of ulna to distal anterior of radius
Action - pronator muscle
Innervation- median nerve