week 4 movement Flashcards
what 3 bones is the elbow joint composed of?
the humerus, ulna and radius
what forms humero-ulner articulations?
the trochlear of the humerus and the trochlea notch of the ulner forms the articulation
what forms humero-radial articulations?
the capitulum of the humerus and the upper surface of the radius head
what is the positioning of the ulna and the radius?
ulna –> medial
radial –> lateral
what is the ligament reinforcement of the elbow joint?
laterally by the radial collateral ligament
medially by the ulna collateral ligament
what two directions is the elbow joint not reinforced and why?
it is not reinforced posteriorly or anteriorly. This allows the elbow to flex and extend
which bone in the elbow joint is responsible for stability?
the trochlea and the trochlea notch of the ulna. The radial does not play a part in stability of the elbow joint
how does posterior dislocation occur and how common is it?
80-90% of dislocation. The distal end of the humrus is driven through the weeken anterior part of the joint capsule
what are the two causes of posterior dislocation?
land on the arm flexed
or land on the arm when is fully hyperextension which causes the elbow to pop out posteriorly or postolaterally
what associate injuries can occur with posterior dislocation
Ulnar collateral ligament torn
Fractures- head of radius, coronoid process, olecranon process
Ulnar nerve injury
what are the symptoms of posterior elbow dislocation?
server pain, widened area of the elbow region, prominant olecranon process
which nerve can posterior dislocation damage and what is the consequence
ulnar nerve be damaged. It is part of the brachial plexus and can cause numbness on the medial part of the palm and the fingers. Also weekness of flexion and adduction of the wrist.
what is simple elbow dislocation?
where there is no fractures of the bone around the elbow joint and only the ligament is damaged. No need for surgery
what is a complex elbow dislocation?
it is usually associated with fracture of the forearm. Surgery is often needed to fix the brocken bone and keep the elbow joint in correct place
what are two movements of the elbow joint?
flexion and extension
how far can the elbow usually extend and what is stopping it from going any further?
it can usually extend ot 180 degrees and usually the olecranond process of the ulna fits nicely into the olecranond fossa of the humerus. Not allowing it to extend any more. Bone on bone
what happens in hyperextension?
this is when the elbow can extend pass 180 degrees. There is a hole in the humerus called olecranond fossae which allows the olceranond process of the ulna to pass through the humerus and extend further
what are the three muscles of flexor?
bicpe brachii, brachialis, and Brachioradialis ( is a acessory flexor muscle that aides brachialis)
what compartment are the flexor muscles on the forearm?
the anterior compartment however the brachioradialis is in the posterior part and classed as a extensor but moves anteirorly when arm is being flexed
what is the main muscle involved in flexion?
brachialis