Elbow and Arm Review Flashcards
Name the bony landmarks on the elbow and arm
- lateral epicondyle
- medial epicondyle
- capitulum
- trochlea
- head of radius
- conoid process of ulna
- radial tuberosity
- ulnar tuberosity
- olecranon process
Describe the trochlea
- medial side of humerus
- meets up with ulna
Describe the medial epicondyle
- looks like thumb sticking out of bone, very prominent because a lot of finger & wrist flexors originate here
Describe the capitulum
- rounded, almost spherical shape along lateral side of articular surfaces of humerus
- meets up with radius
Describe the head of radius
- relatively flat, slight concavity
- rounded surface if you look from above
- will spin around radial notch on ulna (probation & supination)
Describe the radial tuberosity
- on proximal end of radius
- leans towards medial side
- attachment for biceps brachii
Compare the size of the medial epicondyle and lateral epicondyle
Medial: very prominent
Lateral: very subtle
What is the ulnar tuberosity an attachment for?
Brachialis
Where is the conoid process located?
Ulna @end where it meets up with the trochlea of humerus
Describe the olecranon process
- ulna scoops into back of humerus, males olecranon process
- “funny bone”
- most proximal end of ulna
- hooks into olecranon fossa on humerus
How does the structural integrity of the elbow relate to injury?
- elbow has a lot of bony congruency, very stable joint
- ulna wraps around the trochlea of the humerus
- usually need someone with excessive amount of laxity/looseness through the joint or have huge amount of force coming in (especially fast & in extended elbow like Olympic lift)
Name the joints of the elbow
-superior radio-ulnar joint
- humero-ulnar joint
- humero-radial joint
Describe the superior radio-ulnar joint
- head of radius resting against concave notch on ulna
-allows radius to spin through pronation and supination for rest of forearm
*We need the radius to be held against ulna but not so much that it can’t spin = annular ligament!
Describe the annular ligament
- attached to anterior & posterior margins of the radial notch on the ulna
- loops around radial head but doesn’t actually attach to it
- allows radius to spin against ulna but still be attached
Describe the humero-ulnar joint
- olecranon process on back and conoid on front
- scoop around trochlea
Describe the humero-radial joint
- head of radius slightly concave on superior end: meets up with capitulum
Name the elbow ligaments
Radial-collateral ligament
Ulnar-collateral ligament
Describe the radial-collateral ligament
- lateral side of elbow
- almost triangular in shape (it up by two bands)
Bands start @ lateral epicondyle of humerus
- 1 band moves anteriorly, 1 posteriorly
- both blend into annular ligament
- posterior band blends into part of ulna (superior crest)
** pulled apart with varus position (uncommon)
Describe the ulnar-collateral ligament
- has 3 bands: all 3 start @ medial epicondyle of humerus (anterior, posterior, transverse)
- limits valgus forces (common especially in sports with rapid & powerful elbow extension like pitching and throwing)
Describe the location of the anterior band of ulnar-collateral ligament
- start @ medial epicondyle of humerus
- lands on coronoid process on the front
Describe the location of the posterior band of the ulnar-collateral ligament
- starts @ medial epicondyle of humerus
- blends into the olecranon process on the back
Describe the location of the transverse band of the ulnar-collateral ligament
- starts @ medial epicondyle of humerus
- doesn’t cross joint at all
- completes a triangle from coronoid process>olecranon
Describe valgus forces at elbow
- when elbow is in anatomic neutral (full extension), elbow has a valgus leading to it (medial side more open than lateral)
- angle between long axis of forearm and humorus = carrying angle
- whenever we do activity with forceful extension of the elbow, we get valgus traction along medial side of elbow and apply stress to medial structures
**UCL is very developed ligament for this reason
Name the elbow muscles
Biceps brachii
Brachialis
Triceps brachii
Describe the structure of the biceps brachii
- 2 heads:
SHORT (medial side, originating @coracoid on scapula)
LONG (lateral side)
Describe the location of the biceps brachii
traveling up bicipital groove between lesser & greater tuberosity
- tendon goes across head of the humerus & lands on superior aspect of glenoid fossa (supraglenoid tubercle)
- muscle merges into 1 belly & continues down to come past the elbow
- as it passes the elbow it becomes a flexor
2 insertions:
- radial tuberosity
- bicipital aponeurosis (transparent CT that spreads across muscles of forearm that affect risk and hand)
Describe the Brachialis
- originates from anterior aspect of humorous in the distal half
- shorter than bicep, doesn’t touch the shoulder
- converges into 1 tendon which blends into the ulnar tuberosity
Name the muscle actions for the biceps and brachialis
- biceps and brachialis are both elbow FLEXORS
- Biceps brachii has capacity to cause SUPINATION OF RADIO ULNAR JOINTS
Describe the triceps brachii
- 3 heads, all 3 merge into horseshoe -shaped common tendon that blends into olecranon process of ulna
- long, lateral and medial head
- all 3 pull on olecranon process to lock it in place in olecranon fossa on posterior side of the humerus (process of extension)
Describe the location of long, lateral and medial head of triceps brachii
- long and lateral heads are very superficial
- the medial head is deep to both and is best seeing if you “peel” the other two away
- long head originates from infraglenoid tubercle on the scapula
- lateral and medial heads originate from the posterior surface of the shaft of the humerus and land on either side of radial groove
Describe the radial groove
- the radio groove is a diagonal group in which the radial nerve will travel on its way towards the radius
Describe the function of the biceps brachii
- since long head is coming up over the scapula, we can have action at the shoulder: helps with extension of GH joint and a little bit of adduction
- all three pull-on olecranon process to lock it in place in olecranon fossa on posterior side of the humerus (process of extension)
