Humeroulnar (HU), Humeroradial (HR)

what are normal valgus angles of the elbow?

- 13* (standard deviation = 6*) - women > men by 2* - excessive valgus = x > 20-25*

4 LIGAMENTS of the elbow

- Medial collateral ligaments (anterior and posterior) - Lateral (ulna) collateral ligaments - Radial collateral ligament - Annular ligament

for full passive flexion of the HU JOINT what structures are taught

- elongation of posterior capsule, extensor mm, ulnar nerve, the medial collateral ligament (posterior band) and lateral (ulna) collateral ligament * stopped when the coronoid process is fully wedged into the coronoid fossa of the humerus

for full passive extension of the HU JOINT what structures are taught

- flexors must be extensible - anterior fibers: medial collateral lig (ant fibers), anterior capsule and tendon of the brachialis * stopped when the olecranon is fully wedged in the olecranon fossa

Which 4 joints make up the elbow/forearm complex?

1) humero-radial 2) humero-ulnar 3) proximal radioulnar joint 4) distal radioulnar joint

Total PROM avail in elbow

5* hyperextension 145* flexion

what is "CUBITAL VALGUS"

AKA "carrying angle" (termed because it keeps things being "carried" away from the thigh" aka abducted from it) when elbow is in full extension - the asymmetry of the trochlea causes the ulna to laterally deviate, realtive to the humerus

Open and closed pack positions of the HU joint

Open pack: 70* flexion, 10* supination Closed: extension

Open and closed pack positions of the HR joint

Open: full extension, full supination Closed: Elbow flex 90*, forearm supinated 5*

what mm's insert on the radial tuberosity of the radius?

biceps brachii

bones of the humeroradial joint

capitulum of the humerus + fovea of the radial head

ARTHOKINEMATICS OF HR JOINT

convex: capitulim of the humerus concave: fovea of the radial head = SAME *forearm moves on humerus for flex/ext

ARTHOKINEMATICS OF HU JOINT

convex: trochlea of the humerus concave: trochlear notch of the ulna = SAME *forearm moves on humerus for flex/ext

5) Annular Ligament

distraction of radius O and I: wraps around radial head and grabs on to ulna

osteo-kinematics of the: 1) humero-radial 2) humero-ulnar

flexion and extension

what is the main functions of the anterior ligaments (medial collateral (anterior band) and radial collateral)

fxn to stabilize the path of the elbow during sagittal plane motion. extension is not as "stabilized" because the body structures stop its motion.

what kind of joint are the HU and HR joints?

modified hinge "modified" because during flex/ext the ulna slides around

what mm's insert on the olecranon and coronoid process of the ulna

olecranon = insertion of triceps coronoid process = insertion of brachialis

osteokinematics of: 3) proximal radioulnar joint 4) distal radioulnar joint

supination and pronation

What does the ARTICULAR CAPSULE of the elbow enclose?

the HU, HR, and proximal RU

bones of the humeroulnar joint

trochlea of the humerus + trochlear notch of the ulna (olecranon wraps posteriorly, coronoid process wraps anteriorly)

1) Medial collateral ligament (anterior band)

valgus and extension *strongest of all 3 O: anterior part medial epicondyle I: coronoid process of the ulna

2) Medial collateral ligament (posterior band)

valgus and flexion O: posterior part medial epicondyle I: olecranon of the ulna

what is "CUBITAL VARUS"

when forearm is deviated towards the midline of the body (adducted) deformity is usually 5*

4) Radial Collateral Ligament ( aka Lateral collateral ligaments: radial portion)

Varus O: Lateral epicondyle I: blends with the annular ligament on radial head

3) Lateral (ulna) collateral ligaments (ulnar portion)

Varus and flexion O: Lateral epicondyle I: supinator crest of ulna