Elbow Complex Flashcards
What are the jt of the elbow complex
Elbow- humeroulnar and humeroradial
Proximal and distal radioulnar
Describe the elbow jt
Modified hinge jt between
Trochlear notch of ulna & trochlea of humerus (humeroulnar)
And
Head of radius and capitulum of humerus (humeroradial)
What jts are in the elbow jt capsule
Humeroulnar, humeroradial, and proximal radioulnar
The elbow jt capsule is loose and weak where?
Anteriorly and posteriorly
The elbow jt capsule is reinforced laterally by the …
Collateral ligaments
Describe the carrying angle
Medial portion of the trochlea projects more distally than the lateral portion resulting in a Valgus angulation of the forearm
8-15 degrees
What is the function of the carrying angle
Allows a person to carry an object away from side if the thigh
The medial (ulnar) collateral ligament ins comprised of
Anterior, posterior, and transverse medial collateral ligaments
Which collateral ligament stabilizes against valgus torque at the elbow and limits extension at end ROM?
Medial (ulnar) collateral ligament
The lateral collateral ligament complex is composed of…
Lateral (radial) collateral ligament
Lateral ulnar collateral ligament
Annular lig
Which collateral ligament stabilizes against Varus torque at the elbow and combined varus and supination torques
Lateral collateral ligament complex
Describe the articulation of the humeroulnar jt
Concave surface of trochlear notch on the convex trochlea of the humerus
Osteokinematics of the humeroulnar jt
Flex/ext
Arthrokinematics of the humeroulnar jt during flexion
Anterior roll, anterior glide
Arthrokinematics of extension at the humeroulnar jt
Posterior roll posterior glide
Describe the articulation at the humeroradial jt
Concave Radial head with the convex capitulum
Osteokinematics of the humeroradial jt
Flex/ext
Arthrokinematics of flexion and extension at the humeroradial jt
Flex: anterior roll and anterior glide
Extension: posterior roll, posterior glide
What is the closed packed position at the humeroradial jt
90 flexion and 5 supination
What is the closed packed position of the humeroulnar jt
Full ext and sup
What is the open packed position of the humeroulnar jt
Flexed at 70 and supinated at 10
What is the open packed position of the humeroradial jt
Full ext and sup
Consular pattern for the elbow
Flexion > ext
Describe the proximal radioulnar jt
Ulnar radial notch, head of radius and annular lig
Uniaxial pivot jt
Describe the distal radioulnar jt
Ulnar notch of the radius with head of the ulna with an articular disc (triangular Fibrocartilage)
Uniaxial pivot jt
During pronation the proximal radioulnar jt ________________ and at the distal end the concave ulnar notch of the radius _________ around the ulnar head.
Rotation
Slides
Describe the Arthrokinematics of supination at the proximal radioulnar jt.
Lateral rotation/spin of the head of the radius on the ulnar radial notch within the annular lig
Describe the Arthrokinematics of pronation at the proximal radioulnar jt
Medial rotation/spin of the head of the radius on the ulnar radial notch within the annular lig
Describe the Arthrokinematics of supination at the distal radioulnar jt
Lateral roll and glide of the concave ulnar notch of the radius on the convex head of the ulna
Describe the Arthrokinematics of pronation
Medial roll and glide of the concave ulnar notch of the radius on the concave head of the ulna
What is the closed packed position for the proximal radioulnar jt
5 deg. Sup
What is the open packed position of the proximal radioulnar jt
70 deg of flex, 35 deg sup
What is the capsular pattern of the radioulnar jts
Supination = pronation
What is the closed packed position of the distal radioulnar jt
5 deg sup
What is the open packed position of the distal radioulnar jt
10 deg sup
Flexor torque is 20-25% greater when the elbow is in what position?
Supination
How does the supinated position increase flexor torque?
It increases the flexor moment arm of the biceps and brachioradialis
Why brachialis considered the “workhorse” of the elbow flexors?
Large muscle volume
Active involvement in all elbow in all types of elbow flexion (pronated or supinated)
Elbow extension is typically combined with ____________ in explosive pushing activities. What is the synergist relationship in this case?
Shoulder flexion.
Anterior delt has a synergistic relationship with the triceps in this activity
Functionally, pronation is associated with ________ and supination is associated with ________. This combo allows for hand to rotate nearly __________. Why is this important?
IR
ER
360 deg
When testing make sure pt is doing pure pron/sup (will try to cheat with ir/er)
Which muscle generates force with supination at any angle? (Biceps or supinator)
Supinator
Which supinator muscle is normally recruited in high power supination, particularly in those involving elbow flexion?
Biceps muscle
During high power pronation we recruit….
Pronation teres
During low power, everyday activities we use what pronator?
Pronator quadratus
What is the pronator synergist relationship we see?
Triceps act as synergist to counter the tendency of the pronator teres to flex the elbow
