elbow Flashcards
What are the movements of the elbow?
Flexion, extension, pronation, supination
Define VaLgus.
Lateral deviation of a distal segment with respect to proximal segment
Define VaRus.
Medial deviation of a distal segment with respect to proximal segment
What is the range of motion (ROM) for elbow extension?
0-140°
What is the ROM for pronation and supination of the elbow?
0-80-90°
What is the ROM for activities of daily living (ADLs) involving the elbow?
30° extension to 130° flexion, 50° pronation and 50° supination
What ADL creates the biggest elbow load?
1st Work tasks, 2nd push-ups
What does an injury at the cubital tunnel cause?
Laceration or compression of ulnar nerve
How is the distal humerus curved?
30° anteriorly, 6° of tilt in frontal plane
What are the three elbow joints?
- Humeroulnar
- Humeroradial
- Proximal radioulnar
What type of joint is the humeroulnar joint?
Ginglymus (hinge) with 1 degree of freedom
What is unique about the humeroulnar joint space?
Asymmetrical joint space with decreased space at olecranon fossa and increased space at trochlear notch
What joint contact is greater in elbow flexion?
Greater contact at the humeroradial joint
What type of joint is the proximal radioulnar joint?
Trochoid (pivot)
What is the role of the interosseous membrane?
Important static longitudinal stabilizer of the forearm, less to rotation
What are the characteristics of the center of rotation of the elbow?
- Lateral to medial
- Posterior to anterior
- Superior to inferior
What is the carrying angle of the elbow?
10-15° valgus of forearm
What are the primary static constraints for elbow stabilization?
- Ulnohumeral articulation
- Anterior bundle of medial collateral ligament
- Lateral collateral ligaments
What are the secondary constraints for elbow stabilization?
- Radiocapitellar articulation
- Common origin of the flexors
- Common origin of extensors
- Capsule
What stabilizes valgus stress at the elbow?
Radial head and olecranon
What injuries occur during pitching?
Compression force laterally, tension on medial collateral ligaments, increased valgus moment
How should the arm be positioned during the rehabilitation of MCL?
Arm should be in supination
How should the elbow be positioned during the rehabilitation of LCL?
Elbow should be pronated
What are the main elbow flexors?
- Biceps brachii
- Brachioradialis
- Brachialis
- Pronator teres
What are the main elbow extensors?
- Triceps brachii
- Anconeus
What causes lateral epicondylitis?
Overuse of ECRB and EDC
What are the consequences of medial epicondylitis?
Overuse of flexors, pronators, excess valgus force, excess medial tension
What is the strongest angle for elbow flexion?
75-90°
What are the wrist movements?
- Extension/flexion
- Ulnar deviation/radial deviation
- Circumduction
What is the dart-throw motion?
Neutral wrist > radial deviation > ulnar deviation
Why is the dart-throw motion important?
Less movement of scaphoid and lunate, common path of motion and ADL, safe protected ROM
What is the ROM of the wrist for flexion?
80°
What is the normal ulnar variance?
< 1mm
What happens with negative ulnar variance?
2-5mm instead of <1mm, 95% load via radius, increased risk for lunate
What happens with positive ulnar variance?
Smaller than normal ulnar variance, 60% load via radius, increased risk of ligamentous tear
What should be avoided under distal radius fracture?
Excessive hand squeezing and forceful ROM if no solid fixation
