Forearm, Wrist and Hand Mechanics Flashcards
What makes up the carrying angle?
2 lines:
- long axis of the humerus
- line along median aspect of the forearm
What does the wrist do as carrying angle increases?
Adduction
What does the wrist do as carrying angle decreases?
Abduction
What is the definition of the carrying angle?
With arm in anatomic position, it’s the angle formed at the elbow by a line along the long axis of the humerus and a line along the median forearm in a valgus position.
What is the carrying angle in women versus men?
Women: 10-15 degrees
Men: 5 degrees
What is carrying angle called if it is greater than 15 degrees?
cubitus valgus
What is carrying angle called if is less than 15 degrees?
cubitus varus
- AKA gunstock deformity
What happens when the olecranon of the ulna abducts?
Wrist adducts
What happens when the olecranon of the wrist adducts?
Wrist abducts
What is SD of the elbow called? What is primary and secondary?
Adducted or abducted elbow
Primary: ulnohumeral
Secondary: radiohumeral
What 5 findings would you expect with forearm/elbow abduction with medial glide?
- Increased carrying angle
- Olecranon prefers medial glide
- Distal forearm prefers abduction
- Radial head may be compressed on the capitulum of the humerus
- Hand (Wrist) may prefer adduction at radiocarpal joint
What 5 findings would you expect with forearm/elbow adduction with lateral glide?
- Decreased carrying angle - gunstock deformity
- Olecranon prefers lateral glide
- Distal forearm prefers adduction
- Radial head is gapped at capitulum and drawn into the annular ligament
- Hand/wrist perfers relative abduction at the radiocarpal joint
What guides and limits movement of the forearm?
IO membrane
What muscles guide supination?
Supinator
What muscles guide pronation?
Pronator quadratus
Pronator teres
What happens to the radial head during pronation?
Glides posterior
What happens to the radial head during supination?
Glides anterior
What happens to the distal radius during pronation?
glides anterior
What happens to the distal radius during supination?
Glides posterior
What is the SAPP mnemonic?
Supination of forearm = Anterior radial head
Pronation of forearm = Posterior radial head
What happens when you fall forward on your outstretched palm?
Hand is in a pronated position
- forward force vector
- distal radius pushed anterior rotation
- radial head moves posterior
What happens when you fall backward on your outstretched palm?
Hand is in supinated position
- distal radius is moved into posterior rotation
- radial head moves anterior
If a patient presents with wrist pain, what other joints should you look at?
Elbow - wrist pain is sometimes only symptom of SD of elbow
Distal joints
Always evaluate 1 above and below joint
What does SD of the wrist generally involve?
Small gliding motions of the wrist
