Anatomy lecture 11_Upper Limb Joint Mechanics

Question 1

What are the 6 types of synovial joints and what are their directions of movement?

Answer 1

a. Hinge –uniaxial joint with concave to convex articulation. Generally restricted to
flexion/extension. Example: elbow joint (humeroulnar)
b. Pivot –uniaxial joint with rounded surface articulating with a ring that is restricted to
rotation. Example: radioulnar joint (proximal or distal)
c. Condyloid –biaxial joint with an oval surface fitting into an elliptical socket, allowing
flexion/extension and adduction/abduction, but not axial rotation. Example:
radiocarpal joint
d. Saddle –biaxial joint with one concave surface and one convex surface, allowing for
flexion/extension and adduction/abduction. Example: first carpometacarpal
e. Ball and socket –multiaxial joint with a rounded ball-like surface fitting into a concave
cup-like socket. Example: glenohumeral
f. Plane –multiaxial gliding joint with flat articulating surface. Example: intercarpal joints

Question 2

What are the 8 carples? SCLPTTCH

Answer 2

Row 1 (thumb to pinky)
- Scaphoid –boat
- Lunate -moon
- Triquetrum -triangle
- Pisiform -pea
Row 2 (thumb to pinky)
- Trapezium -saddle
- Trapezoid –complex shape
- Capitate -head
- Hamate -hook
• Metacarpals and Phalanges

Question 3

How many degrees of abduction can occure in the upper limb whithout rotation of the scapula. What is the scapulohumeral rhythm

Answer 3

30 degrees can occure without rotation of the scapula. That being said, for every 3 degrees of rotation, typically 2 is from the glenohumeral joint and 1 is from rotation of the scapula.