9/6b Biomechanics Part IV

Question 1

different directions of internal torques

Answer 1

flexion/extension, abduction/adduction, etc

Question 2

why do the biceps not perform shoulder internal and external rotation?

Answer 2

their line of force/action does not permit rotation about the proximal/distal-longitudinal axis

Question 3

why does subscapularis cause int/ext rotation

Answer 3

because it’s line of action occurs along the proximal/distal-longitudinal axis

Question 4

****Movement 1: From a deep squat position, come to standing
Movement 2: From a seated position, straighten the leg
-kinematic pattern?
-commonality?
-more inter-joint coordination?
-how would movement change if ankle was fused?

Answer 4

• kinematic pattern - 1 = proximal on distal, 2 = distal on proximal
• commonality -both doing knee extension
• 1 requires more inter-joint coordination
• if the ankle was fused, COM would have to move further forward with both motions

Question 5

convex on concave

Answer 5

roll

slide, spin opposite direction

Question 6

concave on convex

Answer 6

roll, slide, spin all same direction

Question 7

smaller the external moment arm, the easier it will be to generate muscle force

Answer 7

TRUE