Muscle performance

Question 1

muscle performance

Answer 1

muscle strength
muscle endurance
power

Question 2

muscle strength

Answer 2

force generated by muscle

Question 3

muscle endurance

Answer 3

ability to sustain muscle contraction or repeat muscle contraction over a period of time
- ex: stability or high # of reps

Question 4

muscle torque

Answer 4

rotational force

• T = F x moment arm
• moment arm perpendicular distance from axis of rotation to force

Question 5

factors affecting muscle strength and torque

Answer 5

1) age and gender
2) muscle size
3) type of muscle contraction
4) speed of muscle contraction
5) joint position

Question 6

age and gender

Answer 6

• decrease strength and torque = increase in age(peak at early 20’s)
• less strength and torque = women

Question 7

muscle size

Answer 7

cross-sectional area

- increase in area = increase in strength

Question 8

type of muscle contraction

Answer 8

concentric = least force
eccentric = largest force
isometric = second largest force

Question 9

speed of muscle contraction

Answer 9

concentrically: increase speed = decrease force
eccentrically: increase speed = increase force
- from 0 - 100 degrees

Question 10

active insufficiency

Answer 10

the inability to produce effective contraction when muscle attachments are too close to each other

• usually occurs in muscles that cross 2 or more joints when the muscle is shortened across each joint simultaneously
• origin and insertion are too close together(not enough cross bridges left)
• ex: knee flexion and hip extension

Question 11

passive insufficiency

Answer 11

when no further joint motion can occur because a muscle is elongated over 2 or more joints

• get a firm end feel
• ex: can’t flex knee anymore at hip extension because rectus femoris is being stretched so passively insufficient