Muscle mechanics

Question 1

What is meant by a parallel and pennate muscle fibre arrangement

Answer 1

Parallel - fibers run parallel to the long axis of the muscle, greater range of movement
Pennate - resembling a feather or a feather quill. greater force generation capability compared to parallel muscles

Question 2

Which of parallel or unipennate fibre arrangements is more suited to producing more isometric force

Answer 2

Unipennate is more suites as an angled arrangement allows a larger number of muscle fibers to be packed into a smaller cross-sectional area

Question 3

explain the force-velocity relationship of skeletal muscle

Answer 3

Concentric Contractions (Muscle Shortening): when a muscle contracts more rapidly, its ability to produce force diminishes.
Eccentric contractions (Muscle lengthening): when a muscle lengthens at a faster rate, it can produce more force

Question 4

List the three muscle fibre types and describe their characteristics

Answer 4

Type I (slow):
- slow contraction
- high fatigue resistance
- low to moderate force
Type IIa (fast twitch oxi):
- fast contraction
- moderate fatigue resistance
- moderate to high force
Type IIb (fast twitch gly):
- fastest contraction speed
- low fatigue resistance
- high force

Question 5

How does muscle fibre structure influence force production and shortening velocity? Include a discussion of sarcomere arrangement in your explanation

Answer 5

Optimal sarcomere length, ensuring the appropriate overlap between actin and myosin, maximizes force generation. Additionally, the pennation angle affects the number of sarcomeres in parallel and, consequently, force production.