The force velocity curve describes the relationship between speed of muscle shortening (i.e. ,velocity of movement)and muscle force production.Which of the following statements are true about the influence of muscle fiber type on the force velocity curve?
A)At any given velocity of movement,the peak power generated is greater in a muscle that contains a high percentage of fast fibers (i.e. ,type IIx)compared with a muscle that contains a high percentage of slow fibers (i.e. ,type I).
B)At any given velocity of movement,the peak power generated is lower in a muscle that contains a high percentage of fast fibers (i.e. ,type IIx)compared with a muscle that contains a high percentage of slow fibers (i.e. ,type I).
C)At low movement speeds,the peak power generated is greater in a muscle that contains a high percentage of slow fibers (i.e. ,type I)compared with a muscle that contains a high percentage of fast fibers (i.e. ,type IIx).
D)None of the above answers are correct.

Question

Quizplus · Accepted Answer

Muscle fibers can be categorized as slow-twitch (type I) and fast-twitch (type II) fibers, with type II further classified as type IIa and type IIx. Type IIx fibers have the fastest shortening velocity, but they fatigue quickly, while type I fibers have a slower shortening velocity but can sustain contractions for longer durations. Therefore, at any given velocity of movement, a muscle containing a higher percentage of type IIx fibers generates greater peak power than a muscle with a higher percentage of type I fibers. This is because type IIx fibers can produce greater force than type I fibers due to their larger cross-sectional area and higher myosin-ATPase activity.

The Force Velocity Curve Describes the Relationship Between Speed of Muscle