What kind of fibers is the DMCL chiefly made from?

• A. Class I
• B. Class II
• C. Class III
• D. Class IV

Answer: (B)

The main idea here is that some structures rely on fast, forceful contractions, while others are built for endurance. Class II fibers are the fast-twitch group, designed for rapid, powerful contractions and quick bursts of activity, even though they fatigue more quickly. If the DMCL is built to produce fast, brief movements rather than prolonged, steady force, it makes sense that its fibers would be predominantly Class II. Class I fibers are slow-twitch and support endurance, so they wouldn’t be the primary component for quick actions. Classes III and IV would imply other specialized fiber types that aren’t the dominant contributors in this context. So, the DMCL being chiefly made from fast-twitch, Class II fibers best fits the need for rapid, short-duration force.