What is the effect of having a large number of muscle fibers per motor unit on force and precision?

• A. Greater force and increased precision
• B. Greater force but reduced precision
• C. Lower force and greater precision
• D. Lower force and reduced precision

Answer: (B)

Having a large number of muscle fibers per motor unit means one motor neuron controls many fibers, so when that unit activates it can produce a strong contraction. But because many fibers fire together, the resulting force changes in bigger, less precise steps, making fine-tuned control harder. In contrast, motor units with fewer fibers provide smoother, more precise adjustments but generate less overall force. This trade-off explains why the correct statement is that you get greater force but reduced precision.