Hand cranks should be completed at what rate and for how long maximum?

• A. 4-8 rpm; 10 minutes
• B. 6-10 rpm; 15 minutes
• C. 8-12 rpm; 20 minutes
• D. 5-9 rpm; 5 minutes

Answer: (B)

Controlling manual hand-cranked work relies on a steady, moderate tempo and a finite duration to keep the movement safe and effective. A pace of 6–10 revolutions per minute provides a smooth, controllable rhythm that you can manage without overexerting the patient or the equipment. Limiting the duration to about 15 minutes helps prevent fatigue, hand strain, and potential overheating or loss of control in the mechanism, all of which could compromise safety and the quality of the task. The other options push the rate too far in either direction or extend time beyond what’s prudent, making the task either inefficient or riskier. So the recommended approach is 6–10 rpm for up to 15 minutes.