Paul Swift from BikeFit sent out an infographic showing proper wrist alignment - their example is for a mountain bike, but the concept is identical no matter what you're riding. If you've been to WSSC, BikeFit is the company who provides the very popular bicycle shoe cleat alignment / adjustment service.
Complaints about hand numbness are typically the result of riding with hyper-extended wrists. We've explored the need for proper hand position in detail here at ICI/PRO in these posts:
Correcting Student”™s Form — Proper Hand Position
More on preventing carpal tunnel / hand numbness in your students
5 Tips that will help you (and your hands) feel more comfortable on your bike
- My Life Time Instructor Teach Back - May 24, 2023
- I'm Fine, Thanks - May 21, 2023
- Schwinn AC Performance Plus Improvements - May 18, 2023