I thought shaking it would do it nothing works. What's wrong?

Has this happened before?

Are you on any medication?

Any previous injury? In particular to your wrist/hand or BACK?

Lastly, any other changes in your wellbeing?

It could be something as simple as a trapped nerve in your wrist or more seriously a problem with a disc in your back. You may have been experiencing pain or odd sensations in your hand/arm in the past or maybe not? There are other conditions which cause a numb hand such as Carpal Tunnel Syndrome and broken bones.

If you suspect this could be spine related or can not rule that out, then I would suggest you get this checked out as a matter of urgency. It is unusual not to have pain but it is not impossible. I am not a medical professional remember so do not take my words as gospel, however your symptoms strike me as rather odd and need to be seen by a professional to confirm what is going on.

Good luck.