I had zika like 4 years ago and after that my hands are weak and i cannot hold things strongly because it hurts. it's only hands and fingers, no pain in wrists or arms. as soon as i stop holding whatever i'm holding the pain stops. what is this?

An EMG could determine if the Zika virus caused Guillain-Barré syndrome which is a peripheral neuropathy that could have left you with weakness in your hands. If present, therapy might improve your strength and reduce your pain.

As mentioned by Dr Tamler, an EMG test can reveal whether nerves or muscles are impaired, but also if there is a pinched nerve, such as carpal tunnel syndrome causing your weakness. Specific outcomes can lead to therapeutic improvement. Hand therapy is advised regardless of test outcome.