It looks like your middle finger numbness started after holding weight for a long time, so it is most likely due to temporary nerve pressure or irritation. This is quite common and usually not serious.
The nerve that goes to the middle finger can get compressed either in the hand, forearm, or even from the neck, especially if the posture was not ideal while holding the weight.
In most cases, it improves on its own in a few days.
Next Steps
Avoid heavy gripping for a few days
✔ Keep moving your fingers gently
✔ Maintain good neck posture
✔ Warm compress can help
Health Tips
If numbness continues beyond 3–5 days, increases, or you feel weakness in your hand.