finger spasm mid-set fret hand

[JGbassman]

I used to race road bicycles on the ameture level, and muscle cramping was usually the cause of dehydration,loss of electrodes, and not the right food in prep for a race or training.

A good complex carb dinner the night before, and gator aid cut with water to replace electrolytes will really help if it's muscle cramping due to dehydration as others have said. You need to be drinking the night prior or day of to keep your body hydrated the way it needs to be.

A good rule of thumb is if the color of your urine is very light, close to the color of water, you are in the ball park of being properly hydrated. Stretching was very important as well, and I slowly warm up my hands before a gig by stretching and other excercises. It will help as well

 

[Cowboy in Latvia]

Check out Scott Devine on YouTube. Search "why I wear the gloves". You may have a similar condition/situation

This does not seem to be focal dystonia to me.* But as the condition has not been studied all that much, it could still be. It is more likely a misuse of a muscle group or tendon which resulted in a spasm...or it could be a more serious issue developing. If it were me, I would get it checked sooner rather than later.

*I am not a doctor and any statement made in this post should not be construed as advice, medically or otherwise.

 

[DavetheDude]

Just for the sake of stupidity: that's what you call slapping.

 

[dtripoli]

This ever happen to anyone else? It was incredibly painful. But worse, I also lost control of most of my hand for at least 15 minutes. Got thru the night well enough but damn, prefer to not have it happen again.

Is this a case where I need to stretch beforehand?

Yep, about 4-5 years ago.
Fingers froze up painfully during a long version of Proud Mary - Tina Turner version.
I crawled across the song finish with barely an audible sound and was done for the night.
Scared the bejeebus out of me and I feared it would happen again

Cause: Death grip on the neck, insufficient woodshedding and working with rhythm challenged musicians which stressed me out.
Solution: Went to a professional bass teacher. Got my technique and ergonomics in order.
Learned to use the volume knob and a light touch rather than digging into the strings harder
Woodshed daily
Lastly I quit working with tempo deficient musicians.