Glaugust Grip Check
Feats of strength requiring dexterous movements of the hands or immense grip strength can tire them out and leave them locked up like vises if they aren't allowed to rest.
After such feat roll a death save. Upon failure the hands are useless for anything that requires fine motor skills for the next 1d2 hours. If grip strength is tested again while the hands are exhausted a failure results in tendons tearing and the small muscles of the hand becoming wrecked until healed.