During this week’s practice we were running into fatigue issues. Both fencers were having trouble staying in L’Ange’s recommended Quarta.
Looking closely as the illustration, our mistake is clear. Instead of placing the pommel under the base of the hand, we were allowing it to float near the wrist. This in turn caused us to try to support the entire weight of the sword with the fingers.
This is not much different from how Jeff Jacobson of Tattershall demonstrates in his video How to Hold a Rapier.