All spiders have this defect, though the degree to which the exhibit it varies between individuals, time of day, shed cycle, husbandry, etc.

If he has some minor motor control issues, I wouldn't worry. It's a known issue with spiders, and like the above poster said, they still thrive in captivity, live full healthy lives, and do all 'snake' things just fine, including breeding.

Snakes that are sick or stressed don't eat or breed.