The mid-shin portion of the deadlift includes a lot of leg extension, and weak quads will obviously be a problem. Fix the issue with a partial assistance exercise called the floor to knee deadlift.
- Stand on a slightly elevated surface, about a half-inch from the floor.
- Slowly pull the bar only to the knees and go back down, keeping the torso angle the same throughout the range of motion.
- Don't touch the floor between reps.