How to prove pain and suffering

Last week, a young woman hired me to represent her on a case in which she was injured when she was hit by a car. The incident occurred while she was walking to work. As she was walking on the shoulder of a road near the parking lot of a local business, a car suddenly darted out of the parking lot, crossed two lanes of traffic, and hit her. The front bumper of the car hit her on the right side of her knee, causing her to fall and hit her head on the ground.