The inside of foot trap is use if you want to go trap the ball and go forward.
The ball is passed to you and you are going to go forward so you trap it with inside of your foot.

How to do the Inside of the Foot Trap
1. The nonkicking leg is ahead of the trapping foot.
2. Your foot is turned outward and lift up about 3in.
3. Your leg and angle must be relaxed and drawn back when the hit your foot.
4. At the point of contact in trapping, you bring the inside of the foot to the front and the ball is ready to be played.