It was fake, or did it look fake in the edit? Without knowing the details, like where he fell, why he fell, if other people are involved and if he gets hurt or not, there are still shots you can get to sell it...
Let's say he's hiking with his girlfriend on a narrow foot path. The shots might look like:
1) LS ( long shot) of hikers going up a path, away from the camera.
2) MS (med shot) reverse angle of guy approaching camera, with girl behind him.
3) MCU (med closeup) of guy's right foot stepping on a rock. The rock is not secure and slides...
4) MCU of guy's face - he falls downward out of frame.
5) MS of the two hikers from the side, as the guy falls downslope, towards camera. (There is a matt below the frameline, for him to fall onto.)
6) MCU of girl's face (towards camera) reacting to guy falling. "Rick!!"
7) Falling Wide Angle of Guy's P.O.V. (camera assumes his Point Of View). NOTE: Put the camera on an extended tripod and arc it towards the ground (point of impact). Ramp up the speed in editing if necessary.
Low Angle (on the ground) MCU of guy falling into the frame, hitting ground and kicking up dust. His head stays down. ( This landing can be from a semi-stance position onto soft dirt, pine needles or leaves, so he doesn't hurt himself.)
9) MS of girl (camera on trail) Pan with her as she descends to help her guy.
10) Low Angle MCU of guy. He lifts his bloody face from the dirt, groans and winces. Rack focus to the girl descending towards him in the background of this shot.
11) Handheld Wide Angle following behind girl as she gets to her guy and rolls him over. "Are you okay?"
This is how I plan a scene, instead of just filming every possible angle. I have to see the fall work in my head and write the shots down. The guy's POV falling to the ground and the cutaway to the girl allows me to suggest a pretty good impact. A good thud sound effect will sell it. You can make it as intense as you want with insert shots of a fake arm or leg snapping (from a higher fall), etc. Or it can just be a regular old fall.