With stabilization the viewer gets a surprise when the Bigfoot stumbles forward and the rear shows to the camera and the private parts show. Medical people have speculated that the view shows hemorrhoids, possibly from recent child birth.
Here are five frames that show the event that results in the bulge in the leg of the Patterson subject. When each frame is enhanced and then run at full speed it becomes apparent that there is an injury there.
The Patterson Bigfoot film was shot in several different time periods. This clip shows the first walk sequence and how it ends. Watch “Patty” go down at the end. The clip oscillates back and forth so that strange behavior can be noted.