In response to the above.
When driving a stick shift, either your right foot is above the gas pedal and your left foot is pressing down on the clutch while you shift, or your right foot is on the brake pedal and your left foot is pressing down on the clutch. These are standard positions whether one is driving a right handed vehicle or driving a left handed vehicle. The stick shift in a left handed vehicle as in the US is on the right of the driver and the driver uses the right hand to shift. The stick shift in a right handed vehicle as in the UK is on the left of the driver and the driver uses the left hand to shift.
The only possibility that the abdomen would hurt when the left foot presses down on the clutch is when the abdominal muscles are being either stretched or squeezed. And in both cases, the butt would have to be lower than the knee. The abdominal muscles would be stretched if the left foot is pressing down on the clutch while the right foot is held over the gas pedal and one is shifting gears. The abdomen would be squeezed if the right foot is on the brake pedal and the left foot is pressing down on the clutch. This would happen only if the driver’s seat is very low, i.e., a very low and “deep” bucket seat, and the seat is forward under the steering wheel, or the driver is leaning backwards and suddenly has to sit up to step on the brake and the clutch. This happens while driving older model sports cars with a driver’s seat that can only be adjusted forwards and backwards but not up and down like a driver’s seat in a big newer model SUV. Dodge mini vans for example have driver’s seats that adjust forward and backwards but not up and down.
The abdomen is constantly being compressed if the driver’s seat is a low and “deep” bucket seat. The bucket seats in all small cars will cause severe lower back stiffness and lower back pain. When getting out of the car, one will feel extreme stiffness both in the lower back and in the abdomen, unable to stand up straight.