I was driving home from work in my 2006 trailblazer ext. after stopping at the stop sign in front of my home, i pressed the center button on the overhead console to open the garage door and proceeded to turn right as to position the vehicle to allow for backing-up onto my driveway and into the right parking half of my garage. but as i shifted the trailblazer into reverse, i began to press the accelerator pedal, but the vehicle would not move. i could feel that the transmission was not slipping, the engine was under load, and it was as if i was pressing the brake at the same time i was pressing the accelerator pedal. but, i only use my right foot, and my left foot was in front of, and against, the drivers seat, far away from both pedals. i looked over to the parking brake, but it was completely down. using the parking brake lever, i made certain that is was not engaged. the brake light in the instrument panel was not on at any time, nor was there a warning from the driver information center (dic), nor was there any other warning or indicator showing that something was wrong. i still could not get the car to move. i placed the transmission into drive, and i could feel the transmission shift, but again, i could not get the vehicle to move. and, there was a load on the engine as if i was pressing the brake pedal at the same time as i was pressing the accelerator pedal, but the brake was not being pressed, and my left foot was far away from the pedals. finally, after about a minute, i felt that the car was 'let go', and i was finally able to move the car normally onto my driveway and into my garage, but i was shaking a bit and am very concerned that this is going to happen again. *kb