Jackson running with a bum leg

In the span of 3 months Jackson has transformed from missing half his left leg (exiting cab) to wearing a prosthetic and using a cane (in bookstore)to walking with a limp (when entering the room the President is in) to running (into the stargate in Russia).

This timeline is based on the President's comments that he's had a team drilling in Antartica for 3 months since being given the coordinates by the SG-1 team. Jackson even pivots on his left leg when the President says "you can help or you can leave" and Jackson says "ok, bye" and starts to leave. This shouldn't be possible.

Then when hastily entering the stargate in Russia, the front shot shows him doing the 2-skip-and-hop that someone with a bad leg would do, but then the rear shot shows him running up the ramp with no problems.

He obviously wasn't dealing with an HMO.

Trying is the first step towards failure