Running isn't necessarily bad for the knees, but it will be bad for bad knees.
Here's some tips on return to running following generic knee pain.
1. Walk for 0.1 miles @ a walking pace (3.0-4.0miles/hr) on a flat to 1% incline.
2. Move at Running pace (2 miles/hour over walking pace) for 0.1miles
3. Repeat 10 times (about 2 miles)
The individual should stay at this "level" for about2-3 days before progression.
The subsequent levels would include the same "walk/run" cycle but the individual would then run 0.2miles (and progress by 0.1 miles for each subsequent level).
ie. Level 1: 0.1 miles W, 0.1 miles R (x10)
Level 2: 0.1 miles W, 0.2 miles R (x 10)
How do we determine if we can progress? There's criteria for that!