Workout, finally, after slight tibial stress fracture that lasted 16 days.

Lunge-walking (150m) > 2km >
Lunge-walking (150m) > 2km >
Lunge-walking (150m) > 4km

To mainly strengthen quadriceps, biceps femoris and gluteal muscles.
Learn to PROPERLY run:
1. focus on the hips and glutes;
2. avoid pounding the ground;
3. keep posture in check (upright);
4. avoid overstride (better not larger than 120 degrees between the moving legs).

100% a toddler.
Hope it works. This painful period on the sidelines would be worth its while if it does.