Trial Workout, push ups, squats, sit ups

I tried doing a bit of work to see how it would affect my back:

3 sets of

1. 20 push ups
2. 20 squats
3. 20 sit ups

Results:

• Push ups, no problems.
• Air Squats, hips are tight, legs are tight. Loosened up after the second set. Don’t feel like my hips are making a straight up/down motion. Seems like there is a slight wave (to the left/right) on decent. Maybe this is a result of tightness?
• Sit ups – no problems. No pain.