I messed my lower back up really badly a couple of years ago and this seems to keep it functional, sorry, no idea what the correct names are for each exercise.
1. Five lunges per side, hands by side, step forward and drop the trailing knee to the floor.
2. Ten squats with hands behind neck.
3. Five twists as the hips each side with hands behind neck, alternating sides
4. Five twists each side with hands on stomach
5. One-legged squat and reach. Squat on one leg and reach out with the same arm as far as you can to the 10 o’clock position, then squat again and reach to the 11 o’clock position, then 1 o’clock and 2 o’clock positions. Repeat with the other leg, so you are doing four squats per side.
I do this three times every night or after a ride. The idea is to gently move the muscles through their full range of movement.