Strengthening Exercises:
- https://www.healthline.com/health/fitness-exercise/lower-back-exercises
- https://aaptiv.com/magazine/lower-back-stretches
- https://www.webmd.com/back-pain/ss/slideshow-exercises
- https://www.verywellfit.com/learn-pilates-exercises-to-help-decrease-back-pain-2704746
Lower back spasms: https://www.medicalnewstoday.com/articles/322369
Low Back Stiffness: https://www.verywellhealth.com/back-pain-symptoms-stiffness-2549270