Acute onset stiffness in the lower back region could be due to muscular issue or an acute exacerbation to a chronic lower back problem.
My advise will be to: - to maintain proper posture while working and sleeping
- if pain
is more then you can take a short course of an anti-inflammatory medication which suits you, a proper muscle relaxant can also be added for initial 5-7 days
- physical therapy initially under supervision of a trained physiotherapist
and then to continue at home
- adequate calcium & vitamin d intake if levels are low in body
- ice packs can applied if your pain is acute - analgesic spray for local application can be used and is easily available.
- avoid lifting heavyweight/ acute forward bending in mornings etc in case you are having back pain.