Due to muscle spasm.
Thanks for posting your query.
The pain in the left lower back and the groin is less likely to be associated with a gas or indigestion
. This is more likely to be due to a muscle spasm caused by poor posture.
The low back ache as a result of muscle spasm is itself a protective mechanism body develops so that the back avoids abnormal posture. For pain to go, it takes not only rest (on a comfortable bed) but also avoidance of particular positions (during work, rest or recreation).
Even the sleeping position matters, so avoid sleeping on sides and stomach in case you do. While on work don't sit in one position for more than an hour and take frequent stretch breaks. Do not bend forward to lift things up, bend the knees and hips for that. Also discontinue any strenuous activity or exercises for some time.
Having said that, you might want to consult your orthopaedician for a detailed physical examination and appropriate investigations. It might help with few medications and physiotherapy
for a few days. Physiotherapy particularly back strengthening exercises after pain relief work well.
I hope this answers your query.
In case you have additional questions or doubts, you can forward them to me, and I shall be glad to help you out.
Wishing you good health.
Dr. Praveen Tayal.