Gentle exercise will return them to normal condition. Stress increases the amount of pain you feel. Tension causes muscle spasm and pain. Back pain often comes in spasms. It gets better over a few days then recurs, gradually returning to normal usually within 4 weeks.
Pain travelling down one leg worse than the back pain, is usually nerve root pain or sciatica.
It can reach the foot and be associated with numbness and tingling. The treatment is the same provided the pain is resolving within 4 weeks. You should see a doctor urgently, if your bladder isn't working normally or if you feel numb around your bottom. The old fashioned treatment for back pain was prolonged bed rest. Research shows that bed rest for longer than a day or two actually delays recovery.