<s>[INST] A couple of days ago I bent over to pick up a screw and I heard a pop in my lower back, since then I have had a sore back and especially bending and getting up from a sitting position. Looking at the chart my guess is it is the 5th lumbar. Is I can do to make it better? [/INST] Hi. Sudden onset of back pain following bending looks like u might acute lumbosacral strain. Sudden stretching of the back muscles when bending causes spasm of these back muscles leading to LS strain. Things to do. Strict Bed rest for 3-4 days. Take painkiller and a muscle relaxant(Acoclefenac/Diclofenac + Thiocolchicoside) twice a day. U can use any painkiller ointment, gel or spray. Donor bend, lift weight, squatting. Donot do any physiotherapy like back strengthening till pain persists. If pain persists then visit a doctor for x-rays, +/- MRI scan and further management. </s>