back pain,spine compression.....sir plz help me

my mom is having severe back pain from last 3 months.she had lifted some weight now she can bent ,can't stand longer because she suffers severe pain.but pain is relieved by lying down.pain occurs again on standing some time. my question is whether she is suffering from muscular pain or there is some disc prolapse?

she had gone to a doctor ,he said for MRI,doctor says she is suffering from muscular pain or spasm .he given her muscle relaxants and pain killers but her pain is still there.

what precautions should she take and what is the reason and treatment of her pain?She has not taken muscular relaxants yet.she was taking MECOBALAMINE and CALCIUM from 2 months off and on.
her MRI was done at  T1 and T2 weighted axial and sagital sections at the level of lumber spine without contrast

FINDINGS :

There is evidence of circumferential disc bulge at the level of LV4-LV5 causing thecal sac compression
Minimal dessicatory changes are seen at L4-L5 level
Straightening of lumber spine is noted due to muscular spasm
degenerative changes are noted as well.
vertebral heights are normal
no other pathology seen

IMPRESSION :
circumferential disc bulge L4-L5 causing minimal thecal sac compression.