HI Eion and thanks for the post. Having read your history and recent MRI findings they don't really seem to relate to one another. The slight discal bulging at L4/L5 is pretty normal with aging and whilst it could be associated with some trauma it would more likely lead to an increase in the lumbar lordosis rather than a decrease. The features themselves would more likely product localized low back discomfort rather than a sciatic type distribution that you are experiencing. That said you might have adjusted your posture due to low back discomfort and that has lead to some sciatic referral symptoms. The MRI also shows no nerve root compromise in the lumbosacral area which would be indicated in true sciatica.

My general comment on this would be that the restriction of the seatbelt around the pelvis could result in some sort of traction type 'injury' or disturbance to the balance of the pelvis. I would discuss this with your therapist in relation to how you were hit and where you were in the car. This might indicate some rotational traction trauma which could be assessed and treated directly at the lumbar spine and pelvis. If the therapist is not confident with assessment and treating pelvic asymmetry then perhaps they know a good osteopath or even chiropractor who could assist you in the treatment plan. A year later would for sure indicate a broadening of the treatment team.

I think from the symptoms you describe and the initial MRI results you should be confident of full recovery on this. Your MRI findings would be normal in as many people with low back discomfort as without it which means it is always hard to say what was there first, or what caused what in this instance. That said you will need to be an active participant in some relevant exercise planning specific to your needs as being a passive recipient of treatment lying on a physio plinth won't be enough.

Let us know what the pelvic symmetry investigations show and how your therapist plans to progress.

regards

PhysioBob