2 year old has ‘sore back’

Any ideas what else could present as a sore back in a 2 year old?

All week we’ve been sent back and forth between our GP, Hospital and Paediatrician but still haven’t gotten anywhere.

Blood and urine tests have come back normal.

She holds her lower back on both sides.

Has moments that she’s okay, but will then sit down and say she’s sore. No bruised or scrapes. No specific incident that caused the pain initially.

We have an appointment shortly with our paediatrician, but hoping to have some ideas she may not have thought of already.

Feeling so lost after her being in pain for over a week with no improvement.

Our Paediatician asked the hospital to do scans but they wouldn’t. But I will be pushing for it again at our appointment.

Thanks for any ideas.