It’s 2 horizontal lines where the curve starts. Towards bottom of the picture. And my foot got wrapped up in a strap it tripped me up and I was able to stop myself from falling this happened 4 weeks ago now and I’m still experiencing soreness in my lower back. I was told it was an mri they sent me to another city 45min away to have to done. Went through a white tube and had to endure loud clicking sounds etc for 15min.