Tensioning the nerve on the contralateral side may sometimes reduce acute sciatic pain. I was pleasantly surprised that this technique relieved a client’s acute sciatic pain.
Michael Shacklock explains the mechanism in a video that can be found at:
https://www.instagram.com/p/Cw2UiJrvmo0/?img_index=1
The video on Instagram is divided into four segments, so you need to click the right arrow to see all four segments.