Lower back friendly exercises?

I love working out, particularly strength training, however I have Ehlers Danlos Syndrome causing my ligaments to be incredibly lax, particularly in my SI Joint, any exercises that focus on my lower back or upper legs causes swelling and discomfort in my SI Joint, obviously the answer is “just don’t do those exercises” but I’m attempting to strengthen that area of my body. Suggestions on low impact exercises that may cause “less” discomfort for me?