DL, it's been a challenge to figure out what I can and cannot do due to injuries but the PT I had for the back really helped with everything. I am "blessed" with scoliosis and one leg being longer than the other which gives me pain. I'm restricted on movements, but there are things I can do instead - like crunches instead of sit ups (where it creates a bad arc in the spine). Or I can do modified push ups and not stress the joins in the elbows so much instead of a full one. I can't do lunges but can do squats - so we just go through and test things to see what's possible and what is not.
That probably is the hardest part of work outs for me. I can't do them all (like burpees are a big fat NO still and may always be) but we can find alternatives that work well. My husband is a work out junkie so we all just work together to figure it all out.
Planks are just starting to get back into my core training. Might sound odd but it was on my no list for years due to the stress on my lower back/hips (which is what the scoliosis and leg length issue cause issues). So I am lucky to finally have worked through the injury to even do a plank at all! I feel so old sometimes LOL but there was no working around that until I slowly built up.
So yep, you can find ways to do things. While you might not be able to do a full level of something, you can always modify or scale to do it all. In our house we mix a little bit of a lot of ideas to get it all working. I need to add in yoga for flexibility and relaxation.
I think everyone injuries or physical limitations aside can find some thing to do. Even if it is going for walks every single day, something can be done!!!!
For me personally fortunately it isn't about a weight loss anymore, but it is about gaining strength I lost. I want to be able to pick my 56 pound son up for a long time so this is the only way to keep up with it and him