I have never tried yoga. I injured my back and have a lot of pressure on the sciatic nerve. I also have injured ligaments and tendons in my knees. I cannot do regular exercises and have gained a lot of weight while recovering. Mu question is simple will these injuries be helped or hurt if I try Yoga
It solely depends on which yoga you will do.
As you have these problems you might need to skip some postures that feel uncomfortable.
If it hurts more than a muscle stretching it means you should avoid that posture.
As you never did yoga you should have a teacher singleclass for the first times. Also be aware there are good and bad teachers, so if they think you should stretch further but you feel strange about it you should listen to your body and not to the teacher.
Also stay away from yogas that has a fast tempo.
I wish you good luck.
Thank You now to find a Yogi in my area that will take me on. I will keep the forum posted on my progress in any case.
i would recommend to take few privates first ( great if you can find a yoga therapy teacher in your area)… to c how to modify your practice. if you get into average yoga class with 30 people 
you might get hurt…
i can tell you that you should avoid deep forward folds (and alike poses) with straight knees…and obviously anything that gives you too much discomfort
regarding your knees…depends on which tendons you have injured… but difenately avoid Lotus and alike poses, the easy pose Sukhasana should be done with caution…
Lotus pose (and variations) is very advanced practice and i have no idea why it it taught in every yoga class :???
[QUOTE=CityMonk;75372]i would recommend to take few privates first ( great if you can find a yoga therapy teacher in your area)… to c how to modify your practice. if you get into average yoga class with 30 people you might get hurt…
i can tell you that you should avoid deep forward folds (and alike poses) with straight knees…and obviously anything that gives you too much discomfort
regarding your knees…depends on which tendons you have injured… but difenately avoid Lotus and alike poses, the easy pose Sukhasana should be done with caution…
Lotus pose (and variations) is very advanced practice and i have no idea why it it taught in every yoga class :???[/QUOTE]
Thank you I endure pain daily just looking for a natural way to relieve it and to get back fit