Do whatever you can.
Seated Shoulder work, standing dumbell Bicep work, Tricep Pressdowns, Leg Extensions, Hamstring Machine etc.
If you're savvy you can work around this and do certain things, that will help you not to lose more muscle condition from all over the body, you can help yourself somewhat and help yourself to burn added calories and reduce fat gain that some level of inactivity would cause.
As long as you can perform certain exercsies weight free and have a full range of motion, then you are able to experiment with small amounts of weight you can increase it by bit until you find what you are able to do right now on a given exercise. If something starts to be felt, drop back to the weight below and work within the threashold.
Next time you train, do that little bit more and if it's okay try a bit more. If that fails stick to the little bit extra. However If the little bit extra is still not quite twinge free, stick to what you intially discovered you could work with on that exercise.
Train smart with this, don't necessarily train non-existently, because it's a mild back issue not a broken Leg, so you can work around it by being clever and conservative and don't be afraid of doing anything, because anything is better than nothing and will help with weight control and mindset. If you're in the gym doing something, it will keep the mind stronger, reduce the fear of getting back into the serious stuff and keep you hungry for the serious stuff again, because you can look at the equipment you are not able to use and and get fired up for when you can use it again.
You are not perhaps as durable as you were, in that old running picture aged 17, but you're not a total wreck misses, you're a pretty awesome Lady with decent physical conditioning now. You're strong, fitter and more knowledgeale about what to do and how to do it, so you don't need to worry, you just need to train smart and sensibly and do whatever you can, to stop the weight creeping back up and keep the precious strength you've strived for for months now.
I believe in this, as I've had one or two niggles before, but nothing serious, but in other respects, when you've got stitches in a hand from an accidental blade injury, or you've got a swollen ankle from slipping down some stairs, you could let these things affect you, but by being clever about things, you can still carry on and do things, until you're able to go pretty much as full on as you did before.
I'm sending you a
BIG PAT ON THE BACK, because I am proud of you for the care and attention you have been giving your body. You have really young looks, or youthfully mature as it could be called, you look quite beautiful and you're a really lovely Lady with a great heart and a lot of humanity and inner beauty and I know this issue must be frustrating and may feel like a reality check regards age, but you're a long time from the last few years misses, you can believe that as much as you want to and at times like this, it tells you something about the strength of heart, mind and character, how you let it affect you, or how you work within fluctuating limitations.
You'll get over this back issue, but you'll be stronger for it, by not letting it ruin some of your hard worked for progress, fitness and mindset. Be strong, be brave, be sensible and be you and let this issue fuel the fire and give you a reason to come back, stronger and striving for more, because you're not at your peak and you can still do more with a 50 year old body, to be stronger, fitter and more acocomplished and you've run races and treated your body with a lot more respect in recent years than some do and now that knowledge and trust in your body can be two great bedfellows and you won't let yourself down and make things worse if you approach this situation in the right way(s).
GOOD LUCK and if you need to talk, PM me anytime. I am really proud of you and should be proud of yourself too, you've pushed yourself so hard and even more so in the past 12 months and deserve the health you have created for yourself. I want to be like you in 14 years. I want to still be giving it best and still working towards being as close to the physical happiness I have now as possible, when I'm old.
I don't live up to you, but I admire you and respect you a lot Lynne.and I want you to overcome this back problem and continue to learn more, get stronger and be even better, because you are SO WORTH IT and if you get clever, this back problem doesn't have to sideline you complletely, it may merely be a piece of education and a trifling crimp in your execution of workouts.
Chin up, be strong and best wishes and THANK YOU for your constant messages, humanity and community spirit. You are beautiful and every inch a true Lady and friend to all of us, so I'm speaking to you as not just a moderator, but a friend and supporter of yours
.
Now go to the gym and kick some sort of butt okay . Trust me, you'll thank me in some way for this, when you're doing something instead of nothing and it feels great just be active in some way, not inactive and worrying about when and how you'll get back into it and I'm hoping to see you in another 12 months, coming here and tellng us you're hitting 25% more weight at least and you're down a good 20lbs more at least and another 5% fat at least, so I'm giving you a very doable reason to work it misses okay
.
You CAN do this and you CAN start to be active again in certain ways and then when your back is 100% again, push on and become even more awesome. You could have at least another 50 years of life left for you yet, so make them great and live them well, because as I said before, YOU ARE WORTH IT
.
Be good to yourself and keep on believing, because you are not old and your heart is still very young and always spectacular
.
)
( face after I lifted that box)
(bad, I know) and a handful of dark chocolate covered raisins (if these are bad - don't tell me....they were so good!!!) 
