During the last 10 years, I have really struggled with back injuries, even to the point of being bedridden.  Today, I would like to make a few suggestions to you, so that you can avoid hindering your tt game with back problems.
 
1. Stay Active
Many table tennis club members work office jobs that require lots of sitting each day.  If you have one of these jobs, make sure that you stretch and walk on your lunch break and any other breaks that you have during the day.  If you aren’t heading to the tt club in the evening, then at least do a short workout session at home.  Staying inactive for days on end won’t put your back in good shape on your training days.
 
2. Both Sides
When going to the gym, try to work-out both sides of your body with upper body, core, and leg training.  This is especially true on core conditioning and flexibility.  Much of table tennis involves a 1-sided rotation.  With the proper fitness program, you can have a more balanced body.  In my DVD – International Table Tennis Skills – I demonstrate a few of the exercised that I regularly do as part of my normal routine.
 
3. Pre-Workout
Before practicing tt, it is vitally important that you do a 20 minute warm-up routine.  If you feel embarrassed to jog and stretch at the tt club, then do it before you go there.  Do a mixture of jogging, stretching, jumping jacks, biking, stair climbing, and lunges for your warm-up.
 
4. During Workout
If you feel a major strain on your back or feel numbness down your leg, then stop practicing and rest.  Many injuries can be prevented if you listen to your body and don’t push too hard.  Try to recognize the difference between fatigue and injury.  You should push hard through fatigue, but you should not force it when you are injured.
 
5. On Breaks
When you have a ten minute water break at the tt club, make sure that you put on your jacket and pants to stay warm.  Also consider walking around or going for a light jog.  With a very short break, cooling down is not an option.  Your goal is to stay warm.
 
6. Post Workout
At the conclusion of your workout, take another 20 minutes to stretch.  At this point, you can push through the stretches a bit harder and longer targeting more flexibility.  Stretching at the end of a workout will really help your recovery and help you to train hard on consecutive days.  Also, make sure that you change out of your wet clothes.
 
7. Rest Days
You need rest days.  On the rest days, you can still do a bit of light stretching or walking, but give your body rest. 
 
I have implemented these seven principles, and it has really helped me.  I have now been training for months without any back issues!