Bag it up:
If you have to carry a bag, a rucksack is the best option as long as you carry it over both shoulders, and the straps are adjusted so that the bag is held close to your back.
Keep it light:
Make sure you are not carrying anything unnecessary excess weight – check that you are only carrying essential items.
Best foot forward:
Make sure you are wearing good soft-soled shoes that are supportive and have a good grip on the ground.
Lack of exercise is your worst enemy. Take regular and frequent exercise – the fitter you are, the less likely you are to injure yourself.
Staying still for a long time is bad for your spine. Limit time spent sat at a computer or in front of the TV to just 40 mins at a time.
Make sure your computer or games console is set up correctly and you are in a comfortable position at all times.