A recent Australian study found that 60% of children using computers at school showed early signs of repetitive strain injury. Here are some at-your-desk exercises for young PC-users. (Do them gently; if you feel pain see your doctor.)

1. Stretch your arms above your head and spread your fingers. Then lower your arms so they're straight out in front. Hold for a few seconds.
   
2. Push the bottom of your right palm against the top of your left palm, so you feel a stretch along the underside of your left forearm. Repeat on the other side. Now do it pushing on the backs of your palms.
   
3. In a chair with your back straight, look over your right shoulder. Then slowly move to look over your left shoulder. Go back to the center and nod slowly three times. Then turn your head in a "no" motion three times. Finally stretch as if laying your head on each shoulder.
   
4. Keep your hips forward and turn to look behind on each side, placing your arm across the back of the chair, stretching your back.
   
5. Push your chin forward to stretch the jaw and neck.
   
6. Sitting, roll each shoulder forward and around then back and around. Then lift each shoulder up to your ear and down.