players retire early. Sure its entertaining but your hips and lower back at some point fire right up with Sciatica. http://www.youtube.com/watch?v=D_f7iTnLR5E&feature=related This is why my new cold laser technology which penetrates through equipment and even casts, has been hailed by the four professional athletes that I met with the other night as the GAME CHANGER. It creates a spontaneous healing that can be dealt with on a one minute changeover. Suddenly older tennis players will enjoy far longer careers. This laser is NOT well liked by traditional doctors as it puts most of these hacks out of a job. Cold lasers up till now penetrated skin and perhaps a half centimetre. Ours penetrates 9 centimetres. Federer, and even Sampras and Agassi will, as soon as they are contacted, use this, and play a lot longer than they ever anticipated. So don't worry about Federer retiring any time soon.