Bolt ruled out of 2010 due to back injury

Munich: Usain Bolt's manager says the Olympic champion is taking the rest of 2010 off because of tightness in his lower back.

Manager Ricky Simms says in an e-mail that the world-record holder in the 100 and 200 meters has been examined by a doctor in Germany and the back problem "restricts his ability to generate power in his stride."

Simms says that racing "in this condition could risk injury" to Bolt's legs. Simms also says an MRI exam showed that a previous Achilles' tendon injury is healed.

Bolt will have treatment to loosen his back and then rest, skipping IAAF Diamond League track meets in Zurich and Brussels.

The announcement comes less than a week after Bolt lost to Tyson Gay in the 100 in Stockholm.