Repsol Honda riders Dani Pedrosa and Nicky Hayden commenced a two-day test session at Catalunya this afternoon, but yesterday's race-winner Pedrosa ended the day in hospital after a heavy tumble at the one/turn two chicane. Both riders had planned to spend the day doing back-to-back tests with the RC212V spring-valve and pneumatic-valve engines. Pedrosa started with the conventional engine (best lap time: 1m 43.48s), then switched to the pneumatic-valve unit, but that outing (best lap time: 1m 43.81s) was cut short by a minor electrical problem, so the Spaniard swapped machines again. It was during this outing that Pedrosa suffered a highside tumble, landing heavily on his back. He was taken to Barcelona's Dexeus hospital where x-rays confirmed that he has no broken bones, but he has bruised his back and will need 48 hours of rest and anti-inflammatory medication. Pedrosa will not test tomorrow.