FUKUOKA (AP) In his first public statement since announcing his retirement from sumo, Musashimaru said Sunday he was unable to uphold the responsibility of a grand champion.

Musashimaru, the most successful foreign-born wrestler in sumo, decided to retire Saturday after suffering his fourth loss at the ongoing Kyushu Grand Sumo Tournament.

"I couldn't maintain the responsibility that a grand champion has," Musashimaru said at a press conference. "That was the main reason I decided to retire."

The Samoan-born yokozuna, the winner of 12 titles, has struggled unsuccessfully for two years with a wrist injury.

"The cause was my wrist," added Musashimaru. "The injury left me with virtually no power in my left shoulder."