Prime Minister Yoshiro Mori, who has long suffered low public support ratings, found himself suffering physical pain on Friday, enduring a backache that forced him to walk with a cane.
Mori was treated by a specialist in the afternoon, but said he is still in some pain. "I don't need the cane anymore," Mori told reporters after receiving the treatment, "but (a full recovery) will take about one more day."
Mori is set to leave for a trip to Africa and Greece on Sunday.
The prime minister said earlier in the day his backache was a chronic ailment, and he believes that the pain returned because he did not move around much during the New Year's holidays.
"The second spinal block sometimes slips out of place. It hurts very much when that happens," he said. "It's probably because I was idle for a few days."
Mori, who has had a finger on his right hand bandaged since Thursday, said he suffered the injury while swimming in a pool in an effort to treat his back pain.
"I can treat (the backache) myself. Swimming is the best method," he said. "I tried the treatment in a pool but stubbed my middle finger."