Justin Bieber said his shaky sobriety test Jan. 23 in Florida occurred because he had a hairline fracture in his right foot, according to a Miami Beach police document released Tuesday.

After Bieber was pulled over for allegedly drag racing and driving under the influence, the singer told officers he injured his foot three months earlier while skateboarding. According to the New York Post, the officer noted Bieber appeared to sway and have leg tremors during one of the tests, and also winced as if in pain.

Sounds like he finally listened to one of his own records.

"He appeared to have great difficulty," the report said, adding that the injury never was mentioned or noticed after that test.

Bieber, who has pleaded not guilty, also told police he wasn't drag racing in a rented Lamborghini, along with R&B singer Khalil Amir Sharieff, who was driving a Ferrari when both were stopped.

Aren't 19-year-olds supposed to drive beat-up 1975 Chevy Novas?

Oh ... maybe that was just me.

Anyway, the report describes Bieber -- who turned 20 on March 1 -- as initially "agitated and condescending" and using frequent profanity when brought to the police station.

"He then got upset and said, 'I'm 19 years old. I'm just out having a good time,'" the report quoted him as saying. "'What were you doing when you were 19?'"

Driving a beat-up 1975 Chevy Nova. Why?

The officer replied he wasn't driving around in a Lamborghini at that age.

"Yeah, well, I bet you didn't have millions of dollars in your bank account either," Bieber was quoted as replying.

What a lovable guy.

Contact Tony Hicks at Facebook.com/BayAreaNewsGroup.TonyHicks or Twitter.com/insertfoot.