A naked man was tasered by police officers after allegedly cycling into a car before "crash-tackling" a female police officer into a van in Brisbane's West End.

Officers were called after Ethan Pick, 22, was seen acting erratically near the corner of Browning Street and Boundary Street at West End about 8:00am.

Police said when they arrived the man ran at the female officer and repeatedly punched her.

The female officer suffered concussion in the attack and was undergoing tests, they said.

Pick was tasered after the attack, to subdue him.

Florina Alman told ABC News she saw a man earlier taking off his clothes and yelling, before riding a bicycle into a car.

"Quite surprising, quite disruptive and it was quite confronting as well," she said.

"It's not something you see every day getting coffee."

She said the police officer took a "massive hit".

"It was out of nowhere and he had a good run-up as well towards her and crash-tackled her into the van and then just gave her a couple of one-twos as well, before he got pushed to the ground," she said.

Pick was charged with serious assault of a police officer, wilful damage of police property and another count of wilful damage.

He appeared briefly in the Brisbane Magistrates Court and was granted bail.

He is due to face court again early next month.