A Boulder chiropractor will stand trial on charges of sex assault, after three women testified that he caressed their breasts during "therapy sessions" at his office.

A fourth woman testified that Mathew Titchenal, 45, of Lyons, Colo. (pictured, left), performed oral sex on her during a session to relieve pain from a back problem.

A Boulder judge heard testimony Monday from the women before deciding there was enough evidence to hold Titchenal over for trial.

Titchenal was charged with sexual assault and three counts of unlawful sexual contact.

The women testified Titchenal had asked them to be part of a study on the relationship between chiropractic care and message therapy. As part of the "study," the women testified the chiropractor gave them full body massages before giving them spinal adjustments.

All of the women testified that Titchenal touched their breasts in a sexual nature by playing with their nipples. One woman told her the chiropractor explained that many people carry stress in their chest muscles.

All of the alleged assaults occurred between 1998 and 2000.