Recently a personal trainer recommended I use a foam roller for muscle massage and flexibility. Most research I've done on the web simply states the roller 'massages the muscle' or 'breaks down scar tissue'. Is there a more scientific explanation about the benefits (or negatives) of using a foam roller to improve flexibility and reduce soreness?
Think of it as a gentle meat tenderizer. But instead of weakening the muscle by pulverizing it, the added pressure and use simply promotes blood flow to massaged areas. Foam rollers are great recovery tools because they generate similar benefits as a sports massage, but can be performed by one's self.
If you want the most scientific explanation, look up anything you can find by Dr. Janet Travell. If you're willing to settle for a more layman's explanation, The Trigger Point Therapy Workbook by Clair Davies is likely your best bet (I get the impression foam rollers weren't widely available when it was written, but all the principles talked about using the TheraCane still apply with a foam roller).
I recently saw my physio and she said my knee pain is Fat Pad Impingement which is caused by an excessively tight quad muscle. She told me to get a foam roller because it will be useful for deep tissue massage of tight muscles and will help with the overall state of muscles utilised in exercise (in my case, long distance running).