Delivering parcels from a bicycle is more dangerous than meatpacking, professional football and just about every other occupation in the country, according to a recent study from the Harvard School of Public Health (SPH).

In the study, which appears in the December issue of the American Journal of Industrial Medicine, 113 bike couriers were asked 10 questions about injuries, time off from work and health care.

The study focused on Boston, where bike messengers deliver between 3,000 and 4,000 packages a day.

It found that among the sample group, 90 percent of the couriers reported being injured on the job and 70 percent reported missing at least one day of work due to an injury. However, only 32 percent of couriers have health insurance.

Study co-author Jack T. Dennerlein, assistant professor of ergonomics and safety at SPH, said he has high hopes for the long-term implications of the study.

“I hope that it changes awareness in the general conception of bike messengers, and I hope it prompts companies to give health insurance and workman’s comp,” Dennerlein said.

Because they work as independent contractors, messengers are rarely compensated for work lost to injury.

“We don’t get any kind of sick pay or vacation time...I’ve been in a few [accidents], hit car doors a few times, it happens a lot. I’m definitely afraid of being injured,” said Aaron Harris, who has worked for Boston-based Marathon Messenger Service for two years.

According to the study, most injuries come from colliding with or attempting to avoid a collision with a motor vehicle.

The most common injuries cited are “cuts, scrapes, lacerations, bruises, contusions and road-rash [skin abrasion],” as well as “fractures, sprains-strains and dislocations.”

Dennerlein calculated that for every 100 messengers, 47 workdays per year were lost to injury. Meatpacking, also considered to be extremely dangerous, has an average of 15.6 lost workdays per 100 workers per year.

In the study, only 12 percent of bikers reported that they always wear a helmet.

Sean Cocannon, who worked as a courier for the messenger service Breadrunners for six years, attributes the decision not to wear a helmet to the riders’ personalities.

“[They’re] kind of a little reckless. I guess I’d chalk it up to that. It’s an expression of personal freedom,” Cocannon said.

Amy Griffin, a two-year courier veteran, described the helmet as an inconvenience.

“I briefly tried it, but I usually wear a walkman, and I hop off the bike all the time to visit people and go to record stores and make deliveries and stuff...and since I wear sunglasses, it’s just too much stuff around your head,” Griffin said.

Cocannon described what he sees to be the two kinds of couriers.

“The first kind is just looking for employment, is not going to...put themselves into danger...the other kind is the alpha male, [who] wants to do 90 deliveries a day. Every day’s a struggle, [then] they want to sit at a bar and talk about how they escaped death 10 times that day,” he said.

Couriers said they are often driven by the excitement of the job.

“I’ve always had a passion for bikes,” Harris said. “I race bikes, and I just thought it would be a good job for me.”

However, couriers said their job is often difficult and sometimes painful.

According to more experienced bikers, it’s the more cautious rookies that tend to be injured the most.

“You’re usually not aggressive until you know what you’re doing, so the ones who are not aggressive are the ones who get into accidents,” said Cocannon.

Despite this, being a bike messenger is rarely a lifetime proposition.

“I would compare it to being a professional athlete, you’re usually in it for about 10 to 15 years,” Dennerlein said