Treadmills can be high-risk, especially when users make mistakes or become distracted, as national statistics and doctors can attest.
Treadmill safety has been in the news since the accidental death on May 1 of Dave Goldberg, 47, a Silicon Valley executive and the husband of Facebook chief operating officer Sheryl Sandberg. He was found with severe head injuries alongside a treadmill in a Mexican resort and died of blood loss in a Mexican hospital.
People are accustomed to terra firma. So walking or running on something moving, without the ground or scenery also changing, can lead to imbalance. It's one risk of using the third most popular type of home exercise equipment (behind elliptical machines and stationary cycles).
The U.S. Consumer Product Safety Commission says 24,400 people required emergency room treatment for treadmill injuries nationwide last year, with 23,900 ER visits in 2013 and 24,900 in 2012. Thirty treadmill deaths occurred in the decade ending in 2012.
"Treadmill injuries actually are quite common," said Dr. Louis Alarcon, medical director of trauma surgery at University of Pittsburgh Medical Center Presbyterian. "People fall off the devices with resulting fractures and head injuries. Concussions are quite common. There also are bruises, sprains, lacerations and occasionally there are more life-threatening injuries with head bleeds, spinal injuries or liver and spleen injuries that lead to bleeding."
Some treadmill accidents result from instability caused by overexertion and dehydration. Others are the result of heart attacks, strokes or simply fainting while on the machines.
"Some patients can't remember how they were injured because they sustained a concussion or head injury or they were intoxicated," Alarcon said. "What happens commonly is, people tend to overexert and push themselves to the limit, and that's when things go wrong."
Distractions also occur as people change songs on their smartphone, send a text, read or watch TV while on treadmills. Failure to understand how the treadmill works or follow safety rules can land people in the hospital, he said.
Dr. Victor Prisk, an orthopedic surgeon at West Penn Hospital and the Allegheny Health Network, said caution is warranted when using treadmills at hotels or resorts that can be poorly maintained and situated in isolated rooms. "Personally, I've had a couple of close calls," he said.
The belt can catch, the motor can fluctuate and the deck can be wobbly, all potentially causing the user to trip or lose balance. Prisk said they operate normally at low speeds but get wobbly at higher speeds. "If you don't oil it and clean the belt track, the belt can get sticky and change the cadence, and it can be very easy to trip."
On the other hand, he said, treadmills provide a healthy way for the "activity-deficient" population to get exercise. "But I always say to avoid the terrible 'toos' — too much, too soon and too often," he said.
Dan Griffin, general manager of the Pittsburgh area's Oxford Athletic Club, said health club treadmills are equipped with safety keys, which can be attached with a lanyard to a wrist or clothes. A fall or drastic movement disengages the key and stops the treadmill. However, he said, most people don't use them.
"People are not trained in safety and don't feel comfortable and are raising the speed quicker than they should," he said. "That's one of the advantages of learning to use the treadmill correctly.
"We also don't encourage people to work out with high-intensity levels of music that can be totally immersing," he said. "It cancels noise from the outside world. When you don't have kinetic awareness, which comes from what you hear and feel going on in your surroundings, you have more of a chance of problems."