To Propel or Not to Propel

Repetitive Use Injuries, Aging and Preventative Strategies

Man pushing chairHow many strokes does it take to propel a manual wheelchair each day? The short answer is a lot. Diane Ulmer, OTR/L, manager of the Spinal Cord Injury Program at Madonna Rehabilitation Center in Lincoln, Neb., says the number is between 2,000 and 3,000 strokes. Unfortunately, that amount of repetitive activity can put a person at greater risk for developing a repetitive use injury such as tendonitis, carpal tunnel syndrome or impingement.

Who’s at Risk?

If you think about the stress being put on your upper extremities each day, you might wonder how you’ve managed to come this far without an injury.

“They not only have repetitive motions to the hand and shoulder during wheelchair propulsion but also to complete transfers, loading/unloading a wheelchair and the other activities of daily living,” Ulmer says. “The general population is at high risk due to excessive computer usage, repetitive industry work and other vocational activities that put them at risk. Individuals with SCI have these same risks associated with their work tasks in addition to the risk from the wheelchair propulsion and transfers in their daily routine.”

In fact spinal cord injury (SCI) puts you at a greater risk because your arms are functioning in a much different manner.

“You have fewer muscles to choose from, which means oftentimes the amount of repetition for the muscles that you have active is much higher than normal. For example, for somebody that has a spinal cord injury at their waist level or even at the chest level, they’re using their arms in place of what they used to use their legs for,” says Kristin Kaupang, PT, NCS, ATP, a physical therapy clinical specialist at Harborview Medical Center, which is part of Northwest Regional Spinal Cord Injury System, in Seattle, Wash. “So there’s a lot more strain, a lot more stress on joints that are not meant to be stressed upon in that manner.”

The most common repetitive use injuries occur at the wrist and shoulder. The wrist injury is commonly carpal tunnel syndrome that results in numbness or tingling, Kaupang explains. At the shoulder, the injury is typically impingement or tightening around the shoulder capsule.

And as Ulmer mentioned, it’s not only wheelchair use that’s to blame for these injuries.

“If you’re using different muscles to dress yourself or to transfer or to be able to bathe yourself, those muscles are also being used in an alternative fashion than they were used prior to an injury,” Kaupang says.

Aging and Injuries

Remember the number of strokes per day for a manual wheelchair user? Think about those 2,000 strokes compounded over a lifetime. As the number of strokes grows exponentially, so does your risk for repetitive use injury, Kaupang says.Model of shoulder joint“Repetitive use injuries can become more of a concern as a user ages because as we age our flexibility and strength can be compromised as well as the overall changes in our bodies that occur with aging that place people at greater risk for injury,” Ulmer says.

However, repetitive use injuries don’t automatically mean a move from manual to power. Ulmer says some modifications can be made to reduce the number of transfers, which can take some of the stress off the joint. For example, staying in the wheelchair while driving can reduce the number of transfers in a given day, and using a mechanical lift can cut back on the amount of work required during transfers.

“There are many wheelchair users who maintain a high level of wellness and are successful manual wheelchair users as they age,” Ulmer says. “It really depends on each individual’s lifestyle, his/her personal goals and preferences, any injuries prior to their SCI that may affect their ability to push long term and the age they were when they sustained the SCI, and how they were trained to use their upper extremities for propulsion and daily tasks.”

Of course, Ulmer says it is not unusual for someone to move to a power chair to conserve energy and control chronic pain. She says a power chair helps people address these issues while still maintaining independence.

If a power chair is needed, Kaupang says sometimes a compromise can be made, wherein the individual uses a power char for long distances and community outings but retains the manual chair for use at home or short distances.

Preventative Strategies

Fortunately, there are some ways to minimize your risk for repetitive use injuries and keep yourself healthy enough to propel even into your golden years.

Ulmer says an exercise program that includes balancing the strength in the different muscles of the shoulder as well as increasing flexibility is important. She says this “is a different type of exercise program than a trainer at a gym would typically give someone who is not propelling a wheelchair every day.”

One thing Ulmer says to watch out for is overstrengthening the muscles used for propulsion. Balance is key.

Posture is also a big component of injury prevention, and therapists can spot poor posture a mile away. Kaupang says she typically sees a sunken chest or the shoulders leaning far forward of where the head is positioned.

“That makes pushing less efficient inherently,” she says. “So if you can work on posture and work on strengthening the muscles in your upper back to help you sit up right, your push mechanics are a lot better.”

Although it might seem silly, getting training on wheelchair propulsion is your best defense against repetitive use injury.

“If you use all your energy, all your force, just to make one revolution of the wheel, you’re going to have a lot more damage to your joints over a long period of time,” Kaupang explains. “Whereas, if you have a really efficient stroke, where you’re able to conserve your energy, have maximizing force that you put on the wheel with minimizing the effort, you’re able to preserve your pushing for a lot longer.”

Ulmer agrees. “I see individuals 20 years after their injury who were not trained in proper techniques, who are not using an ultralightweight wheelchair or who could easily make some big changes with the proper training,” she says.

The rehab team can analyze how you’re propelling and then ensure that your stroke is as efficient as possible.

Both Ulmer and Kaupang use tools such as SmartWheel technology to analyze the push forces, frequency and duration during wheelchair propulsion. This technology can provide objective numbers including how much force is being applied at what angle—information that can help therapists ensure proper wheelchair and seating to maximize efficiency and prevent shoulder and wrist complications.

In addition, “a therapist that’s experienced with wheelchair seating and positioning, they can give you some techniques for efficiency,” Kaupang says. “If you’re thinking about a clock position on the wheel, from 11 o’clock to 2 o’clock, you don’t want your hands to be beyond that realm. So you don’t want to reach too far back, or you don’t want to push too far forward.”

Kaupang says the rehab team should also be able to provide the correct equipment, such as an ultralightweight chair or pushrims with grip surface if necessary.

Another way for prevent injury is to analyze your lifestyle.

“I also see college students carrying a 15-pound backpack on the back of their chair all over campus, which puts them at increased risk,” Ulmer says. “I can’t emphasize enough the importance of follow-up care with your rehab team, analyzing how you do each activity and ensuring you have the proper tools/equipment to perform each tasks to prevent injury and preserve life-long independence.”

Examining your daily routine and trying to cut out as many transfers as possible is a good idea.

“Avoid overhead activity that puts the shoulder at increased risk for injury, and pay close attention to the position of the hand/wrist during transfers, pressure relief and wheelchair propulsion,” Ulmer advises.

And don’t neglect your equipment. Make sure your wheelchair is well maintained.

So you think you might have a repetitive use injury. What now?

“The key … is to identify (repetitive use injuries) early and to get treatment as quickly as possible because a lot of (people) I think with just a simple change of mechanics or a simple change of position you can really avoid a lot of the pain,” Kaupang says.

Get information on activity modification for musculoskeletal pain at Northwest Regional Spinal Cord Injury System’s Web site.

About the Author

Elisha Bury is the editor of The Mobility Project. She can be reached at