Mobility Devices

Mobility Devices

Children with spinal muscular atrophy (SMA) may need several specialized assistive devices to complete activities of daily living. An occupational therapist should evaluate all patients with SMA soon after diagnosis and periodically assess for changing needs as the disease progresses. An occupational therapist or related provider should assess the patient’s unique abilities and limitations, and in turn, identify equipment and devices that allow patients to function maximally within their abilities and overcome limitations. 

Standers: Devices to promote weight-bearing

Weight-bearing activities are important for bone growth and development. In fact weight-bearing activity in young people may be a stronger predictor of peak bone mass than calcium intake.1 Children with SMA—even those who are unable to sit—may benefit from devices that help promote weight-bearing. These devices, commonly known as “standers,” come in a variety of configurations to meet the specific needs of each person with SMA. 

If the child is primarily supine, this supine stander is the best choice. With this supine stander, the patient is held nearly upright but with head slightly behind feet, vertically. Supine stander is also the best choice for patients who have insufficient head control—gravity and padding can hold the head in place in the supine stander.

Conversely, children who are mostly prone may use prone standers. Prone standers are configured in much the same way supine standers except the head slightly in front of the feet in the vertical direction. The standers are not solely for static standing; some have integrated wheel systems that can allow children to move while in the standing position, i.e., a standing “wheelchair.” 

Lastly, sit-to-stand standers allow patients to transition between a sitting, “wheelchair” configuration and a standing configuration. In most cases someone has to help the patient make this transition, but gaining independence in this task could be useful goal for appropriate people with SMA.

Wheelchairs: Powered mobility

People with SMA who were non-ambulatory should be evaluated for a wheelchair. The amount of freedom and relative independence that comes from successfully using a wheelchair cannot be understated. Mobility is important for psychosocial development, physical development, and reaching various developmental milestones.2 Early powered mobility is also an important milestone for parents report significantly less stress and greater satisfaction compared to non-powered mobility measures.3

Patients with SMA will likely require a power-assisted wheelchair, that can be controlled with hand or mouth controls. Determining how old the child must be before he or she is eligible for power mobility devices can be a significant issue. Researchers shown that a 20-month old girl with spinal muscular atrophy type 2 was able to independently use a power wheelchair after six weeks of training.4 Anecdotal evidence suggests children as young as early as 18 months old may be able to successfully and independently use power mobility devices. One difficulty is whether insurance will cover devices that are instituted too early in the child’s life. A similar worry is that payment decisions may take many months while children are left relatively immobile. Providers should properly document the cognitive development and physical abilities of the child to demonstrate that powered mobility is suitable. Adequate problem-solving and spatial relationship skills appear to be important factors in the child’s readiness for a powered wheelchair.5

Walkers: Walking with support

Some patients with spinal muscular atrophy are able to walk when they have appropriate support. Without mobility devices this support would come from a parent or caregiver. However walkers are useful surrogate for individuals in this group since they provide weight support and assist with balance. Typically, patients with spinal muscular atrophy will use a rolling walker. A rolling walker generally has four wheels with the handbrake that can stop the wheels from moving for stationary stability. Unlike walkers without wheels, rolling walkers do not need to be lifted and moved during ambulation. 

Like standers, walkers come in various configurations. Anterior walkers support weight in front of the patient, i.e., the person leans forward onto the walker for support. Conversely, posterior walkers support weight behind the patient. As such, the person leans slightly backwards for support. Gait trainers are another form of walker that provides support while standing and walking. Gait trainers may or may not have hand brakes, most do not. Thus patients must be able to stabilize themselves on four wheels while standing for this type of walker to be appropriate.

References

1. Welten DC, Kemper HCG, Post GB, et al. Weight-Bearing Activity During Youth Is a More Important Factor for Peak Bone Mass Than Calcium Intake. Journal of Bone and Mineral Research. 1994;9(7):1089-1096. doi:doi:10.1002/jbmr.5650090717 

2. Guerette P, Furumasu J, Tefft D. The Positive Effects of Early Powered Mobility on Children’s Psychosocial and Play Skills. Assist Technol. 2013;25(1):39-48; quiz 49-50. doi:10.1080/10400435.2012.685824 

3. Tefft D, Guerette P, Furumasu J. The Impact of Early Powered Mobility on Parental Stress, Negative Emotions, and Family Social Interactions. Phys Occup Ther Pediatr. 2011;31(1):4-15. doi:10.3109/01942638.2010.529005 

4. Jones MA, McEwen IR, Hansen L. Use of Power Mobility for a Young Child with Spinal Muscular Atrophy. Phys Ther. 2003;83(3):253-262. 

5. Tefft D, Guerette P, Furumasu J. Cognitive Predictors of Young Children’s Readiness for Powered Mobility. Dev Med Child Neurol. 1999;41(10):665-670.