Vol. 27 • Issue 26
• Page 20
Assistive technology applications for a client with a spinal cord injury (SCI) may include seating, a mobility base, computer, electronic aids to daily living (EADL), home and vehicle modifications, ADL equipment and recreation technology. Let's start with seating.
A seating system has two main goals for the client with a spinal cord injury: to provide support, particularly below the level of injury, and to protect the skin, as these clients are often at high risk for pressure ulcer development.
Depending on the level of injury, the client may have reduced trunk control. If the client cannot stabilize the trunk, then any use of the upper extremities and head are reduced. The client may require increased stability of the trunk to be more functional, to maintain posture throughout the day and to even support respiration. For children, support at the trunk is essential as kids are at such high risk of developing scoliosis. I know one rehab doctor who claims that all children with spinal cord injuries will develop scoliosis.
Clients with lower injuries will require only minimal support at the trunk, as excessive supports may limit trunk movement required to reach forward and to the side, and to achieve optimal self-propulsion of a manual wheelchair. In these cases, a client may opt for a closed angle at the back and thighs, sometimes referred to as bucketing or dump. The pelvis is positioned lower than the knees, "bucketing" the pelvis and increasing stability without limiting trunk movement. This typically requires the feet to be placed under or behind the knees. Some clients prefer to assume a posterior pelvic tilt to increase stability, but a neutral pelvis is ideal, as this improves body biomechanics and improves pressure distribution in the seating system. The back of the chair may be quite low, sometimes only to the top of the pelvis. This optimizes movement, but does not provide much support for resting. Armrests are not typically present.
Clients with midlevel injuries will require moderate support at the trunk, with a non-sling back placed below the scapulas to facilitate self propulsion. Lateral trunk supports may get in the way of propulsion, so a contoured back is often used instead. Anterior trunk support, such as a chest strap, may be used for certain circumstances such as traversing a bumpy path as the client may pitch forward and not be able to independently assume an upright posture. These clients are not as likely to have a closed seat-to-back angle, and armrests may be present for support when the client is not propelling. The armrests need to flip up or swing out of the way.
Clients with injuries at a higher level are not able to self propel a manual wheelchair or reach forward or to the side, so the seating system is no longer supporting these activities. More aggressive support for the trunk is now required and can range from lateral and anterior trunk supports to orthotics (i.e. TLSO) to molded seating systems. The back is now to the level of the shoulders and head support is required, as this client is most likely using a tilt or recline system and requires posterior head support at least during weight shifts. The upper extremities require support, not just a place to rest, to protect the integrity of the shoulder (i.e. armtroughs).
Regardless of the level of injury, pressure must be addressed through pressure distribution and pressure relief. If you were seated on a bleacher at a sporting event, your bottom would have poor pressure distribution, as it is contoured and the seating surface is not. Good pressure distribution prevents one or two small areas from taking most of the weight. Cushions may be generically contoured or custom molded to match a client's shape. Cushions also use a variety of materials that allow the client's bony prominences to sink in and envelope the tissues to maximize pressure distribution. Pressure maps display if pressure is distributed or if "hot spots" are present in those isolated areas.
Pressure relief completely removes pressure from an area, either temporarily or long term. This can be as simple as a manual weight shift (eg. wheelchair push-up) or using tilt or recline to shift weight off of the bottom and put it on the back for a bit. No clear guidelines exist on weight shift duration or frequency, and these recommendations will vary with the individual client's risk level. Some specialized cushions act like a rotating air mattress - only some "cells" are filled at any given time so that those areas are completely unweighted, allowing blood flow to return to the tissues. Some cushions completely unweight the ischial tuberosities (ITs) to prevent pressure-sore development for very high risk clients. Weight shifts are important for other reasons. Changing position, like tilting rearward or reclining, provides a position of rest. Reclining can ease certain ADL, particularly catheterization from the wheelchair. Finally, recline may be necessary to address autonomic dysreflexia.
Depending on the level of injury, a client with a spinal cord injury will require either a manual or a power wheelchair. The goal is functional mobility. Some clients may be able to self-propel a manual wheelchair, but without adequate efficiency to be functional. In this case, a power wheelchair may be indicated.
A client with a low-level SCI generally will be able to self propel. Ultralightweight wheelchair frames are very lightweight, with adequate adjustment to place the wheel in the best position for efficient self propulsion, bucket the pelvis as needed, camber the wheels for increased stability and tight turning, and tuck the feet under. Research has demonstrated decreased repetitive stress injuries to the shoulder with the use of these very lightweight frames. Ideally, the shoulder should be directly over the rear axle; the hand, when hanging from the shoulder at rest, should just reach the middle of the wheel with the fingertips.
A client with a midlevel injury may be able to self propel, but with less strength and an impaired grip. This client may propel by pushing against the tire with the rear of the palm, rather than gripping the hand rim or tire. A rubber coating on the hand rim can increase friction for a better grip, or pegs can provide another surface to push against. These clients tend to use a less effective propulsion pattern that increases shoulder-injury risk, due to the muscles that remain intact. A very lightweight chair is still very important. Some of these clients may benefit from power-assist wheels or moving into a power wheelchair.
A client with a higher level injury will require a power wheelchair. If the client has some upper extremity function (C5-C6), he should be able to use a joystick and may benefit from a goal-post style handle to accommodate lack of grip. Upper-extremity support, such as an arm-trough or mobile arm supports, also should be included. When upper-extremity control is not present, but neck movement is, the client may be able to use a head array, Peachtree or Magitek. If neck movement is not present, the client can use pneumatic control through sip 'n puff.
Weight shifts can be accomplished through a power tilt and/or recline. It is possible to control these power seating functions through the drive control if the client is unable to reach a separate toggle control. The client may require a power wheelchair that can accommodate a ventilator and other medical equipment. Finally, a client with such limited motor control will require other assistive technology for written output and control over household devices such as lights and audiovisual equipment. Some power wheelchairs include mouse emulation for computer access and infrared transmission to control devices in the home environment. Power wheelchairs also interface with other assistive technology, such as an electronic aid to daily living (EADL), allowing the drive method to become the access method for this external assistive technology device.
Michelle Lange, OTR, ABDA, ATP, is owner of Access to Independence in Arvada, CO. She has 20 years' experience working with assistive technology. She is past secretary of RESNA and a frequent author and presenter. She can be reached at MichelleLange@msn.com.