Many clients use assistive technology (AT) devices. Ideally, these clients should have access to the devices whenever needed. This means the device has to be where the client needs it, regardless of the client's position and location.

Several commercially available mounting options are available to mount AT devices on wheelchairs, dependent mobility bases, alternative positioning systems, beds and flat work surfaces.

Why Is Mounting Important?

The mounting system positions the AT device for optimal access and visual regard. It also provides security to prevent the device from falling as well as to prevent theft. At the same time, the mount must be able to move for transfers or other activities.

Optimal access: Tristan uses his left index finger to directly select locations on his SGD. For optimal access, he needs the device's display tilted upward approximately 45 degrees and positioned left of midline so that his elbow is partially flexed when his finger contacts the screen. A mounting system can hold the SGD in precisely this location.

Visual regard: Jeff uses a switch to access his SGD. Due to his brain injury, Jeff only sees functionally out of the left upper quadrant of his visual field. The SGD must be mounted in this quadrant on his manual wheelchair for him to see the display.

Security: Lauren could easily see and access her SGD on the tray of her power wheelchair. However, when she engaged the power tilt to tilt back, the device would slide toward her. She required a mount that could secure the device through the full tilt cycle of the chair.

Mounting Considerations

Speech-generating devices are the most frequently mounted AT devices. These are often accessed directly (i.e. finger to display) and may require precise positioning. Some SGDs are quite heavy and require a more robust mounting system, but some are light enough to be mounted on smaller, less expensive options.

Laptop computers can be mounted on a wheelchair to provide access in various settings. This can be helpful to a client who is independently mobile. Additional considerations for mounting laptops include battery life as well as access method.

EADLs provide independent control of devices within the home. EADLs are typically small and lightweight, so they can be mounted with smaller mounting systems. However, they often need to be able to be mounted on the bed as well..

For more on mounting switches, see "Switches!", ADVANCE, Jan. 7, 2008.

Wheelchair Mounts

Wheelchair mounting systems usually consist of a frame clamp, one or two bars and a mounting plate. Several aspects of the chair affect the type of mount that can be used.

Frame shape/size: A wheelchair frame may include several shapes and sizes of frame tubing. Once the best spot is chosen, the frame clamp must match the frame dimensions in that location. It can be challenging to find the best spot to place the clamp.

Moveable parts: Attaching the mount to movable sections of the frame, such as footrest hangers, can lead to undue wear and tear on these components, as they are not designed to provide the leverage to mount the device so far from the frame clamp.

Tilt: If the chair has a tilt feature, the device must remain in position relative to the client so that the client can still access and see the device while the tilt feature is engaged. The frame clamp must be mounted above the tilt mechanism; if it

is mounted below, the client is likely to hit the horizontal bar with his knees when tilted. Tilting the frame can also make the mount less secure.

Frame space: Avoiding the moveable parts of a frame often leaves only the horizontal bars below the seat and the vertical back canes to mount the frame clamp. If the wheelchair has a tilt, the frame clamp must attach above the tilt mechanism. Back canes are difficult to mount to and do not work for all mounts.. This often leaves only the seat rail.

Seat rails are used to attach seats and seating components such as pelvic positioning belts and hip guides. The seat may sit so close to the seat rail that a frame clamp cannot be placed around the entire frame tubing. In this case, two options are available. For rounded tubing, Daedalus offers a side clamp that does not need to encircle the entire frame tube and requires little space on the frame. Second, many seat rails on power wheelchairs are square and include a groove on the side to attach components. Several mounting manufacturers make a frame clamp that attaches to this groove.

Multiple bases: Many clients have both manual and power wheelchairs and require mounting options that are interchangeable when possible. This requires a separate frame clamp for each chair. However, if the client uses direct access, the mount may not position the AT device in the exact location on both frames, and separate mounts may be required for each frame.

Stability: Many mounting systems allow the AT device to be swung out to the side for transfers. If the base is lightweight, it may tip over when the client is transferred out. In these cases a folding mount, or removing the mount before transfers, may be more appropriate.

Visual regard: Though it may be best for visual regard of the device, placing an AT device directly in front of a client's head can interfere with socialization and limit visual regard for the environment. You may need to compromise between optimal visual regard of the device and the environment.

Alternative Mounting Options

If possible, clients should be able to access their devices anywhere, not just while in their wheelchairs. There are available mounting options for beds or alternative positioning systems.

Alternative mounting poses two main challenges. First, you need to find a frame clamp that can be placed on the alternative base. Second, you must ensure that the client can still access the AT device from an alternative position.

Mounting Options

Rigid mounting systems traditionally include only one L-shaped bar. This can sometimes be swung away by pivoting it on the frame clamp.

Other mounting systems allow the horizontal bar to be swung to the side and folded down. Folding mounts are less likely to compromise the stability of the chair, though the AT device is often left facing outward at the side of the chair where it is at risk for damage. One unique rear-folding mount from Daedalus allows the device to be swung out of the way by lifting up and over the client and remaining behind the wheelchair when not in use.

Only a few mounts are designed for the client to maneuver independently. For example, the Daedalus locking, swing-away mount has a cable hanging from the horizontal bar. The client or caregiver pulls the cable to release a pin which then allows the mount to swing to the side. The new Mount 'n Mover allows the client with adequate upper-extremity motor control to change the AT device height and horizontal location, as well as swing the device out of the way for transfers.

After selecting the best mount for a client, I recommend involving wheelchair suppliers. They often can procure funding and help attach the mount to the frame.

Michelle L. Lange, OTR, ABDA, ATP, is owner of Access to Independence in Arvada, CO. She can be reached at MichelleLange@msn.com or visit her Web site at www.atilange.com.

Mounting Resources

A number of mounting options are available; here are three you may want to explore. Many manufacturers will provide inservices upon request to educate and familiarize clinicians with their products.

C.J.T. Enterprises:

www.cjt-yes.com

C.J.T. makes the Profiler mount and the PROLITE for lighter-weight AT devices. They also make a variety of mounts to be used in non-wheelchair situations.

Daedalus Technologies:

www.daessy.com

Daedalus' Daessy series includes rigid, swing-away and folding mounting systems. The rear-folding and locking, swing-away mounts are designed for independent use. Daedalus also makes an over-the-bed mount, as well as a large selection of frame clamps.

Mount 'n Mover from AbleNet: www.ablenetinc.com

This unique mount, distributed by Ablenet, allows independent control of the location of the mounted AT device.