Julian: Fiberoptics and Proximities for Independent Driving!

Background:

Julian is a young adult and busy college student. He has places to go and things to do! Julian also has spinal muscular atrophy (SMA), type I, which leads to profound muscle weakness. He started using a ventilator at about 1 year of age and has been driving a power wheelchair since he was 3.

Julian’s needs have changed over the years as his muscle weakness progresses. As a result, his seating and access have also changed. Julian requires a custom molded seating system to support his orthopedic asymmetries and provide adequate postural support. Julian has never been able to use any type of joystick, but he has been able to drive with switches since a very young age.

Evaluation – age 11

At age 11, Julian was re-evaluated to determine his best driving method, as he was having difficulty driving. He was able to drive his power wheelchair using the following combination of switches:

  • Forward and Reset: Fiberoptic switches for Forward and Reset were placed under the right index finger and thumb, mounted in the handpad of his armtrough (see Figure 1).
  • Left: a Proximity switch by the left side of his head was used for Left directional control and mounted in the left lateral pad of his head support.
  • Right: a mechanical Microlite switch was used by the right medial knee for Right directional control, mounted with an L bracket to a Gatlin mount to swing out of the way for transfers (see Figure 2).

He was also able to control his power tilt, Reverse, Speeds, and his computer through the driving method, using the Reset switch. He used his power wheelchair at school, home, and in the community.

Evaluation – age 17

By age 17, progressing muscle weakness had resulted in Julian no longer being able to drive his power wheelchair. We re-evaluated him, once again, to identify potential switch sites for Forward, Left, Right, and Reset.

  • Forward: Julian’s strongest movement was now moving his head to his left. He already was using a Proximity switch in this location for Left turns. We now assigned this switch to be Forward as most drivers activate and sustain contact with Forward more than any other direction (see Figure 3). The Proximity switch was mounted in the left lateral pad of a Stealth Products Pro Series iDrive Head Array.
  • Right: Julian was no longer able to move his leg to access a switch by his medial knee for Right turns. A Proximity switch was placed in the right lateral pad of the iDrive Head Array for Right directional control (see Figure 4).
  • Left: Julian’s strongest finger movement was at the left middle finger if his fingers extended slightly beyond the edge of the armtrough hand pad. He could then flex this finger toward the distal edge of the hand pad (see Figure 5). Finger movement is often easier if the fingers are already flexed. A Fiberoptic switch was mounted in this location to capture this movement and serve as Left directional control. The switch was mounted under the armtrough on a gooseneck mount which allowed precise positioning and is hollow to contain the Fiberoptic cables. This switch was then connected to the iDrive system.
  • Reset: Julian previously controlled both Forward and Reset with Fiberoptic switches by his right thumb and forefinger. He could now only move his right index finger from a flexed position, though had difficulty sustaining this movement (see Figure 6). Reset does not require a sustained activation, and so this switch site worked for this function. This switch was also connected to the iDrive system.

After submitting paperwork and obtaining approval, Julian received his new power wheelchair and driving method. Although using new switches in new locations, Julian drove well immediately and was very excited to be independent in his mobility, and other chair functions, once again!

Michelle is an occupational therapist in private practice, Access to Independence. She is a well-respected lecturer and author. She is the co-editor of Seating and Wheeled Mobility: a clinical resource guide, editor of Fundamentals in Assistive Technology, 4th ed., NRRTS Continuing Education Curriculum Coordinator and Clinical Editor of Directions magazine. Michelle is a member of the Clinician Task Force. Michelle is a RESNA Fellow, certified ATP, certified SMS and is a Senior Disability Analyst of the ABDA.

Head Positioning: matching product to client need, part 1 Posterior Supports

Michelle L. Lange, OTR/L, ABDA, ATP/SMS

Quite a variety of head supports are available to meet individual needs. These head supports have unique features designed to match specific requirements. Posterior head supports are by far the most common and may include lateral support. Collars provide support under the jaw and the suboccipital shelf. Forehead supports or straps provide support anterior to the forehead. One product provides support superior to the head, allowing for rotation and some limited flexion and extension while supporting/suspending the head in an upright position.

Head supports are commonly referred to as head rests as many clients use this seating component to rest against. A simple posterior head support provides a surface for the occipital area to rest against but offers little postural support and cannot prevent neck hyperextension unless placed at an angle to cup the suboccipital shelf. Some posterior head supports do include a generic contour designed to contact this suboccipital shelf but may not match the client’s unique contours. Other supports include a separate suboccipital pad designed to be placed inferior to this shelf to provide some actual head support and to limit neck hyperextension in combination with a separate occipital pad.

Lateral supports can be used to limit lateral neck flexion and rotation. When this head position is difficult to correct, 3-point contact may be required: lateral support at either side of the head, as well as lateral support along one jaw, often provided by the suboccipital pad. This force and counterforce help achieve neck alignment.

A critical part of wheelchair seating is achieving and maintaining an upright and aligned head position. Positioning the head involves far more than choosing a head support. Using a combination of seating strategies as well as matching product features to an individual’s needs will improve the final outcome for the client.

More than head support: general interventions to optimize head position

Michelle L. Lange, OTR/L, ABDA, ATP/SMS

Our last Blog addressed some of the causes of poor head position. In this Blog, we will explore general intervention strategies – things to try long before grabbing a specific head support. It is so tempting when we see a client with a sub-optimal head position to immediately try a different head support. However, our solution will be dictated by specific causes. And many of our solutions involve overall client position, not just a head support.

General Interventions include:

  • Ensuring the pelvis is in a neutral rotation
  • Increase trunk extension and scapular retraction
  • Change the impact of gravity on head position
  • Refer to neuro-optometrist, as appropriate

Head position is quite dependent upon the position of the trunk and pelvis. If the pelvis is in a posterior tilt, the trunk will be flexed or kyphotic. Due to the flexion of the trunk, the neck will also be flexed and any attempt to right the head will result in neck hyperextension (see figures below). If the pelvis is in an anterior tilt, the trunk will be extended or lordotic. This may lead to hyperextension of the neck as the client attempts to keep the trunk upright and the head balanced. In general, the pelvis should be placed in a neutral alignment, if possible, and the trunk supported in an upright posture. If the shoulders remain protracted or rounded, seating interventions to promote scapular retraction can help the client maintain a more upright head position.

For people with decreased head control, gravity can pull the head forward. Opening the seat to back angle or providing some posterior tilt in space can reduce the influence of gravity on head position and facilitate head control. For clients with a non-reducible kyphosis, the seat to back angle can be increased and/or tilt used until the head is over or just behind the pelvis (see figures below). This will allow the client to balance their head over the kyphosis without neck hyperextension. In clients without kyphosis, a significant amount of recline or tilt will often maintain the head in contact with a head support but is not a functional position and may even result in further loss of head control.

If the evaluation team suspects that vision is impacting head position, a referral can be made to a Neuro-Optometrist for evaluation and recommendations. Some interventions may improve head alignment, particularly in the case of midline shifts. For clients with Cortical Visual Impairment (CVI), atypical head positions are to be expected, as well as allowed. The client may need to assume a specific position to optimize vision – often with the head slightly forward and/or tilted.

Once head position has been optimized through these strategies, the evaluation team can determine the most appropriate head support. Keep an eye out for our next Blog which will address just that!