Assessing Student's Needs for Assistive Technology (ASNAT)

Chapter 7 – Assistive Technology for Positioning, Seating, and Mobility
Remember that a device should be positioned within an individual’s optimum physical and visual range.
Placing a device on a slant board may facilitate positioning.
Summary of: Positioning Students with Cerebral Palsy to Use Augmentative and Alternative
Communication
McEwen & Lloyd (1990) describe the importance of proper positioning for students to
successfully use a communication device. They cite research that concludes this importance such as the
work by Hardy (1983) and state, "a child's ability to control AAC devices may be totally dependent on
adequate positioning" (McEwen & Lloyd, 1990, p. 15). The premise they base their article on is that
seating and positioning is the domain of physical and occupational therapists, physicians, rehabilitation
engineers, and equipment vendors but it is necessary for everyone on a child's team to know enough
about positioning and seating "to recognize when it is not optimal and know how to make simple
adjustments and recommendations" (McEwen & Lloyd, 1990, p. 15)
The authors note that it is rare that an individual has only one form of communication thus
seating and positioning must be considered for all forms. Individuals who effectively use eye pointing or
a gestural "yes" and "no" system in addition to a communication device need to be positioned optimally
for each of these modes. When in a prone stander or in a side lying position, communication must be
considered as well. When properly positioned, the head and arms are freer and muscle tone is greatly
relaxed to allow the individual to do more than maintain a position.
An upright position is generally the primary desired position for communication as well as other
functional activities. Several researchers have found the upright position to "aid in maximizing cognitive
abilities, motor skills, and improving the variety of life experiences." (McEwen & Lloyd, 1990, p. 16)
The use of a wheelchair also adds functional mobility.
McEwen & Lloyd (1990) provide guidelines for achieving optimal seating and positioning. The
first and most fundamental rule is for the control of the hips and pelvis. The bottom must be positioned
in the back of the chair with the hips flexed at a 90 degree angle. The pelvis should be neutral or slightly
bent forward. The chair should provide a firm and stable seat. The position should not promote internal
hip rotation. Persons with skeletal deformities may need to have the chair specially designed to achieve
the best hip and pelvis placement.
To achieve optimal positioning of the hips and pelvis, the angle of the seat and back of the chair
in relationship to the floor must be considered. The seat should be parallel to the floor and at an angle of
90 degrees from the seat back. They point out that tipped seats and reclined backs result in decreased
performance. Once the hips and pelvis are properly positioned, blocks, towels, and other soft objects can
be place around the hips and pelvis to support the position and help the individual maintain the position
over time. Legs should be slightly apart to provide a better base of support. An abductor block can be
placed between the legs if necessary. A seatbelt low across the hips helps secure the position. It is
imperative that the student be carefully positioned in the chair each and every time.
A second basic rule that McEwen and Lloyd (1990) posit suggests the placement of the knees
and ankles at 90 degrees of flexion to the chair and floor. Less than 90 degrees of knee flexion can
contribute to extension and thrusting. An inappropriately placed footrest can contribute to poor pelvic
tilt.
The third rule applies to head placement. McEwen and Lloyd (1990) note that "head position
influences vision, breathing, listening, vocalization, feeding, and attention" (p. 18) and can also
influence reflexes that can impact hand and arm use. It is important to consider head placement before
trunk placement because of the head’s importance to overall functioning.
Assessing Students’ Needs for Assistive Technology (2004) 185