Follow-up It is imperative that follow-up with the client and/or caregivers takes place to ensure that the seating intervention continues to meet the client’s needs. This follow-up may need to continue over time, as new needs may arise. One way to provide this follow-up is to use outcome measures. Tracking outcomes has several advantages. Using outcomes can verify that client and team goals were met and can reveal whether further information is required. For the clinician, tracking outcomes provides valuable feedback concerning whether recommended interventions are generally successful. Strong outcomes validate
occupational or physical therapy services and can even be used to strengthen funding for services and recommended equipment. Poor outcomes provide an opportunity to learn and improve services. Outcome measures may sound intimidating and time consuming, but a simple post-evaluation survey can be utilized. Formal outcome measures, such as the Quebec User Evaluation of Satisfaction with Assistive Technology – Version 2.0 (Demers, Weiss-Lambrou, & Ska, 2000); the Functional Mobility Assessment (Schmeler, Holm, & Shin, 2008); and the Canadian Occupational Performance Measure, 5th ed. (Law et al., 2014) are also available.
TYPES OF WHEELCHAIR SEATING SYSTEMS
The seating assessment determines client parameters, which are then matched with appropriate product solutions. A seating system is made up of the primary support surfaces (the seat and back) and secondary support components (including anterior and lateral supports, such as lateral trunk supports and pelvic positioning belts). Various seating surfaces are placed in relation Primary support surfaces Primary support surfaces include the seat and back (Waugh & Crane, 2013). The seating surface is under the pelvis and thighs. The back is typically behind the posterior pelvis and trunk. The seat generally supports the entire buttocks and thigh to provide adequate pressure distribution and support. The ischial tuberosities (ITs) and coccyx are sometimes unweighted to remove pressure from these areas, which are at risk for pressure Secondary support surfaces Secondary support surfaces maintain alignment with the primary support surfaces (Waugh & Crane, 2013). Lateral supports can be placed at the trunk, hip, thigh, or knee. A head support primarily provides posterior support to the head. Secondary components Seated angles The angles in a seating system are critical to meeting positioning goals of alignment, support, and stability (Waugh & Crane, 2013). These angles are particularly important in providing some variety of posture for tasks and for comfort. Key seating angles include seat-to-back angle (trunk to thigh); knee angle (upper leg to lower leg); ankle angle (lower leg to foot); and tilt in space. Seat-to-back angle The seat-to-back angle is the angle between the trunk and the thighs. Although the seat-to-back angle is often calculated by measuring the angle of the wheelchair back canes to the seat rails or the angle of the primary seating surfaces, the most accurate measurement is taken on the client’s body. Many chairs (e.g., a dining room chair) are set at a 90° seat-to-back angle. However, in order to maintain an upright trunk position (thighs parallel to the floor and the back at a 90° angle to the thighs), trunk control is required, specifically co-contraction of the trunk flexors and extensors, even if the torso leans against the back of the chair. Maintaining this position is very difficult or impossible for many clients who have muscle paralysis, weakness, or abnormal tone, which can limit co-contraction. If a client cannot maintain an upright trunk, one of two things happens: either the client slides the pelvis forward into a posterior tilt to increase stability and, in effect, opens his or her seat-to-back angle or the client falls forward, flexing at the trunk. Various strategies to control posterior pelvic tilt and forward flexion of the trunk can be employed. First, the optimal seat-to- back angle must be determined. A seat-to-back angle that is too closed for the client (less than 90°) will often result in posterior pelvic tilt and/or trunk flexion, particularly in clients with limited hip flexion or tight hamstrings. Opening the seat-to-back angle slightly (to 95° to 100°) allows the client to find a position of rest against the back, taking advantage of gravity and requiring less active trunk control (Waugh & Crane, 2013). An antithrust cushion will often close the seat-to-back angle by raising the front of the thighs in relation to the pelvis. The seat-to-back angle may need to be increased to compensate.
to each other at specific seated angles to support and maintain the seated posture identified during the assessment. The position in space of the entire seating system (tilt or recline) is also an important consideration when determining the seating system itself. These angles are supported by the mobility base.
injuries. The height of the back varies with the degree of support required by the client as well as the functional activities performed within the seating system. For example, a back that stops under the scapulae allows for greater arm movement and a longer stroke in self-propelling a manual wheelchair. A back that stops at the level of the shoulders is required when anterior trunk supports, such as shoulder straps, are employed.
such as pelvic positioning belts, anterior trunk supports, and anterior knee blocks provide anterior postural support. Medial knee supports limit excessive hip adduction.
Some clinicians close the seat-to-back angle intentionally to “break up tone” and decrease extensor thrust. This “jackknife” position works well for physically carrying a client with high tone. However, it usually does not work well in a seating system. Many clients with high tone need to use some of their muscle tone to sit in their seating system. Breaking up tone often leaves the client with very low underlying tone in the trunk and more difficulty sitting in the seating system. Recline is a feature available on many manual and power wheelchairs that allows the seat-to-back angle to be easily changed from 90° to 180° (Figure 6). Figure 6: Manual Recliner Wheelchair
Note . From Invacare, n.d., retrieved from http://www.invacare.com. © Invacare Corporation. Reprinted with permission. This feature is available in manual (dependent) and power (independent) versions. Recline allows the client’s position to be changed for the task at hand. For example, the client may be partially reclined to rest or completely reclined for catheterization. Eating may be safer if the client is in a slight recline. However, recline has two primary disadvantages. First, opening the seat-to-back angle can elicit extensor tone in some clients. Second, recline creates shear. Shear occurs when the primary support surface moves in relation to the client’s body, resulting in friction forces and loss of position in relation to the
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Book Code: PTNC1023
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