Simulation When possible, it is very effective to simulate the seating intervention that is being considered. Linear and molded seating simulators are available (Figures 3 and 4). Simulation helps determine what seated angles and support surfaces are required. Linear simulators allow the hip and knee angles to be changed,
seat depth and back height to be adjusted, and various lateral and anterior supports to be added, as needed. This helps to determine specific seating recommendations, even if the final seating system does not use linear seating surfaces. A molded simulator is typically used to simulate a molded seating system to determine if it will meet a client’s needs (Figure 4).
Figure 3: Linear Simulator
Figure 4: Molded Simulator
Note . From “Products,” by Prairie Seating Corporation, 2007, retrieved from www.prairieseating.com. © Prairie Seating Corporation. Reprinted with permission. Pressure mapping Pressure maps allow the evaluating team to determine the seated pressures on current seating surfaces and compare them to trial cushions or simulated seating surfaces (Figure 5). The pressure map is a flat electronic sensor that is placed on top of the seating surface. The client then sits on the map surface. The map measures interface pressures along the entire seating surface and can record high and low points of pressure. A pressure map takes numerous pressure readings per second in millimeters of mercury (mmHg). Computer software generates a display that indicates pressure distribution along the seating surface as well as any areas of high pressure. This can be useful for clients who have a history of pressure injuries or who are at high risk for pressure injuries to compare various seating surfaces (Stinson & Crawford, 2015). Pressure maps can also be used to educate the client and caregivers. For example, the map can demonstrate when the client is properly positioned in the seating system and the effect of weight shifts on seated pressures. Figure 5: Pressure Mapping System
Note . From “Products,” by Prairie Seating Corporation, 2007, retrieved from www.prairieseating.com. © Prairie Seating Corporation. Reprinted with permission. functional activities, such as transfers. The client may not be able to accurately compare one cushion to another if only allowed to sit on each cushion for a few minutes. Often, at least a full day per cushion is required for the client to decide which cushion best meets his or her needs. Shape capture When “off the shelf” seating does not provide the support, pressure distribution, and/or off-loading of the bony prominences required, a custom- molded system may be indicated. If a molded seating system is recommended, the client’s body shape in the desired posture is “captured,” often during the assessment or later after funding approval. Various techniques are employed, depending on the manufacturer. Most commonly, the client is placed in a molded simulator (Figure 4), which is made up of two large bags full of small beads (Sparacio, 2018). Air is slowly removed from the bags, stiffening them, and the bags are molded around the client to create a seating system that supports the body in the position identified on the mat exam. Changes can be made during the shape capture until an optimal position is achieved. The air is then fully removed to maintain the shape, the client is removed, and the resultant “shape” of the bags is captured either by plastering this shape or digitally recording it. Activity idea: Borrow some cushions, and sit on a different one each time you type a report. Compare features. Fabrication and fitting The seating assessment is completed by providing specific seating recommendations. The clinician generally completes a letter of medical necessity containing information required by the funding source(s) and provides this letter to the equipment supplier, who submits it, along with all necessary paperwork, for funding approval. Once the equipment is approved, the seating system is either ordered or fabricated. The fitting process is an extension of the assessment. The client is fitted to the seating system, and the evaluation team must verify that the anticipated results were achieved (Minkel, 2018). Even the most careful assessments and measurements will sometimes fail to produce the desired results, and further changes may be required to meet the client’s needs. Changes may also need to be made during the fitting as a result of growth or other client changes that have occurred since the original assessment. Several months may have elapsed between evaluation and delivery.
Note . From “A Wireless Lingual Feedback Device to Reduce Overpressures in Seated Posture: A Feasibility Study,” by O. Chenu, N. Vuillerme, J. Demongeot, and Y. Payan, 2009, PLoS ONE, 4 (10), e7550. Retrieved from http://openi.nlm.nih.gov/detailedresult.php? Equipment trials Highly customized seating interventions are hard to simulate, let alone trial for extended time periods. Trials of cushions may be indicated to ensure that the client does not develop pressure issues and to allow the client to compare cushions during
Page 21
Book Code: PTNC1023
EliteLearning.com/ Physical-Therapy
Powered by FlippingBook