Positioning

• Positioning

  • 
    

    In this topic we will take a look at the importance of the careful positioning of communication aids and their accessories. We will cover:
    

    • Why we need to mount and position access communication devices and their accessories
    • Some examples of equipment used to mount and position devices
    • Positioning

  • Mark as done

    Positioning Switches

    Children with physical disabilities are usually limited in their range of movement for their hands and arms. They may also have uncoordinated movements which can be controlled, to some extent, by gripping onto something, such as the corner of the device. 

    It is very important that when using direct access, or any of the other access methods, that the device is positioned in such as way that it is easy, comfortable and not tiring, for them to access for extended periods of time. If the communication aid requires too much effort or causes discomfort or pain then the child is unlikely to use it.
    

  • Mark as done

    Thinking about the questions that need to be asked

  • Mark as done

    

    Positioning Switches

    The positioning of a switch as an input device, so that the user does not find it awkward or tiring, is a very important part of the AAC assessment.

    

    Understand the User

    How will the switch be controlled? Head, mouth, hand, knees or foot? What pattern of movement is possible and how consistent? Fine motor pattern or gross - more random? How much pressure or force is possible (as this determine the required stability of the switch in a clamp or on a mat)?

    

    Switch Choices

    Each switch may require a specific connection, each type of mount may require a specific clamp, fixing or nonslip mat. Not all switches and mounts are compatible and most switches can have several options in terms of positioning depending on the user and the setting.

    
    Positioning

    Positioning

    This will depend as much on the way the user activates the switch as it does not the setting. Will the switch be activated when the user is in a wheelchair, bed, at a desk or on the floor? Does the switch need to have additonal clamps around the wheelchair tubing, perhaps when using foot or knee access or a head fixing. If the switch is on a desk does it need velcro or a sticky mat or wedge to stop it slipping or provide the right angle?

    

    Review and review again

    Evaluating the success of any positioning is ongoing. Repetitive strain injuries can occur, just as they can when we sit at the computer and use a mouse incorrectly for any length of time. Abandonment of the AAC device may not be because communication is difficult, but because the assistive technology is uncomfortable to use. Keep checking and updating!

    ‹ ›
  • Mark as done

    Activity - Matching movements to switches and position

    Consider these movements:

    1. extend and flex elbow to move forearm (like banging a drum)
    2. move forearm side to side from elbow (like using a pencil eraser)
    3. rotate hand (palm down to palm up and reverse)
    4. make a hand wave (side to side at the wrist)
    5. make a door knocking movement
    6. make a pointy finger or stick thumb out

    Now consider for each of these movements which switch you might use and where you would place it. AbleNet have a series of webinars about switch access, positioning and use on YouTube. 

    Write down your findings in your reflective journal
    

    
    

  • Mark as done

    The importance of placement

    Any type of switch is dependent on the child’s reliable movements. It follows that positioning the switch accurately will be very important in order to use these movements. 

    Take for example a Microlight switch which is very good at activating anything electronic, using very small movements with very little force. The switch requires just 0.7mm of movement in order to cause something to happen and is often used with very small finger or hand movements. In order to be reliable the switch would typically be placed very close to the area of the body part used to activate the switch.

    Often the easiest way to position switches is to use Velcro boards such as the Maxess trays or by fixing Velcro directly to the wheelchair trays.

    Getting head switches into the right position is also very important. It’s essential that the switch can be easily activated through a purposeful head movement, such as a tip to the left or right, but that the switch does not get activated during typical head movements, such as turning to see someone. 

    There are a number of specialist mounts and poles such as those designed by Daessy that can be used to get switches in the right location, usually attached to the child’s wheelchair. 

    
    

  • Mark as done

     Eye Gaze Video - Reviewing use

    Watch the video and think about all of the issues that had to be considered in setting up this system for her use 

    Ava using a Tobii Dynavox I-12+, PCEye Mini, and PCEye Go. Transcript available

    
    
  • Mark as done

    Positioning Eyegaze

    Even eyegaze requires careful positioning. It must be mounted using a floor mount, desk mount, or attached to the wheelchair, so that the device is held around 60cm away from the child’s face. If it is not in the best position then accuracy will be poor and the child will give up quickly!

    Track Boxes

    Each eyegaze system has a Track Box size rating. This indicates the amount of movement that a child can make and still have accurate eyegaze. It also indicates the amount of tolerance for the positioning. As an example, the Tobii Dynavox IS4 camera found in the EyeMobilePlus and i-Series devices has a track box of 35cm by 30cm. This represents an invisible box around 60cm directly in front of the camera. The eyegaze will work as long as the child’s eyes are within the box.  The LC Edge camera, by comparison, has a tracking box that measures 7.6 x 6.4cm so requires the user to keep their head still. 

    This image is taken from the Tobii Dynavox website which also contains a video guide to eye gaze.

  • Mark as done

    Summary 

    • Devices should be comfortable and easy to use, so getting them into the right position is vital for success
    • Positioning switches accurately is very important if someone with a motor impairment is going to consistently hit the switch with minimal effort.
    • Like switches, eyegaze systems also need to be mounted carefully so that they are the correct distance and angle from the child’s eyes. 

  • Mark as done

    Further Reading 

    • Boston Children’s Hospital slides: Get in Position to Communicate seating, mounting, and physical access (Download PDF) In depth information although it mainly shows adults similar mounts and positioning can be set up for children.
    • Ablenet Switch Selection Guide (download PDF)
    • The Eyegaze Edge® : How does it work? What do you need to know? (download PDF)

    
    

  • Mark as done

    Reflective Journal 

  • 

    Journal

    Reflective Journal

    Mark as done
  • Mark as done

    Presentation slides

  • 

    URL

    Positioning and Mounting URL

    Mark as done