Short answer

Incorporate user-specific physiological data, particularly autonomic nervous system integrity, into the design and selection of dynamic wheelchair seating systems to mitigate risks and optimize user health.

Field
Human Factors
Source
PLoS ONE (2017)
Method
Experimental study
Sample
29 participants (19 with SCI, 10 controls)
Evidence
Strong effect

Adjustable wheelchair seating positions significantly impact blood pressure and cerebral blood flow, particularly for individuals with spinal cord injuries affecting autonomic nervous system control. This human factors research insight is drawn from a 2017 study published in PLoS ONE. Using Experimental study with 29 participants (19 with SCI, 10 controls), researchers explored how this design variable affects real-world outcomes. The key design takeaway: Incorporate user-specific physiological data, particularly autonomic nervous system integrity, into the design and selection of dynamic wheelchair seating systems to mitigate risks and optimize user health.

Study
Human FactorsHigh ImpactStrong effect

Dynamic Wheelchair Seating Alters Cardiovascular Function in Spinal Cord Injury Patients

Adjustable wheelchair seating positions significantly impact blood pressure and cerebral blood flow, particularly for individuals with spinal cord injuries affecting autonomic nervous system control.

PLoS ONE · 2017

01

Key Findings

  • 01Individuals with SCI and autonomic pathway lesions experienced reduced supine blood pressure and MCAv, which further declined in standard seating compared to those with preserved autonomic control.
  • 02Elevated seating positions triggered significant drops in blood pressure and MCAv in individuals with autonomic lesions, with the duration spent below supine blood pressure being greatest in this group.
  • 03Lowered seating positions appeared to bolster blood pressure in individuals with autonomic lesions.
02

Application

Design takeaway

Incorporate user-specific physiological data, particularly autonomic nervous system integrity, into the design and selection of dynamic wheelchair seating systems to mitigate risks and optimize user health.

How to apply

When designing or specifying dynamic seating for individuals with SCI, prioritize features that allow for controlled, gradual transitions and offer a range of positions, including lowered options, with clear guidance on appropriate use based on individual autonomic function.

Project actions

  • 01When researching user needs for mobility devices, consider how different physical configurations might affect physiological responses.
  • 02If your design involves adjustable positions, think about how to test the physiological impact on target users.
03

Method & Evidence

AimTo investigate the effects of moderate changes in wheelchair seating position on orthostatic cardiovascular and cerebrovascular reflex control in individuals with spinal cord injury (SCI) and neurologically intact controls.
MethodExperimental study
ProcedureParticipants were tested in supine and three seated positions (neutral, lowered, and elevated) using a dynamic Elevation™ wheelchair. Beat-to-beat blood pressure, heart rate, and middle cerebral artery blood flow velocity (MCAv) were non-invasively recorded. Participants with SCI were stratified based on the severity of their cardiovascular autonomic pathway injury.
Sample29 participants (19 with SCI, 10 controls)
ContextAssistive technology design, rehabilitation engineering, medical device development

Variables

IVWheelchair seating position (supine, neutral seated, lowered seated, elevated seated)
DVBlood pressure, heart rate, middle cerebral artery blood flow velocity (MCAv)
CVParticipant group (SCI with autonomic lesions, SCI with preserved autonomic control, neurologically intact controls), time of day, ambient temperature
04

Strengths & Limitations

Strengths

  • +Inclusion of a control group of neurologically intact individuals for comparison.
  • +Stratification of SCI participants based on autonomic pathway integrity, allowing for more nuanced analysis.

Limitations

It can be challenging to accurately measure physiological responses without specialized equipment and expertise. Generalizing findings to all individuals with SCI may not be appropriate due to the wide variability in injury type and severity.

Reliability & validity

The study used non-invasive physiological monitoring techniques, which are generally reliable for beat-to-beat measurements. Validity is supported by the comparison between different participant groups and the clear physiological outcomes observed.

Think critically

How might the design of the transition mechanism between seating positions influence the magnitude of physiological changes experienced by the user?

05

Design Principles

"User-centric design for assistive technologies must account for individual physiological variability and potential health impacts of product functionality."

Understanding these physiological responses is crucial for designing adaptive seating systems that enhance user well-being and safety. It highlights the need to consider individual physiological differences when developing assistive technologies.

06

What This Means for Your Design

Changing the tilt of a wheelchair can make it harder for some people with spinal cord injuries to keep their blood pressure up, especially when tilted back. Sitting lower in the chair might help them.

How to use in your project

  • 1.Use this study to justify the need for specific design features that address physiological safety and comfort for users with conditions affecting autonomic regulation.
  • 2.Cite this research when discussing the importance of user physiology in the context of assistive device design.
07

Add to My Project

08

Quick Cite

Paragraph starter

The study by Inskip et al. (2017) highlights the critical impact of dynamic wheelchair seating positions on cardiovascular function, particularly for individuals with spinal cord injuries affecting autonomic control. Their findings demonstrate that elevated seating can lead to significant drops in blood pressure and cerebral blood flow velocity in this population, whereas lowered seating may offer a beneficial effect. This underscores the necessity for designers of adaptive mobility devices to consider individual physiological responses and integrate features that allow for safe and beneficial position adjustments.

09

Source

PLoS ONE

Dynamic wheelchair seating positions impact cardiovascular function after spinal cord injury

journal · 2017

View source

Questions About This Research

What does the research say about dynamic wheelchair seating alters cardiovascular function in spinal cord injury patients?
Incorporate user-specific physiological data, particularly autonomic nervous system integrity, into the design and selection of dynamic wheelchair seating systems to mitigate risks and optimize user health. Evidence: PLoS ONE (2017).
Why does "Dynamic Wheelchair Seating Alters Cardiovascular Function in Spinal Cord Injury Patients" matter for design?
Understanding these physiological responses is crucial for designing adaptive seating systems that enhance user well-being and safety. It highlights the need to consider individual physiological differences when developing assistive technologies.
How can designers apply this research?
Incorporate user-specific physiological data, particularly autonomic nervous system integrity, into the design and selection of dynamic wheelchair seating systems to mitigate risks and optimize user health.
What were the main findings?
Individuals with SCI and autonomic pathway lesions experienced reduced supine blood pressure and MCAv, which further declined in standard seating compared to those with preserved autonomic control.. Elevated seating positions triggered significant drops in blood pressure and MCAv in individuals with autonomic lesions, with the duration spent below supine blood pressure being greatest in this group.. Lowered seating positions appeared to bolster blood pressure in individuals with autonomic lesions.
What research method was used?
Experimental study with 29 participants (19 with SCI, 10 controls).
How strong is the evidence?
Evidence strength is rated Strong effect, based on a 2017 journal from PLoS ONE.
What should I do differently in my next project?
When designing or specifying dynamic seating for individuals with SCI, prioritize features that allow for controlled, gradual transitions and offer a range of positions, including lowered options, with clear guidance on appropriate use based on individual autonomic function.
What are the limitations?
The study focused on moderate changes in seating position and did not explore extreme positions or prolonged use. The sample size for specific SCI subgroups was relatively small.