2014 AgrAbility Virtual National Training Workshop
Recommending Seating Supports
for Agricultural Equipment
Carla Wilhite, University of New Mexico-Occupational Therapy
Kevin Sullivan, University of New Mexico-OT Graduate Student
Mark Jaramillo, University of New Mexico-OT Graduate Student
Funded Research-Southwest Center for Agricultural Health, Injury
Prevention, and Education, NIOSH-2U540H007541, CFDA # 93. 262
No other financial disclosures
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• AgrAbility: USDA-sponsored program that
assists farmers, ranchers, and other
agricultural workers with disabilities.
– Partners land grant universities with disability services
– Organizations. Currently 20 state projects
– National AgrAbility Project: Led by Purdue’s Breaking
New Ground Resource Center. Partners include:
• Goodwill of the Finger Lakes
• The Arthritis Foundation, Heartland Region
• University of Illinois at Urbana-Champaign
• Colorado State University
– More information available at
www.agrability.org
Introduction
• Agricultural machinery technology is rapidly evolving.
• Design of seating, seat materials, and management of
seated pressure largely unchanged.
• Current seating may not conform to the needs of people
who vary by size, weight, posture, gender, or health status
(ergonomics of difference).
• People with ergonomics of difference may have to
incorporate after-market accommodations to fit
themselves to the seating conditions.
• No research on risks/benefits of changing the dynamics of
the seating system.
Example: AgrAbility
• Farmers with spinal cord injuries (SCI)
– Access machinery with fabricated man-lifts and operate machinery
with hand controls
– Paralysis create changes in sensation, motor function, circulation,
and tissue health that can pre-dispose the person to skin tears,
lacerations, and pressure-related ulcers
– Most farmers with SCI select additional cushioning materials (WC
cushions, egg-crate foam, sheepskins, etc.)
– AgrAbility Specialists may make recommendations based on
experience and knowledge of seating issues
– What are pros/cons of selecting cushions in this way?
Research Start-Up
• Purpose:
– Test feasibility of mapping
seated pressure on an
average original equipment
foam contour tractor seat,
with and without intervention
wheelchair cushions
• The University of New MexicoHealth Sciences Center
Institutional Review Board (#13129) approved the research.
• Funded by the SW Center for
Agricultural Health, Injury
Prevention, and Education
Research
• Methods
– Mixed methods, singlesubjects with repeated
measures
• Instruments
– FSA Pressure Mapping
System by Vista Medical
– Simulation Platform
– Braden Scale pressure
ulcer risk questionnaire
– Likert Scale Seat Ratings
– Postural photographs
Participants
• People with paraplegia in the University of New
Mexico Health Sciences service area, including from
rural and agricultural communities.
• Located by “word of mouth” from the informal
spinal cord injury / paralysis community.
• No specific individual, service provider, or agency
was used to locate subjects.
Sub
Age
Gender Height
(in.)
Weight Condition
(lb)
Hx DU
Current Cushion
Braden Scale
Sub 1
35
M
73
280
C7-Incomplete
Abrasionhealed
Stimulite
18
Sub 2
32
M
70
160
C4-Incomplete
None
Jay 2
18
Sub 3
58
F
64
125
T8, complete
1-small IT
abrasion
Foam 2"
14
Sub 4
28
M
73
190
CP-Paraplegia
None
Stimulite
21
Sub 5
52
M
70
145
T12-Incomplete
Hx Multiple
DU's; s/p skin
flap
ROHO (high quadtro)
19
Sub 6
56
M
65
198
T-4 paraplegia
complete
DB 6 years
post, s/p skin
flap
High Profile ROHO
16
Sub 7
56
F
64
190
T12-Incomplete
DU 2 years
post, DU 2006
High Profile ROHO
14
Sub 8
59
F
67
170
T-12-Incomplete,
s/p C3-7 fusion
None current,
past Hx
High Profile ROHO
12
Cushion Conditions
• Original tractor seat
cushion
• 2 inch reticulated foam
WC cushion
• Low profile air bladder
WC cushion
• Mid profile air bladder
WC cushion
• High profile air bladder
WC cushion
Lab Setting
• Tractor seat on
moveable platform
• Procedures
• Adjustments to
seating
Pressure Mapping
Results-Clinical Image Examples
Results-Clinical Image Examples
Results-Statistical
Results- Statistical
Results-Statistical
Examples-Statistical
Examples-Statistical
Limitations
•
•
•
•
•
•
•
Laboratory vs. field conditions
Small sample size, non-homogenous
Only one tractor seat, five conditions
Limited number of cushion sizes and makes
Only seated pressures measured
Experience of investigator; not blinded to results
Procedural issues (arms supported on armrests, feet
raised for support, wrinkles on mat, converting data
from cm to inches, pressure sensor sensitivity:
throwing out “noise” or data?)
Analysis Take-aways
• Can say with
confidence:
– A tractor seat alone is
not sufficient cushioning
for an individual with
paralysis
– Foam and air cushions
used in the study were
significantly better for all
users than tractor seat
alone
• Cannot say with
statistical confidence:
– Whether air cushion is
better than foam
• Must carefully clinically
evaluate, not
statistically evaluate:
– Look at the pressure mapping
image, regard client lifestyle,
health factors, seating needs,
other seating supports needs
– Make a decision
Conclusions
• It is feasible to
• Improve procedures
investigate the problem • Select instrument with
of seating support
greater precision for
surfaces in tractors
sensitive data (below 5
• Need to move research
mmHg)
into the tractor
•
• Begin investigations into
other factors related to
farmers acquiring DU’s
References
•
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update: ‘Scoping the scope’ of a Cochrane review. Journal of Public
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•
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operator health and safety assessment. Journal of Agricultural
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•
Bergstrom, N., Braden, B. J., Laguzza, A., & Holman, V. (1987). The
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Eslami, V., Saadat, S., Habibi-Arejan, Vaccaro, A. R., Ghodsi, S. M., &
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•
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•
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•
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•
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•
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