aaron m. yoder, ph.d. penn state university, purdue university & breaking new ground resource...
TRANSCRIPT
Aaron M. Yoder, Aaron M. Yoder, Ph.D.Ph.D.Penn State University,Penn State University,
Purdue University &Purdue University &
Breaking New GroundBreaking New Ground
Resource CenterResource Center
Ergonomic Evaluation of Ergonomic Evaluation of Commercially Available Commercially Available Operator Lifts for Farmers Operator Lifts for Farmers with Disabilitieswith Disabilities
BackgroundBackground
692-1,697 persons in agriculturally 692-1,697 persons in agriculturally related occupations or industries related occupations or industries with a spinal cord injury.with a spinal cord injury.
An estimated 4,500 persons with An estimated 4,500 persons with spinal cord injuries presently in the spinal cord injuries presently in the agricultural population.agricultural population.
Innumerable others (~19%) with Innumerable others (~19%) with mobility restrictions. (e.g. strokes, mobility restrictions. (e.g. strokes, arthritis, amputations, back arthritis, amputations, back injuries, and others)injuries, and others)
Background (cont.)Background (cont.)
Assistive Assistive technology allows technology allows them to return to them to return to workwork• motor vehiclesmotor vehicles• agricultural agricultural
equipmentequipment• agricultural agricultural
workplacesworkplaces
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Many will, Many will, however, return however, return to work without to work without the appropriate the appropriate technologytechnology
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Purdue University’s Purdue University’s Breaking New Breaking New Ground Resource Ground Resource Center has taken a Center has taken a leadership role in leadership role in assisting farmers assisting farmers and ranchers with and ranchers with disabilities continue disabilities continue farming safely.farming safely.
Background (cont.)Background (cont.)
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Background (cont.)Background (cont.)
PurposePurpose
To develop and administer a systems To develop and administer a systems approach for evaluating ergonomic approach for evaluating ergonomic and safety issues related to the and safety issues related to the application of commercially available application of commercially available operator lifts used on agricultural and operator lifts used on agricultural and other off-road machinery to provide a other off-road machinery to provide a means for operators with restricted means for operators with restricted mobility to gain access to the mobility to gain access to the operator’s station. operator’s station.
Objective 1Objective 1
Develop and administer a Develop and administer a standardized approach to conduct standardized approach to conduct 11 on-site visits to collect 11 on-site visits to collect observational and interview data observational and interview data from individuals who currently own from individuals who currently own and use both locally made and and use both locally made and commercially available operator lifts commercially available operator lifts to access and operate their to access and operate their agricultural equipment. agricultural equipment.
Objective 2Objective 2
Conduct a formal ergonomic Conduct a formal ergonomic analysis, with an emphasis on analysis, with an emphasis on safety and usability, of two safety and usability, of two configurations of commercially configurations of commercially available LifeEssentials operator available LifeEssentials operator lifts designed for accessing lifts designed for accessing agricultural equipment. agricultural equipment.
Objective 3Objective 3
Develop a standardized user survey Develop a standardized user survey instrument for obtaining user instrument for obtaining user demographics and feedback on demographics and feedback on operator lifts being used on self-operator lifts being used on self-propelled agricultural equipment propelled agricultural equipment and to test the following hypotheses:and to test the following hypotheses:• HoHo11: A majority of the lift users have spinal cord injuries.: A majority of the lift users have spinal cord injuries.• HoHo22: A majority of the lift users have use of their upper : A majority of the lift users have use of their upper
body.body.• HoHo33: Owning a lift allows the lift users to continue to be : Owning a lift allows the lift users to continue to be
productive in an agricultural operation.productive in an agricultural operation.• HoHo44: Commercially manufactured lifts are safer than : Commercially manufactured lifts are safer than
home built models. home built models.
Objective 4Objective 4
Validate the analysis strategies Validate the analysis strategies and survey instrument by utilizing and survey instrument by utilizing a panel of experts in the field of a panel of experts in the field of assistive technology to conduct an assistive technology to conduct an independent ergonomic evaluation independent ergonomic evaluation of the operator lifts. of the operator lifts.
Objective 5Objective 5
Collect ergonomic and Collect ergonomic and demographic data from demographic data from agricultural operator lift users agricultural operator lift users using the survey instrument using the survey instrument previously mentioned in Objective previously mentioned in Objective 3. 3.
Related LiteratureRelated Literature
Secondary InjurySecondary Injury Systems ApproachSystems Approach Machinery Ergonomics in Machinery Ergonomics in
AgricultureAgriculture Related StandardsRelated Standards Expert PanelsExpert Panels Lift Design CharacteristicsLift Design Characteristics
Secondary InjurySecondary Injury
17% of farm operators had 17% of farm operators had physical disabilities that prevented physical disabilities that prevented them from completing essential them from completing essential farm tasks. farm tasks.
Increasing mean age of farm Increasing mean age of farm operators has led to a higher operators has led to a higher prevalence of disabling conditions.prevalence of disabling conditions.
Secondary injury risk is more Secondary injury risk is more severe for individuals with SCI.severe for individuals with SCI.
The Systems ApproachThe Systems Approach
To ensure completeness in the To ensure completeness in the ergonomic evaluation of operator ergonomic evaluation of operator lifts.lifts.
Hagel – “The whole is more than Hagel – “The whole is more than the sum of its parts”the sum of its parts”
Gestalt psychologists recognized Gestalt psychologists recognized the importance of “objectiveness” the importance of “objectiveness” or wholeness to human perception.or wholeness to human perception.
The Systems Approach The Systems Approach (cont.)(cont.)
Explosion in use during WW II in Explosion in use during WW II in Human FactorsHuman Factors
In 1973, Meredith et al. emphasized In 1973, Meredith et al. emphasized that the systems approach warranted that the systems approach warranted attention and respect as a stand alone attention and respect as a stand alone philosophy, worthy of study, separate philosophy, worthy of study, separate from the engineering discipline.from the engineering discipline.
Used by scientists, engineers and Used by scientists, engineers and agricultural safety specialists.agricultural safety specialists.
The Systems Approach The Systems Approach (cont.)(cont.)
SYSTEMINPUTS
ESSENTIALTASK
FUNCTIONS
PERSON WITH
DISABILITY
PERFORMANCEGAP
TOOLSEQUIPMENTWORKSTATIONINFORMATION
SYSTEMOUTPUTS
ENVIRONMENT
ACCOMMODATION
+
Machinery Ergonomics in Machinery Ergonomics in AgricultureAgriculture
ASAE Publication- Human Factors ASAE Publication- Human Factors (1991)(1991)
An Ergonomic Checklist for Tractors An Ergonomic Checklist for Tractors and Agricultural Machinery. (Hansson, and Agricultural Machinery. (Hansson, 1991)1991)
Cab Accessibility: How important is it? Cab Accessibility: How important is it? (Latif and Christianson, 1988)(Latif and Christianson, 1988)
Safe access to farm tractors and Safe access to farm tractors and trailers. (Hammer, 1991)trailers. (Hammer, 1991)
Machinery Ergonomics in Machinery Ergonomics in Agriculture (cont.)Agriculture (cont.)
Risks in using modified tractors by Risks in using modified tractors by operators with SCI and their co-operators with SCI and their co-workers (Willkomm, 1997)workers (Willkomm, 1997)
Assessment of work-related injury Assessment of work-related injury risk for farmers and ranchers with risk for farmers and ranchers with physical disabilities (Allen et al., physical disabilities (Allen et al., 1995)1995)
Related SAE StandardsRelated SAE Standards
• SAE J2092 – Testing of Wheelchair Lifts for Entry to or Exit from a Personally Licensed Vehicle
• SAE J2093 – Design Considerations for Wheelchair Lifts for Entry and Exit from a Personally Licensed Vehicle
• SAE J1725 – Structural Modifications for Personally Licensed Vehicles to Meet the Transportation Needs of Persons with Disabilities
• SAE J185 – Access Systems for Off-Road Machines
Expert PanelsExpert Panels
Lift Design CharacteristicsLift Design Characteristics
Advantages Disadvantages
Mounting Individual -access to and from machine at -access to only one machine Machine any location Independent -access to an unlimited number of
machines -machinery can only be accessed from the location of the lift
Type Standing -least expensive option -operator must be able to stand Platform Wheelchair -access to wheel chair at all times -large and bulky
Platform -long transfer distances Parallel
Linkage -simple to design and construct -minimal reach and lifting
distances Chair Lift rail/slide -inexpensive to design and
construct -relies on winch for power
swing arm -greater reach (horizontal and vertical)
-cost
-greater range of motion in all directions
Power Hydraulic -escape capacity -requires additional modifications
to attach
-more durable in harsh environments
-more expensive components
Electric winch -least expensive option -safety (see safety section)
linear -made to order -limited range of motion actuator
chain -easy to repair -larger power requirement
screw -generates large amounts of force -cost
-prevents freewheeling or falls
MethodologyMethodology
Objective 1 – Observational and Objective 1 – Observational and Interview AnalysisInterview Analysis
Objective 2 – Initial Ergonomic Objective 2 – Initial Ergonomic Analysis by the ResearcherAnalysis by the Researcher
Objective 3 – Preliminary Objective 3 – Preliminary Questionnaire DevelopmentQuestionnaire Development
Objective 4 – Panel of ExpertsObjective 4 – Panel of Experts Objective 5 – Questionnaire Objective 5 – Questionnaire
AdministrationAdministration
Observational and Observational and Interview AnalysisInterview Analysis
Telephone Telephone ConversationsConversations• Informal surveyInformal survey
11 Site Visits11 Site Visits• PhotographsPhotographs• Informal surveyInformal survey
Initial Ergonomic Analysis by Initial Ergonomic Analysis by the Researcherthe Researcher
Heuristic Analysis Heuristic Analysis and EMEA and EMEA conducted on conducted on LifeEssentials LifeEssentials operator lift operator lift system.system.
Results used for the Results used for the initial development initial development of the lift user’s of the lift user’s questionnaire.questionnaire.
Heuristic AnalysisHeuristic AnalysisRule Description
1.Know thy user, and YOU are not thyuser.
The design should begin with a thoroughunderstanding of the user and the user's task.
2.Consistency, consistency,consistency.
Things that look the same should act the same.
3.Everyone makes mistakes, so everymistake should be fixable.
The user should have feedback on what theydid, they should have help in finding errors andknowing how to correct them, and they shouldeasily be able to correct the errors.
4.When the tool is needed, it should beat hand.
Information for decisions, about options, and soon needs to be there when needed; and if notvisible, users should know where and when tofind it.
5.Make error messages useful to theuser.
Error messages should be written in the user'slanguage, and tell the user how to fix theproblem.
6.Every action should have a reaction. Part of this rule implies subjectively fast andrecognizable feedback.
7.Don't overload the user's buffers. Minimize the need to maintain information inmemory (esp. short term/working memory) inorder to complete a task.
8.Keep it simple. Don't include things users don't need. Make iteasy to find the things they do need. Don'tclutter the design with features or attributes agiven user doesn't want. In general, one simpleuseful thing is going to have more value thanwhen it is buried in enhancements.
9.Make it easy to be fast. The more you do something, the easier it shouldbe to do.
10.Treat the user as manager. The user should feel like they are in control.The user should always know what ishappening, in terms that are useful to them.
Table 2. Ameritech Top 10 Rules of Thumb for Usability. (Ameritech, 2000)
Error Modes and Effects Error Modes and Effects Analysis (EMEA)Analysis (EMEA)
Task Stage Inappropriate or Missing Response (errors and violations)
Effect Behavioral Basis (error mode) Countermeasure (potential or implemented)
purchase
set-up and installed in wrong location damage to machine knowledge-based: step-by-step instructionsinstallation freq : low severity : moderate (user did not know where to
mount)telling user where to mount lift effectiveness : high
freq : moderate
judgement-based: provide easy to use instructions(user decided in a hurry) effectiveness : highfreq : moderate
ordinary use using lift for inappropriate use damage to machine judgement-based: provide warings (lift capacities)(pulling fence posts) severity : moderate (inappropriate use) in user's manual and on liftfreq : moderate freq : moderate effectiveness: low
running lift into tractor damage to machine sk ill-based: modify productfreq : low severity : moderate (user lacks skill in operating) use limit switches to prevent
freq : low contactpersonal injury effectiveness: highseverity : low
modify productdecrease speed of lift movementeffectiveness: moderate
troubleshooting
maintenance and repair
emergency procedures
attempt to use lift when system looses power in emergency
potential injury severity : high
judgment-based : (user knew better, but decided
warning label (do not use in emergency)
freq: high to try anyway) effectiveness : lowfreq : high
disposal
Preliminary Questionnaire Preliminary Questionnaire DevelopmentDevelopment
Based on key areas identified from Based on key areas identified from the preliminary observations, the preliminary observations, interviews and ergonomic analysesinterviews and ergonomic analyses• DemographicsDemographics• Ergonomic InformationErgonomic Information
– controller usabilitycontroller usability– transferstransfers
• MailMail
Panel of ExpertsPanel of Experts
Four MembersFour Members Mailed Mailed
Information Information Met for Two DaysMet for Two Days Heuristic Analysis Heuristic Analysis
and EMEAand EMEA Validation of Validation of
QuestionnaireQuestionnaire
FindingsFindings
Observational and Interview Observational and Interview AnalysisAnalysis
Ergonomic Analysis by the Ergonomic Analysis by the ResearcherResearcher
Questionnaire DevelopmentQuestionnaire Development Panel of ExpertsPanel of Experts Questionnaire AdministrationQuestionnaire Administration
Panel of ExpertsPanel of ExpertsHeuristic AnalysisHeuristic Analysis
Heuristic #1: Know thy user. Is the lift/control designed logically based on the user?
Comments: The lift appears to be designed for a person with "normal"
upper body strength. Awkward placement of controller and cable routing. Sling is uncomfortable. Handholds would be useful for transferring. The swivel seat is a good idea, but it is hard to operate. The seat shape is hindering. The controller needs better labeling. It would be hard to use for someone with visual limitations. Could it be used for more than ingress and egress? Awkward placement of controller storage.
Panel of ExpertsPanel of ExpertsHeuristic Analysis (cont.)Heuristic Analysis (cont.)
Heuristic #2: Consistency. Does everything that looks the same act the same? Comments: All the controls on the controller look the same.
Use pictorials on the controller. The control orientation could be improved. When the operator is in different locations, their perspective of
the controller changes.
Panel of ExpertsPanel of ExpertsHeuristic Analysis (cont.)Heuristic Analysis (cont.)
Heuristic #3: Everyone makes mistakes, so every mistake should be fixable. Are they?
Comments: Use redundancy for the wiring.
Location visibility is difficult at times. What can be done in case of power failure? A learning curve is needed. Many pinch and crush points are present. Can the random rotation on the sling lift be reduced?
Panel of ExpertsPanel of ExpertsHeuristic Analysis (cont.)Heuristic Analysis (cont.)
Heuristic #4: When the tool is needed, it should be at hand. Are they? (remote, seatbelt, etc.)
Comments: The controller is hard to reach and store.
An intermittent location for the controller would be useful. Handholds are needed for transfers. It would be useful if the lift could be used for maintenance. A different restraint system may be useful (bar). Could a circuit breaker be used in place of the main fuse? It would be useful to be able to access the electronics box
without tools.
Panel of ExpertsPanel of ExpertsHeuristic Analysis (cont.)Heuristic Analysis (cont.)
Heuristic #5: Make error messages useful to the user. Are they? Comments: Trouble shooting instructions may be useful.
A failsafe backup should be used. General directions would help. Are error messages needed? There is no positioning feedback. Interference warnings could be used. Audible signals could be used. Limits would be helpful.
Panel of ExpertsPanel of ExpertsHeuristic Analysis (cont.)Heuristic Analysis (cont.)
Heuristic #6: Every action should have a reaction. Is there feedback? Comments: All O.K.
No! Bumping and dragging may not be notice. Controls are not intuitive. Dampen the swing in the sling.
Panel of ExpertsPanel of ExpertsHeuristic Analysis (cont.)Heuristic Analysis (cont.)
Heuristic #7: Don’t overload the user’s buffers. Is the user’s memory load high?
Comments: Leg positioning depends on the user.
Controls are not intuitive. It is mainly a simple system.
Panel of ExpertsPanel of ExpertsHeuristic Analysis (cont.)Heuristic Analysis (cont.)
Heuristic #8: Keep it Simple. Are any of the controls or is any part of the lift complex?
Comments: The seat is too simple.
Controller is too complex. There are no simple emergency procedures.
Panel of ExpertsPanel of ExpertsHeuristic Analysis (cont.)Heuristic Analysis (cont.)
Heuristic #9: Make it easy to be fast. Are there any points where speed could be improved?
Comments: Variable lift speeds would help.
Improve controller design. Use smart logic to program the lift to go up and in. Use transfer aids to speed up transfers. Fast is sometimes bad (Injuries, Sensation of poor control).
Panel of ExpertsPanel of ExpertsHeuristic Analysis (cont.)Heuristic Analysis (cont.)
Heuristic #10:Treat the user as manager. Is there any point where the user doesn’t feel in control?
Comments: Swinging high in the air is very uncomfortable.
Lack of positioning sensations. Use a joystick control.
Panel of ExpertsPanel of ExpertsEMEAEMEA
Task Stage Inappropriate or Missing Response (errors and violations)
Effect Behavioral Basis (error mode)
Countermeasure (potential or implemented)
purchase error: select the wrong style of lift (chair or platform)
effect: lift won't get used knowledge countermeasure: consult with manufacturer
freq: low severity: high freq: high effectiveness: high
error: fit to clients needs, tractor, storage limitations
effect: lift won't get used knowledge / judgment based
countermeasure: educate consumers with a brochure with specifications
freq: moderate severity: high freq: moderate effectiveness: moderate
error: wrong features effect: won't use knowledge / judgment / skill based
countermeasure: inform consumer
freq: low / moderate / high
severity: low / moderate / high
freq: low / moderate / high
effectiveness: low / moderate / high
error: installing the lift on a less accessible tractor
effect: exposure to more hazards
judgment based countermeasure: clearer recommendations through personal contacts
freq: low severity: moderate freq: low effectiveness: low
Panel of ExpertsPanel of ExpertsEMEA (cont.)EMEA (cont.)
set-up and installation
error: install the unit in the wrong location
effect: difficulty in transfers
knowledge / skill based
countermeasure: provide clear instructions / provide standardized mounting
freq: low / moderate / high
severity: low / moderate / high
freq: low / moderate / high
effectiveness: low / moderate / high
error: improper wiring effect: fire hazard skill based countermeasure: clear instructions
freq: moderate severity: moderate freq: moderate effectiveness: moderate
error: improper modifications to the tractor
effect: damage to the tractor
judgment countermeasure: modify with caution
freq: moderate severity: moderate freq: moderate effectiveness: high
Panel of ExpertsPanel of ExpertsEMEA (cont.)EMEA (cont.)
Task Stage Inappropriate or Missing Response (errors and violations)
Effect Behavioral Basis (error mode)
Countermeasure (potential or implemented)
set-up and installation
error: select the wrong style of lift (chair or platform)
effect: lift won't get used knowledge / judgment / skill based
countermeasure: consult with manufacturer
freq: moderate severity: moderate freq: moderate effectiveness: high
error: controller wiring effect: end pulls off judgment countermeasure: better
wiring techniques
freq: high severity: high freq: high effectiveness: high
ordinary use error: difficulty transferring
effect: fall skill based countermeasure: experience
freq: moderate severity: high freq: low effectiveness: moderate
error: activating wrong
switcheffect: move wrong
directionskill based countermeasure: better
labels
freq: high severity: moderate freq: high effectiveness: moderate
error: failure to wear
seatbelteffect: fall judgment countermeasure: warning
label
freq: moderate severity: high freq: moderate effectiveness: low
Panel of ExpertsPanel of ExpertsEMEA (cont.)EMEA (cont.)
trouble-shooting error: fusing in control panel
effect: failure to operate knowledge based countermeasure: better wiring
freq: low severity: moderate freq: moderate effectiveness: moderate
error: improper dealing with failure
effect: damage to unit knowledge / judgment / skill based
countermeasure: troubleshooting manual
freq: moderate severity: moderate freq: moderate effectiveness: moderate
maintenance and repair
error: no instructions for maintenance
effect: knowledge / judgment / skill based
countermeasure: manual
freq: severity: freq: effectiveness:
emergency procedures
error: power failure / fire
effect: stranded / death knowledge based countermeasure: backup system
freq: low severity: high freq: low effectiveness: high
error: poor planning effect: entrapment knowledge based countermeasure: develop
plan
freq: severity: freq: effectiveness:
Questionnaire Questionnaire AdministrationAdministration
Initial mailing sent to 127 potential Initial mailing sent to 127 potential lift userslift users
40 returned due to incomplete or 40 returned due to incomplete or invalid addressesinvalid addresses
60 (69%) of the remaining 87 were 60 (69%) of the remaining 87 were completed and returnedcompleted and returned
4 did not qualify, leaving 56 to 4 did not qualify, leaving 56 to analyzeanalyze
Questionnaire Questionnaire Administration (cont.)Administration (cont.)
Survey CommentsSurvey Comments Question 13 – Were you able to use the same piece of machinery after your injury
without a lift? If yes, how did you access it?
Pull myself up on tractor with my wife helping me, also with leg braces.
Yes, but it requires someone (usually) to lift my legs for me. I can usually pull
myself up and down, but it is safer with another person.
Bought both after accident
Had to park close to a bank and walk a plank.
Prior to intallation of the lift I was only able to use this tractor with assistance
from someone else.
Questionnaire Questionnaire Administration (cont.)Administration (cont.)
Survey Comments (cont.)Survey Comments (cont.) Dangerously used end loader to lift me up on a platform then transfer. Not
recommended.
I pulled myself up on the tractor (broke leg doing it).
It would have been hard.
I had an electric winch hooked to the rafters in my pole barn. I used that a long
with a hoyer seat pad to connect to the lift. Once on the tractor you had to pull the
tractor back in the same spot to get off.
Until 50, I was able to get on my tractors using brute strength However, I should
have used a lift as I injured both shoulders. I have arthritis and rotator cuff tears.
Questionnaire Questionnaire Administration (cont.)Administration (cont.)
Survey Comments (cont.)Survey Comments (cont.)
Question 37 – Have you ever had to use the lift in an emergency situation, such as
a fire or accident?
I broke my femur (left) after bracing – removed myself from the tractor
Caught combine on fire, could smell it burning, called for help save combine.
In the event of a fire, I would not be able to get off the tractor quickly enough to
save myself. I would have to fall off and take my chances.
Questionnaire Questionnaire Administration (cont.)Administration (cont.)
Survey Comments (cont.)Survey Comments (cont.) Question 38 – Have you ever been injured or almost injured while you were using
the lift?
The nut that holds the seat on became loose and the seat slid and I almost fell off.
Was bush hogging and lift arm on tractor broke while I was making a turn to the
left on a 20-25% incline. The bush hog climbed up on wheel, but lift stopped it
from coming up on me, but roll bar may also have stopped it, too.
Always try to be careful to watch feet, legs, fingers, body parts when using
(manlift).
Not me, but there was a sheer point on one of the lifts we built and my brother
broke a toe when using it improperly once. The sheer point has been eliminated.
The screw broke when I was about half way up.
Questionnaire Questionnaire Administration (cont.)Administration (cont.)
Survey Comments (cont.)Survey Comments (cont.) The screw broke when I was about half way up.
I don’t dairy farm anymore. The two tractors are sold and the lifts are in my
machine shed. I can't operate tractors anymore because of recurrent pressure sores
problems. Everything is hired done.
I was on the lift and it started going down itself. If my leg had been in the way I'm
not sure what I would have done. The only happened once in five years. No
injuries, though. Not complaining just answering the question.
The lift broke and fell on the tractor wheel. That is why you have to brace the lift
to the tractor to make it solid. There is to much vibration on a tractor and not have
it braced.
Questionnaire Questionnaire Administration (cont.)Administration (cont.)
Survey Comments (cont.)Survey Comments (cont.) Question 39 – Have you ever used the lift for any other purpose than lifting the
operator into the operator’s station?
Yes, lifting out
My brother uses the lift to lift heavy boulders out of the field to place on the rear
axel of the 4wd. When convenient.
Pull fence posts, carry stuff, works great.
I had to sell out 99 so I don't farm any more.
It lifts a lot of stuff in my shop.
Getting from tractor cab to van seat.
I fell off of wheelchair. I used the lift to get back on wheelchair.
Questionnaire Questionnaire Administration (cont.)Administration (cont.)
Survey Comments (cont.)Survey Comments (cont.) I fell off of wheelchair. I used the lift to get back on wheelchair.
Used it to lift quick hitch on tractor and other implements
Putting fuel in tractor, checking water.
I now use it to stand up.
For adjusting mirrors and reaching equipment.
I used the lift to reach the side of my pole barn.
To get into truck or tractors
I transfer from wheelchair to lift and swing into my wood front deck mower.
For access to pecan trees to graft the tree
ConclusionsConclusions
Observational and Interview Observational and Interview AnalysisAnalysis• Introduction to users and types of liftsIntroduction to users and types of lifts• Collected user dataCollected user data• Initiated ideas of problems with liftsInitiated ideas of problems with lifts• Aided in the development of the Aided in the development of the
QuestionnaireQuestionnaire
ConclusionsConclusions
Ergonomic Analysis by ResearcherErgonomic Analysis by Researcher• Heuristic and EMEAHeuristic and EMEA• Identified additional areas of concernIdentified additional areas of concern• Aided in the development of the Aided in the development of the
QuestionnaireQuestionnaire
ConclusionsConclusions
Panel of ExpertsPanel of Experts• Heuristic and EMEAHeuristic and EMEA
– Identified areas of concernIdentified areas of concern
• Validated analysis strategiesValidated analysis strategies• Validated questionnaireValidated questionnaire
ConclusionsConclusions
Questionnaire AdministrationQuestionnaire Administration• HH0011: 75% of the lift users had SCI: 75% of the lift users had SCI• HH0022: 76% of the lift users had full use of : 76% of the lift users had full use of
armsarms• HH0033: 17% could use same machinery : 17% could use same machinery
beforebefore• HH0044: Low response by locally fabricated: Low response by locally fabricated
– 8(16%) of 49 commercially manufactured8(16%) of 49 commercially manufactured– 1 (14%) of 7 locally fabricated1 (14%) of 7 locally fabricated
RecommendationsRecommendations
An adaptation of the questionnaire and An adaptation of the questionnaire and ergonomic analyses used in this study could ergonomic analyses used in this study could be used to assess other assistive technology be used to assess other assistive technology devices used in the agricultural population.devices used in the agricultural population.
A standard aimed at the testing and use of A standard aimed at the testing and use of operator lifts to access agricultural and operator lifts to access agricultural and other off-road equipment by operators with other off-road equipment by operators with physical disabilities should be submitted to physical disabilities should be submitted to the Adaptive Standards Committee of the the Adaptive Standards Committee of the Society of Automotive Engineers. An initial Society of Automotive Engineers. An initial draft has been developed based on the draft has been developed based on the review of ASAE and SAE standards and the review of ASAE and SAE standards and the findings of this study.findings of this study.
Recommendations (cont.)Recommendations (cont.)
The information gained from this study The information gained from this study should be used to justify the safety and should be used to justify the safety and applicability of operator lifts in agriculture applicability of operator lifts in agriculture to organizations that supply funding for to organizations that supply funding for the use of and research pertaining to the use of and research pertaining to assistive technology.assistive technology.
Additional studies in the area of Additional studies in the area of secondary injuries involving assistive secondary injuries involving assistive technology should be conducted to gain a technology should be conducted to gain a clearer perspective on the issue.clearer perspective on the issue.