Aaron M. Yoder, Ph.D. Penn State University, Purdue University & Breaking New Ground Resource Center...

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


Many will, Many will, however, return however, return to work without to work without the appropriate the appropriate technologytechnology










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.





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.


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.


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.


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.


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.


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?


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.


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.


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.


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.


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.


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).


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


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


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


severity: 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



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


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.


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.


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.


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.


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.


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.


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



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



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


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.

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