Ergonomic Evaluation and Recommendations of Football Field Demarcation Yijun
2 Liu ,
Nicolette McGeorge2, Xinhui Zhou1, Dr. Gwanseob Shin1 (Advisor)
Dept. of Industrial Systems and Engineering – Physical Ergonomics Focus, 2 Dept. of Industrial Systems and Engineering – Cognitive Ergonomics Focus
Abstract
Ergonomic Job Assessment Comparison
Method
As part of Auburn Engineers annual ergonomics design competition we observed and analyzed the various tasks associated with football stadium demarcation (e.g., measuring and painting lines, logos, etc.). A variety of ergonomic risk assessment methodologies were applied, including the University of Michigan's 3D SSPP, the NIOSH lifting equation, and Auburn Engineering's eTools ergonomic job analysis comprehensive suite of tools. Analysis identified multiple high and moderate risk task components related to heavy lifting, repetitive motion, and awkward postures. Short-term and Long-term design and administrative recommendations were developed and prioritized based on post-implementation job analyses along with cost/benefit analyses to provide recommendations for job improvements. The recommended short term solutions have moderate impact and low up-front costs and a one year return on investment (ROI) of ~ $28,615 while long-term solutions have high impact and high up-front costs with a ten year ROI of ~ $1.32M.
Background – Field Demarcation Field demarcation is the task of measuring and marking the various components that define the boundaries of a sports field, as well as aligning and transferring team or other logos to the playing surface. This process is typically carried out by a crew of workers who must manually measure and mark the precise locations of where to then paint the field. While industrial equipment does exist to assist in the various tasks of demarcation, there are still numerous ergonomic risk factors related to prolonged holding of awkward postures, repetitive motions, heavy lifting, and more. The task itself requires 250 gallons of paint per week during the season and requires painting of over 400 individual field markings, twice during each week.
After observing the tasks of interest and understanding variables such as crew capabilities, task frequency, equipment characteristics (e.g., weight, capacity, etc.), our team selected the following ergonomic assessment tools to analyze the tasks for ergonomic risks: Auburn Engineering’s eTools Ergonomic Software Suite ◦eTools is a comprehensive suite of web-based ergonomics assessment tools Univ. of Michigan 3-Dimensional Static Stature Prediction program (3DSSPP) ◦UM 3D SSPP software predicts static strength requirements for tasks such as lifts, presses, pushes, and pulls. National Institute for Occupational Health & Safety (NIOSH) Lifting Equation ◦This equation is designed to assist in the identification of ergonomic solutions for reducing physical stresses associated with manual lifting.
Stencil Alignment & Transfer • Stenciling includes the carrying of stencils to the field, alignment on the field, and transfer of stencil patterns onto field for a 30’ x20’ 50-yd logo, 2x 20’x15’ 25-yd logos, 12x 10’x8’ end-zone letters, and 22 8’x3’ yardage digits. Stencils are made of ridged plastic and must be carried and aligned by multiple crew members as shown in the photo to the left. Stencil Pattern Painting/Filling • Stencil painting is the task of filling in all of the pre-transfer patterns from the task of stencil alignment & transfer. This task is done using a hand-held spray gun that is attached to a paint bucket and compressor system. Current systems require that the gun be held approximately 1 foot off the ground during spraying. Field Boundary and Primary Marker Demarcation • This task involves the precise measurement, placement and painting of the field boundaries and 10-yard cross-field marker lines. Measurement and marking is done by hand by at least 2 crew members and painting is done using a human pushed line painter such as the one shown to the left.
Existing Jobs
Recommended Jobs
Stencil Measure/Transfer
Stencil Measure/Transfer
Identified Risks: ◦Palm supination- Low risk ◦Bending forward- High risk ◦Carrying load- High risk ◦Squatting- Low risk
Stencil Painting/Filling
Identified Risks: ◦None
Stencil Painting/Filling
Identified Risks: ◦ Torso bending- High risk ◦ Reaching behind- Moderate risk ◦ Shoulder repetition- High risk
Identified Risks
Identified Risks: ◦None
Based on analysis of tasks using the above tools, the following risks were identified:
Task Stencil Outlining
Stencil Filling
Identified risks Pronated wrist (to carry stencils) Carrying load (stencils) Static bending and squatting (spray can close to ground while spraying) Static bending (spray gun close to ground) Reaching behind (to keep paint hose off the ground) Shoulder repetition (sweeping action of hand) Lifting and carrying(5 gallon paint buckets to refill tank)
Warning related (fire/explosion, pressurized equipment, personal protective equipments) Mechanical stress (driving pin into the ground, spray control) Field Demarcation Supinated wrist (pushing line striper) Handle height of line striper Lifting (5 gallon paint buckets to refill tank)
Tasks of Interest
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Top Recommended Solutions • Description: Tool lets user spray cans used for stencil transfer from the end of an extension pole. • Justification: • Reduces repetitive bending posture • Reduces repetitive trigger motion • Re-evaluated Ergonomic Job Analysis: • No Identifiable Risks
• Description: Combination of an add-on to extend the hand held spray gun tip and a custom tri-pod to manage the paint hose. • Justification: • Reduces repetitive bending posture • Eliminates awkward walking posture • Re-evaluated EJA: • No Identifiable Risks
Spray Close Spray Extender
Spray Gun Tip Extension
Long-Term Recommendation
Line Striper Handle Modification
• Description: Use of powered pump to transfer new paint into LineLazer & LineStripers. • Justification: • Eliminates repetitive heavy lifting task • Eliminates prolonged awkward posture during pouring • Re-evaluated EJA: • No Identifiable Risks
Paint transfer pumping system
Primary Field Demarcation
Identified Risks: ◦ Palm pronation- High risk ◦ 2-handed lifting- High risk ◦ Mechanical stress- High risk
Paint Filling
Identified Risks: ◦ Mechanical Stress- Moderate risk
Paint Filling
Based on the recommended solution of using a pumping system to transfer paint, the crew member no longer is responsible for holding and pouring the buckets of paint so no 3DSSPP results were generated for this task postrecommendation.
RWL = LC*HM*VM*DM*AM*FM*CM; LI = L/RWL At Origin: RWL = 22.448 lb; LI = 2.67 At Destination: RWL = 24.645 lb; LI = 2.43 Since 1≤LI ≤3 there is an increased risk for lifting-related low back pain and injury for some fraction of the workforce
RWL = LC*HM*VM*DM*AM*FM*CM; LI = L/RWL At Origin: RWL = 35.417 lb; LI = 1.69 At Destination: RWL = 48.183 lb; LI = 1.24 LI ~1 therefore the risk for lifting-related low back pain and injury is reduced
Conclusions Ergonomic risks found to be associated with field demarcation were effectively mitigated based on either short-term, low-ROI recommendations or long-term, high-ROI recommendations. The effectiveness of these recommendations was validated by using a consistent ergonomic job analysis methodology based on the current task and working environment and compared against the predicted changes to the task and working environment based on the recommended solutions.
Autonomous Painter Robot (APR) • Description: Modification to paint striper handle modified to allow easy adjustment (angle & height) based on user anthropometry. • Justification: • Allows user to push with wrists in neutral position • Allows equipment to be customized to user height • Re-evaluated EJA: • No Identifiable Risks
Primary Field Demarcation
• Description: Autonomous line and logo painting robot, operating on custom input patterns or human-laid guide wires. • Justification: • Eliminates manual painting, which eliminates prolonged awkward postures and repetitive motion • Eliminates measuring & stencil alignment, reducing task time greatly • Re-evaluated EJA: • All Tasks: No identifiable risks
Predicted return-on-investment was calculated for each recommended solution taking into account costs associated with tool acquisition, reduced operational efficiencies, and additional training requirements along with savings associated with improved operational efficiencies and a reduced potential for work-related injuries. The resulting ROI based on a combination of the top short-term recommendations yielded an estimated $10,813 for first year and $21,745 for the second year in savings. The resulting ROI based on recommended long-term solutions yielded an estimated ten year ROI of $1.14M , with $100,400 in savings in the second year of implementation.
Acknowledgements This project was partially funded by Dr. Ann Bisantz, SUNY, University at Buffalo.