By Dr. Ann Marie Dale
Repetition:
- Pace yourself; alternate tasks or alternate hands.
- Use power tools instead of manual ones.
- Perform stretches, or take breaks from repetitive tasks.
Awkward Postures:
- Avoid prolonged postures: alternate tasks (work practice).
- Avoid end range of joint angle:
- Extreme bent knee: Use knee saver, K2S, half kneel, knee pad with additional support.
- Bent wrist to trowel adhesive, finish, or filler: Use inline trowel or angled handle traditional trowel (avoids flex/extension but increases ulnar deviation).
- Bent back: Use extended handles; work on raised surface (i.e., cut wood).
- Raise cutting pieces to waist height (off floor to raised surface such as a portable workbench).
- Position work for ideal worker position: Plan location of work to prevent extra bending, reaching, or twisting.
- Use long handles; cheater bars; and extended power tools, handles, or wands.
- Preplan: Set up work area before working.
Forceful Exertion:
- Transport heavy equipment/material: Use wheels to carry equipment or material (flat surface with wheels).
- Purchase material in smaller quantities or break up loads.
- Avoid double handling materials/equipment: Preplan task; position close to installation location the first time handled.
- Reduce pinch/grip: Use tools (knife, scissors, scorer) to open containers.
- Increase friction by adding grip on handles or wear gloves (good for viscous adhesive).
- Use tools that fit your hand.
- Use power/pneumatic tools in place of manual tools (i.e., nailer).
- Use only sharp blades.
- Lift with your legs.
- Add handles on the object to improve grip (surface carts).
Contact Stress:
On knees:
- Consistently wear knee pads or use floor cushions.
- Stand when able.
On hands:
- Wear gloves.
- Avoid tools that end in the palm of the hand
Vibration: moderate level (i.e., grinders, sanders, impact drivers, drills)
- Wear antivibration gloves.
- Avoid excessively large handles.
- Perform regular equipment maintenance to minimize vibration.
- Select equipment with vibration-damped mechanism or avoid hand contact with vibrating surface.
- Avoid combined risk (bent back and vibratory sander; kneel/bent back with saw on floor).
- Combined risks are worse:
- Forceful lifting and bent back objects on floor.
- Kneeling on all fours with bent back for prolonged periods.
- Bent back and forceful exertion to hammer/nail wood for long periods.
- Good work practices:
- Preplan work tasks to reduce risks.
- Have ideal equipment/tools when needed.
- Alternate tasks to avoid long periods of the same risk (awkward posture, forceful exertion, contact stress).
- Avoid double handling or unnecessary handling of equipment or materials.
- Use personal protective equipment consistently (knee pads; hearing, eye, and respiratory protection; and others as indicated).
- Work in upright positions as much as possible.
Flooring material and installation methods: Trade-off in ergonomic risks
A. Floating
Pro: Low force required to install.
Con: Prolonged kneeling/bent-back posture.
Recommendations: Wear good kneepads consistently; frequently alternate racking and assembly tasks; stand upright to saw boards/retrieve material.
B. Nail-down
Pro: Alternates body postures by kneeling to rack wood and standing up to nail boards.
Con: Combined risk to nail (bent back/forceful exertion).
Recommendations: Use light weight pneumatic nailer.
C. Glue-down
Pro: Avoids impact from nailer; frequently alternates task of gluing and wood installation.
Con: Forceful exertion with awkward wrist postures to apply adhesive.
Recommendations: Use an inline or angled trowel handle with a handle that allows good friction with palm (reducing required grip force).
Helpful Ergonomic Resources:
cpwrconstructionsolutions.org/
cdc.gov/niosh/docs/2007-122/
Presented by instructors from the Floor Layers Joint Apprenticeship Program of St. Louis and Washington University.
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