New Rakes for Harvesting Berries:
Problem: |
Two Solutions: |
Harvesting blueberries with a traditional rake
is hard on the body.. |
1. Modify existing rake.
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Stooped position hurts the back. |
Add electrical tape or pipe foam to make the handle diameter right for the worker. |
Thin handle is hard to grip comfortably. |
Add a handle on each side of the rake, so it can be held with both hands. |
Rake design causes worker to flex wrists
and to use pinch grip with fingers, risking
tendinitis in wrists and hands. |
Use an aluminum rake rather than steel. |
Steel rake is heavy, up to four pounds. |
2. Use a stand-up rolling rake.
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Can be used while standing upright. |
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Eliminates awkward pinch grip with hand. |
Blueberry Rake
Why Not Use a Traditional Rake?
Because wild blueberries grow only about eight inches
from the ground, harvest workers rake in a very
stooped position. Their short-handled steel or aluminum
rake, costing about $60, causes the wrist to
flex as the rake is dragged through the berries. To help
guide the rake, most workers hold on to its side, using
a pinch grip, which can cause tendinitis in the hands.
The rake handle is too thin, at 1ΒΌ inches in diameter,
for most people to use comfortably.
Encourage workers to keep their wrists straight while
working.
How Can I Improve a Traditional Rake?
- Add electrical tape or foam pipe insulation, available
in hardware stores, to enlarge the diameter of the center
handle. The best size is 1-3/8" for small hands, up
to 2-1/8" for large hands, with an average of 1-3/4".
When gripping, the finger and thumb should overlap
slightly.
- Attach a handle on each side of the rake, which
workers can grab without using a pinch grip. The idea
is to have one hand on the center handle and the
other hand on one of the side handles. Holding the
rake by two hands will stabilize it and decrease its tendency
to swivel when raked through the plants. Also,
having a handle on either side will allow the worker to
switch the main raking hand.
Use handles that have a rubber or plastic coating and
that are 1-3/8" to 2-1/8" in diameter, depending on the
hand size of the worker who will be using the rake.
Drill a hole in each side of the rake. Put the bolt of the
handle through the hole and connect with a washer
and nut on the inside of the rake (see drawing on page
19).
- Encourage workers to keep wrists straight while raking
(see illustration, left). They should let the larger
muscles of the shoulder and elbow do the work, and
switch hands often.
- Encourage workers not to fill their rakes or buckets
too full. Tell them to stop if they feel pain, and to put
something cold on the sore spot. Encourage stretch
breaks.
Where Can I Get a
Long-Handled Rake?
Acadian Machine Works Ltd.
Tignish, Prince Edward Island C0B 2B0 Canada
902-882-2349
Cost: $550 Canadian or about $300 U.S., plus shipping
This rake rolls on two wheels, making it easy to push
through the bushes.
Some workers have also made homemade stand-up
rakes, by attaching a long handle to a traditional rake,
via a frame around the back and a cylindrical roller
(like a rolling pin) attached to the bottom. Such homemade
roller rakes are heavy, but still easier on the
back than the traditional rake.
Cost Analysis
At a cost of $300, it would take 17 to 30 hours for a
blueberry harvester to pay for a manufactured standup
rake. The rake should be sturdy enough to last for
many seasons.
Contact Information:
This Tip Sheet was produced by NIOSH.
NIOSH, 4676 Columbia Parkway, Cincinnati, OH
45226. Or visit http://www.cdc.gov/niosh.
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