|Company: Delta Industries
product: Smart Handle Pro Upright Broom
evaluation number: #023
evaluation: December 14, 2002
materials (according to manufacturer):
with wall thickness .045 inches, handle ribbed vinyl, foam grip, and angled broom head
with plastic casing and fine bristles.
Type of product:
designed to function as a broom while providing 2 secure grips that place the hands in
neutral position, which results in increased applied force. The handle length is designed
to keep the user in the upright position with the hands in the "thumbs up"
used in evaluation:
120A 0-6" Dial Calipers, Cal Date 01/10/02
100 S/N D 35542 Dynamometer, Cal Date 03/15/02
tape measure, English units
handles, center of grip to center of grip: Spread 18 inches
Shaft: Length 41
Length 24 inches in neutral posture
height: 38 inches
Weight: 2 pounds
fall within the anatomical range and strength capabilities of the anthropometric data for
the U.S. Industrial Population from the 5th percentile female to the 95th
percentile male. In addition, the positioning of the hands through use of the handle and
foam grip places the hands shoulder width apart.
handle is a lighter weight material than wood or plastic, and the rigidity of the metal
provides for a more efficient transfer of force to the desired target. Due to the extended
handle length, the user is able to maintain an upright posture, which is inherently more
stable than a stooped or bent posture. Remaining upright, rather than bending, decreases
the stress to the spine, both in the lumbar area and in the neck area by preventing the
neck extension required to see the task while in a bent posture. This allows the user
better concentration and visual acuity. By keeping the users hand in neutral
position, the extrinsic muscles of the hand are used more than the intrinsic muscles of
the hand, which decreases the stress on the carpal tunnel. Keeping the hand and wrist in
the neutral position also decreases the stress on other components of the wrist such as
the carpometacarpal joints, the trifibrocartilage complex and the first compartment
complex (involved in DeQuervains tenosynovitis.) Also, with the hands and wrists in
neutral position, both ulnar and radial deviation (side to side deviation at the wrist) is
eliminated, which eliminates arthritis pain and decreases torque forces on the wrist.
Also, the stress of the work is applied to the bones of the forearm in a ratio of 80%
force to the radius and 20% force to the ulna with the hands in the "thumbs up"
position, which is exactly how the body is designed to work. The straight handle of an
ordinary broom applies the force of the work in the opposite ratio, 20% to the radius and
80% to the ulna, which is not how the body is designed to work. By keeping the work close
to the center of gravity, the reach envelope is diminished, which decreases the strain on
the shoulders and lower back. Even with an upright posture, with the hands and arms in
neutral position and with the force applied located close to the users center of
gravity; the sweep length of the implement is such that it is more
ground area covered per sweep). The positioning of the user is almost automatic, certainly
intuitively obvious; and allows the larger muscles of the chest and arms (pectoralis major
and minor, biceps and triceps) to do the work. This decreases strain on the shoulders and
wrists. Due to the positioning of the user, work over a given area is accomplished by use
of the legs to traverse the distance, rather than bending the back to increase the sweep
length. The device thus has the effect of retraining the user to maintain good work habits
have Ergonaut approval?
Gladden, EdD, CPE, CEM
Steve Davis, CEM
entitles Delta Industries International, Inc. to use the Ergonauts Official Seal of
Approval. This privilege expires on 12/31/05.