HOSENOZZLETIM TOCCI | PROF. V.P. HJELTNESS | 10 JAN 2010IDUS 221: HUMAN FACTORS IN INDUSTRIAL DESIGN

ENVIRONMENTALCONSIDERATIONS

USAGESEQUENCE

In addition to considering the user’s anthropometry, attention must also be given

to the task and the environment in which the user will be working. Initially, a

competitive product comparison is conducted to research exisiting options for

the current hose nozzle market (see next page). The benefits and impediments of

representative models are discussed and design opportunities are delineated from

that analysis. Next the process of watering is analyzed and the dynamic muscle

groups are determined by creating usage sequence diagrams. Additionally,

research is conducted to determine the likely injuries and the effect of design on

those injuries. Finally, conclusions are drawn from the results.

Shown below are the typical exercises performed while using a standard garden hose nozzle. The diagrams depict (1) lifting the nozzle off

the ground with a distributed load from the hose itself growing as it is lifted, (2) changing the elevation of the nozzle in the y direction, (3)

changing the angle of the nozzle in the x-z plane (rotate about y-axis), (4) changing the rotation of the nozzle (rotate about the x axis)

erector spinae

bicep

deltoid (medial)

1 2 3 4

y

x

z

bicep

gluteusmaximus

hamstring

metacarpalflexors

forearmflexors

forearm flexors

latissimusdorsi (lats)metacarpal

flexors

bicep

forearm flexors

deltoid (posterior)

metacarpalflexors

tricep

forearmflexors

deltoid (medial)

metacarpalflexors

trapezius

d

b

COMMONINJURIES

c

a

Common injuries that occur while using a hose nozzle include lower back injuries (see 1.a),

carpal tunnel syndrome (see 2.b), shoulder impingement injuries (see 3.c), and tendonitis

such as lateral epicondylitis (tennis elbow, see 4.d).i Lower back injuries are typically

caused by stiff muscles and improper lifting technique—lifting with the back instead of

with the legs. Carpel tunnel and tennis elbow injuries are the resultants of repetitive

motion,ii such as sweeping a nozzle while watering the garden. Shoulder impingement

injuries can also occur as the result of reptitive motion, especially for overhead

movements.iii Many of these injuries could be avoided by an ergonomic design which

suggests proper use and eliminates fatigue through a trigger locking device.

HOSENOZZLETIM TOCCI | PROF. V.P. HJELTNESS | 21 JAN 2010IDUS 221: HUMAN FACTORS IN INDUSTRIAL DESIGN

PRODUCTCOMPARISON

PHASE2CONCLUSIONSThe results from the analysis indicate that an ergonomic garden hose nozzle should account for repetive watering motions such as sweeping, rotating,

elevating, and lowering the nozzle. In consideration of these motions and common injuries associated with gardening, experiments will be conducted in

phase 3 to determine the limits of these motions. Finally, competitive product analysis reveals the simplicity and durability are key consumer values.

Gilmour Zinc Pistol Grip Dramm Revolver Bon-Aire Ultimate Hose Nozzle Orbit XL-Stream Nozzle

To understand the existing market and avoid reinventing the wheel, a

simple competitive product analysis is performed. Initially I visited Home

Depot to examine the tactile features of the respective nozzles. After

reviewing their physical properties and basic functionality, I continued

my analysis by researching the products online to determine how users

are responding to the various designs. Surprisingly, users seem to be the

most disappointed in the most expensive model, suggesting that

satisfaction and price are not correlated when purchasing a hose nozzle.

price

user rating

materials

features

pros

cons

remarks

$25.38 (amazon)

| 6 reviews

metal, polymer handle

adjustable spray

concentration and volume

via rings

firehose nozzle emulation

leads to more control

requires two hands to turn

nozzle on and off

bale (u-shaped lever) helpful

for arthritic gardeners, poor

customer reviews

$14.99 (amazon)

| 191 reviews

aluminum, stainless steel,

fiberglass, rubber

five-pattern spray nozzle,

two-way shut off

triggerless design leads to

reduced grip fatigue

no instant off

1-year warranty, positive user

reviews

Current designs offer a trigger-locking

function by means of a triangular wire which

can be rotated to prop the handle in the

open position. Unfortunately, placement of

this feature requires either two hands or a

long and adroit index finger. An easier

locking mechanism could resemble the

safety feature on a firearm, where a cylinder

is positioned by either the thumb or index

finger. Another solution could resemble the

pinky finger loop shown above.

$11.84 (amazon)

| 16 reviews

die-cast metal,fiberglass lever,

elastomer grip

nine-pattern spray nozzle: fan,

cone, center, jet, mist, soaker,

flat, angle, and shower

variety of spraying options for

multiple watering tasks

durability concerns: powder

coated finish fades, plastic

inner parts wear out

lifetime guarantee, 6 color

options, positive user reviews

$7.08 (amazon)

| 3 reviews

zinc body, brass stem

male threaded nozzle cap,

trigger-lock

inexpensive, conventional

design leads to consistency

grip can be slippery when wet

and become uncomfortable

after long periods of use

trigger requires two hands,

positive user reviews

DESIGNOPP