CONTENTS

INDIAN BREAD MAKING TOOLS - CONSUMER EVALUATION AND DESIGN MODIFICATION
Table 5. Difference in heart rate (b.min -1 ) and energy expenditure (kilo joules)
Rolling pin and
rolling board
Heart rate
Energy
expenditure
Model 1 11.3 3.0
Model 2 13.9 4.6
Model 3 9.7 7.5
Model 4 15.1 6.9
Heart rate and energy expenditure of the user
were taken as the indicators to assess the
physiological status of the user. The physiological
evaluation was carried out while using the rolling pin
and rolling board to assess the workload of roti making
using the identified tools.
Energy consumption is the means by which
the severity of physical stress was estimated but it
is evident that energy consumption alone may not
be a sufficient measure. The degree of physical stress
not only depends on the number of kilojoules
consumed but also on the number of muscles
involved and on the extent to which they are under
static load. The same energy consumption by static
muscular effort is distinctly more tiring than if it is
applied to dynamic work. It is evident that work at a
given energy consumption can make different
demands on the heart.
In the present study there is an increase in
heart rate while using model 4. The difference of heart
rate was less pronounced using model 3. While using
model 3 the deviation from the neutral posture is more
resulting in increase of physical stress of rolling the
dough. There is minimum of increase in heart rate
for model 4, where the board is stable and the light
weight body pin. The results are in accordance with
the study by Kroemer and Grandjean (1997) who
mentioned that the heart rate increases linearly with
the work performed, provided it is dynamic, not static
and is performed with a steady rhythm and is
influenced by the posture adopted, force applied and
the type of product. As the heart rate increases energy
consumption also increases. From the experiments,
the problems identified and the suggested
modifications are as follows
Table 6. Design flaws and modifications of pins and boards
Problem Reason Suggested modification
- Decreased grip
strength
- Muscle fatigue
- Sticky nature
of rolling pin
and rolling
board
- Instability of
the rolling
board
- Pressure on
Palm area
while rolling
More force has to be applied by both
the hands due to lack of adequate grip
and light weight material of the rolling
pin in order to roll the dough on the
board.
The adding of flour in order to avoid
sticking the dough to the board and the
pin, the texture changes and the
frequent movement of hand for adding
flour creates pain in hand.
Due to the imbalance of base of the
board make the board move while
rolling
The shapes of the handles and the
length (7.6 cm) of the handles of the
rolling pin tends more force to be
applied on the palm to roll.
The length of the handles can be
increased which would be across the
palm width with the proper grip
diameter of the handles of the rolling
pin.
Provide non-stick finish to the rolling
pin and the rolling board
The board should be designed with
stoppers underneath to avoid
application of high force as the board
can be fixed to a position and roll.
The barrel shaped handles and
increase in length of the handles
across the palm area, avoid the
pressure on the palm while rolling.
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