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Effects of shape and operation of chopsticks on food-serving performance

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The study evaluated the effects of six chopsticks designs on the food-serving performance of three tasks (food-pulling, food-pinching, and food-moving) under two different operations (pincers-pinching and scissors-pinching). A total of 40 male junior college students were employed as subjects for the laboratory experiment. Subjects who were experienced in pincers-pinching were superior in pinching precision and stability to those experienced in scissors-pinching. Nevertheless, the scissors-pinching group gave a more powerful pinching force while pulling the experimental food. Chopsticks with rounded handle and carved grooves on the tip were preferred in all the six experimental pairs. The research suggests that, in general, the pincers-pinching operation is recommended for daily food-serving and teaching children primary use of chopsticks. Therefore, chopsticks with rounded handle and carved grooves on the tip are suggested for family utensils (non-disposable chopsticks). Considering the cost and cleaning, chopsticks with rounded handle and square tip are recommended for general dining. However, the square handle and rounded tip chopsticks are the type most commonly used in Taiwan.
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PII: S00036870(97)00046-X Applied Ergonomics Vol. 29, No. 4, pp. 233238, 1998
(1998 Elsevier Science Ltd
All rights reserved. Printed in Great Britain
00036870/98 $19.00#0.00
Effects of shape and operation of
chopsticks on food-serving performance
Yi-Lang Chen
Department of Industrial Engineering and Management,Mingchi Institute of ¹echnology,84 Gungjuan Road,
¹aishan,¹aipei Hsien,¹aiwan 243,ROC
(Received 4 November 1996; in revised form 20 June 1997)
The study evaluated the effects of six chopsticks designs on the food-serving performance of three
tasks (food-pulling, food-pinching, and food-moving) under two different operations (pincers-pinch-
ing and scissors-pinching). A total of 40 male junior college students were employed as subjects for
the laboratory experiment. Subjects who were experienced in pincers-pinching were superior in
pinching precision and stability to those experienced in scissors-pinching. Nevertheless, the scissors-
pinching group gave a more powerful pinching force while pulling the experimental food. Chopsticks
with rounded handle and carved grooves on the tip were preferred in all the six experimental pairs.
The research suggests that, in general, the pincers-pinching operation is recommended for daily
food-serving and teaching children primary use of chopsticks. Therefore, chopsticks with rounded
handle and carved grooves on the tip are suggested for family utensils (non-disposable chopsticks).
Considering the cost and cleaning, chopsticks with rounded handle and square tip are recommended
for general dining. However, the square handle and rounded tip chopsticks are the type most
commonly used in Taiwan. (1998 Elsevier Science Ltd. All rights reserved.
Keywords: chopsticks; chopsticks shape; pinching operation
Introduction
Chopsticks have been the most fundamental and conve-
nient utensils used daily by the Chinese people in food-
serving. Unlike the knife and fork, commonly used by the
people living in America and Europe, which often need to
be manipulated together and so require both hands to
serve, chopsticks allow humans to handle all kinds of
food easily with one-handed operation. Contrary to
some ergonomic studies which have focused on the knife
handle (Cochran and Riley, 1986a, b), the ergonomic
investigation of chopsticks had been relatively neglected.
Perhaps the assumption has been that evolution caused
chopsticks to be well designed.
Few studies relative to chopsticks have been conduc-
ted. Hsu and Wu (1991) investigated the effects of the
length of chopsticks on the food-serving performance of
adults and children. Their results showed that food-serv-
ing performance was significantly affected by the length
of the chopsticks, and that chopsticks of about 240 and
180 mm long were optimal for adult and pupils, respec-
tively. Wu (1995) found that the chopsticks’ handle dia-
meter and tip angle have a significant influence on eating
efficiency. He suggested that the chopsticks with 6 mm
handle diameter, 2°tip angle and 4 mm tip diameter
would be optimum.
The aforementioned studies focused on disposable
chopsticks with rounded shape which are easy to make.
In the early 1980s in Taiwan, the government pressured
restaurants to use disposable chopsticks as a preventive
measure against hepatitis-B. However, from the view-
point of ecology, the disposable chopsticks should be
discouraged to avoid cutting bamboos and trees since
hepatitis-B is now controlled in Taiwan.
Another important factor also affecting the food-
serving performance is the operation of chopsticks. The
pinching skill of chopsticks is very difficult to learn.
Several months, or even years of daily use are necessary
for people to learn during childhood (Hsu and Wu, 1991).
Once people become adept at the pinching operation of
chopsticks, they hardly alter the operation from then on
(Chen et al., 1996).
Typically, there are two modes of chopstick operations
adopted by people, one is pincers-pinching and the other
is scissors-pinching. In pincers-pinching, one stick passes
through the space between the thumb and first finger; it is
held against the flesh at the side of the ring finger so the
stick cannot move. The other stick is held by the middle
and index fingers so that they can move apart or together
and thus bring morsels to the mouth. The operation of
pincers-pinching can be classified as third-class lever
(Hsu and Wu, 1991). In scissors operation, two sticks
cross each other between the thumb and the index fin-
gers, and force is applied to them by the interior sides of
the thumb and index fingers when the tips of the index
and middle fingers just hold and aid the sticks. Corres-
ponding to the pinching mechanism, its operation can
be classified as first-class lever (Chen et al., 1996).
233
Figure 1 The definition of chopsticks pinching operations
Consequently, the scissors-pinching is possibly more
powerful than pincers-pinching because the operation
with higher mechanical advantage and the palm grasp
force can be used. On the other hand, the pincers-pinch-
ing is multi-directional by micro-motion of fingers. Pin-
cers-pinching could be easier than scissors-pinching
when the human being needs to pinch up and move food
accurately.
An investigation of chopsticks type and pinching op-
erations was reported by Chen et al. (1996). A sample of
412 Taiwanese adults was surveyed by a questionnaire.
The findings were summarized as follows: (1) The most
popular shape of chopsticks in Taiwan was square
handle and rounded tip (76%); (2) The percentage of
more than two types of chopsticks in Taiwanese families
was 79%; (3) About half of chopsticks operations was
pincers-pinching and the other half was scissors-pinch-
ing. Recently, a Japanese Education Ministry survey of
school children found that only 48% of them used chop-
sticks in pincers-pinching (Tang, 1992). The finding was
similar to that of Chen et al, even though their subjects
were adults.
However, based on both grace and custom, pincers-
pinching is generally considered as the normal operation
(Hsu and Wu, 1991). To date, it is still not known why the
pincers- or scissors-pinching operation of chopsticks is
adopted by people. In this paper, the effects of shape and
operation on the food-serving performance of chopsticks
were studied. Additionally, this study suggests the opti-
mal combination of handle and tip shapes of chopsticks
for human use.
Method
Subjects
Forty subjects, aged between 18 and 22 years (mean 20
years), participated in the study. They were male junior
college student volunteers and all were right-handed.
While eating, 20 subjects used pincers-pinching and the
remaining 20 used scissors-pinching. The definition of
pinching operations is illustrated in Fig. 1 from Chen
et alsstudy (1996). The subjects’ hand lengths ranged
from 172 to 200 mm (average 186 mm). Subjects were
familiarized with the experimental purpose and proced-
ures before the experimental data were collected.
Experimental chopsticks
Four pairs of chopsticks (numbers 1, 2, 4 and 5 in ¹able 1)
were purchased from a supermarket; they are widely used
in Taiwan. The only chopsticks with carved grooves in
the tip (numbers 3 and 6) were homemade. Chopsticks of
types 3 and 6 surveyed in the Taiwanese market, were too
short to be experimentally compared (Hsu and Wu,
1991). For groove-carved chopsticks, nine grooves (1 mm
in diameter and 0.5 mm deep) were equally spaced
around the tip. In this study, the grooves were carved
only for the chopsticks with round tip. All experimental
chopsticks were made of wood and were 230 mm long.
The diameter/diagonal distance of the handle and the tip
were 6 and 4 mm, respectively. The tip was 30 mm in
length with a taper angle 2°(Wu, 1995). Additionally, the
experimental chopsticks were all finished by a fine sand-
paper (600 gpi) to minimize the effects of the surface
friction differences.
Experimental design
The experimental design was a two-factor type with
a blocking on subjects. The factors were the handle shape
with two levels (round or square) and the tip shape with
three levels (round, square or round with carved
grooves). Both were considered as fixed factors and status
of the subjects (experienced in pincers- or scissors-pinch-
ing) was a between-group random factor in this design.
Each subject performed three tasks (food-pulling, food-
pinching and food-moving) with six treatment combina-
tions (two handle shapes three tip shapes) in a random
order.
234 Effects of chopsticks design on food-serving performance:½.-¸.Chen
Table 2 Means (and standard deviations) of three criterion measures and Duncan MRT groups for each main effect.
Variables Number of Pinching-force (kg) Pinching-precision (s) Pinching-stability (s)
observations
Operations
Pincers-pinching 120 0.54(0.24)*a 49.2(9.5) b 29.9(6.9) b
Scissors-pinching 120 0.62(0.20) 53.8(7.3) 37.2(6.9)
Handles
Round 120 0.61(0.22) a 51.3(9.0) 33.5(7.7)
Square 120 0.55(0.23) 51.7 (8.5) 33.6(7.9)
Tips
Round 80 0.57(0.23) 51.6 (8.9) 34.1(8.1)
Square 80 0.60(0.23) 51.2(8.4) 32.8(7.0)
Round (carved) 80 0.57(0.21) 51.6(9.0) 33.8(8.4)
Note:a:p(0.05, b: p(0.0001, *standard deviation
Table 1 Experimental chopsticks shapes of handle and tip
Chopsticks Handle shape Tip shape
number
1 Round Round
2 Round Square
3 Round Round, with carved grooves
4 Square Round
5 Square Square
6 Square Round, with carved grooves
Simulated food-serving tasks and criterion measures
The food-serving tasks of food-pulling, food-pinching,
and food-moving were simulated to test whether the
shape and operation would significantly affect the perfor-
mance of different tasks. The three tasks were used to
measure pinching-force, pinching-precision, and pinch-
ing-stability, respectively. The criterion measures in-
cluded objective measures of food-serving performance
and subjective ratings in each task. In addition, the
subjects were asked to rank their preference among the
six types of chopsticks after all the tasks were completed.
The details of the simulated tasks and their criterion
measures are as follows.
1. Food-pulling task: this task was the same as in Hsu
and Wu (1991). When the test began, the subject used
chopsticks to grip a simulated food (a rubber eraser
60 mm in length, 20 mm in width and 5 mm in height) in
front of the subject (450 mm) and pull it from the table
toward the mouth until it slipped off. The experimenter
read the maximum pulling force on the pushpull scale
(MP-1, Attonic, Aichi, Japan) tied to this simulated food.
Since pulling force is a necessary aspect of food-serving
performance, it was used as one of the criterion measures.
Each subject was asked to repeat the same task three
times and the average of the three readings was used in
the analysis.
2. Food-pinching task: this task was also the same as in
Hsu and Wu (1991). The subject sat on an adjustable seat,
and picked up 30 shelled peanuts one by one from a dish
(120 mm diameter) in front of the subject (450 mm) and
moved them to a cup (150 mm high and 80 mm diameter)
under the mouth. The experimenter recorded the time.
The reason for using peanuts was that picking them up
requires a high degree of precision and hence was as a
measure of a different aspect of food-serving performance.
3. Food-moving task: this task was similar to the pinch-
ing. The subject sat on an adjustable seat, and picked
up10 cubes of bean-curds (1.5]1.5]1.5 cm), one by one,
moving from a dish to a cup under the mouth, as in the
pinching task. The experimenter recorded the time. Bean-
curd, a typical Chinese food, is popular among
Taiwanese. However, it is delicate and soft and thus not
easily picked up. The chopsticks must be wielded by the
subject as carefully as possible in this task. The time
taken to complete the task was recorded and used as
a measure of pinching-stability.
After the subject had finished the three tasks with each
pair of chopsticks, he completed a semantic-differential
scale comprised of four adjective pairs, i.e. ‘arm aching
arm not aching’, ‘grip easilygrip with difficulty’, ‘exer-
tion easilyexertion with difficulty’, and ‘comfortable
uncomfortable’. Each pair had an unmarked scale from
one to nine; arm not aching, grip easily, exertion easily
and comfortable were scored as 9 (Wu, 1995).
Experimental procedure
Before collecting the experimental data, each subject
practiced (for 1 h) the pinching, pulling and moving food
tasks until he was familiar with the experimental purpose
and procedure. The order of experimentation was ran-
domized for each subject. To minimize any effect of
fatigue, subjects were given a 2 min rest period between
successive measurements. In addition, a 30 min tea break
was provided in the middle of the test session.
Before the test, the subject adjusted his seat to a com-
fortable height, holding the handle of the chopsticks with
his experienced hand; the experienced hand was placed
on the edge of the table. In addition, the subject was
instructed to put his left hand on his lap.
When the test began, the subject performed the follow-
ing tasks sequentially: (1) pull a simulated food; (2) pick
up 30 shelled peanuts; (3) pick and move 10 pieces of
bean-curds; (4) respond semantic-differential scales, for
each pair of chopsticks. Finally, the subject was reques-
ted to rank his preference from 1 (favourable) to 6 (un-
favourable) for the six pairs of chopsticks (cf. Chi and
Drury, 1988).
Results
Criterion measures on simulated food-serving tasks
Table 2 shows the means and standard deviations of the
three criterion measures of each independent variable
when averaged across other variables. It shows that type
of pinching operation had a significant effect on the
Effects of chopsticks design on food-serving performance:½.-¸.Chen 235
Table 4 Results of Duncan MRT groups for four subjective criterion measures under two different pinching operations
Arm Grip Exertion
Operations Rank not aching easily easily Comfortable
1 (best) 3!(6.3)"3 (6.4) 3 (6.1) 3 (6.4)
2 2 (5.6) 6 (6.0) 1 (5.6) 1 (5.8)
Pincers- 3 1 (5.6) 1 (5.8) 6 (5.5) 6 (5.4)
pinching 4 6 (5.1) 2 (5.3) 5 (5.5) 2 (5.3)
5 5 (5.1) 5 (5.2) 2 (5.2) 5 (4.2)
6 (worst) 4 (4.9) 4 (4.5) 4 (4.4) 4 (3.7)
1 (best) 3 (5.6) 3 (6.9) 3 (6.2) 3 (6.3)
2 2 (5.5) 2 (5.9) 2 (6.2) 2 (5.9)
Scissors- 3 1 (5.0) 6 (5.9) 6 (5.8) 1 (5.5)
pinching 4 5 (5.0) 4 (5.9) 5 (5.7) 4 (5.4)
5 6 (4.8) 5 (5.5) 4 (5.5) 6 (5.3)
6 (worst) 4 (4.7) 1 (5.2) 1 (5.2) 5 (4.7)
Note:!Experimental chopsticks number in the study,
"Mean rating values on 09 scale
Table 3 Analysis of summary variance for the four subjective criterion measures
Arm Grip Exertion
Operations Sources D.F not aching easily easily Comfortable
Handle 2 p(0.05 ns ns p(0.01
Pincers- Tip 1 ns p(0.05 ns p(0.01
pinching Handle Tip 2 ns ns ns ns
Handle 2 ns ns ns p(0.05
Scissors- Tip 1 ns ns ns ns
pinching Handle Tip 2 ns ns ns ns
Note: ns: non-significant difference
food-serving performances (all p(0.05). The pincers-
pinching was superior in food-pinching (49.2 vs 53.8 s)
and moving tasks (29.9 vs 37.2 s); in contrast, the scissors-
pinching was more powerful in pulling force (0.62 vs
0.54 kg). Pinching force was the only significant
(p(0.05) difference between handles. Except that the
round shape of chopsticks exceeded the square shape in
the food-pulling task (0.61 vs 0.55 kg), the effects of
handle and tip of chopsticks on various task criterion
measures were not significantly different. No interaction
effect was significant (all p'0.05).
Subjective rating
To confirm the subjective rating test’s reliability, the
Cronbach value was calculated for the test following
Cronbach, 1951. The calculated values were 0.822 and
0.918 for pincers- and scissors-pinching rating tests, re-
spectively, showing good internal consistency and relia-
bility. The analysis of variance for subjective rating
scores revealed that, under the two pinching operations,
the effects of handle and tip of chopsticks were signifi-
cantly different from each other. As shown in Table 3,
while for pincers-pinching, the shapes of handle and tip
had significant effects on the scores of ‘arm not aching’
and ‘grip easily’, respectively (p(0.05), the ‘comfortable’
score was affected by both of these factors (p(0.01).
However, for subjects experienced in scissors-pinching,
only the ‘comfortable’ score significantly differed in
handle shapes (p(0.05). The other subjective rating
scores showed no differences between each variable.
The subsequent Duncan multiple range test (Table 4)
indicated that the rating scores of the chopsticks No. 3
(rounded handle and carved grooves tip) were signifi-
cantly better than those of others. It is surprising that
chopsticks No. 4 (square handle and round tip), most
frequently used in Taiwan, was the worst in subjective
ratings among others, especially in pincers-pinching. In
general, the chopsticks with rounded handle were the
best subjective choice. Regarding the effects of the tip
factor, they depended on the pinching operations and the
criterion measures.
Subjective ranking
Ranking data on subjective preference of 40 subjects for
six pairs of chopsticks were analyzed. The results, using
a Wilcoxon test on the rank data, indicated that the
handle and tip factors were significantly different on
subjective preference in either type of pinching (all
p(0.01). Considering the overall preference, the six
pairs of chopsticks were grouped into the Best,Middle,
and ¼orst, depending on whether their estimated median
was significantly smaller or greater than 3.5 (Chi and
Drury, 1988), with the results shown in Table 5. They are
similar to the subjective rating scores in that the chop-
sticks with rounded handle and carved grooves in the tip
(number 3) was the best. The chopsticks with square
handle were the worst (numbers 4, 5) except for those
with the tip with carved grooves.
Discussion
This study evaluated the effects of shape and operation
of chopsticks on food-serving performance and then
236 Effects of chopsticks design on food-serving performance:½.-¸.Chen
Table 5 Subjective rankings of the Wilcoxon tests while food-serving with pincers- and scissors-pinching for various experimental chopsticks
Pincers-pinching Scissors-pinching Overall
Rank Chopsticks No. (mean) Chopsticks No. (mean) Chopsticks No. (mean)
1 (best) 3 (2.5) 3 (2.2) 3 (2.3) Best
2 1 (2.7) 2 (3.3) 2 (3.2)
3 2 (3.1) 6 (3.3) 1 (3.2) Middle
4 6 (3.7) 1 (3.7) 6 (3.5)
5 5 (4.4) 5 (4.3) 5 (4.3)
6 (worst) 4 (4.9) 4 (4.6) 4 (4.8) Worst
Note: Significant level 0.05
proposed successful combinations of these factors for the
chopsticks design. The type of pinching operation used
did influence the food-serving performances. Generally,
subjects experienced in pincers-pinching were superior in
pinching precision and stability to those who used scis-
sors-pinching. Nevertheless, the scissors-pinching opera-
tion was more powerful in pinching force while pulling
the experimental food. In addition, the chopsticks with
a round handle and carved grooves in the tip were the
most subjectively preferable. The results showed that not
only the length, handle diameter, and tip angle (pre-
viously studied by Hsu and Wu, (1991) and Wu, (1995))
had significant effects on food-serving performances, but
also the operation and shape of chopsticks might be
important factors.
The results of the study can help explain why the
scissors-pinching operation was still adopted by many
people in Taiwan or even Japan. One of the possible
reasons is that the child’s hand is too small and weak to
wield the chopsticks skillfully with pincers operation.
Another method (scissors-pinching) may then be adopted
for taking meals since the operation is easier to learn for
children. However, the scissors-pinching is a powerful
operation, clamping the sticks using thumb and index
fingers, but lacks precision and stability. Therefore, in
a transition from spoon to chopsticks for a child, the
pincers-pinching operation should be taught. Naturally,
as suggested by Hsu and Wu, (1991), shorter chopsticks
must be provided for children because of the weakness of
their fingers and the mechanical disadvantage from
smaller hands.
The results also showed that the shape of chopsticks
affected food-serving performance, but had a greater ef-
fect on subjective scores. The chopsticks with rounded
handle were found to be the subjectively best and those
with a square handle to be worst. The finding correspon-
ded to Konz’s (1983) who postulated the cross-section of
the handle should be circular to minimize sharp edges.
Additionally, the chopsticks with carved grooves in the
tiptip were the most preferred, followed by those with
square tip and last the ones with rounded tips. The
results of the effects of tips on food-serving performances
were very different with those of handles. In fact, the
rounded handle made pinching easy, and the square
handle even caused people to be uncomfortable. On the
contrary, the tip with carved grooves can add the friction
between the food and the tip to improve the performance
of food-serving. The fact that objective measures were
seldom identical to subjective ones could reflect the effect
of overlearning of subjects, since the tasks duration could
have been too short to reflect performance differences.
From this viewpoint, the rounded tip is apparently
a poorer design than square tip. Although the chopsticks
with carved tips are excellent in pinching, they cost more
to make, and daily cleaning becomes inconvenient. Con-
sidering the trade-offs between ergonomics and cost,
chopsticks with a rounded handle and square tips would
be a reasonable substitute. However the square handle
and rounded tip chopsticks are the one most often used
in Taiwan. The effects of the shape and operation of
chopsticks for other population (e.g., female, elderly or
children) are an issue for further investigation, as this
study used only male students.
Conclusions
In summary, the study evaluated six chopsticks designs
using three food-serving performances. The major con-
clusions are as follows:
(1) Subjects who were experienced in pincers-pinching
were superior in pinching precision and stability to those
experienced in scissors-pinching. Nevertheless, the scis-
sors-pinching group gave more powerful pinching force.
The pincers-pinching method of operation is recommen-
ded for daily food-serving and teaching children, the
primary use of chopsticks.
(2) The chopsticks with rounded handle and carved
grooves in the tip were the most preferred subjectively.
Thus, these chopsticks are suggested for the family uten-
sils (non-disposable chopsticks).
(3) Though the chopsticks with carved tip were excellent
in pinching, they cost more and cleaning becomes incon-
venient. Chopsticks with rounded handle and square tip,
therefore, are recommended for general dining.
Acknowledgements
The author wishes to acknowledge the assistance of S. Z.
Deng, P. H. Huang, C. F. Chen and K. Y. Chen (Mingchi
Institute of Technology, Taiwan) for their contributions
to the experiment.
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238 Effects of chopsticks design on food-serving performance:½.-¸.Chen
... These utensils are used by more than 1.5 billion people around the world, mostly in East Asia, and their shape, material, and method of production differ with each country's unique culture [3]. As with other Western-style utensils, the relationship between shape and manipulation performance have been studied [1,4,5]. A clear difference between chopsticks and other hand tools is that there are different ways to hold chopsticks [6][7][8][9][10][11]. Methods of holding chopsticks are largely divided into the traditional pincers-pinching (P) mode and the scissors-pinching (S) mode [6][7][8]10] (Fig. 1). ...
... A clear difference between chopsticks and other hand tools is that there are different ways to hold chopsticks [6][7][8][9][10][11]. Methods of holding chopsticks are largely divided into the traditional pincers-pinching (P) mode and the scissors-pinching (S) mode [6][7][8]10] (Fig. 1). In general though, it can be said that all users of chopsticks use either P mode or S mode, with approximately half using one mode and half the other [4,[6][7][8]. When someone is gripping a chopstick with one hand, they grasp it with their index finger, middle finger, and thumb. ...
... In this way, P mode leverages the advanced coordination of the human hand so that independent force can be applied to both chopsticks. The traditional P mode has been shown to have higher operational performance than S mode [4,7]. However, aside from ergonomic operational performance, the only reasons why P mode is considered the "correct holding method" are the superior aesthetic appearance and the fact that this mode is customary [4,5]. ...
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Full-text available
Background: The purpose of this study was to clarify the influence of manipulation mode of chopsticks on the learning process, using assessment of task performance and electromyography, and to understand the significance of the traditional manipulation mode from the viewpoint of physiological anthropology. Previous studies have described two modes of manipulating chopsticks, the traditional pincers-pinching mode and the scissors-pinching mode. Methods: We conducted experiments with two conditions of holding chopsticks: scissors mode and pincers mode. Eight subjects participated and were assigned to these modes, and they learned handling tasks in their assigned mode for 5 days with the non-dominant hand. We measured task execution times and conducted electromyography of the following muscles: first dorsalis interosseus, flexor pollicis brevis, flexor digiti minimi brevis, flexor digitorum superficialis, and extensor digitorum. Results: The training effects were found in each mode. The pincers mode showed significantly shorter task performance times than did scissors mode. On electromyography, significant increases in activity of flexor digiti minimi brevis and tended an increase in flexor digitorum superficialis and a decrease in extensor digitorum occurred in pincers mode but not in scissors mode. Conclusions: The traditional mode of holding chopsticks was associated with not only high task performance but also an advantage in terms of learning motor control.
... There are several ways to handle chopsticks. Normally, when people use chopsticks, they pass two chopsticks through the space between the thumb and index finger ( Figure 1) [2,6]. One stick is caught in the angle between the thumb and the index finger and is supported by the ring finger. ...
... Several studies related to chopsticks have been conducted. Specifically, in regards to the effective use of chopsticks, their mechanism, optimum size, and shape have been studied [2,3,6,7]. Furthermore, virtual chopsticks driven by captured movement of a user's hand have been demonstrated in a virtual reality system [8]. In addition, by applying the advantages of chopsticks to surgery and other research areas, new devices and techniques have been developed for grasp and transport [9][10][11][12][13]. ...
... Chopsticks are a common and simple tool used for picking up food in oriental culture [1,2]. At least 1.5 billion people use chopsticks daily [3]. ...
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Chopsticks are a popular tool used every day by 1.5 billion people to pick up pieces of food of different sizes and shapes. Given that the use of chopsticks requires sophisticated muscle control, they are difficult to use for unskilled people. In this study, a chopstick robot that uses a new soft actuator was developed. Firstly, we developed an X-shaped soft actuator and tested its performance. When a voltage was applied to the actuator, the gap in the X shape was reduced by the resulting electrostatic force. Conversely, when the power was turned off, the actuator recovered its original shape owing to the elasticity of its material. We attached the X-shaped soft actuator between the chopsticks. The chopstick robot, controlled by the input voltage, can pick up various objects in the switched-on state and is able to release them when switched off. We tested the performance of the chopstick robot and analyzed the forces acting on the chopsticks. The robot can be used for picking up various objects. Moreover, the X-shaped actuator can be adapted for use in various studies, through different shapes and configurations.
... In scissors operation, two sticks cross each other between the thumb and the index fingers, and force is applied to them by the interior sides of the thumb and index fingers when the tips of the index and middle fingers just hold and aid the sticks. Corresponding to the pinching mechanism, its operation can be classified as first-class lever [6]. Chen, et al. [4] conducted a questionnaire survey of chopstick type and pinching operations on 412 adults in Taiwan and determined that approximately half of the respondents use the pincers-pinching mode, whereas the other half adopt the scissors-pinching operation. ...
... Tang [7] presented the survey results provided by Japan's Ministry of Education, Culture, Sports, Science and Technology, which reported that only 48.4% of 15,400 elementary school third and sixth graders were able to use chopsticks correctly. Chen [6] evaluated the effect of chopstick operations on food-serving performances and experimentally determined that pincers-pinching operations rendered a significantly higher pinching precision and stability. Chen also indicated that the scissorspinching group gave a more powerful pinching force while pulling the experimental food. ...
... The bamboo chopsticks were 220 mm long, with 30 mm tip length, grooved tips, a 6 mm handle diameter, a 4mm tip diameter, and a 2° tip angle. The external geometric design of the chopsticks conformed to the optimal configuration described in previous studies [2,5,6,8,11]. The chopstick auxiliary device design was based on Lee and Chen [10] (Figure 2). ...
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This study adopted the chopstick auxiliary device which was previously developed to assess how such a device improves the chopstick-use performance of foreign novices. Fifty male international exchange students participated in the study and their data on three food-serving performance indicators were collected after they performed three stages of tasks. Results showed that after users whose original chopstick operation was scissors-pinching had practiced using the auxiliary device for 1-h, the precision and stability of their pincers-pinching operation was superior to those of their scissors-pinching technique (p<.05). This study also found that the auxiliary device is applicable for novices who already knew how to use chopsticks correctly (i.e., pincers-pinching). Using this device significantly improved their pinching force, whereas the pinching precision and stability remained no significant change. This study verified that foreigners who just started using chopsticks can employ the auxiliary device to learn how to correctly hold chopsticks, thereby improving their food-serving performance.
... The phrases "arm not aching, grip easily, exertion easily, and comfortable" were rated as scores of 9. The previous semantic-differential scale questionnaire for evaluating the motor skill performance of the fingers was applied in this study [28][29][30]. ...
... This implies that the participants could use more fingers for greater finger strength to control the Chinese brush when pressing down and touching the rice paper continuously to complete the complex movements and rotations in the maze track task. Previous studies have also revealed that using more fingers for a particular hand tool operation resulted in greater strength [28,31,38]. This may be the reason why the five-finger gripping method of manipulating the Chinese brush produced fewer errors than that of the three-finger gripping method in hand-eye coordination tasks. ...
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This study aimed to investigate the effects of finger grip and wrist position on Chinese calligraphy handwriting (CCH). Thirty participants were recruited in the study and asked to manipulate the Chinese brush using two finger grip methods (three-finger grip and five-finger grip) and two wrist positions (suspended wrist and raised wrist). Three experimental writing tasks were applied to investigate writing stability, agility, and hand–eye coordination, and to evaluate the completion time(s), area of error (cm2), and error times. Subjective responses (arm aching level, ease of grip, exertion level, and comfort) regarding the four combinations of Chinese brush manipulation were measured. The results indicated significantly better performance with the three-finger grip for the stability and agility tests, and with the five-finger grip for the hand–eye coordination task. Using the suspended wrist position for CCH allowed better agility and hand–eye coordination than the raised wrist position. In consideration of the results of the four operational combinations, the three-finger grip with a suspended wrist position demonstrated the best performance in both objective and subjective measurements. It is recommended for application in the early learning stage. These findings can be considered when teaching Chinese brushes for beginners of CCH in schools.
... Then he put forward six common combinations for experiment. It was discovered that chopsticks with circular cross-section shape have better food-pinching performance and chopsticks with carved grooves on tips have better performance of pinching food than those without grooves (Chen, 1998). Wu and other researchers also compared the performance of four cross-section shapes of chopstick handles, which were: circular, rectangular, hexagonal, and rounded square, and it was discovered that cross-section shapes which are circular and rounded square have the best performance (Wu and Tsai, 2012). ...
... Therefore, bamboo was the choice of chopstick substance in the experiment. In addition to the material of bamboo, all four pairs of chopsticks had a 6 (Chen, 1998). ...
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Total 40 college students (16 males and 24 females), with an average age of 22, were surveyed in this study. The participants are highly familiar with the use of chopsticks and were tested with their handedness (95% of the participants are right-handers and 5% of the participants are left-handers). The control variable in this study is chopsticks 6 millimeters in diameter. Instruments used in this experiment were four pairs of chopsticks of different lengths:120 mm (Type A), 150 mm (Type B), 180 mm (Type C), 210 mm (Type D). Each participant was requested to randomly use these 4 pairs of chopsticks to pick up peanuts (10 millimeters in diameter). Least Significant Difference (LSD) was utilized for measuring quantity of pinched peanuts and participants’ satisfaction at four different types of chopsticks.. The research results revealed that quantity of pinched peanuts showed significant difference (p=0.017) when the length of chopsticks changed from 120 mm to 180 mm. In terms of satisfaction, it presented significant difference (p=0.001) among four types, and participants showed higher satisfaction at longer chopsticks. Correlation Analysis will be further applied in future study, with a larger quantity and a random approach, and the future study can be used to find out the most appropriate chopsticks length for the reference of chopsticks manufacturers.
... Previous research has discussed the food-serving performance of chopsticks associated with exterior parameters (i.e. shape, length, materials, etc.) and method of use ( Hsu & Wu, 1991 ;Wu, 1995 ;Chen, 1998 ;Chan, 1999 ;Ho & Wu, 2006 ). Most of the research has focused on which method of use or exterior parameters result in optimal gripping performance. ...
... In addition, only 80 g of rice were provided in the experiment, so it would be worth investigating actual consumption in the real world. Previous evidence has suggested that the food-serving performance of chopsticks is related to exterior parameters (i.e., shape, length, materials, etc.) and method of use ( Hsu & Wu, 1991 ;Wu, 1995 ;Chen, 1998 ;Chan, 1999 ;Ho & Wu, 2006 ). For example, a combination of bamboo chopsticks with grooved tips operated with a pliers-grasp tends to be preferable for more favorable gripping performance ( Ho & Wu, 2006 ). ...
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-This study explored the influence of the length of chopsticks on taste evaluations. Participants (N = 78; M age = 21.1 yr., SD = 3.8) reported a greater liking for their food and higher purchase intentions when using long rather than short chopsticks. Findings also indicated that the long (vs short) chopsticks caused people to slow down when eating, resulting in greater eating duration and a higher number of mouthfuls. The findings of this study provide insights on research into the role of tableware in food intake.
... Most studies on chopsticks have discussed the influences of exterior parameters (such as shape, length, and materials) or method of use on food-serving performance [20][21][22][23][24][25]. For example, Lin et al. [25] investigated the influence of chopstick size on taste evaluation and found that long chopsticks led people to extend the time they spent eating as well as to enjoy the ambiance more compared with when short chopsticks were used. ...
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Even though the influences of eating environments and the food environments on consumption have been discussed, little has been done to examine whether the food environments would be influenced by the eating environments. For example, the size of plate has been proved to have impact on consumers’ consumption volume; it is still unknown whether the eating environment would interact with the food environment and in turn influences consumers’ consumption volume. This research explores the underlying mechanisms how consumers are influenced by the size of bowl when they consume food. In addition, eating environments are also incorporated to discuss their effects on the relationship between bowl size and consumers’ consumption volume. The results indicate people who receive a large bowl with large chopsticks exhibit greater food consumption than those who receive a small bowl with small chopsticks. However, when people use tableware inconsistently, they exhibit similar food consumption. Under bright illumination, people given large bowls with large chopsticks exhibit greater food consumption than those given small bowls with small chopsticks; however, when people use inconsistently sized tableware, they exhibit similar food consumption. Under dim illumination, no significant differences in food consumption amount are evident in association with bowl and chopstick sizes.
Article
In order to help the disabled who have difficulty eating meals and to help their caretakers or family members, various types of meal assistant robots (MARs) have been developed worldwide in the last few decades. Some of them have been already commercialized. For these robotic systems, the eating utensil serves as an end-effector and plays a vital role, as it determines the type of food that MARs can handle. In addition, the eating utensils for MARs must be carefully designed while taking into consideration the local traditional culture and food culture. Most existing MARs developed by Western society are not suitable for Asian food, including the Korean one. Asian foods include various vegetables and steamed rice, and Asian people enjoy using chopsticks as well as spoons. In this paper, a novel integrated spoon-chopsticks mechanism was proposed. The proposed mechanism was integrated to the advanced MAR as its end-effector. The proposed mechanism was designed to change eating utensils and the operation of chopsticks with a single actuator. The kinematic solution to deal with this unique mechanism was also provided in this work. The feasibility and the effectiveness of the proposed system have been verified after integrating it with MAR by a series of experiments.
Article
Motor development was investigated in 114 children aged 4-9 years, and the effects of different cross-sectional shapes of chopsticks (octagonal, square, and triangular) on manipulation ability were examined. Children's chopstick manipulation was found to be related to the developmental stage and their way of holding them. Manipulation was enhanced when they transmitted the optimal force to the tips when closing, the bottom chopstick was stabilized when opening, and the upper chopstick was encouraged to rotate moderately. In addition, opening chopsticks is more difficult than closing them. Square chopsticks increase the force of the tips, whereas octagonal chopsticks encourage more rotation of the upper chopstick, indicating that differences in the ability to manipulate chopsticks during development affect the preference for cross-sectional shapes. We plan to examine the effectiveness of chopsticks with different cross-sectional shapes of the upper and bottom chopsticks by focusing on the opening operation.
Chapter
For children living in East Asia, chopsticks are important eating utensils. Providing children with appropriate training chopsticks to help them learn how to hold chopsticks properly facilitates not only better hand muscle development, but also fine motor skills. However, commercially available children’s training chopsticks come in a variety of designs and styles that have different effects on the way children hold them. Because of the lack of scientific research exploring chopstick design criteria, there are no data for designers to refer to when designing chopsticks. To help resolve this issue, we collected and compiled chopstick design studies and analyzed the designs of commercially available chopsticks to develop 10 systematic design criteria for the design of training chopsticks. Subsequently, we used the analytic hierarchy process (AHP) and conducted interviews with three experts who were familiar with children’s chopstick usage behavior and/or who had experience in designing children’s tableware to derive the weights of the criteria. The results showed that operating part design (the design of the upper-chopstick), bridge size, and chopstick material were the primary design criteria that designers should consider when designing children’s training chopsticks.
Article
The effects of chopsticks handle diameter and tip angle on the food-serving performance of pinching food, pulling food, shearing food and thrusting food, were investigated in this study. A total of 24 male subjects was tested using 12 pairs of experimental chopsticks, consisting of three types of different handle diameters and four types of different tip angles. These results indicated that chopstick handle diameter and tip angle have a significant influence on eating efficiency, and that these two variables have a significant interaction. In addition, chopstick tip diameter also had significant effects on performance at the four tasks and subjective ratings. Generally, according to the results, when the chopsticks design is presented in terms of handle diameter, tip angle and tip diameter, a pair of chopsticks with 6 mm handle diameter × 2 ° tip angle × 4 mm tip diameter would be optimum.
Article
A general formula (α) of which a special case is the Kuder-Richardson coefficient of equivalence is shown to be the mean of all split-half coefficients resulting from different splittings of a test. α is therefore an estimate of the correlation between two random samples of items from a universe of items like those in the test. α is found to be an appropriate index of equivalence and, except for very short tests, of the first-factor concentration in the test. Tests divisible into distinct subtests should be so divided before using the formula. The index [`(r)]ij\bar r_{ij} , derived from α, is shown to be an index of inter-item homogeneity. Comparison is made to the Guttman and Loevinger approaches. Parallel split coefficients are shown to be unnecessary for tests of common types. In designing tests, maximum interpretability of scores is obtained by increasing the first-factor concentration in any separately-scored subtest and avoiding substantial group-factor clusters within a subtest. Scalability is not a requisite.
Article
This research evaluated two variables affecting the performance of tang guards in preventing injury due to the hand slipping forward on a knife handle: the radius of transition from the handle to the blocking portion of the tang and the height of the tang. For the radii evaluated, there was no effect for either men or women. The guard height, however, did have a significant effect for both genders. There is a height, different for men and women, that appears to be critical. Guard heights exceeding this critical height do not enhance the capability of the guard to prevent the hand from slipping. Guard heights less than this critical value are less capable of preventing slipping.
Article
This research empirically evaluated the effects of handle shape and size on the hand's ability to resist or exert force in six directions. Thirty-six handles of four sizes and nine shapes were tested for maximum force exertion by male and female subjects. The results show that subjects were able to generate higher forces with different sizes and shapes of handles, depending upon the direction of force exertion. This suggests that handles that are associated with high forces on particular directional tests are probably suited for tasks that incorporate that particular type of force or movement; they may not be appropriate for other tasks that do not incorporate such movement.
Article
Chopsticks are one of the most simple and popular hand tools ever invented by humans, but have not previously been investigated by ergonomists. Two laboratory studies were conducted in this research, using a randomised complete block design, to evaluate the effects of the length of the chopsticks on the food-serving performance of adults and children. Thirty-one male junior college students and 21 primary school pupils served as subjects for the experiment. The results showed that the food-pinching performance was significantly affected by the length of the chopsticks, and that chopsticks of about 240 and 180 mm long were optimal for adults and pupils, respectively. Based on these findings, the researchers suggested that families with children should provide both 240 and 180 mm long chopsticks. In addition, restaurants could provide 210 mm long chopsticks, considering the trade-offs between ergonomics and cost.
Article
The problem of measurement of effectiveness of handle design was addressed directly by scales. Ratings on several subjective scales were used and compared with maximum force exertion capabilities and grip force efficiency. Three of the handles were selected by overall preference ranking and tested using the Point of Subjective Equality (PSE) measure proposed by Hsia and Drury (1986). Factor analysis revealed two orthogonal factors, one related to overall preference and one related to strength. The PSE measure failed to give significant results.
Chopsticks? Just reach out and grab it! ¹rademarks of the Chinese I, Published by Sinorama Magazine Effects of the handle diameter and tip angle of chopsticks on the food-serving performance of male subjects
  • John Wiley
  • J Wu
John Wiley Sons, Kansas State University Tang, J. (1992) Chopsticks? Just reach out and grab it! ¹rademarks of the Chinese I, Published by Sinorama Magazine, Taipei, Taiwan Wu, S. P. (1995) Effects of the handle diameter and tip angle of chopsticks on the food-serving performance of male subjects Applied Ergonomics, 26(6), 379—385
¼ork Design: Industrial Ergonomics ch. 15 Chopsticks? Just reach out and grab it! ¹rademarks of the Chinese I
  • S J Konz
Konz, S. (1983) ¼ork Design: Industrial Ergonomics ch. 15. John Wiley Sons, Kansas State University Tang, J. (1992) Chopsticks? Just reach out and grab it! ¹rademarks of the Chinese I, Published by Sinorama Magazine, Taipei, Taiwan
A questionnaire survey of types and pinching operations of chopsticks Mingchi ¹echnical Report
  • Y L Chen
  • S Z Deng
  • P H Huang
  • C F Chen
  • K Y Chen
Chen, Y. L., Deng, S. Z., Huang, P. H., Chen, C. F. and Chen, K. Y. (1996) A questionnaire survey of types and pinching operations of chopsticks Mingchi ¹echnical Report
) ¼ork Design: Industrial Ergonomics ch. 15
  • S Konz
Konz, S. (1983) ¼ork Design: Industrial Ergonomics ch. 15. John Wiley Sons, Kansas State University