This paper deals with the comfortable sitting posture for prolonged period of driving. Today automobile comfort expectation has been on a steady rise. To offer the driver sufficient comfort during a long journey, sitting posture plays a vital role in safety and comfort. Upright driving position is to enhance comfort especially on prolonged periods of driving. The purpose of using mounted low-cost load cell is to provide a real-time data of seated person. Optimum posture is more prominent for sitting comfort for long time of driving. Predictions of discomfort is mainly based on the various sitting posture and to enhance the optimize posture is greatly to minimize fatigue. The optimum sitting position is to play an important role in fulfilling comfort expectations. Propose the improvements in recommended practices in order to accommodate the driver in best seated position. In optimal sitting position is to enhance the natural curvature of elongated “S” shaped curve with evenly distributing the load. Good sitting posture and relaxed position of driving is mainly focused on concentration and responsibilities. It is also beneficial to assess the ease Ingress/egress.

1. http://www.iaeme.com/IJMET/index.asp 292 editor@iaeme.com
International Journal of Mechanical Engineering and Technology (IJMET)
Volume 10, Issue 06, June 2019, pp. 292-302, Article ID: IJMET_10_06_025
Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJMET&VType=10&IType=6
ISSN Print: 0976-6340 and ISSN Online: 0976-6359
© IAEME Publication
VIRTUAL OPTIMIZATION OF SITTING
POSTURE ANALYSIS ON USING LOW-COST
LOADCELL BASED ON VARIOUS SITTING
POSITION IN AUTOMOBILE SEATING FOR
COMFORT AND SAFETY
Rajesh. P. K., Maniarasu.R, Sudhir Kumar. V
Department of Automobile Engineering, PSG College of Technology,
Coimbatore, Tamilnadu, India
Manikandan. N
Department of Mechatronics Engineering, Sri Krishna College of Engineering and
Technology, Coimbatore, Tamilnadu, India
ABSTRACT
This paper deals with the comfortable sitting posture for prolonged period of
driving. Today automobile comfort expectation has been on a steady rise. To offer the
driver sufficient comfort during a long journey, sitting posture plays a vital role in
safety and comfort. Upright driving position is to enhance comfort especially on
prolonged periods of driving. The purpose of using mounted low-cost load cell is to
provide a real-time data of seated person. Optimum posture is more prominent for
sitting comfort for long time of driving. Predictions of discomfort is mainly based on
the various sitting posture and to enhance the optimize posture is greatly to minimize
fatigue. The optimum sitting position is to play an important role in fulfilling comfort
expectations. Propose the improvements in recommended practices in order to
accommodate the driver in best seated position. In optimal sitting position is to
enhance the natural curvature of elongated “S” shaped curve with evenly distributing
the load. Good sitting posture and relaxed position of driving is mainly focused on
concentration and responsibilities. It is also beneficial to assess the ease
Ingress/egress.
Key words: Ergonomics; body posture; biomechanics; comfort; optimum sitting
posture.
Cite this Article: Rajesh. P. K., Maniarasu.R, Sudhir Kumar. V and Manikandan. N,
Virtual Optimization of Sitting Posture Analysis on Using Low-Cost Loadcell Based
on Various Sitting Position in Automobile Seating for Comfort and Safety.
International Journal of Mechanical Engineering and Technology 10(6), 2019, pp.
292-302.
http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=10&IType=6

2. Virtual Optimization of Sitting Posture Analysis on Using Low-Cost Loadcell Based on Various
Sitting Position in Automobile Seating for Comfort and Safety
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1. INTRODUCTION
Comfort makes a major contribution to today‟s consumer demand. The objective is to predict
the discomfort reliably and for the possible reduction of the prevalence of musculoskeletal
problems associated with driving [1, 6, and 16]. It is necessary to monitor the discomfort of
sitting or keeping a certain posture for a long time as improper sitting postures can lead to
discomfort and health disorders [3]. Ensuring the optimum sitting posture tends to improve
the occupant‟s comfort and health.
The driver seat is equipped with force transducers, which allows continuously monitoring
and tracking the sitting behavior of a person in order to identify the actual sitting posture of a
seated person in real time and ultimately improve driver performance [4, 27]. Nowadays,
most of the people spend their average time in awkward sitting posture while driving. As a
consequence, this improper posture leads to back problem. Prolonged sitting position is
associated with muscular disorders, the development of disc degeneration and the increase of
spine stiffness [5, 6]. Equipped with mounted load cell, the common sitting posture can be
easily detected [26].
There are various possible sitting positions such as upright with backrest and without
backrest, leaning towards back or forward, sitting at the front edge, leaning towards the right
or left position, and the slouched/slumped position [9, 23]. Force sensors placed on the sitting
support directly give the information of the actual sitting position. Optimum, completely
surface with back support posture is the most recommended position to prevent backache and
to improve flexibility in muscle activities [24].
The estimated bio-mechanical behavior of a certain sitting posture is greatly responsible
for spine alignment [5, 7]. The slouching position is more harmful to spine compared to other
sitting postures, as seen in this monitoring system .The four load cell are located at each
corner of the seating support, thus it generates the actual sitting position data [16].
The reason to identify the unhealthy posture, and indicate a warning /alert signal to driver
is to provide high awareness to the person sitting on the driver seat so as to minimize the
fatigue. The ultimate aim is to implement the optimum correct sitting posture for a prolonged
period of driving. To optimize awareness of improper sitting position is to improve the human
sitting behavior. Improper posture or extra stress on the spine leads to a variety of spinal
disorders including chronic back pain [8].
This sensing system persistently monitors posture in real-time and provides real-time
feedback when poor posture is assumed. Mainly spine stress and strain are caused by poor
back posture, resulting in pain and discomfort and may lead to unpleasant changes in disc
pressure and spinal musculoskeletal disorders [8, 20]. Estimating that about 80% of adults
experience back pain at some point in life, a graphical representation of each sitting posture
and position is displayed on chart form. In driving , the driver enhance the perceived in longer
period of journey without back pain has been monitored and stored in Arduino board with
systematic program installed in vehicles [10].That particular set up continuously monitored
the driver sitting posture and give the warming signal when position of driver varied [11].
2. PROBLEM DEFINITION
Long-time driving results in Work –Related Musculoskeletal Disorders (WMSDs) are mainly
caused by poor posture; stress tension; position for extended period .Discomfort & lower back
pain are frequent complaints in driver [21]. That can be mainly referred as RDI - Repetitive
Driving Injury.Ergonomically incorrect sitting posture quickly leads to abrasion of spinal disc
and to back problems

3. Rajesh. P. K., Maniarasu.R, Sudhir Kumar. V and Manikandan. N
http://www.iaeme.com/IJMET/index.asp 294 editor@iaeme.com
Figure 1 Problems Percentage
According to the survey for prolonged period of driving, most predominantly pain occurs
in back region due to improper sitting posture of driving. Lower back pain and backache are
caused by postural stress, uneven body pressure distribution, muscular effort, vehicle
vibration, impact and shock [9, 13].
Normally, in human body mechanism, disc movement is able to take blood, oxygen and
nutrients for spine function. Pressure and squeezing on discs in some sitting positions starves
the spine of nutrients and oxygen. Spine becomes less flexible and forces the lower back to
carry more burdens. Spinal vertebrae expand and contract more in the disc region leading to
back pain [20]. By helping to maintain the right sitting posture, ultimately excessive stress on
spine is avoided. In optimum sitting posture the stress caused by poor posture of sitting must
be reduced [11, 12].
3. RECOMMEND POSTURE
To sustain good posture – the natural posture -the muscles of the body must be in balance to
support an aligned spine. In this position, the body is in its strongest and the most balanced
posture to allow the optimal efficiency and minimal stress on the joints and the rest of body.
To predict optimum whole-body sitting posture tends to improve the driving performance for
longer period of time.
Table 1 Recommend Posture Angle
Description Posture Angle (in °)
Elbow Angle 95-115
Backrest Inclination Angle 90-120
Knee Angle 90-115
Ankle Angle 95-120
Thigh/Hip /Trunk Angle 90-120
Upper Arm Angle 15-25
MSD
Prevalenc

4. Virtual Optimization of Sitting Posture Analysis on Using Low-Cost Loadcell Based on Various
Sitting Position in Automobile Seating for Comfort and Safety
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Figure 2 Body Segment Posture
Each of the subjects sat for an hour in various sitting postures (i.e., upright with and
without backrest, slumped, and forward leaning sitting postures) [15, 19].Subjects rated
perceived body part discomfort using Borg‟s CR-10 to indicate pain location in different
sitting posture
Figure 3 Borg‟s Scale Recording
An adapted Borg CR-10 scale was used to access the subjective discomfort on each body
parts, A rating was given for each of 10 regions of the body parts including neck, shoulder,
upper back, arm and hands, low back, buttocks, thighs, knees, calf and feet.Based on the
results, the sitting postures with the highest low back discomfort after prolonged sitting were
found the forward leaning posture & slumped / slouched sitting posture [2, 14, 17].
4. ANALYSIS OF DIFFERENT POSTURE
4.1. Upright Sitting Position with Backrest
Figure 4 Upright sitting position with backrest

5. Rajesh. P. K., Maniarasu.R, Sudhir Kumar. V and Manikandan. N
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When viewed from lateral direction (side view), the natural curve of elongated “S” shaped
spine prevents the back slouch & strengthens muscles. In this posture, the occupant is
completely on surface with the back support of the seat, so that the seat profile matches with
the occupant„s spine curve. Hence, this posture is mainly consider as good sitting position to
minimize the fatigue.
4.2. Upright Sitting Position without Backrest
Figure 5 Upright sitting position without backrest
When viewed from the lateral direction (side view), the natural curve of spine was the
elongated “C” shape, compressing internal organs and improper spine alignment with
decreasing blood circulation. The figure clearly indicates that occupant is not completely on
surface with the seat. This position is considered as incorrect/bad sitting posture for a
prolonged period of time.
4.3. Forward Leaned Sitting Position
Figure 6 Forward leaned sitting position
When viewed from the lateral direction (side view), the natural curve of spine “C” shape
with spinal deformity and postural stress. The occupant is semi surface attach with seat, so it
is consider as Improper / wrong sitting position. This posture can potentially lead to
musculoskeletal issues. Bending this naturally elongated, "S" out of shape for long periods of
time can often leads to muscle fatigue and back-pain. Poor sitting posture causes the
unnecessary problems.

6. Virtual Optimization of Sitting Posture Analysis on Using Low-Cost Loadcell Based on Various
Sitting Position in Automobile Seating for Comfort and Safety
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4.3. Slouched / Slumped Sitting Position
Figure 7 Slouched/slumped sitting position
When viewed from the lateral direction (side view), it looks like a „crab‟ position with
strain on the back muscle. The person is seated in a slouched position of sitting and it mainly
leads to disc degeneration in the lumbar region. So, it is consider as bad / poor sitting posture
and it does not satisfy the body segment angle. Improper sitting positions of driving add more
stress to the spine and tighten the muscles in the shoulders and chest area.
Table 1 Comparison of different sitting posture angle
The above table, clearly illustrates that the green color indicates optimum sitting posture
angle within recommended range to enhance overall health comfort. Naturally, in a stress free
position the body achieves equidistant space of the vertebrae and an ideal balance in the
muscles, tendons and ligaments. Relaxed posture helps to relieve the pressure on optimum
sitting postural, muscles which can decrease fatigue and increase comfort .The red color
shows the improper sitting posture angle in various sitting position. Low back problems, toe
pain, numbness, deformities are caused by poor postures [18, 20]. If one continues with the
bad posture, it weakens the ligaments surroundings the vertebral discs. An incorrect position
while driving is the leading cause of backaches and serves pain [21].
Various sitting position such as leaning forward and slouching causes more load on
vertebral disc. One is prone to more damage in the spinal region. Sitting in the optimum
position, the spine bears the evenly distributed load. It indicates that the highest pressure is
placed on the disc of the lumbar spine as in leaning - forward sitting position.
In order to perform an ergonomic analysis of several sitting positions such as upright
sitting with backrest, upright sitting without backrest, slouched/slumped sitting position,
towards-left sitting position ,towards-right sitting position, leaning forward and backward
Sitting Posture
Upper arm
angle
Elbow
angle
Knee angle
Ankle
angle
Hip
angle
Back rest
inclination
angle
Upright with
Backrest
15-20 105-115 100-115 100-120 90-120 90-120
Upright without
Backrest
18-25 95-110 100-110 100-120 115-130 90-120
Forward Leaned 20-25 115-130 100-115 100-120 115-125 90-120
Slouched/
Slumped
15-25 120-125 100-120 105-120 110-125 90-120

7. Rajesh. P. K., Maniarasu.R, Sudhir Kumar. V and Manikandan. N
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sitting position [22]. The awkward posture, improper driving position and incorrect / poor
posture habit are easily identified. When sitting flattens lumbar curve, the biomechanics of
curve is changed, and the force on disc and also muscle strain are increased [25].
5. EXPERIMENTAL SET-UP
To ensure the optimum sitting posture of driving is very crucial. The load cell is placed in
each corner of the back support of seat.This monitoring system helps to assess the posture in
real - time and helps to improve sitting posture, and easily identify the awkward posture,
improper driving position and incorrect / poor posture habit.
5.1. Load cell
Load cell is a device which converts one form of energy into another. It is a transducer that is
used to create an electrical signal whose magnitude is directly proportional to the force being
measured.
Figure 8 Seat with load cell
5.2. HX balance Sensor 711
HX711 is a precision 24-bit analog - to - digital converter (ADC) designed for weigh scales.
The connection from load cell to HX 711 and from HX 711 to Arduino are listed below:
Figure 9 HX balance sensor

8. Virtual Optimization of Sitting Posture Analysis on Using Low-Cost Loadcell Based on Various
Sitting Position in Automobile Seating for Comfort and Safety
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5.3. Jumper wire
Also known as jumper wire, Du-Point wire and the connector pin at each end is used to
interconnect the component.Conducting wires establish an electrical connection between two
points in a circuit
Figure 10 Jumper wire
5.4. Arduino Uno board and USB cable
Arduino board: It is a Single board microcontrollers interactive objects that can sense and
control objects in the physical and digital world. It„s feature is serial communication interface
IDE: Integrated Development Environment – computer program for software development
Figure 11 Arduino board and USB
Connection is to be made to load cell and Arduino on using HX711 balance sensor to
measure load acting on sitting posture of occupant. This system helps to maintain natural
curvature of spine with evenly distributed pressure in lumbar region. It provides the support to
promote the health and reduce the fatigue. Increased risks of back pain for prolonged period
of driving are mainly caused by poor driving habits. Maintaining a correct posture leads to
correction of misalignment of spine curvature and relieving back pain which is caused sitting
incorrectly –Reducing pressure on tail bone and the soft tissue in lumbar region
5.5. Connection
The connection details are shown in the below Table.

9. Rajesh. P. K., Maniarasu.R, Sudhir Kumar. V and Manikandan. N
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Table 2 Connection details
5.6. Final set-up
The real-time data of a seated person to be captured on using the low-cost load cell mounted
in each corner back support and transferred to personal computer (PC) via the Arduino board.
Figure12 Final set-up
Connect Arduino serial communication data to excel on using Data Acquisition for Excel.
Plot the graph as per the reading from load cell in different sitting positions of the occupant
Figure 13 Load on each sitting posture
Load cell to HX711 HX711 to Arduino
E+ BLUE V cc 5v
E- GREY GND GND
A+ YELLOW SCK D2
A-: VIOLET DT D6

10. Virtual Optimization of Sitting Posture Analysis on Using Low-Cost Loadcell Based on Various
Sitting Position in Automobile Seating for Comfort and Safety
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6. CONCLUSION
The data is obtained from Arduino for various sitting postures such as upright with backrest
and without backrest, forward leaning and slouched position. The objective of developing the
low- cost load cell equipped with seat is ultimately to give the optimum real time sitting
posture. The comparison of body segment posture angle of different sitting position is
estimated. Based on these results, optimum upright sitting posture is proposed for comfortable
position. The correct posture enhances the support to daily functions, in addition to supporting
internal processes such as breathing, vision, digestion, circulation and temperature regulation.
The optimum upright sitting position allows better blood flow, which in turn increases the
oxygen intake and therefore is more sustainable as a natural and comfortable position.
FUTURE SCOPE
In order to visualize the extended period of comfort, based on the different sitting postures of
driving, relevant information and data are acquired from the mounted load cell sensor. This
real time system is linked to Internet of Things (IOT), a web-enabled device to acquire the
exact data of sitting posture, using mounted load cell sensor. It gives a warning signal to the
driver when it senses incorrect sitting posture and ensures the optimum posture and minimizes
fatigue during a prolonged period of driving.
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