Most commercial vehicles used for transportation are not manufactured in Nigeria. As a result, the design of these vehicles, which relies on anthropometric measurements from the manufacturing countries, does not adequately accommodate the variations in anthropometric measurements of Nigerian drivers. This mismatch can lead to musculoskeletal disorders. Therefore, this study aims to examine the ergonomics of the commercial vehicles used by occupational drivers in Southwest Nigeria. A total of 161 drivers were randomly selected, and data was collected through questionnaires. The anthropometric characteristics of the drivers were measured using a stadiometer and measuring tape. Seat design variables were also measured using a tape rule and steel rule. The collected data were subjected to statistical analysis, including the calculation of means, standard deviations, and 5th, 50th, and 95th percentiles of the anthropometric measurements. A comparison was made between the existing seat dimensions and the required anthropometric measurements of the drivers for proper seat design. The analysis revealed a discrepancy between the anthropometric measurements of the drivers and the seat design variables, which may contribute to musculoskeletal disorders. The average anthropometric measurements for sitting height (erect), sitting height (normal), shoulder height, buttock-knee length, and buttock-popliteal length were found to be 83.01cm, 77.86cm, 52.71cm, 57.07cm, and 50.20cm, respectively. Based on these findings, it is recommended that the seat variables should be adjusted to better accommodate the anthropometric characteristics of Nigerian drivers. Specifically, the recommended seat dimensions are 32.80cm to 42.70cm for seat width, 44.51cm to 55.88cm for cushion depth, 44.45cm to 59.69cm for backrest height, and a seat angle of 900 to 1300 to improve driver comfort and reduce the risk of musculoskeletal disorders.

1. ERGONOMIC CHARACTERIZATION
OF COMMERCIAL VEHICLES
IN SOUTH WEST NIGERIA.
Supervised by:
Prof. A.S Onawumi (FNSE)
Friday, February 9, 2024
1

2. • Abisoye Akinloye Samson (160173)
• Olalere Sodiq Olalekan (164135)
• Okojo Friday Eloho (164398)
• Saka Adekunle Ridwan (170020)
• Ibrahim Israel Adekunle (164531)
• Ishola Samson Ayodeji (162666)
• Ganiyu Mariam Jumoke (170111)
• Ayoade Ayodeji A. (160446)
Group members
2

3. Contents
Methodology
Chapter 3
Literature Review
Chapter 2
Results
Chapter 4
Introduction
Chapter 1
3
Conclusion
Chapter 5

4. YOUR
LOGO
System
It could be vehicle (both interior &
exterior), its components or
environment.
Introduction
Ergonomics
It is at central of it all. Ergonomic
principle factored in at early
design stage.
Transport
Revolves around modern
economic. Determinant of
quality of life in society.
Human
Comfortability of user eliminates
recklessness and ensures safety.
4

5. Problem Statement
• Mismatch in anthropometry
measurement and vehicular design.
• Force fitting to the unfit man-
machine system causing discomfort.
• Increased Musculoskeletal disorder,
Low back pain due to constraint
posture or vibration.
5

6. YOUR
LOGO
Bad posture
Nature of vibration or
poor workstation
configuration.
Low back pain
Seated posture exposes
to variety of disorder.
Herbal medical
Evident why herbal
medication are used to
alleviate pain.
Fatigue
Regardless, the
performance of the
driver decreases.
Musculoskeletal disorder
Source: Google images 6

7. 0
1
2
1
2
%
AIM
Aim
To study the ergonomics of
commercial vehicles used among
occupational drivers in Southwest
Nigeria.
7

8. Objectives
• Identify human body variables that
interfere with in-vehicle.
• Study the design of drivers’ seat and
measure its variables.
• Investigate level of mismatch between
anthropometric characteristic and in-
vehicle variables.
8

9. YOUR
LOGO
Ergonomic
Apply human ability & limitation to
improve interaction with system
Vehicles
Private or Commercial for business
purposes. E.g. Mazda, Toyota.
Characterization
Measurable features of the in-vehicle
that interfere with user.
Anthropometric
Body physical geometry (shape, size),
mass properties and capabilities.
Literature Review
9

10. 10
Author(s) Title of the articles Research Findings Research Gaps
Lucas, E.B. and
Onawumi, A.S.,
2013.
Ergonomic assessment
of the In-Vehicle Design
of Taxi Cabs.
Concluded that poor design of the
workspace is a major risk factor
contributing to the level of
discomfort experienced by drivers
during long-distance journeys
No hypothesis testing
techniques was carried out
to ascertain the research
finding.
Ismaila et al.,
2022.
Anthropometric Seat
Design for Bus Drivers in
Southwestern Nigeria
Discovered that the seats offered by
vehicle manufacturers were not
ergonomically appropriate for
drivers.
The sample was collected
from only three States (Oyo,
Lagos, Ogun) in the
Southwest Nigerian.
Ajayeoba et al.,
2012.
Evaluation of the
Ergonomic Suitability of
Passenger Seats in
Molue Buses in
Nigeria
Discovered that design dimensions
needing major adjustments are the
components of the seats (as in the
seat depth, seat/backrest length, and
seating clearance).
The research scope was
restricted to only Molue
buses without considering
other commercial vehicles.

11. Methodology
Sampling
Survey
Measurement
Data Analysis
Major bus terminal:
• Ogbomoso,
• Ogun (Mowe),
• Akure,
• Lagos (Iyanapaja),
• Osogbo,
• Ado-Ekiti.
• Participatory Ergonomic
Invention Approach (PEIA)
• Demo-graphic Information
like name, age, gender.
• Nordic questionnaire.
• Anthropometry variables
• In-vehicle variables
• Comparison of variables
• Descriptive and Percentile
Analysis
• Hypothesis Tests (T-test &
ANOVA)
• Correlation Analysis
11

12. Tools:
• Statistical: Excel, SPSS, Python
• Measuring tape, ruler.
• Stadiometer
• Questionnaire
12
30
36
18
27
26
24
Sample size (n)
Mowe, Ogun State Iyanapaga, Lagos State Ora and Owode, Ogbomoso
Osogbo Akure Ado Ekiti

13. 0
2
4
6
8
10
12
14
16
18
Frequency
Vehicle Model
Sampled Commercial Vehicles
13

14. 14
1 - Seat width; 2 - Seat cushion depth; 3 - Seat cushion length; 4 - Seat backrest height; 5 - Seat lumbar
support; 6 - Seat shoulder support; 7 - Seat total height (backrest height + headrest height)

16. 0
5
10
15
20
25
30
21 - 25 26 - 30 31 - 35 36 - 40 41 - 45 46 - 50 51 - 55 56 - 60 61 - 65
Frequency
Age Range
23.8%
22.4%
32.0%
16.3%
4.1%
1.4%
NIL PRIMARY SSCE OND HND B.Sc.
Age Range & Educational Background
Questionnaire
16

17. 3%
49%
31%
17%
5 – 10 yrs
11 – 15 yrs
16 – 20 yrs
20 yrs above
1%
6%
12%
39%
21%
20%
1%
0
10
20
30
40
50
60
7 8 9 10 11 12 13
No.
of
drivers
Hours per day
Working hours & Years of Experience
17

18. 28%
72%
42%
58%
Yes No
Driving Prolonged Sitting
46%
54%
70%
30%
Yes No
Smoke or Tobacco Alcoholic beverages
Drug intake & Previous Job
18

19. 42.23
50.05
53.76
47.30
48.03
57.42
76.27
45.20
Backrest width (shoulder)
Backrest width (lumber)
Cushion seat length
Cushion seat depth
Seat width
Seat backrest height
Seat total height
Seat-pedal distance
Seat Design Variables
19

20. 42.23
50.05
53.76
47.30
48.03
57.42
76.27
45.20
47.70
0.00
55.60
0.00
49.80
53.30
77.10
34.40
44.50
49.00
49.67
47.50
50.33
53.67
76.67
42.83
Backrest width (shoulder)
Backrest width (lumber)
Cushion seat length
Cushion seat depth
Seat width
Seat backrest height
Seat total height
Seat-pedal distance
Comparison of Results
Current Study Fajobi (2019) Ismaila (2021)
20

21. 83.01
77.86
52.71
36.06
17.90
77.07
57.07
50.20
Mean
Sitting height erect Sitting height normal Shoulder height
Shoulder elbow length Thigh clearance Thumb-tip reach
Buttock-knee length Buttock-popliteal length
64.64
59.69
44.45
33.02
12.70
71.12
50.93
44.51
85.09
80.01
54.61
35.56
15.24
76.20
55.88
50.80
90.17
86.36
59.69
40.64
25.40
83.82
63.50
55.88
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
1 2 3 4 5 6 7 8
Percentile
5th 50th 95th
21

22. 83.01
77.86
52.71
36.06
17.90
77.07
57.07
50.20
83.18
0
55.4
34.61
0
55.6
48.75
83.36
79.32
57.54
37.26
14.06
81.44
58.89
48.97
83.7
54.2
31
58
48.2
Sitting height erect
Sitting height normal
Shoulder height
Shoulder elbow length
Thigh clearance
Thumb-tip reach
Buttock-knee length
Buttock-popliteal length
Comparison of Anthropometric Measurements
Current Study Ismaila (2021) Fajobi (2013) Onuoha (2012)
22

23. Table 1: Driver’s Seat Design Variables fitted with related Anthropometric Variables
Design Variables
Mean
Dimension
Anthropometric Variable Mean
Percentile
5th 50th 95th
Backrest width 50.05 Shoulder breadth
45.42 40.04 45.1 50.10
Cushion seat length 53.76 Buttock-knee length
57.07 50.93 55.88 63.50
Cushion seat depth 47.30 Buttock-popliteal length
50.20 44.51 50.80 55.88
Seat width 48.03 Hip breadth sitting 37.95 32.8 37.90 42.70
Seat backrest height 57.42 Shoulder height
52.71 44.45 54.61 59.69
Seat total height 76.27 Sitting height normal
77.86 64.64 85.09 90.17
All parameters were measured in centimeters (cm)
Mismatch Match 23

24. 32.8
50.93
44.51
40
44.45
13.1
42.7
63.5
55.88
50.01
59.69
25.15
0
20
40
60
80
100
120
140
Seat width Seat cushion
length
Seat cushion
depth
Backrest
width
Seat backrest
height
Headrest
height
Range
Min Max
Proposed Design
24

25. Table 2: Independent T-test of the Existing and Recommended Seat Variables
Seat Height
Dimension
Seat Depth
Dimension
Existing Recommended Existing Recommended
Mean 57.45 52.71 Mean 47.27 50.20
Std. dev 4.03 5.05 Std. dev 3.80 3.76
Variance 16.28 25.46 Variance 14.41 14.15
T stat 9.287060549 T stat 6.899459249
P value 2.56807E-18 P value 2.831E-11
25
p < 0.05

26. 56.05
51.70
52.49 52.66 52.73
49.95
Akure Ekiti Lagos Ogun Osogbo Oyo
Mean
of
shoulder
height
Region
Table 3: Analysis of Variance (ANOVA)
Sum of Squares df Mean Square F Sig.
Between Groups 452.313 5 90.463 3.878 0.002
Within Groups 3615.285 155 23.324
Total 4067.598 160 26

27. Table 4: P-value corresponding to the correlation
matrix (p < 0.05)
SH BKL BPL SHE SHN
SH 0.00 0.18 0.11 0.63 0.58
BKL 0.18 0.00 0.02 0.48 0.53
BPL 0.11 0.02 0.00 0.56 0.61
SHE 0.63 0.48 0.56 0.00 0.00
SHN 0.58 0.53 0.61 0.00 0.00
27

28. Conclusion
• The evaluation of the driver's workstation, with a focus on the driver's seat,
provided insights into improving the layout, design, placement, and adjustability
of the seat
• Upon comparing the results of the seat variables with the relevant
anthropometric characteristics, disparities in the measurements were observed.
• This led to the conclusion that the existing commercial vehicle seats in the
Southwest region are not compatible with the necessary anthropometric
dimensions of the drivers.
28

29. Recommendation
29
• Future research with a larger sample size.
• Additional anthropometric and seat variables.
• Specific dimensions for driver's seats:
1. Seat width (32.80 - 42.70 cm)
2. Cushion length (50.93 - 63.50 cm)
3. Cushion depth (44.51 - 55.88 cm)
4. Backrest width (40.04 - 50.01 cm)
5. Backrest height (44.45 - 59.69 cm)
6. Headrest height (13.12 - 25.15 cm)
7. Seat backrest angle (90° to 130°).
1
3
2
7
5
4
6

30. Selected References
Fajobi, M.O., Onawumi, A.S., Mfon, U.M., and Awoyemi E. (2019). Mismatch between anthropometry
characteristics of Nigerian occupational bus drivers and the in-vehicle measurement. Covenant Journal of
Engineering Technology (CJET), 3(1), 20-37.
Ismaila, S.O., Akanbi, O.G., Adekunle, N.O., Adetunji, O.R., and Kuye, S.I. (2010). An ergonomics assessment of
passenger seats in buses in South Western Nigeria. Sigurnost (Safety), 52(4), 329-334.
Onawumi, A. S., Adebiyi, K. A., Fajobi , M. O., & Oke, E. O. (2016). Development of Predictive Models for some
Anthropometric Dimensions of Nigerian Occupational Bus Operators. European International Journal of Science
and Technology. Vol. 5 No. 5 pg 13-15.
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