Anthropometric characteristics of Iranian military personnel and their changes over recent years.

BACKGROUND: In most armies, clothes, equipment and weapons are designed according to the physical characteristics and anthropometric data of soldiers.
OBJECTIVE: To study the anthropometric characteristics of Iranian army force and their changes over recent years.
METHODS: 12 635 Iranian military personnel aged between 18 and 30 years with tenure of <10 years who were normally engaged in educational military activities and soldiers were enrolled in this study, which was conducted in 2010.
RESULTS: The military personnel had a mean±SD stature of 174.1±6.3 cm and sitting height of 89.7±3.8 cm. They had a mean weight of 70.0 kg, and body mass index of 23.3 kg/m2.
CONCLUSION: The stature of Iranian army has increased by 14 mm during the last 15 years. The stature was less than those of the western countries and 3-4 cm more than those of East Asian personnel. The body mass index has had an increasing trend.

Most of the injuries and damages which occurred during military trainings happened to those who suffered from inappropriate body dimensions.

Most of the armies produce their military clothes, weapons, and equipment according to soldiers' body dimensions and ergonomic principles.

Body dimensions of Iranian soldiers were generally 2–4 cm lesser than those of the Western countries and 3–4 cm more than those of East Asian nations.

There is an increasing trend in BMI of Iranian military personnel over the past 15 years.

We need to study the temporal changes made in the physical dimensions and military force ability over years.

Problems with ergonomics at work may cause musculoskeletal disorders, early fatigue, physical inabilities, and even accidents and diseases. Design of military machinery, weapons, and equipment should thus be according to soldiers’ body dimensions and ergonomic principles. The standard program to measure physical dimensions of the US military force dates back to 1775. Thereafter, a database of the anthropometric dimensions of the military force was developed in 1970 and has been in use as a standard for the physical dimensions for designing the required equipment and accessories of the army. These standards have been modified constantly over the past 200 years. Each sector of the US army has declared a number as the maximum allowable weight to height ratio for employment and recruitment. The military sectors are obliged to pay attention to these ratios. In 1995, almost 5000 American military forces were dismissed from the army because of weight to height mismatch.[1]

Nowadays, most of the armies produce their military clothes, weapons, and equipment according to the physical characteristics of their soldiers. To prevent the production of instruments which are not fit for their personnel, the need to perform anthropometric measures.[2] Furthermore, they need to study the temporal changes made in the physical dimensions and military force ability over years. In a study on the physical dimensions of the US military personnel, Anderson asserted that most of the injuries and damages which occurred during military trainings happened to those who suffered from inappropriate body dimensions.[3]

Many countries measure the anthropometric dimensions of their military personnel on alternate years to be able to design their work settings and tools and equipment based on anthropometrically updated information.[4] In a study on a large sample of 17–20-year-old American population, Rochelle found that 13%–56% of participants were not fit for military standards with regard to their gender and age, and that most of the mismatch was among the Afro-Americans.[5] It is possible for various people with different dimensions to work properly with tools and equipment suitable for their physical characteristics by employing anthropometry to equipment and work setting design. Designing based on anthropometric data leads to eliminating awkward postures and their subsequent complications for the body.[6] Therefore, being informed of body characteristics and individuals’ anthropomorphic dimensions is essential for having an effective work setting, even for those with physical disabilities.[7]

McNolty showed that anthropometric dimensions of personnel are among the most important factors causing physical injuries in the US army.[8] Henderson believes that most of the injuries occurred in US military personnel are due to unfit physical dimensions and their mismatch with tools and equipment.[9]

The significance of ergonomics and considering the physical dimensions of the soldiers in designing are increasingly acknowledged by Iranian army. The earliest data available on Iranians’ body dimensions dates back to an anthropological research performed in 1934 by Henry Field, affiliated to the American Museum of Natural History.[10] Field analyzed different Iranian tribes, including Kurds, Lors, Turks, Arabs, Fars, and the Jews, and measured many anthropometric parameters, especially stature and cranial dimensions.

The first research on anthropometry and design in Iran’s army was proposed and designed in 1970 by Nourani and Dillard[11] in Army’s Department of Health and was performed by Kennedy, White, and Hendrix[12] who measured the anthropometric data of 7784 Iranian soldiers for designing military shoes and clothes. The last study conducted on the anthropometry measurements of Iranian Military ground forces was conducted in 1995, where 2130 soldiers and military staff were evaluated.[13] We therefore conducted this study to determine the ergonomics and anthropometric measures of the military forces of Iran. We also studied the temporal changes occurred over recent years in the indices.

Materials and Methods

A total of 12635 military ground force personnel aged between 18 and 30 years (including soldiers) with tenure of <10 years who were normally engaged in educational activities, was studied. The participants were selected using a systematic random sampling method. They were also stratified by age, ie , 18–20, 21–25, and 26–30 years.

Physical dimensions of the personnel were measured by a stadiometer, which is consisted of two scaled perpendicular sheets with a measurement accuracy of 1 mm. For the measurements, the proposed method of National Health and Nutrition Examination Survey (NHANES) was used.[14] This method, which has also been used by the US army, conforms to the proposed ISO methods for anthropometric and ergonomic design principles.[15,16] Body weight was measured with an accuracy of 0.1 kg (Ziemens, Germany).

For each participant, we recorded weight and 89 more parameters.[17] The most important parameters studied were standing posture, sitting posture, and breadth and depths of different parts of the body.

Appropriate instructions and guidelines for measurement teams were provided. Measurement teams were first instructed about the way they should work; they were familiarized with all landmarks (Fig 1) that were to be measured and about how to choose them.[18] The team became fully proficient in working with stadiometer and practicing the anthropometric methods.

Figure 1

Some anthropometric parameters measured in this study

The accuracy and reliability of anthropometric data are related to method of measurement, standardization of tools and characteristics of population.[19] The stadiometer was calibrated after each replacement; all calipers were used according to the recommended method by Osquei-Zadeh.[20] An expert in anthropometry supervised each site before starting data collection. The coefficient of reliability of parameters calculated was above 95% for all measurements.

The collected data was analyzed by SPSS® for Windows® ver 17. Student’s t test for independent variables was used to compare the means between two groups. A p value <0.05 was considered statistically significant.

Result

Table 1 shows a number of statistics for the standing and sitting height of the studied participants. Measures of hands, legs, head, and body surfaces are presented in Table 2.

Table 1: Stature and sitting height of the studied participants. The unit of measurement is cm. For numbers in the first column, see Figure 1.
No.	Parameter	Mean±SD	Range	Percentile
				5 th	25 th	50 th	75 th	95 th
1	Stature	174.1± 6.3	153.6–225.0	164.6	170.0	173.9	178.0	185.4
2	Cervical Height	147.9±5.9	131.2–195.2	138.9	144.0	147.7	151.7	158.0
3	Shoulder (Acromion) Height	144.6±5.8	125.7–166.0	135.5	140.7	144.6	148.2	155.0
4	Waist Height Standing	101.6±5.8	73.9–128.0	92.0	98.0	101.5	105.2	111.3
5	Crotch Height Standing	75.5±5.0	47.8–92.0	67.7	72.2	75.4	79.0	84.0
6	Knee Height Standing	50.5±4.1	44.0–60.5	45.0	48.2	50.3	52.5	56.3
7	Calf Height Standing	37.3±3.8	22.0–56.6	31.0	35.0	37.3	39.6	43.0
8	Functional Arm Reach Forward	83.9±4.3	56.2–99.2	77.5	81.4	84.0	86.6	90.5
9	Elbow Height Standing	108.9±5.4	97.7–158.8	101.0	105.3	108.9	112.0	117.5
10	Tip Finger Height Standing	72.9±4.3	49.3–93.4	66.0	70.4	72.8	75.5	80.0
11	Eye Height Standing	163.6±6.6	143.0–191.0	153.0	159.0	163.3	167.8	175.4
12	Vertical Functional Arm Reach Standing	212.2±8.1	188.2–246.6	199.5	206.8	212.0	217.5	225.7
13	Elbow to Elbow Length Standing	46.7±4.0	35.0–61.8	41.0	44.1	46.7	49.0	53.7
14	Arm Reach Up Sitting Rest	136.5±5.1	119.4–164.5	129.8	133.6	136.7	139.2	143.8
15	Sitting Rest Height	89.7±3.8	83.0–122.8	85.8	87.5	89.3	91.1	94.3
16	Eye Height Sitting Rest	77.7±4.1	69.5–98.3	73.2	75.5	77.7	79.6	82.9
17	Min-Shoulder Height Sitting Rest	63.2±3.5	51.0–82.5	59.7	61.1	63.0	64.6	67.5
18	Shoulder (Acromion) Height Sitting Rest	60.6±3.6	40.5–69.9	57.0	59.0	60.6	62.0	65.2
19	Knee Height Sitting Rest	54.5±3.3	41.5–64.6	50.0	53.0	54.3	56.0	59.0
20	Popliteal Height Sitting Rest	42.4±2.4	31.0–55.5	39.0	41.0	42.3	43.8	46.0
21	Elbow Height Sitting	25.5±3.1	21.5–42.7	22.5	24.0	25.5	26.7	19.0
22	Functional Leg Length	105.1±6.9	83.0–153.5	95.9	101.0	104.3	408.5	118.0
23	Acromion to Right Wrist Height	71.7±7.6	49.0–95.9	61.0	65.4	70.9	78.2	84.0
24	Hip Length	33.2±2.7	20.0–64.0	29.3	32.0	33.2	34.6	37.1
25	Chest Length	27.9±3.1	16.2–52.1	23.3	25.9	27.8	29.9	33.3
26	Chest Depth	21.4±2.7	11.0–42.3	17.2	20.0	21.3	22.7	25.7
27	Arm Reach Forehead	76.7±4.5	47.2–99.0	70.3	73.8	76.4	79.0	85.0
28	Shoulder Elbow Length	36.6±2.5	23.7–49.2	32.4	35.3	36.8	38.3	40.4
29	Forearm Hand Length	46.5±2.9	26.0–59.0	42.6	45.0	46.6	48.1	50.8
30	Shoulder Length	43.6±3.2	30.2–59.0	38.9	41.6	43.5	45.6	49.4
31	Elbow to Elbow Length	41.2±5.0	22.2–59.8	34.2	37.8	40.8	44.1	50.6
32	Hip Breadth Sitting Rest	35.5±3.2	20.3–66.7	31.1	33.7	35.3	37.3	40.5
33	Elbow to Elbow Length	46.4±4.9	21.1–61.8	39.0	43.2	46.1	49.4	55.0
34	Buttock-Knee Length	57.2±3.4	25.1–69.5	52.1	55.8	57.4	59.3	61.7
35	Buttock-Popliteal Length	45.5±3.1	36.7–58.3	40.6	43.6	45.5	47.5	50.6
36	Depth Abdominal	20.9±4.0	13.4–48.0	16.0	18.5	20.2	22.8	28.8
37	Depth Thigh Sitting Rest	13.9±2.0	9.9–25.5	10.9	12.6	13.8	15.2	17.9
38	Elbow Height Sitting Rest	25.7±3.5	15.4–57.5	20.2	23.5	25.7	27.8	31.2
39	Back Waist Length	50.0±3.9	36.8–64.0	43.5	48.0	50.0	52.0	57.0
40	Shoulder Length	16.3±2.5	9.5–25.0	12.1	14.1	17.0	18.0	20.0
41	Armpit to Armpit Back	42.1±4.8	26.0–63.1	32.4	39.5	42.4	45.2	49.0
42	Back Chest Length	57.3±7.8	30.0–74.1	35.5	55.6	59.0	62.0	66.2
43	Hand Armpit to Wrist	49.0±4.8	30.5–71.3	42.4	46.3	49.0	51.0	55.7
44	Spine to Wrist (Hand Forward)	85.9±5.8	56.8–100.6	77.5	83.0	86.5	89.5	93.3

Table 2: Hands, legs, head, and body surface sizes of the studied participants. The unit of measurement is cm. For numbers in the first column, see Figure 1.
No .	Parameter	Mean±SD	Range	Percentile
				5 th	25 th	50 th	75 th	95 th
45	Head Circumference	55.7±2.8	32.0–76.4	53.0	55.0	56.0	57.0	59.0
46	Neck Circumference	36.3±2.8	22.5–57.4	32.7	34.5	36.0	37.8	42.0
47	Shoulder Circumference	114.9±7.5	85.0–146.4	103.9	110.0	114.2	119.0	129.0
48	Chest Circumference	93.6±7.4	53.0–125.0	83.9	89.0	93.0	97.7	108.0
49	Waist Circumference	83.8±9.2	55.2–128.3	71.0	78.0	82.0	89.0	101.0
50	Hip Circumference	97.2±6.5	69.0–126.5	88.0	93.0	96.5	100.8	109.7
51	Vertical Trunk Circumference	171.9±9.3	147.0–230.0	157.0	166.0	171.5	177.5	188.0
52	Armpit Circumference	64.5±5.3	21.6–63.0	38.4	43.0	46.6	50.0	55.5
53	Upper Arm Circumference Relaxed	29.6±3.2	20.5–49.0	25.0	27.5	29.0	31.0	36.0
54	Biceps Circumference Relaxed	32.5±3.2	21.0–44.5	28.0	30.2	32.0	34.4	38.3
55	Forearm Circumference Relaxed	28.2±3.1	20.6–41.5	24.0	26.0	27.9	30.0	34.3
56	Wrist Circumference	17.5±1.5	14.0–28.5	15.8	16.8	17.5	18.0	19.4
57	Hand Circumference	21.7±1.6	16.0–38.0	19.5	21.0	21.8	22.6	24.0
58	Crotch Thigh Circumference	55.0±6.8	40.0–99.0	46.0	50.5	54.0	58.3	66.6
59	Lower Thigh Circumference	41.7±4.2	28.5–59.0	36.0	39.0	41.0	44.1	49.1
60	Calf Circumference	36.8±3.1	22.0–48.4	32.0	35.0	37.0	39.0	42.0
61	Ankle Circumference	26.1±2.2	20.0–38.6	23.0	25.0	26.0	27.1	29.5
62	Hand Length	19.2±1.0	14.7–29.9	17.7	17.6	19.3	19.9	20.8
63	Palm Length	11.0±0.8	8.9–18.2	10.0	10.5	11.0	11.4	12.3
64	Hand Breath	8.4±0.6	6.6–10.9	7.5	8.1	8.5	8.8	9.3
65	Wrist Depth	2.8±0.4	2.0–5.7	2.3	2.6	2.8	3.0	3.6
66	Hand Breath Open Thump	10.2±0.8	6.3–15.6	9.0	9.8	10.2	10.6	11.3
67	Ear Top Head Height	11.1±1.1	6.3–18.8	9.3	10.4	11.1	11.9	13.0
68	Head Length	19.1±1.4	12.0–30.8	16.9	18.5	19.2	19.8	20.6
69	Maximum Head Height	22.3±2.1	12.9–37.0	19.6	21.0	22.0	23.7	26.0
70	Head Breadth	15.3±1.1	10.6–27.1	13.6	14.9	15.4	15.8	16.7
71	Head Length Maximum	22.2±1.5	16.2–34.3	20.0	21.5	22.2	23.0	24.2
72	Face Breadth	11.3±1.3	6.8–21.0	9.0	10.7	11.4	12.1	13.3
73	Ear to Ear Length	14.5±1.3	10.2–22.8	13.0	13.8	14.4	15.1	16.5
74	Face Height (Eyes to Haggle)	13.1±1.2	10.0–22.0	11.5	12.5	13.0	13.7	14.8
75	Inter Pupillary Distance	5.5±0.5	2.9–7.6	4.7	5.2	5.6	5.9	6.2
76	Foot Length	25.8±1.7	18.8–39.2	23.6	24.9	25.8	26.7	28.0
77	Instep Length	18.5±2.9	7.3–26.0	10.0	18.3	19.2	20.0	21.3
78	Foot Breadth	9.7±0.8	6.5–13.9	8.4	9.4	9.8	10.2	10.9
79	Heel Breadth	6.3±0.6	4.3–9.8	5.4	6.0	6.4	6.7	7.4
80	Ball of Foot Circumference	26.0±1.8	20.5–38.5	23.5	25.0	26.0	27.0	28.5
81	Instep Circumference	25.6±1.7	21.0–48.0	23.0	24.5	25.5	26.5	28.2
82	Heel-Ankle Circumference	33.5±2.0	20.1–46.4	31.0	32.5	33.8	35.0	36.8
83	Head Height (Eyes to Vertex)	5.7±1.0	3.5–9.2	4.1	5.0	5.7	6.3	7.5
84	Right Ear Height	6.1±0.5	3.0–9.3	5.3	5.8	6.1	6.4	6.9
85	Right Ear Width	3.4±0.4	1.9–8.2	2.9	3.2	3.5	3.7	4.1
86	Nose Width	3.6±0.4	2.2–6.7	3.0	3.4	3.6	3.9	4.3
87	Nose Height	5.6±0.5	3.0–8.6	4.8	5.4	5.7	6.0	6.4
88	Index Finger Length	8.8±1.3	5.8–12.5	6.8	7.5	9.0	10.0	10.9
89	Index Finger Depth	1.9±0.1	1.0–3.8	1.7	1.9	2.0	2.0	2.2
90	Weight (kg)	70.0±9.0	45.0–123.0	57.0	64.0	70.0	76.0	92.0

Discussion

The studied military personnel had a mean±SD stature of 174.1±6.3 cm; the mean±SD sitting height was 89.7±3.8 cm. In comparison with measurements of Henry[10] who recorded Iranians’ anthropometric data in 1934, the mean height of 20–30-year-old Iranians has increased by 8.6 cm (Table 3). The mean stature of Iranian soldiers was 172.7 cm in the study conducted by Pourtaghi and Salem in 1995;[13] this reflects a 1.4 cm increase in the stature over the past 15 years.

Table 3: Comparison of various parameters measured in Iranian soldiers in various studies. Figures represent mean±SD in cm.
Study	Year	Stature	Sitting Height	Weight
Present study	2010	174.1±6.3	89.7±3.8	70.0±9.0
Pourtaghi and Salem	1995	172.7±5.9	89.2±3.6	67.0±9.3
Noorani and Hendrix	1970	166.6±7.4	87.7±3.3	61.3±7.4
Henry Field	1934	165.5±66.3	84.0±3.5	—

In a study on Iranian male students, their stature was found to be 174.2 cm,[21] that was similar to our findings. The mean stature found by Habibi, et al ,[22] was 174.9 cm—0.7 cm more than what we found. However, because they studied only the Isfahani male students (in central Iran), their findings could not be generalized to all Iranian students. Osquei-Zadeh reported a stature of 166.9 cm for students;[23] this value was different from that found by Mirmohammadi and Habibi, most likely because the data for males and females were combined.

Body dimensions of Iranian soldiers were generally 2–4 cm lesser than those of the Western countries and 3–4 cm more than those of East Asian nations (Tables 3 and 4).

Table 4: Comparison of Iranian soldiers stature, sitting height, and elbow height with some other populations. All measurements belong to the past 15 years. Also, the leg (lower limb) length was calculated by the researcher through estimating the sitting height from stature.
	Stature	Sitting Height	Upper Limb/Stature	Lower Limb/Stature
US Army	175.6	91.4	0.521	0.479
Australian Army	178.5	93.2	0.522	0.478
UK Army	177.4	90.5	0.510	0.490
Iranian Army	174.1	89.7	0.515	0.475
Chinese Males	167.8	90.8	0.541	0.459
Japanese Males	169.0	90.9	0.538	0.462
Taiwanese Males	169.9	90.7	0.534	0.465
Korean Males	170.7	92.1	0.540	0.460

To determine the difference in sitting and elbow height among Eastern and Western countries, the sitting height to stature ratio and elbow height or leg length to stature ratio were compared (Table 4); the elbow height to stature is 48% in the US, Australia, and the UK (Table 4), while it is 46% in China, Japan, Korea, and Taiwan,[24] that reflects the elbow height to stature ratio is lower in Eastern countries compared to the Western nations; this means that European people’s legs have grown more than their body—in other words, the higher height of Europeans compared to the Eastern people is attributed to their legs rather than their body.

In the current study, the mean weight was 70.0 kg, the mean body mass index (BMI) was 23.3 kg/m2 —11.5% of participants had a BMI >25 kg/m2. The mean BMI in the study conducted by Nourani, et al , in 1970 was 22 kg/m2; it was 22.4 kg/m2 in Pourtaghi’s study[13] —9% had a BMI >25 kg/m2. All these reflect the increasing trend of BMI over years. The prevalence of overweight people is less than that reported in the US army, which was 13%.[5]

Now that we have the anthropometric dimensions of Iranian military personnel, we can design ergonomic military tools and equipment for them, however, since the dimensions are constantly changing, we need to conduct national anthropometric examinations every ten years. Given the increasing trend of BMI in the studied participants, it is also suggested to establish weight control and body fit programs for the Iranian defense personnel.

Acknowledgements

The authors would like to express their gratitude to Colonel Khoshroo, who has cooperated in performing anthropometry in Iranian classic army and Colonel Sajedi who has cooperated in performing anthropometry in Iranian Revolutionary Army (Sepah ).

Conflicts of Interest:

None declared.