A Study of Correlation Lumbar Lordosis, Stress, Central Adiposity with Low Back Pain in Undergraduate Medical Students

Abstract

Objective

Low back pain (LBP) is a multifactorial musculoskeletal condition that reduces productivity at work and causes disability. Due to their lengthy lectures and heavy workload, medical students are more prone to experience LBP. This study aims to investigate the relationship between central adiposity, stress, lumbar lordosis and LBP.

Methods

This study uses a cross-sectional analytical observational design. A total of 73 medical students served as the study’s sample. Respondents self-completed the K-10 psychological assessment and the Nordic musculoskeletal questionnaire. Physical examination was then carried out to identify central adiposity and lumbar lordosis. Respondents having a history of malignancy, deformity, or spinal injury are excluded.

Results

In the prevalence of LBP, 53.21% of respondents reported not experiencing LBP symptoms, while the remaining 46.79% experienced pain. Central adiposity had no significant association with LBP (p=0.872). Although moderate stress was common among those with LBP, stress did not show a clear association in the chi-square test. Logistic regression showed that lumbar lordosis had the strongest impact on the presence of LBP, with an odds ratio of 10.524 (p=0.001), and stress also contributed to LBP complaints (p=0.044).

Conclusion

This study shows LBP is correlated with lumbar lordosis and stress; however, central adiposity is not correlated with LBP.

INTRODUCTION

Low back pain (LBP) that extends from the lower edge of the rib to the fold of the buttocks is known as lower back pain [11]. Global Burden of Disease Study estimates that by 2017, that over 551 million people were affected by LBP [25]. Meanwhile, in 2020 it estimated that 619 million people were affected by LBP globally [10]. A systematic review shows the prevalence of chronic LBP for individuals aged between 24 and 39 years old was 4.2% [16]. Another study in India, with 1335 respondents, age 20 to 29 years old shows LBP prevalence 42.4% per year [9]. According to Makkiyah et al. [14]’s research, 50.4% of adult respondents in Jakarta, Indonesia, and nearby areas in 2020 reported having LBP. According to Hendi et al. [12] research, medical students are more likely than pharmacy and health sciences students to experience musculoskeletal symptoms.

Numerous research has been carried out using body weight and body mass index as variable to examine risk factors for LBP. The findings, however, show there is no significant correlation [1,12,14]. According to study by Makkiyah et al. [14], the three most important risk factors for LBP of middle-aged adult (30 to 60 years of age) with a total sample of 3005 residents of DKI Jakarta and its surrounds, are sex, smoking habit, and long sitting periods. The study also showed LBP is not correlated by weight or body mass index [14]. Another study conducted by Alturkistani et al. [1] in 2020 on medical student research revealed that most of the participants with LBP had a normal body mass index. Additionally, another study revealed no conclusive evidence of a connection between higher body mass index and LBP [5]. There was no connection between obesity or a higher body mass index and prevalence of LBP, according to another study done by Anggraini [2] in 2021 on 56 employees of a logistic company. These studies demonstrate that neither obesity nor a rise in the body mass index are linked to LBP. Considering the previous study, this study instead focusses on fat distribution, we aim to find the correlation between LBP and central obesity.

Academic, physical and mental health issues can all be a result of stress in medical students. According to the findings of a study up to 27.5% of them reported having at least moderate depression [21]. Psychosocial stress is a substantial risk factor for musculoskeletal symptoms among medical students, according to research by Hendi et al. [12]. Stress is said to be one of the risk factors for LBP. Previous studies by Arumsari et al. [4] in 2016 discovered a connection between stress levels and the degree of pain experienced by patients with LBP at Central General Hospital Dr. Kariadi, Semarang City, Indonesia. Another study by Tsunoi et al. in Japan with nurses age ranged 21 to 74, shows LBP is correlated with stress [23]. However, according to a study by Alturkistani et al. [1], stress is not correlated with LBP in medical students.

Medical students also have a heavy academic load that eventually forces them to sit for extended periods of time, such as when attending lectures [1]. Prolonged sitting in an unnatural position can cause shift in lumbar lordosis curve’s angle. One of the causes of LBP is changes in the angle of lumbar lordosis, which puts strain on the posterior lumbar ligament [7]. El-Hamalawy [8] reported a correlation between low back pain and the lumbar lordosis angle, based on the exercise program implemented in the study. In contrast, Nourbakhsh and Arab [17], arrived at a different conclusion, stating that there was no significant association between low back pain and the angle of lumber lordosis. Nevertheless, the lumbar lordosis angle remains a functionally and clinically important parameter, playing a key role in maintaining sagittal balance and in the assessment of spinal deformities [15].

Considering the previous studies results and results, the purpose of this study was to determine whether there was a correlation between central adiposity, stress, lumbar lordosis, and LBP.

MATERIALS AND METHODS

This research has been approved by the Ethics Committee of Health Research of Universitas Pembangunan Nasional Veteran Jakarta with the No. 282/VI/2023/KEPK.

Subject

This study used a simple random sampling method. The research sample includes students as respondents who fulfill the inclusion criteria. The sample size was calculated by hypothesis testing two proportions, namely the proportion of LBP in the exposed group (P1) and the proportion of LBP in the unexposed group (P2).

Inclusion criteria include active student status and availability to become respondents and fill out questionnaires. While the exclusion criteria are students who were previously diagnosed with disorders in LBP that cause pain complaints such as vertebral disc degeneration, spinal stenosis, vertebral disc hernias, equine syndrome, fractures, infections, and malignancies.

The subjects of this study were 73 medical students from 2019, 2020, and 2021 with an age range of 19–24 years. The majority of respondents were female and 20 years old. Fig. 1 shows the schematic diagram of data collection.

Fig. 1.

Schematic diagram of data collection.

Data analysis

Respondents self-completed surveys that have been distributed previously. The questionnaire includes a section for informed consent, the respondent’s name, age, height, and weight. The next questionnaire is the Nordic musculoskeletal questionnaire to assess the presence of LBP complaints. The questionnaire showed Cronbach’s alpha value 0.945 or excellent reliability, the test also showed high validity [6]. The K-10 questionnaire is used to assess stress level. The questionnaire has reliability coefficient 0.881 or reliable and all item in the questionnaire showed r value above 0.2 or valid [18]. Lastly, a section for informed consent for a physical examination.

The respondents who had completed the questionnaire and agreed to attend the physical assessment were then contacted by the researchers. One hundred people in all answered the questionnaire, and 73 of the agreed to get a physical examination. The first physical examination consists of a central obesity screening utilizing measuring tapes in accordance with World Health Organization (WHO) recommendations. Respondents were categorized as having central obesity when their waist circumference was more that 80 cm on female respondents and 90 cm on male respondents [24].

The second physical examination involved measuring the angle of the lumbar lordosis curve using a flexible ruler in accordance with procedures from Youdar’s (1995), Seidi’s (2009), and Reshma’s (2020) research [19,20,26]. The subjects were instructed to stand comfortably with feet 15 cm apart before the examination began. The researchers then palpated and marked the T12 and S2 on the spinous process (Fig. 2A). Flexible ruler the placed on the lumber curve; the ruler was then bent in the direction of the lumbar curvature (Fig. 2B). The results of T12 and S2 palpations are marked on the ruler. The lumbar curve is then drawn using the bent ruler that has been placed on a paper (Fig. 2C).

Fig. 2.

Lumbar lordosis measurement process. A : Palpation of anatomical landmarks on the lower back to identify the curvature of the lumbar spine. B : Molding of a flexible ruler (flexicurve) along the lumbar spine to capture its shape. C : Tracing the curve of the flexicurve onto paper for subsequent analysis of lumbar lordosis.

Vertical line or L line drawn to connect T12 and S2, horizontal line or H line drawn to connect the steep of the curve and L line. Both lines were measured in cm lordosis angle then calculated using Equation 1 [19,20] : 0=4Arctn $\frac{2H}{L}$.

Hyperlordosis is a term used to describe respondents whose lumbar lordosis angle is greater than 45° [22].

RESULTS

This study comprised 73 medical students (74% of them were female) who volunteered to participate in a physical examination. The mean age of the respondents is 20.5±1.1 years old. Thirty-eight respondents (52.1%) have no complaints based on LBP symptoms. The 73 respondents, 41 do not have central obesity and 53 do not have lumbar hyper lordosis (Table 1).

Table 1.

Characteristics respondents

Characteristic	Value
Age (19–24 years old)	20.5±1.1
Sex
Male	19 (26.0)
Female	54 (74.0)
Low back pain
Yes	35 (47.9)
No	38 (52.1)
Central obesity
Yes	32 (43.8)
No	41 (56.2)
Stress
No stress	31 (42.5)
Mild stress	18 (24.7)
Moderate stress	10 (13.7)
Severe stress	14 (19.1)
Lumbar lordosis
Normal	53 (72.6)
Hyperlordosis	20 (27.4)

Values are presented as mean±standard deviation or number (%)

The majority of respondents with LBP do not have central obesity (57.1%) compared to those with central obesity (42.9%). Among the respondents with LBP, most of the respondents have mild stress (31.4%), followed by respondents with severe stress (25.7%), and moderate stress (17.2%). Based on lumbar lordosis, more respondents (51.4%) with normal lumbar lordosis angle have LBP. Hyper lordosis and LBP significantly correlated, according to the chi-square test results (p<0.01). however, the chi-square test did not demonstrate a significant association between central obesity and lower back symptoms (p=0.872) (Table 2).

Table 2.

Prevalence of low back pain based on central obesity, stress and lumbar lordosis

Variable	Low back pain		Total	p-value
	Yes (n=35)	No (n=38)
Central obesity				0.872*
Yes	15 (42.9)	17 (44.7)	32 (100.0)
No	20 (57.1)	21 (55.3)	41 (100.0)
Stress				0.017†
Severe stress	9 (25.7)	5 (13.2)	14 (100.0)
Moderate stress	6 (17.2)	4 (10.5)	10 (100.0)
Mild stress	11 (31.4)	7 (18.4)	18 (100.0)
No stress	9 (25.7)	22 (57.9)	31 (100.0)
Lumbar lordosis				<0.001*,‡
Hyperlordosis	17 (48.6)	3 (7.9)	20 (100.0)
Normal	18 (51.4)	35 (92.1)	53 (100.0)

Values are presented as number (%).

^*Statistically significant at p<0.05.

^†Result from independent sample t-test.

^‡Result from one-way ANOVA

There were three respondents did not complain of LBP but had hyper lordosis (Table 3). All three respondents are female. One of respondents had a moderate level of stress, the other had a waist circumference of 80 cm, which is exactly the limit of obesity for women according to the WHO. The third respondent did not complain of LBP, but had central obesity, severe stress, and hyper lordosis.

Table 3.

Characteristics of respondents without lower back pain complain but have hyperlordosis

Respondent	Sex	Age (years)	Stress level	Waist circumference (cm)
A	Female	21	No stress	80
B	Female	21	Moderate stress	69
C	Female	22	Severe stress	88

Logistical regression on Table 4 showed that lumbar lordosis had the most significant influence with the presence of LBP (p=0.001) with odds ratio of 10.524. In addition, stress also affects the presence of LBP complaints (p=0.044).

Table 4.

The significancy of lumbar lordosis and stress to low back pain

Variable	OR	95% CI	p-value
Stress	1.597	1.013–2.519	0.044*
Lumbar lordosis	10.524	2.653–41.739	0.001*

^*Statistically significant at p<0.05.

OR : odds ratio, CI : confidence interval

DISCUSSION

This study’s objective is to determine the association between stress levels, central adiposity, and lumbar lordosis as LBP risk factors. This study indicates that stress and lordosis lumbar are contributing to the development of LBP. The study’s respondents were medical students with an average age of 20.5 years. Most of the respondents were female and reported not having LBP.

The analysis of study’s findings shows a noteworthy association between the incidence of LBP and lumbar hyper lordosis. This outcome is consistent with the findings of El-Hamalawy [8)]s study. This research seeks to identify exercise methods that can support the Association between lumbar hyper lordosis and LBP. The study’s participant was those with persistent back pain who were 30–45 years old and had hyper lordosis, or a lordosis angle greater than 50°C. The lumbar lordosis angle was determined using the Cob technique. Subjects with spinal nerve damage, neurological disorders and deformities like scoliosis and spondylolisthesis were excluded. After participating in the program three times per week for 2 months, the results demonstrated a significant decrease in the lumbar curve of 3.00 and the absence of LBP complaints from the patients. According to research, lumbar hyper lordosis and lower and LBP are related [8].

Three participants in this study who had hyper lordosis were noted as not experiencing LBP. Three of the respondents are at risk for LBP. According to this study’s findings, hyper lordosis is associated with LBP, which is consistent with earlier studies by El-Hamalawy [8]. Additionally, this study’s limitation included the fact that there are some unresearched causes of LBP, including sitting time, exercise routines and smoking [17].

The findings of this study are inconsistent with the results reported by Nourbakhsh and Arab [17]. According to the previous study, structural factors such as a large lumbar lordosis or a pelvic tilt are not related to symptoms of LBP, which are instead linked to muscular weakness. Muscle weakness is not considered an independent factor in this study, which is a study limitation.

This research result is in line with a study by Tsuboi et al. [23] on senior nurses in Japan, their findings indicated a connection between LBP and stress levels. The respondents ranged in age from 21 to 74. The question of whether respondents had experienced LBP that lasted for 24 hours in the past month determines if they have LBP. Pain between the 12th rib and the lower buttock fold. The perceived stress scale was used in the study as a stress questionnaire. According to the study, stress should be considered as a risk factor for LBP because it has been linked to higher levels of stress [23].

Arumsari et al. [4] reported in another study that psychological stress has an impact on the intensity of LBP patients experience. According to the study, psychological factors like emotional stress can lead to muscle tension and pain, which includes LBP. Forty-three patients’ worth of medical records from a hospital were used in the study. The Ardell wellness stress test was used to measure stress levels. According to a review of the results of the research, individuals who had moderate to high levels of stress were more likely to experience LBP [4].

This study found a connection between medical school students’ stress levels and LBP. These results seem to be in contradiction with those of Alturkistani et al. [1]’s study, which found no correlation between psychological stress and LBP. The average age of the study’s respondents, who were medical students, was 21.5 years. The NMQ questionnaire, used to assess LBP, and the K-1-questionnaire, used to assess stress levels, were both used in the study. According to the study, lengthy work hours, female sex, and second-year medical students were significant risk factors for LBP complaints. Additionally, inappropriate weightlifting, overuse of the lower back muscles, and unhealthful sitting habits can all contribute to low back pain [1].

In accordance with a study by Arma et al. [3], in 2019 with respondent public transportation drivers, no relationship between back pain and central obesity. Male respondents were separated based on their age; those over 40 and those under 40. Respondents were said to have central obesity when the waist circumference was greater than 90 cm. respondents with a spinal injury history was excluded. This study showed that waist circumference is not correlated to the presence of LBP [3].

Another study by Shiri et al. [22] in young adults with an average age of 31.5 years revealed that waist circumference or central obesity had a significant correlation with LBP only in women but not in men. By considering metabolic and inflammatory activity, such as C-reactive protein, adiponectin, and leptin in adipose tissue, the study aims to assess the association between weight-related parameters and the prevalence of LBP in young adult populations. The study investigated sex-specific weight-related parameters. According to the findings, LBP in women of almost all age groups is associated with central obesity. This can be caused by changes in the proportion of visceral and subcutaneous fat at different ages [22].

In contrast to others research conducted by Carolin et al. [5], this study’s findings revealed no association between central adiposity and LBP. The study case-control methodology involved dividing 42 samples into 21 individuals with a high risk of LBP and 21 individuals with a low risk of LBP. The measurement of waist circumference indicates obesity when the waist circle is more than 90 cm in men and more than 80 cm in women. The Keele start back questionnaire was used in this study to assess the risk of a lower back injury [5]. The study also examined the connection between computer usage, exercise, and sitting attitudes. This study’s limitation was the absence of research on variable.

The lack of correlation between central adiposity and LBP in the study could be due to various reasons, such as differences in sample characteristics, the study sample may differ from those in previous studies. For example, the age, gender, ethnicity, or health status of the participants could vary, which might influence the relationship between central adiposity and LBP. For instance, older adults or those with preexisting health conditions might show a more pronounced association, while younger or healthier participants may not. Additionally, previous studies may have used different methods to measure central adiposity (e.g., waist circumference, waits-to-hip ratio, or body mass index) and LBP (e.g., self-reported pain, diagnostic imaging). The lack of consistency in measurement tools could explain why the relationship wasn’t found. Then, study design, confounding factors, or the type of LBP being assessed. Further research may be needed to clarify these findings [5,22].

A comprehensive strategy is needed to prevent LBP, which includes regular exercise, keeping a healthy weight, adopting good posture, employing safe lifting techniques, and making ergonomic and daily activity adjustments. In addition to lowering the chance of getting LBP, implementing these strategies into daily life can help manage current pain and stop it from returning. A long-term plan for preserving spinal health must include early intervention, education, and expert counsel [13].

This study has several limitations, considering the respondents themselves filled out the questionnaire for this study, there is a chance that there was bias or inconsistency at the time of filling it out. Additionally, the study did not take into account other causes of LBP as independent factors. Although the study found no connection between central adiposity and LBP, we assessed the lumbar lordosis angle using a non-invasive, non-examination technology that required radiation. The technique can be used to conduct examination in locations for from or without radiological facilities and provides safety for participants and researchers.

CONCLUSION

This study investigates how lumbar lordosis, stress and central obesity are related to LBP. This study’s findings indicate a relationship between LBP with stress and lumbar lordosis, but not central adiposity.