Prevalence and risk factors of low back pain among commercial motorbike riders in Kathmandu Valley

Low back pain is a major health problem because of its high prevalence and has a consequence for disability and burden in the use of health services. It has a great impact on an individual’s economic productivity and quality of life. Motorbike riders are the vulnerable population for musculoskeletal disorders including low back pain. The objective of the study was to find out the prevalence and risk factors for low back pain among motorbike riders in Kathmandu Valley. An analytical cross sectional study was conducted in 265 commercial motorbike riders in Kathmandu. To collect data, convenience sampling technique and face to face interview was employed by using structured interview questionnaire. Data was analyzed in IBM SPSS software. Descriptive statistics and regression analysis was calculated. The study findings demonstrated that 43.8% of the respondents had low back pain among them 31.1% experienced more than 3 episodes of pain in last year. Similarly, 38% of the respondents had low back pain in last seven days. Low back pain is associated with BMI (p = 0.004), duration of commercial motorbike rides (p = 0.000), mileage per day (p = 0.002) and total riding hour per day (p = 0.001). It is concluded that nearly half of the commercial motorbike riders had low back pain in last one year and a significant association was found between low back pain with BMI, commercial motorbike riding duration, riding mileage and riding hour per day. As commercial motorbike riding is a trending business, there should be some government regulations on working hours and other safety measures for the riders.


INTRODUCTION
Work related musculoskeletal pain is progressing to be the major threat to public health and low back pain (LBP) is frequently reported body area with 53% prevalence rate 1 and the main cause of disability adjusted life years i.e. 61.6% of years lived with disabilities. 2 It occurs in people of any age group, cultures, sex and interferes with quality of life and work performance, and is the most common reason for health care consultation. 3 Motorcycles have been an indispensable component of the transport systems in many cities in the Southern and Eastern Asia regions as they are inexpensive, highly accessible, relatively fast mode of transport. 4 In a study done in commercial motorbike riders in Nigeria, revealed 40.7% had low back pain in the last 12 months. 5 Similarly, 22.04% of motorbike riders had experiences low back pain in Vietnam. 4 Since the first wave of COVID-19 pandemic, ride-hailing business are becoming popular in Nepal among passengers to avoid crowded public vehicle and also for freelance work for the riders on a short term basis. 6,7 Commercial motorcycle drivers often work for long hours having quite high exposure to weather conditions, air pollution, failed road conditions, poor posture , carrying heavy loads, noncompliance with traffic safety rule affects their back health. 4,5 Thus, the study aimed to find out the prevalence and risk factors of LBP among commercial motorbike riders in Kathmandu.

MATERIALS AND METHODS
A cross-sectional study was conducted among 265 commercial motor bike riders (Pathao and others) in Kathmandu Valley. Sample size was calculated for the infinite population by using the specified absolute precision formula (n=z2 pq/e2) where, z (standard normal variate) = 1.96 at 95% confidence interval, p (prevalence) = 22.04%, q = 1-p = 77.96%, e (allowable error) = 5% with the reference prevalence of low back pain in motorcycle riders in Vietnam. 3  The instrument contains two parts: part one contains questions related to sociodemographic, personal behavioral factors and motorbike ride variables and part two contains questions related to prevalence of the pain. Extensive literature search, consultation with the pain management expert and pretesting of instruments was done for the validation of the instrument. Data was collected by face to face interview by using structured interview questionnaire during the evening period (7:30 to 10:30 pm) which is the peak time for riding request. Highly populated (Chabahil, Koteshwor, Satdobato, Yekantkuna, Kalanki, Samakhusi, Narayangopalchowk) areas were selected randomly from the list of an intersection areas in ring road. At first, commercial riders were identified, explained the purpose of the study. Written informed consent was taken from each participants.
The researcher and one enumerator (BSc Nursing graduates) collected the data between the period of May 3 to June 13, 2022. The riders who had history of back pain and back injury before starting of commercial motorbike riding was excluded from the study. About 15-20 minutes was taken to collect data from each participants. Though there was difficulty to get separate space for interview, the researcher tries to maintain privacy by conducting interview one by one in each setting. They were given full authority to withdraw their participation from the study without any fear. Data were analyzed using IBM SPSS 16. Descriptive statistics (frequency, percentage, range, mean and standard deviation) were used to describe the socio-demographic variables and prevalence of LBP. Regression analysis was done to identify the risk factors for low back pain. (Table 1), majority (n=151, 57.0%) were belong to 20-30 years of age. In terms of education, 41.9% reported they had higher secondary education, majority (64.9%) of them were married and were Hindu (n= 194, 73.2%) followed by Buddhist (n=55, 20.8%). Regarding ethnicity, 47.5% identified themselves as Janajati, 42.3% as Brahmin/ Chhetri. Regarding BMI, more than one third (n=105, 39.6%) were overweight.

Out of 265 participants
Regarding their smoking habit, alcohol consumption, rest break in between ride, sleeping habit and exercise (Table 2), two third (66.4%) of the participants were current smoker, 71.7% stated to consume alcohol. Majority (69.8%) reported not taking rest break in between rides, regarding sleeping habit, 95.5% have less than or equal to 8 hours sleep, more than three fourth (77.7%) stated that they did not perform exercise. Table 3 represents the information related to duration, speed and mileage of riders. More than half 52.5% of study participants stated riding duration of motorbike for less or equal to 5 years. In terms of commercial motorbike riding, 52.5% stated that they were riding for less or equal to 12 months. Most of the participants (57.4%) reported working for less or equal to 7 hours per day and the mean working hours per day is 7.76± 3.0. More than three fourth (78.5%) reported the riding speed was less or equal to 60 km per hour. In terms of mileages, more than half (56.2%) noted of maintaining less or equal to 100 km mileages per day.   Gautam et al Table 4 shows the participants' prevalence of LBP. Less than half (43.8%) said that they had LBP in the last one year. Among them, more than two third (68.9%) stated facing less or equal to three episodes of pain while 31.1% faces more than three episodes of pain in a year. Regarding the duration of pain in terms of days, 46.6% had experienced pain for less than 3 days followed by 3 to 6 days 32 (27.6%) and more than 6 days 30 (25.8%). Similarly, regarding severity of pain, most of study participants (55.1%) had mild pain.
For the experience of LBP in the last 7 days 38.1% had LBP, among them majority (80.2%) stated of having mild pain and 19.8% stated of having moderate low back pain. When they were further asked about the duration of the pain in terms of days, more than half (55.4%) said that the pain lasted for less or equal to 3 days.
Concerning to the risk factors (

DISCUSSION
This study assessed the prevalence and risk factors of low back pain in commercial motorbike riders. Globally, low back pain is one of the common causes for the Disability Adjusted Life Years (DALYs) 8 and cause for frequent visits to hospital, as well as absence from work and activity. 9 In this study, the prevalence of LBP among commercial motorbike riders in last one year was 43.8%, the result was comparable with the study conducted in Nigeria among commercial motorcyclist that showed 41% experienced LBP. 5 In contrary to the current study findings, the LBP prevalence was higher among motorcyclist student in a university of Pakistan and police officer who rode motorcycle in Poland. 10,11 Similarly, the findings of several published studies reveled the lower prevalence rate of LBP than the finding of present study. 12,4 Additionally, the study was conducted to examine the musculoskeletal disorders among two wheeler riders in India, found that low back region was the highly affected body region among studied population during last 12 months. 13 In this study, the prevalence of LBP among commercial motorbike riders during last 12 months and last 7 days were 43.8% and 38.1% respectively. This result was inconsistent with that of study conducted in Nigeria in which twelve months prevalence was 30% and last seven days prevalence was 22.0%. 5 The present study showed that prevalence of low back pain for last seven days was less than that during twelve 12 months and this was consistent with findings of the another study conducted in Nepal. 14 In this study, LBP was significantly associated with BMI (p = 0.004). Riders who were overweight and obese were 2.0 times more likely to have low back pain than having normal BMI. However, there was no association between BMI and LBP in study conducted in other two studies. 5,15 Similarly, the present study revealed that LBP was associated with the duration of commercial motorbike ride (p = 0.001). The findings are parallel with the findings of the pilot study in USA and in Nigeria. 12,15 Furthermore, LBP was associated with the motorbike riding mileage per day (p = 0.002). The motorbike who rode more than 100 kilometers per day were 2.1 times more likely to have lower back pain than who ride less than 100 kilometers per day. Similarly, LBP was associated with total riding hour per day (p = 0.001). The motorbike riders who rode more than 7 hours per day were 2.4 times more likely to have LBP than who ride less than 7 hours per day (OR: 2.354: CI: 1.429-3.877). This could be because of decrease in muscle power due to constant posture for >20 minutes which leads to reduced flexibility of joints. 14 This finding consistent with the findings of various studies. 5,10 In the present study, the prevalence of LBP was assessed through the verbal reporting of the participants, not through any diagnostic investigations. Similarly, BMI was calculated as the verbal reporting of body weight and height by the participants so there may be recall biases. It is recommended for further study to observe other risk factors such as the riding posture, measurement of height and weight of the riders, types of a motorbike, conditions of road.
Based on the findings of the study it is concluded that nearly half of the commercial motorbike riders had LBP during last one year and one third of them had LBP in the last seven days. Significant association was found between LBP with BMI, duration of commercial motorbike riding duration, riding mileage per day and riding hour per day. It is recommended that there should be some government regulations for the working hours and other safety measures for the ride sharing company. The ride sharing company should organize periodic health checkup camps, regular class on riding posture for the maintenance of back health of the riders.