This is the primary study that investigated the prevalence of NP and the association of individual, psycho social and physical characteristics among medical students NP. The previous twelve-month self-reported prevalence of NP among medical students was 49.2% (95% CI: 44.5–54%), the results indicated that NP is a common health problem among medical students. This finding is consistent with similar studies conducted in Pakistan (44.8%) [26], Australia (52.8%) [8] and Central Saudi Arabia (54%) [33]. However, the prevalence of this study is higher than the studies conducted in Brazil (8.23%) [10], Thailand (22.3%) [34], China (33.8%) [9], United States of America (35%) [6], Iran (39.4%) [35], Malaysia (41.8%) [3] and Nigeria (34.9%) [12].
This difference observed in the prevalence rate of NP could be due to the differences in the study area, sample size, sampling method, and assessment tools. The study in Brazil has used convenience sampling technique with a small sample size [10] and the study from Iran was used the Oswestry questionnaire and descriptive analytical study design with a small sample size [35].
The study of China was used different methods of assessment of NP for medical students and used survey among all fourth-year students with a small sample size [9] and study from Nigeria used a mixed population of medical and non-medical students [12].
Studies from the USA and Malaysia used a survey and an online self-administered questionnaire. Besides, it could be because of high awareness regarding NP among the USA and Malaysian medical students [3, 6].
The study of Thailand [34] has used a cohort study with small sample size. But the present study has used a cross-sectional study and simple random sampling technique with fairly large sample size, and it includes only medical students from the year one -year six. The other reasons could be a facility provided for the students at their institution or social and economic differences between Ethiopia and the countries of the studies mentioned, the way in which classes, the library, and clinical places were organized and the protective factors involved contribute to the differences observed compared to the present study. In addition to this, psychosocial, and physical characteristics may increase the prevalence rate of NP among Ethiopian medical students. Furthermore, this study’s prevalence was lower than studies conducted in Nevada, Las Vegas (84.6%) [36], Pakistan (65%) [7], and another study from the USA (56%) [37]. The possible reasons could be due to a different sampling technique, data collection procedure and sample size. Studies conducted in Nevada, Las Vegas, and the USA included students by purposive sampling and mailing for data collection. The study done in Pakistan used non-probability convenience sampling technique, a mixed population (medical and non-medical students) with small sample size and interview type of data collection procedure [7]. But this study used simple random sampling technique, a large sample size with a self-administered type of data collection procedure.
In this study, the factors associated with NP were past history of NP, a physical exercise, duration of reading and bending or twisting in an awkward neck position.
This study found that medical students who had a past history of NP symptoms were approximately12 times more likely to develop NP as compared to those without past history of NP. This result was consistent with studies have done in Central Saudi Arabia and Malaysia [3, 33]. The significant association between NP and past history of NP in the present study is understandable, and the possible explanation is because of those individuals who had a previous history of NP symptoms were at a higher risk developing NP. Beside, persistent NP can have broad and profound effects on wellbeing with significant impairment of physical and psychological health [34].
This study showed that medical students who were not doing a regular physical exercise were 2 times more likely to develop NP than those who were doing a regular physical exercise. This result was consistent with the studies have done in the USA [22]. The possible explanation could be shortened and weak muscles can cause NP as they can cause misalignment of neck anatomical structures. In contrast, medical students those who did a regular physical exercise can strengthen, lengthen, improve flexibility and make their muscles and ligaments strong to support and keep the neck alignment for proper functioning and preventing injury [38]. A prior study in America showed those who participated in sports activities were less likely affected by musculoskeletal pain of the upper body [7].
Experiencing a twisting or bending position during a computer or tablet use and a clinical attachment has resulted in 3.87 times higher odds of NP in this study. Studies from the United States of America, Brazil, and Thailand, medical students reported a similar association [6, 10, 16]. This association could be explained as an awkward position, including excessive flexion and rotation of the neck, increases muscle tension and resulted in spasm and musculoskeletal symptoms [39]. On the other hand, awkward posture was not significantly consistent with the musculoskeletal study conducted in New York, United States of America [6]. This could be due to a high awareness of body mechanics or ergonomics factors, especially physical factors among USA medical students [40].
Medical students who read three or more hours per day with a static head down posture were 1.5 times more likely to develop NP compared to those who read for less than 3 h per day. This result was similar to studies done in Pakistan and Thailand [26, 34]. The possible reasons could be due to clinical exposure, overload of exams for long duration to perform sustained and frequent activities such as reading, clinical procedures inwards and other during their study year repeatedly under unfavorable positions could, lead to discomfort, muscle stiffness or tightness around the cervical region, eventually lead to NP [41].
Another study in Uttar found that the most common cause of NP among medical students was prolonged reading followed by the use of computers and prolonged writing [42]. Prolonged sitting during studying, positions assumed during lectures are related to a high prevalence of NP [34]. Also, long study hours were found to be greater among medical undergraduates but no significant association was found in medical students [7].
Limitation of the study
Considering the remunerations of future research, there are a few limitations to be stated. This study was carried out in just one institute, ergonomic evaluation of a posture of students while using a computer or during the study was not done. The cross-sectional nature does not allow inferring of causality and effect. Another limitation of this study was the possibility of recall bias and the impact of a 12 month recall question. Since it was self-reported which could lead to over or under-estimation of the true prevalence and height and weight of respondents were self-reported.