With recent rapid socioeconomic development, people are more mindful of their health. Increasingly more individuals who work in the office environment are seeking treatment for pain. In China, outpatients with CS are common in rehabilitation medicine, orthopedics, or traditional Chinese medicine. These patients often complain of neck and back pain, and have occasional complaints of dizziness, limb numbness, walking instability, perineal paresthesia, urinary and fecal incontinence, and sexual dysfunction. Such symptoms can have serious impacts on patients’ lives and can result in a sharp decline in the quality of life. In a study conducted at the University Clinical Hospital in Olsztyn, Poland between 2011 and 2015, the most frequent MRI-diagnosed diseases were musculoskeletal diseases (58.0%), cervical disc disorders (12.5%), and spondylosis (4.6%). The authors concluded that the significant number of patients presenting with spinal disorders at young ages (31–40 years) pointed to the necessity of introducing methods in school-aged individuals to prevent disorders of the vertebral column . In the present study, we also found that participants had a high incidence of neck pain syndrome (74.19% for males and 66.31% for females).
Previous research reported that most patients with CS were in occupations that required working long-term at a desk or work station, where it is common to remain for extended periods of time with the head tilted downward [16-18]. The cervical spine has seven vertebrae, and the joints formed by each vertebra are more flexible. The anatomical features of the neck provide a large range of movement. Overloading the neck musculature can lead to cervical tissue damage. Holding the head in a lowered or flexed posture maintains the neck muscles in a tensile state, which may cause muscle strain if the position is held over a long period of time. This forward flexion posture may lead to static imbalance and accelerate degeneration of the intervertebral discs, small joints, and ligaments of the neck, eventually resulting in CS.
The NDI covers 10 dimensions of neck-specific disability: pain intensity, personal care, lifting, reading, headache, concentration, work, driving, sleeping, and recreation . This is closely correlated with cervical spine function , which can reflect neck pain intensity  , and can ultimately be used to evaluate the quality of life . Feng et al.  analyzed survey data and found that among ultrasound technicians, lowering of the head for a long period of time led to rates of neck discomfort as high as 93.5%. Gremark Simenson et al.  found that the prevalence of CS among ultrasound technicians was 58%, and positively related to the length of time that the technician’s head was held in a downward position while working. These results are consistent with those of our study. We found that DCF was positively correlated with the NDI regardless of unadjusted or adjusted covariates. When DCF increasing by 1 hour, NDI will increased by 0.28 or 0.26 score (β =0.28 and 0.26 respectively, see table3).Office workers should be mindful of DCF as much as possible. Our study found that there was a fold point (K=6) between DCF and NDI scores, and the differences were statistically significant (P<0.01). Many patients with CS have symptoms of neuropathy, however most symptoms are relatively benign and ultimately have a good prognosis . The results of our study suggest that when DCF is greater than 6 hours, participants may adapt to neuropathy symptoms related to neck posture, leading to a decrease in symptoms. Even with this adaptation, cervical syndrome can persist. Therefore, we recommend that office workers limit DCF in order to decrease cervical syndrome.
In the 21st century, the rapid development of technology has resulted in the widespread use of electronic devices, leading to a near-universal presence of computers and smart phones in many countries, including China. One study found active arthritic changes caused by repetitive strain injury from excessive text messaging using smartphones. Another study reported that smartphone use induced a more flexed posture on the neck and trunk than other visual display terminal work Pain and fatigue worsened with longer smartphone use, and the authors suggested correct posture and breaks of at least 20 minutes when using smartphones. Although our research found that using flexed neck postures to use smart phones and for other activities had no effect on NDI scores, DCF was positively correlated with NDI scores. We suggest that office workers need to control DCF to reduce NDI scores when using smart phones or engaging in other activities that require flexed postures for extended periods of time. When using a laptop computer, we can use a book to elevate the computer to keep the center line of the screen and the line of sight on a level surface, and we can lift the book or smart phone or other electronic products in front of us to reduce the possibility of flexed posture of cervical. We can also use an APP or a clock with timing and reminder functions, setting DCF to be less than 6 hours, or according to the actual situation of the individual, if using the smart phone for longer than the setting time, which can sound an alarm to remind you, or force the screen to turn off. Of course, these are all passive measures. The most important thing is that we need to develop good living and working habits. If not necessary, try not to lower our cervical to engage in activities, which may harmful for our cervical.
One limitation to our study was the lack of follow-up, therefore, the long-term results of our investigation were unknown. All recruitment filled out the questionnaire through self-reporting. Due to the use of online filling methods, and taking into account medical ethics rule, all participants were anonymous. We cannot ensure the validity of the survey content; this is a common limitation of survey design. And we cannot make sure the ratio of subjects suffering from cervical spondylosis before our survey, even though we adopted a random survey method, which may still affect the incidence of neck pain syndrome. We did not find suitable literature to extract the effect size for sample size estimation, so we cannot fully determine whether there are false positives and false negative situation. We did not analyze other risk factors associated with NDI scores such as mental stress, the time of day that people are working, working hours, work pressures, sleep quality, and financial situation. In the future, we hope to expand sample size to conduct further studies and evidence-based research on DCF and NDI scores.