## 4 Discussion
\begin{table}
\begin{tabular}{l c c} \hline \hline
**Predictor** & **NDI** & \\ \hline  & **Unadjusted Beta** & _p-Value_ \\ \hline Chin tuck neck flexion test & \(-\)0.08 & 0.005 \\ \hline Extensor muscle test & \(-\)0.03 & 0.042 \\ \hline DN Flexor CSA & 4.07 & 0.297 \\ \hline DN Extensor CSA & \(-\)4.47 & 0.025 \\ \hline \hline \end{tabular} Abbreviations: NDI, neck disability index; DN, deep neck muscle; CSA, cross-sectional area.  
\end{table} 
Table 3: Summary of multivariable regression analysis for the NDI score. studies are needed in this regard, the data of the present study could suggest that the initial stages of neck pain with low self-perceived disability and pain intensity could be an ideal period to start specific neck exercises and use them for prevention. Specific neck exercise has been shown to be effective in improving the endurance of the neck musculature [60]. However, if this were the case, it would be imperative to target and raise awareness among patients exhibiting these characteristics, as well as to disseminate this knowledge within healthcare facilities. As previously mentioned, these patients typically refrain from seeking medical attention due to the mild nature of their disability and pain. No statistically significant correlations were found between the CSA, endurance test and pain intensity in this study. The results of this study are different from those with patients with chronic neck pain, where a smaller muscle size was observed compared to healthy subjects, as well as a negative correlation between the CSA and the intensity of the neck pain [17]. In this sense, it is also suggested that the smaller the size of the muscle, the greater the pain and disability; this fact could be one of the reasons why a relationship between muscle size and pain and muscle size and neck disability was not found in the present study. The patients in this study had low neck disability, low pain intensity and were not patients with chronic neck pain. From a clinical point of view, in patients with neck pain for less than 3 months and low levels of disability, clinical tests such as the endurance tests for the neck flexor and extensor muscles may be more useful to test and track the status of the patients in terms of disability and impact than the measurement of the CSA. However, once the situation turns chronic, the evidence showed correlations between the CSA and the main symptoms of the patients. So, future studies should consider the relationship of these outcome variables, taking into account the evolution time and the age of the patients. This study used the VAS to assess the neck pain, the NDI for the self-perceived neck disability, the HIT-6 for the impact of headache and clinical tests to measure the endurance of the neck flexor and extensor muscles and to evaluate the morphological characteristics of deep neck using ultrasonography. Several limitations were observed during the current study. Although neck pain is more prevalent among women, it is important to acknowledge that the study sample exclusively consisted of female participants. Consequently, caution must be exercised when generalizing the results to male populations. The inclusion criteria were patients with low levels of pain and disability, so the relationships may not be the same for patients with higher levels of pain and disability. Third, the linear mixed model partially explained the results, so more outcome variables should be taken into consideration. The results of this study must be taken with caution; an attempt was made to carry out a study of correlations between seven different variables, and for this purpose 12 subjects per variable were recruited, completing a sample of 82 subjects. This type of study, with such large samples, can bias the results and weaken or strengthen different correlations, so it would be important to carry out a study analyzing the variables that showed correlations in this study.