Unlocking Posture: Determining Ideal Cut-Off Points for Forward Head Stance in Young Adults with Neck Pain

This research explored the connections between lifestyle variables and forward head posture (FHP), and determined the threshold values for the principal predictors of FHP risk among young adults experiencing neck discomfort. A significant finding of the research reveals that time spent lying down and the physical activity level (PAL) index score differed substantially between FHP and non-FHP (NFHP) groups, with a threshold value of 6.50 hours for lying time and a PAL index score of 2.88. The findings underscore the necessity to reduce lying time outside of working hours and to enhance activity levels throughout the day to mitigate FHP. Additionally, specific numerical guidelines for physical activity aimed at managing FHP risk were provided.

In this analysis, the FHP group exhibited a greater lying time and a lower PAL score in comparison to the NFHP group. This disparity can be linked to a diminished capability to uphold an upright posture within the FHP cohort. Earlier studies have indicated that individuals with FHP possess a reduced ability to maintain an upright posture relative to those without FHP [25] and exhibit heightened muscle activity associated with maintaining an upright posture [26]. Lifestyle factors concerning posture were categorized into lying, sedentary, and standing durations over a 24-hour span. An increase in lying duration generally results in a decrease in both sedentary and standing time, which subsequently leads to lower PAL, PAW, and PAS index scores. Nevertheless, there exists a minor distinction between these two factors. For example, extended lying time results in reduced availability for physical activity. However, the nature of the activity conducted during this limited timeframe can yield either favorable or adverse effects on FHP.

Within both crude and thoroughly adjusted logistic regression analyses, the likelihood of FHP increased threefold with extended lying time and was reduced by 60% with improved PAL index scores. Prolonged engagement with electronic devices, such as computers and smartphones, adversely affects health, and the necessity of physical activity and exercise is widely acknowledged [27, 28]. Furthermore, FHP can be ameliorated through various corrective exercises, and individuals who participate in regular physical activity and sports are more prone to experience improvements in neck discomfort [2, 29]. However, as indicated by this study, the opportunity for a positive effect on FHP diminishes in instances of increased lying time and resulting reduced sedentary and standing durations, meaning in scenarios with limited time for physical activity. Higher PAL scores are associated with both increased frequency and duration of dynamic activities, such as walking and cycling, alongside reduced television viewing durations [18]. Consequently, a low PAL index score denotes limited participation in dynamic activities like walking or cycling and prolonged engagement in static activities that exacerbate FHP, such as utilizing computers or smartphones and viewing television. Thus, young adults suffering from neck discomfort should lessen lying time and commit to sufficient physical activity.

Additionally, the results from the receiver operating characteristic (ROC) curve offer explicit numerical guidelines pertaining to lying and activity durations, providing insight on the optimal thresholds for assessing FHP risk. This study identified 6.5 hours of lying time and a 2.88 Inverse PAL score as the optimal thresholds for predicting FHP risk, with moderate accuracy observed. This signifies that lying for 6.50 hours or more and a PAL index score of 2.125 (PAL = 5 – Inverse PAL) or less substantially heighten the risk for FHP development. The advised sleep duration for adults is between 7–9 hours [30], and deviations from this range (< 5 hours or ≥ 9 hours) correlate with escalated neck and musculoskeletal discomfort [10]. The identified lying duration of 6.50 hours throughout this study aligns with these observations. However, it is crucial to distinguish between lying time and sleep duration; to avert FHP, individuals ought to prioritize sleep and avoid distractions from other activities while lying down. The PAL index score can exceed 2.25 with sporadic walking or cycling for 5–15 minutes, without television viewing, or more frequent walking or cycling for 15–30 minutes coupled with regular television watching. Previous research indicates that there is no definitive correlation between physical activity and neck discomfort in adolescents, while the connection between these variables remains vague for adult workers. This may stem from adolescents often being more active than adults [31]. Furthermore, engaging in light activities such as walking or cycling for a cumulative total of 150 minutes weekly has been documented to positively affect neck annoyance [32]. While FHP does not invariably lead to neck discomfort, they are still correlated. Hence, the total recommended PAL in this study (105–210 minutes per week) closely corresponds with guidelines from prior investigations. Notably, these findings imply that preventing FHP does not necessitate extensive time or high-intensity exercises. Thus, the outcomes advocate that young adults with neck discomfort should limit lying time to 6.5 hours daily, ideally dedicating this duration entirely to sleep. Additionally, reducing time spent on sedentary tasks in adulthood should be promoted, with the suggestion of incorporating light activities such as walking or cycling. The area under the curve (AUC) values for lying time and Inverse PAL were roughly 0.60, marginally below the generally accepted threshold of AUC > 0.7 and inferior to the AUC value of 0.88 for cervical vertebral alignment (CVA), a direct measure of FHP [33]. Nevertheless, referencing a preceding study that indicated AUC values of 0.623/0.596 (for men and women, respectively) and 0.608/0.579 for body mass index (BMI) and skeletal muscle mass index, the lying duration and Inverse PAL continue to retain some predictive significance for FHP, albeit weaker in comparison to CVA [34].

Moreover, we could not detect a considerable effect of lying time and PAL index on CVA over the short-term follow-up period of 6 months in this research. In a previous investigation, the absolute alteration in CVA after 3–6 months of therapeutic exercise remained minimal, despite reaching statistical significance in individuals with FHP [35]. Therefore, the brief follow-up duration might have contributed to the absence of notable changes seen in this observational research, which did not implement any interventions. However, individuals with prolonged lying durations displayed a tendency toward lower CVA (closer to FHP), whereas those with elevated PAL index scores exhibited higher CVA (closer to NFHP); these trends warrant consideration in subsequent investigations.

Lastly, other ancillary factors such as sedentary duration, standing time, PAW index score, and PAS index score showed no significant distinctions between FHP and NFHP groups. The activation of muscles influencing FHP varies with posture and activity [26]. This suggests that sedentary duration, standing time, PAW index score, and PAS index score might not have been adequately distinct to differentiate between FHP and NFHP within this study. Likewise, factors such as gender, age, height, weight, BMI, radiographic findings, Numerical Rating Scale (NRS), and McGill Pain Questionnaire Short Form (MPQSF) did not show significant differences between the two groups. Furthermore, previous studies have revealed inconsistent results concerning these factors. The occurrence of FHP is elevated among adults experiencing neck discomfort compared to those without any symptoms, and age, gender, height, weight, and BMI could act as confounding variables [7]. Nonetheless, the results concerning pain and disability levels between adults with neck discomfort and those without FHP symptoms were inconsistent in various studies [36]. In spite of this, we conducted additional analyses and adjusted for these factors considering their potential mutual influence. Future research ought to include an adequate number of participants, taking into account gender and age, to provide more thorough insights. The Harrison posterior tangent method utilized during radiographic evaluations is appropriate for assessing posture but may be more suitable for evaluating cervical lordosis rather than FHP, which could clarify the absence of significant distinctions observed in this research [37].

Limitations

This study is subject to several limitations. Firstly, although organized tools were employed to gauge lifestyle elements, there could be recall bias stemming from the use of self-reported surveys. Future research should utilize objective instruments such as activity monitors or wearable technology. Secondly, the study concentrated on a specific age demographic (30–40 years); thus, the conclusions possess limited applicability to alternative age groups. Future studies should ensure an adequate sample size and diverse study cohort. Finally, this research could not establish causation due to its cross-sectional design. Hence, longitudinal studies with appropriate follow-up periods are essential to investigate the causal links between FHP and lifestyle factors.