Characteristics of head and neck alignment and function of deep cervical flexor muscles in patients with nonspecific neck pain.

OBJECTIVES: The objectives were to compare forward head posture (FHP) in natural and corrected head postures between patients with nonspecific neck pain (NSNP) and controls and to clarify the relationship between natural and corrected head posture angle differences and deep cervical flexor function. This study aimed to provide useful evidence for postural assessment and treatment in patients with NSNP. METHODS: In this cross-sectional study, 19 patients with NSNP reporting a pain score of 3-7 for at least 3 months and 19 participants with no neck pain within the previous 12 months were recruited. To evaluate FHP, the cranial rotation and vertical angles were measured using lateral head and neck photographs. The craniocervical flexion test was used to evaluate deep cervical flexor activation and endurance. We evaluated the head and neck alignment in natural and corrected head postures and the relationship between the degree of change and deep cervical flexor function. RESULTS: FHP in the natural head posture did not differ between groups. In the corrected head posture, FHP was significantly smaller in the NSNP group than in the control group. In the NSNP group, the cranial rotation and vertical angles were significantly different between the natural and corrected head postures, and the angle difference correlated significantly with deep cervical flexor function. CONCLUSIONS: Patients with NSNP show hypercorrection in the corrected head posture, which may be correlated with deep cervical flexor dysfunction. Further investigation into the causal relationship between hypercorrection, deep neck flexor dysfunction, and neck pain is required.

Humeral Head Morphometry Can Predict the Presence of Subacromial Spurs: Measurements of Dried Bones from Human Shoulder Girdles.

OBJECTIVE: To clarify the relationship between the morphological characteristics of the bones of the shoulder girdle and the presence of subacromial spurs (SS). METHODS: The bones of 36 cadaveric shoulder girdles were measured. After dividing the bone specimens into SS present and absent groups, various bone parameters between the two groups were statistically compared. Logistic regression analysis was conducted to assess the significance of each parameter as a predictor of SS formation. A receiver operating characteristic curve analysis was used to determine the cut-off point and to assess the sensitivity and specificity of the parameters showing significant differences. RESULTS: SS were found in 16 scapulae. The values for five parameters of the examined shoulder girdles were significantly different between the two groups. The presence of SS depended on the humeral head ratio, which was calculated by dividing the length of the greater tubercle of the humerus by the length of the lesser tubercle. A cut-off value of 1.97 was suitable for discriminating between the presence and absence of SS (sensitivity, 75%; specificity, 80%). CONCLUSION: The presence of SS is related to several morphological characteristics of the shoulder girdle and, the presence of SS can be predicted using humeral head morphometry.

Effect of forward head posture on thoracic shape and respiratory function.

[Purpose] This study investigated the effect of forward head posture on upper and lower thoracic shape in adults to better understand the relationship between a forward head posture and respiratory function. [Participants and Methods] Fifteen healthy males were recruited after obtaining informed consent from all participants. All participants were instructed to respire in both the forward and neutral head postures while seated. Respiratory function was assessed using spirometry. Thoracic shape during respiration was assessed using 23 markers on both the upper and the lower thorax and compared between the 2 postures. [Results] Forced vital capacity, expiratory and inspiratory reserve volumes, forced expiratory volume at 1 second, and the peak flow rate observed with the forward head posture were significantly lower than that with the neutral head posture. The upper thorax showed a greater forward shift and the lower thorax showed a greater forward and inward shift with the forward head posture than with the neutral head posture. No significant difference in upper thoracic mobility was observed during respiration between the forward head posture and the neutral head posture. However, mobility of the lower thorax during respiration was significantly reduced with the forward head posture. [Conclusion] The forward head posture causes expansion of the upper thorax and contraction of the lower thorax, and these morphological changes cause decreased respiratory function.