Decreased neck muscle strength in patients with the loss of cervical lordosis

• The loss of cervical lordosis leads to disrupted biomechanics in the cervical spine.
• No study has examined cervical muscle strength in patients with the loss of cervical lordosis.
• Neck muscle weakness, especially in extension, was found in patients with the loss of cervical lordosis.
• Neck extensor strengthening is likely to be suitable for patients with the loss of cervical lordosis.

BackgroundThe loss of cervical lordosis is associated with some negative clinical outcomes. No previous study has examined cervical muscle strength, specifically in patients with the loss of cervical lordosis. This study aims to investigate whether there is weakness of the cervical muscles or an imbalance between cervical flexor and extensor muscle strength in patients with the loss of cervical lordosis compared with healthy controls matched by age, gender, body mass index (BMI), and employment status.MethodsThirty-two patients with the loss of cervical lordosis (23 F, 9 M) and 31 healthy volunteers (23 F, 8 M) were included in the study. Maximal isometric neck extension and flexion strength, and the strength ratio between extension and flexion were used as evaluation parameters. All measurements were conducted by a blinded assessor using a digital force gauge. The participants were positioned on a chair in a neutral cervical position and without the trunk inclined during measurements.FindingsMaximal isometric neck extension and flexion strength values were significantly lower in the patients versus healthy controls (P < 0.001 and P = 0.040, respectively). The mean (SD) values of the extension/flexion ratio were 1.21 (0.34) in the patients and 1.46 ± 0.33 in the controls (P = 0.004).InterpretationAccording to our results, patients with the loss of cervical lordosis have reduced neck muscle strength, especially in the extensors. These findings may be beneficial for optimizing cervical exercise prescriptions.