Effects of hanger reflex on the cervical muscular activation and function: A surface electromyography assessment.

Introduction: Cervical muscular dysfunction is closely associated with disorders and neuromuscular diseases of the cervical spine, and the hanger reflex (HR) has the potential to become a rehabilitation method. The muscular electrophysiology mechanism of HR is unclear. This study aims to identify the impacts of HR on cervical rotators' myoelectrical activity and function. Methods: We designed a self-control clinical trial, and asymptomatic volunteers were continuously included from 1 September 2021 to 30 April 2022 in our department. Rotation tasks were performed on both sides under each of the situations: no HR, unilateral HR, and bilateral HR. Surface electromyography (SEMG) was used to detect the myoelectrical activity of agonistic splenius capitis (SPL), upper trapezius (UTr), and sternocleidomastoid (SCM). The co-contraction ratio (CCR) during rotation tasks was calculated. Correlation analyses and multiple linear regression were performed. Results: Finally, 90 subjects were enrolled (power >90%). The adjusted EMG value (aEMG) of SPL UTr, SCM, and rotating CCR under the unilateral HR and bilateral HR were higher than no HR; the aEMG of SPL and rotating CCR under the bilateral HR were higher than the unilateral HR. Multiple linear regression showed that HR pattern and age were the independent affecting factors for the aEMG of SPL (p < 0.001, p < 0.001), UTr (p < 0.001, p < 0.001), and SCM (p < 0.001, p < 0.001); BMI was an independent affecting factor for the aEMG of SPL (p < 0.001) and SCM (p < 0.001); HR pattern was the only affecting factor for CCR (p < 0.001). Conclusion: HR can increase the cervical rotators' myoelectrical activities and rotating CCR, and the effects of bilateral HR are greater than unilateral HR, suggesting that bilateral HR has a greater clinical potential to become a rehabilitation method for treating cervical neuromuscular disorders.

Hanger reflex and cervical dystonia-negative sensory trick in normal person / 中华神经科杂志

Hanger reflex is a common phenomenon in the population that involuntary head and neck rotation or skew occurs when applying pressure to the forehead, tempus or occipitalia with an ordinary wire hanger tightly around the head. The hanger reflex is consistent with the characteristics of sensory tricks in dystonia, and the phenomenon induced by it in normal people should be regarded as negative sensory tricks in dystonia. The mechanism of dystonia behind the hanger reflex and its therapeutic potential deserve more clinicians′ attention.

Pilot Study of a Device to Induce the Hanger Reflex in Patients with Cervical Dystonia.

The hanger reflex (HR) is an involuntary head rotation that occurs in response to a clothes hanger encircling the head and compressing the unilateral fronto-temporal area. Here, we developed an elliptical device to induce the HR and examined its utility for the treatment of cervical dystonia (CD). The study included 19 patients with rotational-type CD. The device was applied to each subject's head for at least 30 min/day for 3 months. Severity scores on part 1 of the Toronto Western Spasmodic Torticollis Rating Scale were evaluated at baseline and after the 3-month trial. Mean scores without and with the device were significantly different both at baseline (16.6 vs. 14.7, respectively; P < 0.05) and after the trial (14.9 vs. 13.6, respectively; P < 0.05). This preliminary trial suggests that our device can improve abnormal head rotation in patients with CD.