Does vibration frequency and location influence the effect of neck muscle vibration on postural sway? A cross-sectional study in asymptomatic participants.

INTRODUCTION: Postural control is of utmost importance for human functioning. Cervical proprioception is crucial for balance control. Therefore, any change to it can lead to balance problems. Previous studies used neck vibration to change cervical proprioception and showed changes in postural control, but it remains unknown which vibration frequency or location causes the most significant effect. Therefore, this study aimed to investigate the effect of different vibration frequencies and locations on postural sway and to serve as future research protocol guidance. METHODS: Seventeen healthy young participants were included in the study. We compared postural sway without vibration to postural sway with six different combinations of vibration frequency (80, 100, and 150 Hz) and location (dorsal neck muscles and sternocleidomastoid). Postural sway was evaluated using a force platform. The mean center of pressure (CoP) displacement, the root mean square (RMS), and the mean velocity in the anteroposterior and mediolateral direction were calculated, as well as the sway area. The aligned rank transform tool and a three-way repeated measures ANOVA were used to identify significant differences in postural sway variables. RESULTS: Neck vibration caused a significant increase in all postural sway variables (p < 0.001). Neither the vibration frequency (p > 0.34) nor location (p > 0.29) nor the interaction of both (p > 0.30) influenced the magnitude of the change in postural sway measured during vibration. CONCLUSION: Neck muscle vibration significantly changes CoP displacement, mean velocity, RMS, and area. However, we investigated and found that there were no significant differences between the different combinations of vibration frequency and location.

Postural control and the relation with cervical sensorimotor control in patients with idiopathic adult-onset cervical dystonia.

Cervical dystonia (CD) is a movement disorder characterized by involuntary muscle contractions leading to an abnormal head posture or movements of the neck. Dysfunctions in somatosensory integration are present and previous data showed enlarged postural sway in stance. Postural control during quiet sitting and the correlation with cervical sensorimotor control were investigated. Postural control during quiet sitting was measured via body sway parameters in 23 patients with CD, regularly receiving botulinum toxin treatment and compared with 36 healthy controls. Amplitude and velocity of displacements of the center of pressure (CoP) were measured by two embedded force plates at 1000 Hz. Three samples of 30 s were recorded with the eyes open and closed. Disease-specific characteristics were obtained in all patients by the Tsui scale, Cervical Dystonia Impact Profile (CDIP-58) and Toronto Western Spasmodic Rating Scale (TWSTRS). Cervical sensorimotor control was assessed with an infrared Vicon system during a head repositioning task. Body sway amplitude and velocity were increased in patients with CD compared to healthy controls. CoP displacements were doubled in patients without head tremor and tripled in patients with a dystonic head tremor. Impairments in cervical sensorimotor control were correlated with larger CoP displacements (rs ranged from 0.608 to 0.748). Postural control is impaired and correlates with dysfunction in cervical sensorimotor control in patients with CD. Treatment is currently focused on the cervical area. Further research towards the potential value of postural control exercises is recommended.

Prognostic indicators for decrease in tinnitus severity after cervical physical therapy in patients with cervicogenic somatic tinnitus.

BACKGROUND: Tinnitus can be related to many different aetiologies such as hearing loss or a noise trauma, but it can also be related to the somatosensory system of the cervical spine, called cervicogenic somatic tinnitus(CST). Recently, a positive effect of multi-modal cervical physical therapy on tinnitus severity in patients with CST was demonstrated. To date however, the outcome of the intervention cannot be predicted. OBJECTIVE: To identify prognostic indicators for decrease in tinnitus severity after cervical physical therapy in patients with CST. PATIENTS: Patients with moderate to severe subjective tinnitus (Tinnitus Functional Index(TFI):25-90points) and neck complaints (Neck Bournemouth Questionnaire(NBQ) > 14points). INTERVENTION: All patients received multimodal cervical physical therapy for 6 weeks (12 sessions). This physical therapy contained a combination of manual mobilizations and exercises of the cervical spine. MEASUREMENTS: TFI and NBQ-scores were documented at baseline, after treatment and after a 6-weeks follow-up period. Impairments in cervical spine mobility and muscle function were identified at baseline and after 6-weeks follow-up. RESULTS: Patients with co-varying (increasing or decreasing simultaneously) tinnitus and neck complaints had significantly lower TFI-scores after treatment (p = 0.001) and follow-up (p = 0.03). The presence of this co-variation and a combination of low pitched tinnitus and increasing tinnitus during inadequate cervical spine postures are prognostic indicators for a decrease in TFI-scores after cervical physical therapy (adjusted R2 = 0.357). CONCLUSION: Patients who experience a decrease in tinnitus annoyance from cervical physical therapy are those with co-varying tinnitus and neck complaints and those with a combination of low-pitched tinnitus and increasing tinnitus during inadequate cervical spine postures.

Does multi-modal cervical physical therapy improve tinnitus in patients with cervicogenic somatic tinnitus?

BACKGROUND: Tinnitus can be related to many different aetiologies such as hearing loss or a noise trauma, but it can also be related to the somatosensory system of the cervical spine, called cervicogenic somatic tinnitus (CST). Case studies suggest a positive effect of cervical spine treatment on tinnitus complaints in patients with CST, but no experimental studies are available. OBJECTIVE: To investigate the effect of a multimodal cervical physical therapy treatment on tinnitus complaints in patients with CST. DESIGN: Randomized controlled trial. PATIENTS: Patients with a combination of severe subjective tinnitus (Tinnitus Functional Index (TFI): 25-90 points) and neck complaints (Neck Bournemouth Questionnaire (NBQ) > 14 points). INTERVENTION: All patients received cervical physical therapy for 6 weeks (12 sessions). Patients were randomized in an immediate-start therapy group (n = 19) and a 6-week delayed-start therapy group (n = 19). MEASUREMENTS: TFI and NBQ-scores were documented at baseline, after the wait-and-see period in the delayed-start group, after treatment and after 6 weeks follow-up. The Global Perceived Effect (GPE) was documented at all measuring moments, except at baseline. RESULTS: In all patients (n = 38) TFI and NBQ-scores decreased significantly after treatment (p = 0.04 and p < 0.001). NBQ-scores remained significantly lower after follow-up (p = 0.001). Immediately after treatment, 53% (n = 38) experienced substantial improvement of tinnitus. This effect was maintained in 24% of patients after follow-up at six weeks. CONCLUSION: Cervical physical therapy can have a positive effect on subjective tinnitus complaints in patients with a combination of tinnitus and neck complaints. Larger studies, using more responsive outcome measures, are however necessary to prove this effect. TRIAL REGISTRATION: NCT02016313.

Lack of impairment of kinaesthetic sensibility in cervicogenic headache patients.

To compare the cervical kinaesthetic sensibility of cervicogenic headache (CEH) patients and asymptomatic controls, the head repositioning accuracy of 10 CEH patients and 23 asymptomatic controls was measured. Should an impaired kinaesthetic sensibility be demonstrated, its assessment could be of diagnostic value in the evaluation of patients with suspected CEH. Additionally, specific exercises to improve cervical kinaesthesia could be prescribed. Kinaesthetic sensibility was assessed using a head repositioning task: subjects were asked to relocate their heads as accurately as possible to a previously memorized head position following an active movement (flexion, extension and left and right rotations). The repositioning error was registered using a validated magnetic tracking device (Flock of Birds). No significant differences were found between the asymptomatic controls and the CEH patients (independent-samples T-test, P < 0.05). We conclude that cervical kinaesthetic sensibility is not impaired in non-traumatic CEH. The use of kinaesthetic assessment and treatment in this patient group seems to be limited.