Feasibility and effectiveness of thoracic spine mobilization on sympathetic/parasympathetic balance in a healthy population - a randomized controlled double-blinded pilot study

Effects of mobilization or manipulation of the thoracic spine on autonomic nervous system markers in symptomatic and asymptomatic participants - a systematic review and meta-analysis

OBJECTIVES

To identify the effects of thoracic mobilization/manipulation on autonomic nervous system responses.

METHODS

Four electronic databases were searched for controlled trials published before February 2024. Studies on mobilization/manipulation of the thoracic spine were included evaluating effects on the autonomic nervous system (ANS). Risk of bias was assessed by two independent assessors using the Cochrane risk-of-bias tool 2, the RoB-2 tool for crossover studies or the ROBINS-I tool. Meta-analyses using random-effects models present the overall combined mean effects.

RESULTS

2139 articles were identified, 20 studies (863 participants) were included in the qualitative data analysis and 15 in meta-analyses. Four studies had a high risk of bias in one or more domains. Meta-analyses indicated no statistically significant effect of mobilization or manipulation on markers of the ANS. The ratio of low-frequency-to-high-frequency power did not significantly decrease after thoracic mobilization/manipulation compared to any type of control intervention (-0.28; 95% CI -0.59 to 0.04; p=0.09). Skin conductance and root mean square of successive RR interval differences as well as LFab (ms^2; absolute power of the low-frequency band) did not significantly increase after thoracic mobilization/manipulation. Subgroup and sensitivity-analyses indicated no significant effects.

DISCUSSION

Methodological limitations and heterogeneity (I2=0-94%) in reported outcomes, reduce the level of evidence. Future studies with a rigorous methodological approach and studies on symptomatic participants with longer follow-ups are warranted.

CONCLUSION

No significant effects of mobilization/manipulation of the thoracic spine on ANS markers were found. The direction of changes towards increased or decreased sympathetic or parasympathetic nervous system activity was ambiguous.

Comparative Effects of Neurodynamic Slider and Tensioner Mobilization Techniques on Sympathetic Nervous System Function: A Randomized Controlled Trial

Objective: To investigate the effect of slider and tensioner neurodynamic techniques (NDTs) on the sympathetic nervous system (SNS) activity, aiming to identify which technique more effectively modulates autonomic responses in asymptomatic individuals. Materials and Methods: In this double-blind controlled trial, a total of 90 healthy participants were randomly allocated into three groups: slider, tensioner, and control. Skin conductance (SC) was continuously monitored throughout the entire 20 min experiment, while body temperature and blood pressure were measured pre- and post-intervention. Results: The SC levels significantly increased in both the slider and tensioner groups compared to the control group during the intervention and end rest period on the left leg (slider vs. control: p < 0.001, d = 1.20; tensioner vs. control: p < 0.001, d = 1.64) and on the right leg (slider vs. control: p < 0.001, d = 1.47; tensioner vs. control: p < 0.001, d = 0.73). There were no significant differences between the two NDTs on the left (p < 0.13, d = 0.89) and right legs (p < 1.00, d = 0.36). The body temperature of the slider group showed a significant increase compared to both the control group (p < 0.001, d = 0.95) and the tensioner group (p < 0.001, d = 1.48). There were no significant differences between the groups in systolic (p = 0.95) or diastolic blood pressure (p = 0.06). There were no side-specific effects on SNS activity between the left and right legs (p < 0.019) during all intervention phases. Conclusions: Significant sympathoexcitatory responses were elicited by both slider and tensioner NDTs in asymptomatic participants, demonstrating their efficacy in modulating the SNS. The differences between the two techniques were not statistically significant; however, the tensioner NDT showed a slightly more pronounced effect, suggesting that the tensioner NDT can be considered superior in terms of overall SNS effect. These findings indicate that both techniques may have the potential to enhance autonomic regulation in clinical practice; however, the tensioner NDT may be more effective. The consistent responses across participants highlight the systemic benefits of NDTs, providing a foundation for further research into their application in symptomatic populations. This study contributes to evidence-based practice by providing baseline data that support the development of theoretical frameworks and aid in clinical decision-making.

Effects of ankle joint mobilization on dynamic balance muscle activity and dynamic balance in persons with chronic ankle instability - Feasibility of a cross-over study

INTRODUCTION

Studies with focus on effects of manual therapy techniques on postural control and muscle activity in patients with chronic ankle instability (are lacking. The purpose of this study was to evaluate the feasibility of a planned cross-over study to assess efficacy of manual therapy techniques applications in patients with chronic ankle instability.

METHODS

This feasibility study used a randomized controlled, blinded assessor cross-over design. Criteria of success under evaluation were adherence and attrition rates and adverse events. while preliminary treatment effects of manual therapy techniques on muscular activity (measured by surface electromyography) and on dynamic balance (measured by time to stabilization test) were secondary aims.

RESULTS

Thirteen participants (mean age: 24.4 ± 3.8 years) with chronic ankle instability volunteered in this feasibility study. Success criteria showed a high adherence (98.7%) and low attrition (0%). No missing data were reported but four out of 26 data sets could not be used for statistical analysis because of non-readability of the recorded data. Preliminary treatment effect showed divergent results for surface electromyography and time to stabilization. One significant result (p = 0.03, ES = 1.48) in peroneus longus muscle activity after jump landing between 30 and 60 ms could be determined.

CONCLUSIONS

This study showed that the study protocol is feasible but should be modified by offering participants the opportunity to familiarize to the jumps and to the test repetitions. This study generates better understanding of manual therapy techniques for patients with chronic ankle instability.

Vertebral Subluxation and Systems Biology: An Integrative Review Exploring the Salutogenic Influence of Chiropractic Care on the Neuroendocrine-Immune System

In this paper we synthesize an expansive body of literature examining the multifaceted influence of chiropractic care on processes within and modulators of the neuroendocrine-immune (NEI) system, for the purpose of generating an inductive hypothesis regarding the potential impacts of chiropractic care on integrated physiology. Taking a broad, interdisciplinary, and integrative view of two decades of research-documented outcomes of chiropractic care, inclusive of reports ranging from systematic and meta-analysis and randomized and observational trials to case and cohort studies, this review encapsulates a rigorous analysis of research and suggests the appropriateness of a more integrative perspective on the impact of chiropractic care on systemic physiology. A novel perspective on the salutogenic, health-promoting effects of chiropractic adjustment is presented, focused on the improvement of physical indicators of well-being and adaptability such as blood pressure, heart rate variability, and sleep, potential benefits that may be facilitated through multiple neurologically mediated pathways. Our findings support the biological plausibility of complex benefits from chiropractic intervention that is not limited to simple neuromusculoskeletal outcomes and open new avenues for future research, specifically the exploration and mapping of the precise neural pathways and networks influenced by chiropractic adjustment.

[Manual spinal therapy techniques to stimulate the autonomic nervous system: a scoping review]

BACKGROUND

Physical interventions or manual therapeutic techniques (MTTe) such as mobilisation, manipulation or soft tissue techniques not only have an influence on the target tissue with improvement of metabolism or reduction of hypertonic muscles. They are also used for balance regulation in central nervous changes of the autonomic nervous system (ANS). To date, there is a lack of empirical evidence on impact mechanisms and target locations of MTTe on the ANS. This scoping review aims to provide an overview of the evidence on the application of MTTe at diverse levels of the spine with a view to the ANS.

METHOD

A systematic literature search was conducted on CENTRAL, Google Scholar, Osteopathic Research Web, PEDro and PubMed. The scope and content of the literature were documented. The results of the included and referenced studies were summarised in a narrative approach with the focus being on the most significant clinical aspects.

RESULTS

MTTe was described as manipulations, mobilisations, myofascial techniques and cervical traction. In 27 out of 35 studies, therapeutic treatments were carried out on healthy volunteers. Ten studies analysed immediate effects in patients, while two studies were designed as longitudinal studies in patients with hypertension. Over a period of four to eight weeks, the frequency of intervention was between one and three MTTe sessions a week.

CONCLUSION

The study results proved to be heterogeneous. For this reason, it is not possible to draw definitive, explicit and generally valid statements regarding the type and intensity as well as the segmental level at which MTTe should be applied in order to trigger specific positive ANS response mechanisms. Consequently, longitudinal studies with follow-up are recommended for future studies. In addition, comprehensive effects of MTTe should be evaluated in groups of patients with different characteristics.

One Session of Spinal Manipulation Improves the Cardiac Autonomic Control in Patients with Musculoskeletal Pain: A Randomized Placebo-Controlled Trial

STUDY DESIGN

Three-arm, parallel, randomized, placebo-controlled, assessor-blinded trial.

OBJECTIVE

To compare the immediate effect of manual therapy at the upper thoracic spine on the cardiovascular autonomic control of patients with musculoskeletal pain.

SUMMARY OF BACKGROUND DATA

Musculoskeletal pain increases the risk of cardiovascular events. Thus, manual therapy applied to the upper thoracic region is likely efficient to improve the cardiac autonomic control.

METHODS

The study included 59 patients with musculoskeletal pain enrolled at an outpatient clinic. Participants were randomly assigned to spinal manipulation (n = 19), myofascial manipulation (n = 20), or placebo (n = 20) administered to the upper thoracic region. Resting heart rate variability provided indexes of the cardiac autonomic control, and the blood pressure response to the cold pressor test as a proxy of the sympathetic responsiveness to a stressor stimulus.

RESULTS

Groups were similar for baseline variables except for blood pressure. Two-way repeated-measures one-way analysis of covariance (ANCOVA) revealed that only spinal manipulation induced immediate increase of the square root of the mean squared differences of successive RR intervals (RMSSD), absolute (ms2), and normalized units (n.u.) of the high-frequency power (HF) as compared with pre-intervention evaluation, indicating an improvement in the parasympathetic activity to the heart. Normalized units of low-frequency power (LF) and the LF/HF ratio reduced after the spinal manipulation solely, suggesting a reduction of the sympathetic activity to the heart. There were no significant differences in the blood pressure responsiveness among the three treatments. There were no adverse events.

CONCLUSION

In patients with musculoskeletal pain, spinal manipulation on the upper thoracic spine led to an immediate improvement in the resting cardiac autonomic control without an effect on the blood pressure responsiveness to a sympathoexcitatory stimulus. Myofascial manipulation or placebo did not change cardiovascular autonomic control.Level of Evidence: 2.