Hypocapnia in Patients with Chronic Neck Pain: Association with Pain, Muscle Function, and Psychologic States

Hypocapnia in women with fibromyalgia

OBJECTIVES

The purpose of this study was to investigate whether people with fibromyalgia (FM) have dysfunctional breathing by examining acid-base balance and comparing it with healthy controls.

METHODS

Thirty-six women diagnosed with FM and 36 healthy controls matched for age and gender participated in this cross-sectional study. To evaluate acid-base balance, arterial blood was sampled from the radial artery. Carbon dioxide, oxygen, bicarbonate, base excess, pH and lactate were analysed for between-group differences. Blood gas analyses were performed stepwise on each individual to detect acid-base disturbance, which was categorized as primary respiratory and possible compensation indicating chronicity. A three-step approach was employed to evaluate pH, carbon dioxide and bicarbonate in this order.

RESULTS

Women with FM had significantly lower carbon dioxide pressure (p = 0.013) and higher lactate (p = 0.038) compared to healthy controls at the group level. There were no significant differences in oxygen pressure, bicarbonate, pH and base excess. Employing a three-step acid-base analysis, 11 individuals in the FM group had a possible renally compensated mild chronic hyperventilation, compared to only 4 among the healthy controls (p = 0.042).

CONCLUSIONS

In this study, we could identify a subgroup of individuals with FM who may be characterized as mild chronic hyperventilators. The results might point to a plausible dysfunctional breathing in some women with FM.

Comparison of breathing pattern and diaphragmatic motion in patients with unilateral cervical radiculopathy and asymptomatic group

BACKGROUND

The associations between neck pain and respiratory dysfunction were clarified in patients with neck pain. There is dearth of evidence on pulmonary dysfunction and diaphragmatic excursion in patients with unilateral cervical radiculopathy (CR). The purpose of this study was to compare the breathing pattern and diaphragmatic excursion in patients with unilateral CR with those in an asymptomatic group.

METHODS

Twenty-five patients with unilateral CR and 25 asymptomatic individuals aged between 30 and 55 participated in this study. Diaphragmatic motion, breathing pattern, active cervical range of motion and kinesiophobia were investigated in both groups by using fluoroscopy, manual assessment of respiratory motion (MARM), cervical range of motion device, and Tampa scale of kinesiophobia. Statistical significance was set at 0.05.

RESULTS

No statistically significant differences were found between the two groups with regard to sex, age and body mass index. The mean excursion of the hemi diaphragm on the involved side (the side of CR) was significantly lower than that on the uninvolved side in patients with unilateral CR with a large effect size. The excursion of the involved hemi diaphragm in patients was reduced compared to the matched hemi diaphragm in the control group. There was no significant difference between the hemi diaphragms excursion in the control group. The results of the MARM variables showed that the volume of breathing and the percentage rib cage motion in normal and deep breathing were significantly different between the two groups, but there was no significant difference in the balance of breathing between the two groups. Additionally, the active cervical range of motion was reduced in these patients in comparison to the control group, and it was less on the involved side than on the uninvolved side.

CONCLUSION

The results of this study revealed a dysfunctional breathing pattern in normal and deep breathing and a unilateral reduction in diaphragmatic excursion on the side of radiculopathy in patients with unilateral CR compared to the control group.

Effects of breathing reeducation on cervical and pulmonary outcomes in patients with non specific chronic neck pain: A double blind randomized controlled trial

OBJECTIVE

The purpose of this randomized controlled trial was to study effects of breathing reeducation in the treatment of patients with non specific chronic neck pain.

METHODS

A total of sixty eight eligible patients with chronic neck pain were randomly allocated to breathing reeducation (BR) group (n = 34) and routine physical therapy (RPT) group (n = 34). Clinical outcomes were neck pain measured through visual analogue score, cervical active range of motion through CROM device, strength of neck muscles through hand held dynamometer and endurance of neck muscles measured through craniocervical flexion test. The neck disability was measured through neck disability index (NDI) and pulmonary outcomes such as forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and FEV1/FVC ratio were measured through Spirolab 4. The outcomes were assessed at baseline and at 4 and at 8 weeks from baseline.

RESULTS

There were significant improvements in the BR group compared with the RPT group (P = 0.002) for cervical flexion, extension (P = 0.029), endurance (P = 0.042), strength of neck flexors (P <0.001), neck extensors (P = 0.034). Likewise there was a significant change in NDI (P = 0.011), FEV1 (P = 0.045), FVC (P <0.001), and FEV1/FVC ratio (P <0.001) in the BR group compared with the RPT group. The cervical side flexion and rotation showed no significant difference in breathing reeducation group with p > 0.05.

CONCLUSION

Breathing reeducation combined with routine physical therapy is an effective treatment in patients with non specific chronic neck pain.

TRIAL REGISTRATION

IRCT 20200226046623N1, https://www.irct.ir/trial/46240.

Respiratory dysfunction in patients with chronic neck pain: systematic review and meta-analysis

PURPOSE

To determine the differences in respiratory muscle strength and pulmonary function between patients with chronic neck pain (CNP) and asymptomatic individuals.

METHODS

Databases were MEDLINE, CINAHL, Scopus, Web of Science and EMBASE up to the end of September 2021. Studies with cross-sectional and longitudinal design were selected, with adult patients with CNP and asymptomatic individuals with reports respiratory function.

RESULTS

11 studies met the inclusion criteria and 10 were included in the meta-analysis showing a statistically significant reduction in inspiratory/expiratory muscle strength (MIP/MEP) in the patients with CNP compared with the asymptomatic individuals (mean difference (MD) for MIP, -11.67 [-14.57 to -8.77]; MD for MEP, -11.80 [-14.99 to -8.60]) and pulmonary function: vital capacity (standardized mean difference (SMD), -0.31 [-0.56 to -0.06]); maximum voluntary ventilation (SMD, -0.36 [-0.59 to -0.14]); forced vital capacity (SMD, -0.53 [-0.99 to -0.06]); peak expiratory flow (SMD, -0.58 [-1.03 to -0.12]); and forced expiratory volume in the first second (SMD, -0.28 [-0.51 to -0.05]).

CONCLUSIONS

Patients with CNP have reduced respiratory muscle strength and pulmonary function compared with asymptomatic individuals, and this difference could be clinically meaningful. However, more studies of high methodological quality and longitudinal studies are needed to strengthen the results of this meta-analysis. IMPLICATIONS FOR REHABILITATIONRespiratory dysfunction has been observed in patients with chronic neck pain.Patients with chronic neck pain present a decrease in respiratory muscle strength and pulmonary function compared with asymptomatic individuals.Respiratory pattern disorders should be considered in the clinical context of chronic neck pain.Interventions focused on respiratory muscle training could be helpful for this population.

Associations of neck muscle strength and cervical spine mobility with future neck pain and disability: a prospective 16-year study

Background

Neck pain has been associated with weaker neck muscle strength and decreased cervical spine range of motion. However, whether neck muscle strength or cervical spine mobility predict later neck disability has not been demonstrated. In this 16-year prospective study, we investigated whether neck muscle strength and cervical spine mobility are associated with future neck pain and related disability in women pain-free at baseline.

Methods

Maximal isometric neck muscle strength and passive range of motion (PROM) of the cervical spine of 220 women (mean age 40, standard deviation (SD) 12 years) were measured at baseline between 2000 and 2002. We conducted a postal survey 16 years later to determine whether any subjects had experienced neck pain and related disability. Linear regression analysis adjusted for age and body mass index was used to determine to what extent baseline neck strength and PROM values were associated with future neck pain and related disability assessed using the Neck Disability Index (NDI).

Results

The regression analysis Beta coefficient remained below 0.1 for all the neck strength and PROM values, indicating no association between neck pain and related disability. Of the 149 (68%) responders, mean NDI was lowest (3.3, SD 3.8) in participants who had experienced no neck pain (n = 50), second lowest (7.7, SD 7.1) in those who had experienced occasional neck pain (n = 94), and highest (19.6, SD 22.0) in those who had experienced chronic neck pain (n = 5).

Conclusions

This 16-year prospective study found no evidence for an association between either neck muscle strength or mobility and the occurrence in later life of neck pain and disability. Therefore, screening healthy subjects for weaker neck muscle strength or poorer cervical spine mobility cannot be recommended for preventive purposes.

Neck Pain and Disability: Are They Related to Dysfunctional Breathing and Stress?

Purpose: People with neck pain are likely to have negative respiratory findings. The purpose of this study was to investigate the relationship between neck pain and dysfunctional breathing and to examine their relationship to stress. Method: This cross-sectional study included 49 participants with neck pain and 49 age- and sex-matched controls. We measured neck pain using the numeric rating scale (NRS); neck disability using the Neck Disability Index (NDI); dysfunctional breathing using the Nijmegen Questionnaire (NQ), Self-Evaluation of Breathing Questionnaire (SEBQ), breath hold time, and respiratory rate (RR); and stress using the Perceived Stress Scale (PSS). Results:Participants with neck pain scored higher on the NQ ( p < 0.001) and the SEBQ ( p < 0.001) than controls. NQ and SEBQ scores correlated moderately with NDI scores ( r > 0.50; 95% CI: 0.25, 0.68 and 0.33, 0.73, respectively) and PSS scores ( r > 0.50; 95% CI: 0.29, 0.78 and 0.31, 0.73, respectively). SEBQ scores showed a fair correlation with NRS scores and RR a fair correlation with NDI scores. Conclusions: Participants with neck pain had more dysfunctional breathing symptoms than participants without neck pain, and dysfunctional breathing was correlated with increased neck disability and increased stress. The NQ and SEBQ can be useful in assessing dysfunctional breathing in patients with neck pain.

The study of respiratory muscles activation during respiratory muscle strength effort in adult females with chronic neck pain

[Purpose] This study aimed to compare maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP) values and muscle activity during MIP and MEP between chronic neck pain and healthy participants. [Participants and Methods] Twenty chronic neck pain and 20 non-symptomatic females participated in this study. Maximal airway pressure (MIP and MEP) and surface electromyography (sEMG) for both sides of the upper trapezius, anterior scalene, pectoralis major and 6th intercostal muscles were recorded simultaneously. [Results] Significant differences of MIP and MEP values were found between the groups. The muscle activities of both sides of upper trapezius and 6th intercostal muscles during MEP were significantly higher in the chronic neck pain group than the healthy group except both sides of anterior scalene and pectoralis major muscles. During MIP, the activities of upper trapezius, 6th intercostal muscles and anterior scalene were significantly different between the two studied groups. Higher activity of left pectoralis major was found in the chronic neck pain group. [Conclusion] Decreasing values of MEP and MIP as well as muscles activities elevation in chronic neck pain participants were clearly demonstrated. Besides the musculoskeletal treatment, we suggest breathing exercise training to be considered in treatment programs.

Cardiorespiratory Functioning in Youth with Persistent Post-Concussion Symptoms: A Pilot Study

Dysregulation of the autonomic nervous system (ANS) may play an important role in the development and maintenance of persistent post-concussive symptoms (PPCS). Post-injury breathing dysfunction, which is influenced by the ANS, has not been well-studied in youth. This study evaluated cardiorespiratory functioning at baseline in youth patients with PPCS and examined the relationship of cardiorespiratory variables with neurobehavioral outcomes. Participants were between the ages of 13-25 in two groups: (1) Patients with PPCS (concussion within the past 2-16 months; n = 13) and (2) non-injured controls (n = 12). Capnometry was used to obtain end-tidal CO2 (EtCO2), oxygen saturation (SaO2), respiration rate (RR), and pulse rate (PR) at seated rest. PPCS participants exhibited a reduced mean value of EtCO2 in exhaled breath (M = 36.3 mmHg, SD = 2.86 mmHg) and an altered inter-correlation between EtCO2 and RR compared to controls. Neurobehavioral outcomes including depression, severity of self-reported concussion symptoms, cognitive catastrophizing, and psychomotor processing speed were correlated with cardiorespiratory variables when the groups were combined. Overall, results from this study suggest that breathing dynamics may be altered in youth with PPCS and that cardiorespiratory outcomes could be related to a dimension of neurobehavioral outcomes associated with poorer recovery from concussion.

Peak expiratory flow rate and thoracic mobility in people with fibromyalgia. A cross sectional study

BACKGROUND AND AIMS

Fibromyalgia (FM) is characterized by chronic widespread pain and affects approximately 1-3% of the general population. Respiratory function has not been given much consideration in people with FM. Few studies have been published concerning FM and respiratory function and conflicting data still exist. The aim of this study was to compare differences in forced expiration, but also to investigate chest expansion, spinal mobility and segmental pain intensity between a group with fibromyalgia and healthy controls.

METHODS

Forty-one women with diagnosed FM based on American College of Rheumatology 1990 criteria and forty-one controls without pain matched for age and gender participated in this cross-sectional study. For evaluation of forced expiration, a Wright peak expiratory flow rate meter was used. A tape measure was used to measure the mobility of the thorax at maximum inhalation and exhalation known as chest expansion. Spinal mobility was measured with the Cervico-thoracic ratio method. The spinal mobility was measured as range of motion from C7 to 15 cm below in flexion and manual palpation was conducted between C7-T5. For differences in pain intensity a palpation-index was defined for each level, respectively; C7-T1, T1-2, T2-3, T3-4 and T4-5 by calculating the mean value for the four different palpation points for each motion segment. A combined measure of expiration and thoracic mobility (expiratory/inspiratory ratio) was calculated by dividing peak expiratory flow rate (L/min) with chest expansion (cm). Statistical analyses included descriptive statistics to describe subjects and controls, means and standard deviation to compare differences between groups and student-t and Chi-square (χ²) tests, using SPSS 22 software. Confidence interval was set to 95%.

RESULTS

In the FM group 17 had the diagnosis for more than 5 years and 24 less than 5 years. The FM group demonstrated significantly lower forced expiration (p < 0.018), less thoracic expansion (p < 0.001), reduced spinal mobility (p < 0.029), higher expiratory-inspiratory ratio value (p < 0.001) and increased palpation pain over C7-T5 (p < 0.001) compared to healthy controls. There were more smokers in the FM group (n = 9) compared to the controls (n = 5) though this difference was not statistically significant (p < 0.24) and excluding the few smokers yielded similar result. No significant correlations for manual palpation, chest expansion, peak expiratory flow rate and spinal mobility were found in the FM group.

CONCLUSIONS

Women with FM demonstrated significantly lower forced expiration and thoracic mobility compared to healthy controls.

IMPLICATIONS

The results of this study point to a plausible restriction of respiratory function which in turn may have effect on physical endurance and work capacity in people with FM.

The effectiveness of combining inspiratory muscle training with manual therapy and a therapeutic exercise program on maximum inspiratory pressure in adults with asthma: a randomized clinical trial

OBJECTIVE

The objective of this study was to evaluate whether the addition of manual therapy and therapeutic exercise protocol to inspiratory muscle training was more effective in improving maximum inspiratory pressure than inspiratory muscle training in isolation.

DESIGN

This is a single-blinded, randomized controlled trial.

SUBJECTS

In total, 43 patients with asthma were included in this study.

INTERVENTIONS

The patients were allocated into one of the two groups: (1) inspiratory muscle training ( n = 21; 20-minute session) or (2) inspiratory muscle training (20-minute session) combined with a program of manual therapy (15-minute session) and therapeutic exercise (15-minute session; n = 22). All participants received 12 sessions, two days/week, for six weeks and performed the domiciliary exercises protocol.

MAIN MEASURES

The main measures such as maximum inspiratory pressure, spirometric measures, forward head posture, and thoracic kyphosis were recorded at baseline and after the treatment.

RESULTS

For the per-protocol analysis, between-group differences at post-intervention were observed in maximum inspiratory pressure (19.77 cmH₂O (11.49-28.04), P < .05; F = 22.436; P < .001; η²_p = 0.371) and forward head posture (-1.25 cm (-2.32 to -0.19), P < .05; F = 5.662; P = .022; η²_p = 0.13). The intention-to-treat analysis showed the same pattern of findings.

CONCLUSION

The inspiratory muscle training combined with a manual therapy and therapeutic exercise program is more effective than its application in isolation for producing short-term maximum inspiratory pressure and forward head posture improvements in patients with asthma.

Relationships among head posture, pain intensity, disability and deep cervical flexor muscle performance in subjects with postural neck pain

Objectives

Information Technology (IT) professionals working with computers gradually develop forward head posture and, as a result, these professionals are susceptible to several neck disorders. This study intended to reveal the relationships between pain intensity, disability, head posture and deep cervical flexor (DCF) muscle performance in patients with postural neck pain.

Methods

A cross-sectional study was conducted on 84 IT professionals who were diagnosed with postural neck pain. The participants were recruited with a random sampling approach. A Visual Analogue Scale (VAS), the Northwick Park Neck Pain Questionnaire (NPQ), the Modified Head Posture Spinal Curvature Instrument (MHPSCI), and the Stabilizer Pressure Biofeedback Unit were used to measure neck pain intensity, neck disability, head posture, and DCF muscle performance, respectively.

Results

The Pearson correlation coefficient revealed a significantly strong positive relationship between the VAS and the NPQ (r = 0.734). The cranio-vertebral (CV) angle was found to have a significantly negative correlation with the VAS (r = −0.536) and a weak negative correlation with the NPQ (r = −0.389).

Conclusion

This study concluded that a smaller CV angle corresponded to greater neck pain intensity and disability. Furthermore, there is no significant relationship between CV angle and DCF muscle performance, indicating that head posture re-education through postural correction exercises would not completely correct the motor control deficits in DCF muscles. In addition, a suitable exercise regimen that exclusively targets the deep cervical flexor muscle to improve its endurance is warranted.

Respiratory muscle endurance training reduces chronic neck pain: A pilot study

BACKGROUND

Patients with chronic neck pain show also respiratory dysfunctions.

OBJECTIVE

To investigate the effects of respiratory muscle endurance training (RMET) on chronic neck pain.

METHODS

In this pilot study (single-subject design: 3 baseline measurements, 4 measurements during RMET), 15 neck patients (49.3 ± 13.7 years; 13 females) conducted 20 sessions of home-based RMET using a SpiroTiger® (normocapnic hyperpnoea). Maximal voluntary ventilation (MVV), maximal inspiratory (Pimax) and expiratory (Pemax) pressure were measured before and after RMET. Neck flexor endurance, cervical and thoracic mobility, forward head posture, chest wall expansion and self-assessed neck disability [Neck Disability Index (NDI), Bournemouth questionnaire] were weekly assessed. Repeated measure ANOVA (Bonferroni correction) compared the first and last baseline and the last measurement after RMET.

RESULTS

RMET significantly increased MVV (p= 0.025), Pimax (p= 0.001) and Pemax (p< 0.001). During RMET, neck disability significantly decreased (NDI: p= 0.001; Bournemouth questionnaire: p= 0.002), while neck flexor endurance (p< 0.001) and chest wall expansion (p< 0.001) increased. The changes in respiratory and musculoskeletal parameters did not correlate.

CONCLUSIONS

RMET emerged from this pilot study as a feasible and effective therapy for reducing disability in patients with chronic neck pain. The underlying mechanisms, including blood gas analyses, need further investigation in a randomized controlled study.

Respiratory dysfunction in patients with chronic neck pain - influence of thoracic spine and chest mobility

Patients with chronic neck pain exhibit various musculoskeletal deficits and respiratory dysfunction. As there is a link between thoracic and cervical spine motion, the aim of this study was to investigate the relationship between thoracic spine and chest mobility with respiratory function and neck disability. Nineteen patients with chronic neck pain (7 male, 46.6 ± 10.5 years) and 19 healthy subjects (7 male, 46.5 ± 9.9 years) participated. Spirometry was conducted to determine maximal voluntary ventilation (MVV), maximal inspiratory (Pimax) and maximal expiratory pressure (Pemax). Thoracic spine mobility was measured using the Spinal Mouse(®). Chest expansion was assessed by subtracting chest circumference during maximal inspiration and expiration. Neck function was investigated by examining range of motion, forward head posture, neck flexor muscle synergy endurance and self-assessment (Neck disability index (NDI)). Correlation analyses and multiple linear regression analyses were conducted using MVV, Pimax and Pemax as independent variables. Thoracic spine mobility during flexion and chest expansion correlated significantly to MVV (r = 0.45 and 0.42), all neck motions (r between 0.39 and 0.59) and neck muscle endurance (rS = 0.36). Pemax and Pimax were related to NDI (r = -0.58 and -0.46). In the regression models, chest expansion was the only significant predictor for MVV, and Pemax was determined by neck muscle endurance. These results suggest that chronic neck pain patients should improve the endurance of the neck flexor muscles and thoracic spine and chest mobility. Additionally, these patients might benefit from respiratory muscle endurance training, possibly by increasing chest mobility and Pemax.