Cross friction algometry (CFA): Comparison of pressure pain thresholds between patients with chronic non-specific low back pain and healthy subjects

The Relationship between Abdominal Diastasis and Lumbar Pain Pressure Threshold in Women Who Have Given Birth between the Ages of 30 and 45 Years-An Observational Pilot Study

Background and Objectives: Current evidence confirms that the magnitude of the inter-rectus distance (IRD) is associated with the severity of abdominal pain. Furthermore, evidence exists in the literature about the impact abdominal muscles have on low back pain, lumbopelvic pain, breathing and lumbar abdominal strength; however, no studies analysing the level of association between abdominal diastasis and lumbar pain pressure threshold (PPT) exist. The aim of this study was to analyse the level of association between the rectus abdominis distance and pain pressure threshold in the lumbar spinous processes in women who have given birth between the ages of 30 and 45 years. Secondly, it was to study the level of association between the time elapsed since the last delivery and low back pain in women who have given birth between 30 and 45 years of age. Material and Methods: This was a pilot observational study in which 21 females participated. The abdominal diastasis was measured by ultrasound, the pain pressure threshold was assessed by an algometer and the pain perception by the Mc Gill questionnaire. Results: There was no significant relationship between increased abdominal distance and increased lumbopelvic pain in women who gave birth between the ages of 30 and 45 years. However, there was a correlation between the time that had elapsed since the last delivery and low back pain. Conclusions: there was a correlation between the time that had elapsed since the last delivery and low back pain. Further studies analysing factors that may perpetuate the chronicity of symptoms, such as lifestyle and intrinsic factors, are needed.

Reference intervals and sources of variation of pressure pain threshold for quantitative sensory testing in a Japanese population

Quantitative sensory testing (QST) is useful when analysing musculoskeletal pain disorders. A handheld algometer is most commonly used for pressure pain threshold (PPT) tests. However, reference intervals for PPTs are not elucidated. We assessed reference intervals of PPTs for QST in 158 healthy adult Japanese with no history of musculoskeletal or neurological problems. A handheld algometer was used to record PPT at five different assessment sites on the body: lumbar paravertebral muscle, musculus gluteus maximus, quadriceps, tibialis anterior muscle, and anterior talofibular ligament. Multiple regression analysis was performed to explore sources of variation of PPT according to sex, age, body mass index, UCLA Activity Level Rating, and Tegner Activity Score. Reference intervals were determined parametrically by Gaussian transformation of PPT values using the two-parameter Box-Cox formula. Results of multiple regression analysis revealed that age was significantly associated with PPT of lumbar paravertebral muscle and musculus gluteus maximus. In females, body mass index showed significant positive correlation with PPT of anterior talofibular ligament, and UCLA Activity Level Rating also showed significant positive association with tibialis anterior muscle and anterior talofibular ligament. Site-specific reference intervals of PPTs for Japanese are of practical relevance in fields of pain research using a handheld algometer.

Current Concept of Quantitative Sensory Testing and Pressure Pain Threshold in Neck/Shoulder and Low Back Pain

In recent years, several published articles have shown that quantitative sensory testing (QST) and pressure pain threshold (PPT) are useful in the analysis of neck/shoulder and low back pain. A valid reference for normal PPT values might be helpful for the clinical diagnosis of abnormal tenderness or muscle pain. However, there have been no reliable references for PPT values of neck/shoulder and back pain because the data vary depending on the devices used, the measurement units, and the area examined. In this article, we review previously published PPT articles on neck/shoulder and low back pain, discuss the measurement properties of PPT, and summarize the current data on PPT values in patients with chronic pain and healthy volunteers. We also reveal previous issues related to PPT evaluation and discuss the future of PPT assessment for widespread use in general clinics. We outline QST and PPT measurements and what kinds of perceptions can be quantified with the PPT. Ninety-seven articles were selected in the present review, in which we focused on the normative values and abnormal values in volunteers/patients with neck/shoulder and low back pain. We conducted our search of articles using PubMed and Medline, a medical database. We used a combination of “Pressure pain threshold” and “Neck shoulder pain” or “Back pain” as search terms and searched articles from 1 January 2000 to 1 June 2022. From the data extracted, we revealed the PPT values in healthy control subjects and patients with neck/shoulder and low back pain. This database could serve as a benchmark for future research with pressure algometers for the wide use of PPT assessment in clinics.

Synergistic effect of chronic pain and nonsuicidal self-harm on pain sensitivity

Abnormalities in pain processing have been observed in patients with chronic pain conditions and in individuals who engage in self-harm, specifically nonsuicidal self-injurious behaviors (NSSI). Both increased and decreased pain sensitivity have been described in chronic pain patients, while decreased pain sensitivity is consistently observed in individuals with NSSI. The objective of the study was to identify the differential effects of chronic pain and NSSI on experimental pain sensitivity, specifically pressure pain threshold, in depressed patients. Moreover, the role that hopelessness may play between depression severity and pain sensitivity was also examined. Depressed patients with and without chronic pain, and with and without lifetime self-harm behaviors were analyzed into four groups. Group 1 (N = 42) included depressed patients with both Chronic pain ( +) and Self-harm ( +), Group 2 (N = 53) included depressed patients with Chronic pain ( +) but no Self-harm (-), Group 3 (N = 64) included depressed patients without Chronic pain (-), but Self-harm ( +), and Group 4 (N = 81) included depressed patients with neither Chronic pain (-) nor Self-harm (-). Healthy controls (N = 45) were also recruited from the community. Depressed patients with both Chronic pain ( +) and Self-harm ( +) reported higher pressure pain threshold measures when compared with the other groups. Mediation analysis indicated that hopelessness mediates the relationship between depression severity and pressure pain threshold. Our findings suggest that a multiprong approach including adequate mental health services and pain control for depressed patients with comorbid chronic pain and nonsuicidal self-harm is needed to yield effective outcomes.

Effects of ear acupuncture combined with cupping therapy on severity and threshold of chronic back pain and physical disability: A randomized clinical trial

Background and aim

Chronic back pain causes physical, functional, and emotional disabilities. Traditional Chinese Medicine therapies have been shown as interventions to treat chronic back pain. The present study aimed to clinically evaluate the effects of ear acupuncture combined with cupping therapy on people with chronic back pain.

Experimental procedure

We conducted an open-label, randomized, parallel-group controlled clinical trial. Following the CONSORT statement recommendations, 198 participants were randomized into ‘ear acupuncture’ and ‘ear acupuncture and cupping therapy’ groups. Data were collected in three different points; before the first session (initial) with the patient, after the last session (final), and seven days after the end of the treatment (follow-up). The Brief Pain Inventory, a digital algometer, and the Rolland Morris Disability Questionnaire were used for data collection. Generalized Estimation Equation model was used to examine the association between the interventions and the primary outcome pain severity.

Results

Pain severity, pressure pain threshold, and physical disability improved over time in both groups. However, for the patients being treated with both ear acupuncture and cupping therapy, significant changes were seen in pain severity, pain relief, and physical disabilities between the initial and final sessions. For the ‘ear acupuncture and cupping therapy’ group, significant changes were also seen for pain relief and physical disability in the follow-up session.

Conclusion

Ear acupuncture combined with cupping therapy was shown to be more effective in the treatment of chronic back pain when compared to treatment using only ear acupuncture.

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Ear acupuncture plus cupping therapy is effective to treat chronic back pain.

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Patients treated with both interventions achieved positive changes in all variables.

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These are interventions that can be implemented in clinical practice.

Pressure Pain Threshold in Patients With Chronic Pain: A Systematic Review and Meta-Analysis

INTRODUCTION

In chronic pain conditions, the pressure pain threshold has been used to investigate the presence of central sensitization.

METHODS

A systematic review and meta-analysis were conducted to compare the threshold in chronic pain patients and healthy individuals. Ovid MEDLINE and Embase up to July 2019 were used to conduct the search. Search strategy included terms and sets of terms that describe the concepts "sensory testing" and "pain measurement."

RESULTS

The included studies consisted of 24 were case-control studies and 12 cross-sectional studies. The pooled total sample size was 1280 cases of patients with different diagnoses of chronic pain and 1463 healthy controls. Among the included studies, 32 reported a significant decrease of the pressure pain threshold among patients compared with the controls and four reported no statistically significant difference. The pooled pressure pain threshold mean difference was -1.17 (95% confidence interval = -1.45 to -0.90). There was, however, evidence of significant heterogeneity across the studies (I2 = 87.42%, P < 0.001).

CONCLUSIONS

Patients who experience chronic pain have a significantly lower pressure pain threshold compared with healthy controls. Future research is needed to elucidate factors attributed to the change in pressure pain threshold among patients with chronic pain, as well as the time that the central sensitization occurs.

Pressure pain threshold and temporal summation in adults with episodic and persistent low back pain trajectories: a secondary analysis at baseline and after lumbar manipulation or sham

BACKGROUND

People with chronic low back pain (LBP) typically have increased pain sensitivity compared to healthy controls, however its unknown if pain sensitivity differs based on LBP trajectory at baseline or after manual therapy interventions. We aimed to compare baseline pressure pain threshold (PPT) and temporal summation (TS) between people without LBP, with episodic LBP, and with persistent LBP, and to compare changes over time in PPT and TS after a lumbar spinal manipulation or sham manipulation in those with LBP.

METHODS

Participants were aged 18-59, with or without LBP. Those with LBP were categorised as having either episodic or persistent LBP. PPT and TS were tested at baseline. LBP participants then received a lumbar spinal manipulation or sham, after which PPT and TS were re-tested three times over 30 min. Generalised linear mixed models were used to analyse data.

RESULTS

One hundred participants (49 female) were included and analysed. There were 20 non-LBP participants (mean age 31 yrs), 23 episodic LBP (mean age 35 yrs), and 57 persistent LBP (mean age 37 yrs). There were no significant differences in PPT or TS between groups at baseline. There was a non-significant pattern of lower PPT (higher sensitivity) from the non-LBP group to the persistent LBP group at baseline, and high variability. Changes in PPT and TS after the interventions did not differ between the two LBP groups.

DISCUSSION

We found no differences between people with no LBP, episodic LBP, or persistent LBP in baseline PPT or TS. Changes in PPT and TS following a lumbar manual therapy intervention do not appear to differ between LBP trajectories.

TRIAL REGISTRATION

The trial was prospectively registered with ANZCTR (ACTRN12617001094369).

Lumbar interspinous pressure pain threshold values for healthy young men and women and the effect of prolonged fully flexed lumbar sitting posture: An observational study

BACKGROUND

Low back pain (LBP) is a common condition with large burden worldwide. Exposure to prolonged sitting with a flexed lumbar posture has been suggested in the literature to be a potential risk factor for self-reported LBP. No study has previously investigated whether exposure to prolonged flexed sitting posture provokes discomfort/pain and decreased interspinous pressure pain thresholds for healthy young men and women without back pain, despite this being a suggested risk factor for LBP.

AIM

To investigate whether sitting in a prolonged flexed lumbar posture provokes discomfort and lowers interspinous pressure pain thresholds in the lumbar spine for healthy young men and women without previous LBP.

METHODS

This is a an observational before and after study of 26 participants (13 men, 13 women) between 20-35 years old. Algometry was used to examine the pain threshold for pressure applied between spinous processes of the lumbar spine L1-L5. Pressure algometer measures were performed in prone before and after participants were instructed to sit in a fully flexed posture for a maximum of 15 min or until discomfort was experienced in the low back (Borg CR10 = 7/10). Wilcoxon signed-rank test was used for analyze values from the before and after test conditions. Mann-Whitney U test was used to investigate potential gender difference.

RESULTS

Fully flexed lumbar spine sitting posture up to 15 min provoked temporary discomfort but the proportion of participants experiencing discomfort 7/10 in the low back was 62%. For all pain pressure threshold locations tested, there was a significant difference for the study population with moderate-large decreased (r = -0.56) pressure pain threshold after exposure to prolonged flexed sitting posture (P < 0.01). Comparisons between gender did not show any significant difference.

CONCLUSION

The result showed that exposure to fully flexed lumbar sitting posture for up to 15 min produced temporary discomfort in the low back in young healthy adults with no previous history of LBP and significantly reduced lumbar interspinous pressure pain thresholds. No gender-based differences were observed.

Targeting the Autonomic Nervous System Balance in Patients with Chronic Low Back Pain Using Transcranial Alternating Current Stimulation: A Randomized, Crossover, Double-Blind, Placebo-Controlled Pilot Study

Background

Chronic low back pain (CLBP) is characterized by an alteration in pain processing by the central nervous system that may affect autonomic nervous system (ANS) balance. Heart rate variability (HRV) reflects the balance of parasympathetic and sympathetic ANS activation. In particular, respiratory sinus arrhythmia (RSA) solely reflects parasympathetic input and is reduced in CLBP patients. Yet, it remains unknown if non-invasive brain stimulation can alter ANS balance in CLBP patients.

Objective

To evaluate if non-invasive brain stimulation modulates the ANS, we analyzed HRV metrics collected in a previously published study of transcranial alternating current stimulation (tACS) for the modulation of CLBP through enhancing alpha oscillations. We hypothesized that tACS would increase RSA.

Methods

A randomized, crossover, double-blind, sham-controlled pilot study was conducted to investigate the effects of 10Hz-tACS on metrics of ANS balance calculated from electrocardiogram (ECG). ECG data were collected for 2 mins before and after 40 mins of 10Hz-tACS or sham stimulation.

Results

There were no significant changes in RSA or other frequency-domain HRV components from 10Hz-tACS. However, exploratory time-domain HRV analyses revealed a significant increase in the standard deviation of normal intervals between R-peaks (SDNN), a measure of ANS balance, for 10Hz-tACS relative to sham.

Conclusion

Although tACS did not significantly increase RSA, we found in an exploratory analysis that tACS modulated an integrated HRV measure of both ANS branches. These findings support the further study of how the ANS and alpha oscillations interact and are modulated by tACS.

ClinicalTrials.gov

Transcranial Alternating Current Stimulation in Back Pain – Pilot Study, NCT03243084.

Pressure Pain Threshold in Subjects With Piriformis Syndrome: Test-Retest, Intrarater, and Interrater Reliability, and Minimal Detectible Changes

OBJECTIVE

This study aimed to assess the test-retest, intrarater, and interrater reliability of using the pressure pain threshold (PPT) in healthy and affected piriformis muscles and to estimate its absolute reliability. As a secondary objective, the degree of tenderness of the affected piriformis muscles was compared with healthy piriformis muscles.

STUDY DESIGN

This study used a comparative and reliability-based design.

SETTING

Rehabilitation clinic.

PARTICIPANTS

Patients (N=30) with unilateral piriformis muscle syndrome (30 affected and 30 healthy piriformis muscles) were recruited, and the PPT of both the healthy and affected piriformis muscles was recorded using digital algometry. Measurements of PPT were done by 2 raters (rater 1 and 2), which were selected at random order. Rater 1 repeated the PPT measurements 24-72 hours after initial assessment.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

PPT.

RESULTS

Excellent intrarater intraclass correlation coefficient (ICC) values were observed for the PPT of the affected piriformis (ICC: 0.86-0.96) and the healthy piriformis (ICC: 0.88-0.96) in the same session. The PPT measurements using digital algometry showed good-to-excellent interrater reliability (ICC: 0.64-0.92) and test-retest reliability (ICC: 0.72-0.95) in both the healthy and affected piriformis muscles. The findings revealed a significant decrease in the PPT of the affected piriformis muscle in comparison to the healthy piriformis muscle (mean difference 12.76; 95% confidence interval, 15.69-9.82; P<.001).

CONCLUSIONS

Digital algometry is a reliable tool for measuring piriformis PPT, regardless of the testing session and the rater. Patients with unilateral piriformis muscle syndrome have increased tenderness and decreased PPT in the affected piriformis muscle in comparison to the healthy piriformis muscle.

The Effects Of Myofascial Release Technique Combined With Core Stabilization Exercise In Elderly With Non-Specific Low Back Pain: A Randomized Controlled, Single-Blind Study

Purpose

To evaluate the effects of Myofascial Release Technique (MRT) with a roller massager combined with core stabilization exercises (CSE) in elderly with non-specific low back pain (NSLBP).

Patients and methods

A total of forty-five participants were randomly divided into two groups (CSE and CSE+MRT). A core stabilization exercise program was applied for the participants in the CSE group for 3 days per week for a total of 6 weeks. In addition to the core stabilization exercises, myofascial relaxation technique with a roller massager was performed for 3 days per week for 6 weeks for the participants in the CSE+MRT group. Participants were assessed in terms of pain, low back disability, lower body flexibility, kinesiophobia, core stability endurance, spinal mobility, gait characteristics and quality of life both pre- and post-treatment.

Results

It was found that the improvement in core stability endurance (p=0.031) and spinal mobility (in the sagittal plane) (p=0.022) was greater in the CSE+MRT group compared to the CSE group. There was no significant difference between the two groups in terms of pain, low back disability, lower body flexibility, kinesiophobia, gait characteristics and quality of life (p>0.05).

Conclusion

The current study suggests that myofascial release technique with a roller massager combined with core stabilization exercises can be a better choice in the treatment of NSLBP in elderly.

ClinicalTrials.gov Identifier

NCT03898089.

Pain Mechanisms in Low Back Pain: A Systematic Review With Meta-analysis of Mechanical Quantitative Sensory Testing Outcomes in People With Nonspecific Low Back Pain

BACKGROUND

Mechanical quantitative sensory testing (QST) assesses sensory functioning and detects functional changes in (central) nociceptive processing. It has been hypothesized that these functional changes might be apparent in people with nonspecific low back pain (LBP), although the results are mixed.

OBJECTIVE

The aim of this systematic review was to examine whether sensory function, measured with QST, was altered in people with nonspecific LBP.

METHODS

This systematic review was conducted according to PRISMA guidelines. Six databases were searched for relevant literature. Studies comparing mechanical QST measures involving people with subacute and chronic LBP and healthy controls were included if (1) pressure pain thresholds (PPTs), (2) temporal summation, or (3) conditioned pain modulation were reported. Risk of bias was assessed using the Newcastle-Ottawa scale. When possible, the results from different studies were pooled.

RESULTS

Twenty-four studies were included. Scores on the Newcastle-Ottawa scale varied between 1 and 6 points. People with nonspecific LBP, compared to healthy controls, had significantly lower PPTs at remote sites and increased temporal summation at the lower back. The PPTs measured at the scapula were significantly lower in patients with nonspecific LBP than in healthy controls (pooled mean difference, 119.2 kPa; 95% confidence interval: 91.8, 146.6 kPa; P<.001).

CONCLUSION

The PPT measurements at remote body parts were significantly lower in people with nonspecific LBP compared with healthy controls. Temporal summation and conditioned pain modulation measurements had mixed outcomes.

LEVEL OF EVIDENCE

Therapy, level 3a. J Orthop Sports Phys Ther 2019;49(10):698-715. Epub 23 Aug 2019. doi:10.2519/jospt.2019.8876.

Cupping therapy and chronic back pain: systematic review and meta-analysis

OBJECTIVES

to evaluate the evidence from the literature regarding the effects of cupping therapy on chronic back pain in adults, the most used outcomes to evaluate this condition, the protocol used to apply the intervention and to investigate the effectiveness of cupping therapy on the intensity of chronic back pain.

METHOD

systematic review and meta-analysis carried out by two independent researchers in national and international databases. Reference lists of systematic reviews were also explored. The quality of evidence was assessed according to the Jadad scale.

RESULTS

611 studies were identified, of which 16 were included in the qualitative analysis and 10 in the quantitative analysis. Cupping therapy has shown positive results on chronic back pain. There is no standardization in the treatment protocol. The main assessed outcomes were pain intensity, physical incapacity, quality of life and nociceptive threshold before the mechanical stimulus. There was a significant reduction in the pain intensity score through the use of cupping therapy (p = 0.001).

CONCLUSION

cupping therapy is a promising method for the treatment of chronic back pain in adults. There is the need to establish standardized application protocols for this intervention.