Superficial temperature and pain tolerance in patients with chronic low back pain

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.

Thermal profile classification of the back of sportive and sedentary healthy individuals

BACKGROUND

Infrared thermography (IRT) is a non-harmful, risk-free imaging technique and it has application for healthy and pathological population.

OBJECTIVE

The aim of this study is to evaluate the thermographic profiles of the back of sport practitioners from different disciplines and compare it with those of sedentary healthy individuals.

METHOD

The back of 160 healthy subjects were evaluated, and participants were grouped considering their sport practice: team sport (TS), individual sport (IS), weight training (WT), inactive (I). Three regions of interest were identified to analyze the cervical, thoracic and lumbar temperatures of the back.

RESULTS

The Multivariate analysis of variance (MANOVA) resulted significant showing statistical differences for the cervical (p < 0.001), dorsal (p = 0.0011), and lumbar areas (p = 0.0366). The Tukey post-hoc test for pairwise comparison showed statistically significant differences between groups. For the cervical area significance was found between the IN and WT group (p = 0.002), the IN and IS group (p < 0.001), IN and TS group (p = 0.020). The dorsal area resulted significant between the IN and WT group (p = 0.007), the IN and IS group (p < 0.001), IN and TS group. The lumbar area showed significant differences only between the IN and WT group and the IN and IS group (p = 0.043).

CONCLUSION

This study demonstrated that inactive individuals manifest a statistically significant higher temperature in the cervical, dorsal and lumbar area of the back compared to sportive individuals.

Pain-motor integration in chronic pain: A neurophysiological study

OBJECTIVE

Chronic pain may lead to functional changes in several brain regions, including the primary motor cortex (M1). Our neurophysiological study aimed to probe M1 plasticity, through a non-invasive transcranial magnetic stimulation protocol, in a cohort of patients with chronic pain.

METHODS

Twenty patients with chronic pain (age ± SD: 62.9 ± 9.9) and 20 age- and sex-matched healthy controls (age ± SD: 59.6 ± 15.8) were recruited. Standardized scales were used for the evaluation of pain severity. Neurophysiological measures included laser-evoked potentials (LEPs) and motor-evoked potentials (MEPs) collected at baseline and over 60 minutes following a standardized Laser-paired associative stimulation (Laser-PAS) protocol.

RESULTS

LEPs and MEPs were comparable in patients with chronic pain and controls. The pain threshold was lower in patients than in controls. Laser-PAS elicited decreased responses in patients with chronic pain. The response to Laser-PAS was similar in subgroups of patients with different chronic pain phenotypes.

CONCLUSIONS

M1 plasticity, as tested by Laser-PAS, is altered in patients with chronic pain, possibly reflecting abnormal pain-motor integration processes.

SIGNIFICANCE

Chronic pain is associated with a disorder of M1 plasticity raising from abnormal pain-motor integration.

Infrared thermography for the evaluation of adolescent and juvenile idiopathic scoliosis: A systematic review

INTRODUCTION

Adolescent and Juvenile Idiopathic Scoliosis are a three-dimensional spine deformity characterized by a muscle alteration of the convex and concave sides of the scoliosis, which can be evaluated with different non-invasive and radiation-free methods such as infrared thermography. The objective of the present review is to assess infrared thermography as a potential method to evaluate alterations of the scoliosis.

MATERIALS AND METHODS

A systematic review was performed by collecting articles from PubMed, Web of Science, Scopus, and Google Scholar, published from 1990 to April 2022, on the use of infrared thermography to evaluate adolescent and juvenile idiopathic scoliosis. Relevant data were collected in tables, and the primary outcomes were discussed narratively.

RESULTS

Of the 587 articles selected, only 5 were in line with the objective of this systematic review and were eligible for the inclusion criteria. The findings of the selected articles corroborate the applicability of infrared thermography as an objective method to assess the thermal differences of the muscles between the convex and concave sides of scoliosis. The overall quality of the research was uneven in the reference standard method and assessment of measures.

CONCLUSION

Infrared thermography is providing promising results to discriminate thermal differences in scoliosis evaluation, albeit there are still some concerns about considering it as a diagnostic tool for scoliosis evaluation because specific recommendations for collecting data are not met. We propose additional recommendations to existing guidelines to perform thermal acquisition to reduce errors and provide the best results to the scientific community.

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.

The duration of chronic low back pain is associated with acute postoperative pain intensity in lumbar fusion surgery: a prospective observational study

BACKGROUND

Pre-existing chronic pain has been associated with severe postoperative pain. In this study, we sought to prospectively analyse the association between the duration of chronic low back pain and the intensity of acute postoperative pain after lumbar fusion surgery.

METHODS

A total of 330 patients who underwent lumbar fusion surgery were divided into three groups (chronic low back pain less than 1 year, one to 5 years, and more than 5 years) based on the duration of chronic pain. On the first postoperative day, the maximum pain scores of each patient were recorded during the day and at night. Bivariate correlation and logistic regression were performed to identify relationships between acute postoperative pain and related variables (age, sex, smoking history, body mass index, operation history, duration of surgery, level of preoperative pain, aetiology of back pain, Self-rating Anxiety Scale, Self-rating Depression Scale, FRAIL scale, and duration of chronic low back pain). If the postoperative pain score was > 3 when the patient reported was at rest, the patients were treated with postoperative intravenous self-controlled analgesia or rescue analgesics if necessary.

RESULTS

There was an association between severe acute postoperative pain and the duration of chronic low back pain. In terms of VAS day, multivariable logistic regression showed the duration of chronic low back pain was not statistically significant (OR = 2.48, 95% CI: 0.900 to 6.828, p = 0.0789). The result is uncertain because the confidence interval included the null after controlling for SAS, SDS, BMI, and aetiology of back pain. In terms of VAS night, patients with a duration of chronic low back pain of more than 5 years were more likely having moderate to severe acute postoperative pain (VAS > 3) compared to patients with a duration of chronic low back pain less than 1 year (OR = 3.546, 95% CI: 1.405 to 8.95, p = 0.0074). Hospital stay, the pain score on the day of discharge and the pain score after 3 months displayed no significant difference among the three groups (P > 0.05). However, the need for postoperative rescue analgesics was different among the three groups (P < 0.05).

CONCLUSION

The longer the duration of chronic pain was, the higher the incidence of moderate to severe acute postoperative pain was and the greater the amount of analgesics required after surgery.

TRIAL REGISTRATION

This study was registered at the Chinese Clinical Trial Registration Center ( http://www.chictr.org.cn/index.aspx , clinical trial number: ChiECRCT20200165, date of registration: July 6, 2020).

Applications of thermal imaging with infrared thermography in Orthopaedics

BACKGROUND

Pathological conditions with ongoing inflammatory processes result in specific heat signatures at the affected body parts; infrared thermography (IRT) detects these changes and can be utilied in screening such conditions. The modern devices are advanced and their non contact, convenient and precise readings can aid in multiple medical sub fields. Orthopaedics as a broad entity has witnessed utilisation of this technology for different indications and the present scoping review was done to assess these established indications and further scope of its utility.

METHOD

ology: A Medline search was done on April 26, 2021 with specific keywords for studies of any design in English language discussing the usage of thermography in Orthopaedics. Animal studies, conference abstracts, systematic reviews, e-posters, case reports, book chapters, and studies describing the use of thermography in non-Orthopaedic patients were excluded.

RESULTS

Total number of hits were 1380. 43 studies including case series and case control studies were included in the review. The subfields or indications described were pain/arthritis, Charcot's foot/neuropathic ulcers, infections associated with diabetic feet and arthroplasties, reflex sympathetic dystrophy, carpal tunnel syndrome, sports medicine, paediatric orthopaedics, spine, ergonomics and compartment syndrome.

CONCLUSION

IRT has been described to be effective in orthopaedic conditions with specific heat signatures and this can assess the trend of the ongoing inflammatory process as well as response to a particular treatment. Additionally, it can specifically determine the exact loci of the pathology for targeted interventions.

Infrared Thermography Images Acquisition for a Technical Perspective in Screening and Diagnostic Processes: Protocol Standardized Acquisition

In this technical report we describe the thermographic setting protocol suitable for the FLIR T650SC thermal imager (FLIR Systems, Inc., Wilsonville, OR), an instrument that detects electromagnetic radiation in the infrared field which is physiologically emitted from the human body. FLIR T650SC thermal imager processes infrared radiations graphically and analyzes them through a specific software. In biomedicine, infrared thermography is a promising technique amongst other conventional methods used for detecting skin temperature differences considered as a possible sign of disturbances in the human body. Currently, automatic screening of temperature from a safe distance is an instrument utilized in the front line of the SARS CoV2 emergency.

The processing method of the thermogram considers an initial setting of constant parameters that cannot be subsequently modified such as temperature range, focusing and image composition. After the acquisition variable values important in the processing and analysis of the thermogram, such as detection of environment temperature, reflected temperature, emissivity, relative humidity and contrast palette, are set in the software. The analysis is performed using the FLIR Tools software.

In the biomedical field standardized acquisition of thermograms facilitates the identification of trigger points and areas of hyper- and hypothermia distributed on the skin surface and muscle bundles. The protocol made it possible to create images with the same acquisition method for all patients.

The thermal imaging camera is a valid screening tool because its execution is rapid, it is non-invasive, well-tolerated, and at a low cost for patients.

Relationship between exercise-induced muscle soreness, pain thresholds, and skin temperature in men and women

Infrared thermography (IRT) has gained popularity in sports medicine for determining whether changes in skin temperature relate to pain and muscle damage. Such a relationship would support IRT as a non-invasive method to monitor these physiological responses. However, the literature remains controversial. Here, we determine the relationship between exercise-induced muscle soreness (DOMS), pain, and skin temperature in men and women before and after exercise. Twenty-two physically active adults (10 men and 12 women) completed a squat exercise protocol to induce muscle damage. Skin temperature, DOMS, and pressure pain threshold (PPT) were assessed in the quadriceps pre, post-exercise, and 48 h post-exercise. DOMS increased similarly in men and women post-exercise and 48 h post-exercise. PPT was lower in women compared to men. PPT decreased 48 h post-exercise for men but did not differ between the moments for women. Skin temperature responses were sex-dependent. Mean and maximum temperatures increased post-exercise for men, and maximum temperature reduced 48 h post-exercise. In women, the minimum temperature increased 48 h post-exercise. DOMS was not predicted by skin temperature but showed a direct association between pre and 48 h post-exercise variation of maximum skin temperature and PPT. We conclude that there is a sex-dependent effect in analyzing skin temperature changes in response to exercise, something that seems to not have been addressed in previous studies. To date, inferences are generally assumed as similar for both men and women, which we show may not be the case.

A cross-sectional analysis of persistent low back pain, using correlations between lumbar stiffness, pressure pain threshold, and heat pain threshold

Introduction

Little is known about the underlying biomechanical cause of low back pain (LBP). Recently, technological advances have made it possible to quantify biomechanical and neurophysiological measurements, potentially relevant factors in understanding LBP etiology. However, few studies have explored the relation between these factors. This study aims to quantify the correlation between biomechanical and neurophysiological outcomes in non-specific LBP and examine whether these correlations differ when considered regionally vs. segmentally.

Methods

This is a secondary cross-sectional analysis of 132 participants with persistent non-specific LBP. Biomechanical data included spinal stiffness (global stiffness) measured by a rolling indenter. Neurophysiological data included pain sensitivity (pressure pain threshold and heat pain threshold) measured by a pressure algometer and a thermode. Correlations were tested using Pearson’s product-moment correlation or Spearman’s rank correlation as appropriate. The association between these outcomes and the segmental level was tested using ANOVA with post-hoc Tukey corrected comparisons.

Results

A moderate positive correlation was found between spinal stiffness and pressure pain threshold, i.e., high degrees of stiffness were associated with high pressure pain thresholds. The correlation between spinal stiffness and heat pain threshold was poor and not statistically significant. Aside from a statistically significant minor association between the lower and the upper lumbar segments and stiffness, no other segmental relation was shown.

Conclusions

The moderate correlation between spinal stiffness and mechanical pain sensitivity was the opposite of expected, meaning higher degrees of stiffness was associated with higher pressure pain thresholds. No clinically relevant segmental association existed.

Positive affect and distraction enhance while negative affect impairs pain modulation in recurrent low back pain patients and matched controls

ABSTRACT

Pathophysiological causes of low back pain (LBP) remain generally unclear, so focus has shifted to psychosocial features and central pain processing. Effects of attentional and affective manipulation on conditioned pain modulation (CPM) and tonic pain perception were examined in thirty recurrent LBP patients in two sessions, one with and one without clinical pain, and compared to healthy participants. Phasic cuff pressure on one leg, scored on a numerical rating scale (NRS), was used for test-stimuli (TS) and contralateral tonic cuff pain rated on an electronic visual analogue scale (eVAS) was the conditioning-stimulus (CS). TS were assessed before and during: 1) control with no manipulation/CS, 2) three attentional manipulations (Flanker with/without CS or CS-Only), and 3) three affective manipulations (positive, neutral, negative pictures) with CS. Greater inhibition of TS-NRS scores was observed in CS-only (P=0.028), combined CS&attention (P=0.026), and CS&Positive (P=0.006) than Control paradigms, and greater in CS&Positive (P=0.019) than CS&Negative paradigms. eVAS scores of CS pain increased throughout all paradigms with CS (P<0.05), except the CS&Positive paradigm, and greater facilitation was observed in the CS-Only paradigm than all others (P<0.02) and lower facilitation was additionally observed in the CS&Positive paradigm compared to CS&Attention and CS&Negative paradigms (P<0.01). Flanker effects and interruptive effects of CS pain on attention were observed consistent with prior findings, and affective manipulation produced less shift in valence among people with RLBP than controls (P<0.05). Attention and positive affect with CS pain evoked CPM, and all attentional/affective tasks, especially positive affect, reduced facilitation of CS pain.

Musculoskeletal applications of infrared thermography on back and neck syndromes: a systematic review

INTRODUCTION

Thermography is a noninvasive method to detect temperature changes on or near the surface of the body. Despite its utility has not yet been fully verified, it may be used as a complementary method to screening and/or monitoring treatment effectiveness. This systematic review evaluates the role of infrared thermography as a helpful outcome measure tool in subjects with back and neck syndromes.

EVIDENCE ACQUISITION

A literature search was conducted across the National Library of Medicine (MEDLINE), Web of Science and Scopus databases for studies that evaluated the role of infrared thermography as a helpful outcome measure tool in subjects with back and neck syndromes. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA).

EVIDENCE SYNTHESIS

The search strategy and selection criteria yielded 812 articles. From these, 268 duplicates were removed, and only 16 were in line with the aim of this review. Ultimately, only seven precisely fulfilled the inclusion and exclusion criteria and were included in the review. According to the articles reviewed, thermography seems to give an objective notion of change in inflammatory activity, which can corroborate the usefulness of treatment or the improvement/worsening of the patient's symptoms. The overall quality of research was uneven in the study design, endpoint measures, and sample characteristics.

CONCLUSIONS

The number of high-quality studies of the role of infrared thermography in patients with back and neck syndromes remains limited. More than a diagnostic tool, thermography can be an objective tool for monitoring the effectiveness of treatment by identifying deviations from a healthy state.