Pressure pain sensitivity maps of the neck-shoulder and the low back regions in men and women

The association of the localized pain sensitivity in the residual limb and prosthesis use in male veterans with transtibial amputation

The association of localized pain sensitivity in the residual limb and prosthesis use has clinical implications, however, rarely been assessed. This study aimed to investigate pain sensitivity and explore its range, variability, and association with prosthesis use alongside other demographic and clinical characteristics of veterans with transtibial amputation. Pain sensitivity was determined as pressure pain threshold (PPT) and pressure tolerance (PT) in 19 male veterans with a mean age of 49.5 years using pressure algometry at 12 anatomical locations on‎ the residual limb. A comparison of pain sensitivity at each location, and among anatomical locations and participants was explored using independent t-test, analysis of variance, and Kruskal-Wallis tests, respectively. Pain sensitivity range (PSR), the difference between PT and PPT, was significantly different (p < 0.05) at mid-patellar tendon, medial tibial flare, and the distal end of the tibia. The lowest PPT and PT (20.5 and 33 Ncm-2, p = 0.13) were recorded at the distal end of the residual limb, and the highest PPT and PT (73.4 and 94.3 Ncm-2, p = 0.03) were recorded at the mid-patellar tendon. Pain sensitivity was significantly different among anatomical locations and participants. The correlation tests (Pearson and partial eta squared) showed non-significant associations of pain sensitivity with participants' demographic and clinical characteristics except for daily prosthesis use. The mid-patellar tendon, medial tibial flare, and distal end of the tibia revealed the lowest pain hypersensitivity ‎due to higher PSR. Longer daily prosthesis use was associated with increased pain sensitivity.

The Impact of 120 Minutes of Soccer-Specific Exercise on Recovery

Purpose: The extra-time (ET) period of soccer is competed during fixture congested schedules with often limited recovery time between matches. The aim of this study was to assess muscle damage recovery following 90- and 120-min (i.e., incorporation of ET) of simulated soccer match-play. Methods: Twelve semiprofessional soccer players completed 90 and 120-min treadmill-based soccer-specific exercise in a counterbalanced order. Creatine kinase (CK), creatinine, urea, aspartate aminotransferase, perceived muscle soreness, pain pressure threshold, reactive strength index, countermovement jump height, and isokinetic strength assessments of eccentric knee flexors at 60, 180 and 270 deg‧s^-1 were taken at baseline and immediately-, 24, 48 and 72-hr post-exercise to assess recovery. Results: No significant between-trial interactions except for CK were found. Pairwise comparisons detected a 53% increase in CK at 24-hr (455 ± 29 μ∙L^-1) following 120-min of simulated match-play vs. the corresponding post 90-min time-point (299 ± 29 μ∙L^-1; p < .01). The 120-min trial caused a 58% higher CK response at 72-hr (244 ± 25 μ∙L^-1) vs. post 90-min comparisons (154 ± 29 μ∙L^-1; p = .02). No interaction effects were detected for any other recovery variables. Creatine kinase and perceived muscle soreness remained elevated up to 72-hr in both trials (p < .01). Conclusions: These data indicate that 120 min of simulated soccer match-play delays the time-course of CK recovery up to 72-hr post-match. However, 120 min of simulated soccer has no additional impact on functional recovery and perceived muscle soreness vs. 90 min. Recovery should be investigated following 90- and 120-min of actual match-play.Trial registration The study was pre-registered on the Open Science Framework (DOI: 10.17605/OSF.IO/VGU6T Date: 10/06/2019).

Effects of a warm-up intervention at the workplace on pain, heart rate, work performance and psychological perception among vineyard workers

OBJECTIVES

Warm-up sessions before physical activity are widely used in sports to help prevent injury and improve performance. Nowadays, companies assume that the effects observed in a sport context can be transferred to the workplace, particularly among workers exposed to biomechanical strain. Yet research on the use of warm-up interventions at the workplace is rather scarce and, when available, leads to conflicting results due to the low quality of the studies. To the best of our knowledge, there are no published studies to date assessing the effects of warm-up sessions among vineyard workers. The present study was designed to investigate if and how a single supervised warm-up session could be effective on perceived pain intensity, heart rate, work performance, and psychological perceptions among vineyard workers.

METHODS

A total of 31 vineyard workers completed a randomized crossover study at the workplace. They were observed in real work settings, i.e. during the pruning activity. Each participant performed the activity under two conditions: 1) with a warm-up session beforehand (WU) and 2) without any warm-up (NWU). Heart rate (HR) was assessed continuously before and during the warm-up, and during the first hour of pruning. Perceived pain intensity over fifteen anatomical locations was assessed before (T0) and immediately after (T1) warm-up, and after the first hour of work (T2). Readiness to work was assessed at T1. Work performance was assessed in terms of the number of completed tasks (number of pruned vines). Perceived work quality and perceived work ability were assessed at T2.

RESULTS

Perceived pain intensity over the lumbopelvic region was significantly higher at T2 than at T0, and at T2 than at T1, in both WU and NWU. Perceived pain intensity was not significantly different at T2 in WU and NWU. HR at T1 was significantly higher in WU than in NWU. Work performance, readiness to work, and perceived work ability were significantly higher in WU than in NWU.

CONCLUSION

This study showed that offering vineyard workers a supervised warm-up session at the workplace can lead to promising results where work performance and psychological perception are concerned.

Pain sensitivity and shoulder function among breast cancer survivors compared to matched controls: a case-control study

OBJECTIVE

Persistent pain and loss of shoulder function are common adverse effects to breast cancer treatment, but the extent of these issues in comparison with healthy controls is unclear for survivors beyond 1.5 years after treatment. The purpose of this study was to benchmark differences in pressure pain thresholds (PPT), maximal isokinetic muscle strength (MIMS), and active range of motion (ROM) of females with persistent pain ≥1.5 years after breast cancer treatment (BCS) compared with pain-free matched controls (CON), and examine the presence of movement-evoked pain (MEP) during assessment of MIMS.

METHODS

The PPTs of 18 locations were assessed using a pressure algometer and a numeric rating scale was used to assess intensity of MEP. Active ROM and MIMS were measured using a universal goniometer and an isokinetic dynamometer, respectively.

RESULTS

A two-way analysis of variance revealed that PPTs across all locations, MIMS for horizontal shoulder extension/flexion and shoulder adduction, active ROM for shoulder flexion, horizontal shoulder extension, shoulder abduction, and external shoulder rotation were significantly lower for BCS compared with CON (P < 0.05). MEP was significantly higher for BCS and MEP intensity had a significant, negative correlation with PPTs (P < 0.01).

DISCUSSION/CONCLUSION

BCS with persistent pain ≥1.5 years after treatment demonstrates widespread reductions in PPTs and movement-specific reductions in MIMS and active ROM of the affected shoulder, along with MEP during physical performance assessment.

IMPLICATIONS FOR CANCER SURVIVORS

BCS with persistent pain ≥1.5 years after treatment shows signs of central sensitization and may benefit from individualized rehabilitation.

The Effect of Spinal Muscle Fatigue and Psychosocial Factors on Pressure-Pain Threshold in Healthy Adults

Objective

Pain sensitivity decreases following isometric exercise. It is not clear whether this exercise-induced hypoalgesia (EIH) occurs to the same extent in men and women. It is also unclear if the effect is systemic or local to the exercised musculature. The aim of our study was to investigate whether fatiguing isometric exercise of the spinal and hip extensors would result in increased pressure pain threshold (PPT) at sites local to and remote from the exercised muscles in healthy men and women and whether there is a relationship between central sensitization, psychosocial factors, and PPT.

Subjects

35 healthy adults (age 27.1 ± 4.5 years, 22 women).

Methods

This was a within-subjects cohort study. Participants completed questionnaires quantifying central sensitization, pain catastrophizing, sleepiness/insomnia, anxiety, and depression. PPT was assessed at the lumbar and thoracic paraspinals, hamstrings, gastrocnemius, wrist, and third digit before and immediately after participants performed the Biering-Sorensen test to failure.

Results

PPT increased postexercise in the thoracic paraspinals, hamstrings, and gastrocnemius in men and women and in the lumbar paraspinals in men only but did not change at the wrist and digit sites. A lower average PPT at baseline was associated with a higher central sensitization scores. A greater increase in average PPT postfatigue was significantly associated with higher average PPT at baseline.

Conclusions

Exercise-induced hypoalgesia occurs at sites overlying the muscles involved in fatiguing exercise, but not at remote sites, and is more evident in males than females. The magnitude of EIH depends upon baseline PPT. Even in healthy individuals, greater central sensitization is associated with lower baseline PPT.

Inter-individual variability in mechanical pain sensation in patients with cervicogenic headache: an explorative study

Currently, evidence for effective physiotherapy interventions in patients with cervicogenic headache (CeH) is inconsistent. Although inter-individual variability in pain response is predictive for successful physiotherapy interventions, it was never explored in patients with CeH. Therefore the objective of the current study was to explore inter-individual variability in mechanical pain sensation, and its association with biopsychosocial-lifestyle (BPSL) characteristics in patients with CeH. A cross-sectional explorative analysis of inter-individual variability in mechanical pain sensation in 18 participants with CeH (29-51 years) was conducted. Inter-individual variability in mechanical pain sensation (standard deviations (SDs), F-statistics, Measurement System Analysis) was deducted from bilateral pressure pain thresholds of the suboccipitals, erector spine, tibialis anterior. BPSL-characteristics depression, anxiety, stress (Depression Anxiety Stress Scale-21), quality of life (Headache Impact Test-6), sleep-quality (Pittsburgh Sleep Quality Index), and sedentary time (hours/week) were questioned. Inter-individual variability in mechanical pain sensation explained 69.2% (suboccipital left), 86.8% (suboccipital right), 94.6% (erector spine left), 93.2% (erector spine right), 91.7% (tibialis anterior left), and 82% (tibialis anterior right) of the total variability in patients with CeH. The significant p-values and large F-statistic values indicate inter-individual differences in SDs. Significant associations between (1) lower quality of life and lower SDs of the suboccipital left PPT (p .005), and (2) longer sedentary time and higher SDs of the suboccipital left PPT (p .001) were observed. Results from our explorative study could suggest inter-individual variability in mechanical pain sensation at the left suboccipitals which associates with quality of life and sedentary time. These novel findings should be considered when phenotyping patients and 'individually' match interventions.

The effect of seating recline on sleep quality, comfort and pressure distribution in moving autonomous vehicles

The revolution of technologically advanced vehicles with a high level of automation involves a profound transformation. The focus of most research in this area has been on the use of travel time for different use cases. Sleeping is one of the most time-consuming activities in everyone's life; therefore, this has been described as one of the most desired use cases for fully automated vehicles. In order to identify the best conditions to allow sleep and improve sleep quality while travelling in such vehicles, two studies were performed: a sleep study and a pressure distribution study, the results of which are included in this document. The focus of both studies was on two seat positions: reclined (60° backrest recline) and flat (87° backrest recline). In the sleep study, forty participants had the opportunity to sleep during a 90-min drive in order to evaluate long-term comfort and subjective sleep quantity and quality. Although both positions resulted in generally similar results in terms of sleep and comfort, some significant differences were identified. Karolinska Sleepiness Scale results showed that sleepiness increased in the reclined position, whereas it decreased in the flat position. Moreover, the self-reported parameter Wake After Sleep Onset was higher in the reclined position. In the pressure distribution study, it was possible to identify specific seat prototype limitations indicating inadequate support, which was related to discomfort detected during the sleep study. As a conclusion, the comparison between the reclined and flat positions showed indications that, in moving fully automated vehicles, the flat seat position is the most comfortable and effective for sleeping.

Pressure pain threshold map of thoracolumbar paraspinal muscles after lengthening contractions in young male asymptomatic volunteers

This study aimed to characterise topographic distribution of pressure pain thresholds (PPTs) of thoracolumbar paraspinal muscles and its change after lengthening contractions (LCs) of the back muscles. Using young male asymptomatic participants in Experiment 1, we systematically examined the distribution of PPTs bilaterally in the range of Th1–L5 at measurement points 2 and 4 cm from the midline. PPTs were found to be higher in the lumbar segments of the paraspinal muscles than in the thoracic segments, and in muscles closer to the vertebrae (2 vs. 4 cm from the midline). The PPTs did not differ between the left and right sides in each segment. In Experiment 2, LC was applied by asking a part of participants recruited in Experiment 1 to fall their trunk from a starting position (parallel to the floor) to 40° flexed position, and then made it back as quickly as possible to the starting position. This cycle was repeated until participants could not keep contractions (30 times/set, 25.4 ± 10.6 sets). PPTs of the LC group decreased prominently in the lower thoracic and lumbar segments, and the decrease was more evident 24 h after LC compared to that 48 h after. In contrast, PPTs in the control group without LC remained unchanged. These results provided broad topographic images of PPTs in the thoracolumbar paraspinal muscles of young male participants with and without LC, and the obtained PPT maps could be a useful guide for better treatment of exercise-induced myofascial pain in the lower back.

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.

Pressure Sensitivity of Buttock and Thigh as a Key Factor for Understanding of Sitting Comfort

In seating comfort research, it is known that the pressure should not exceed a certain threshold from the viewpoint of tissue compression and should be widely distributed. However, its ideal distribution is not defined in past research. It is also known that the comfortable pressure distribution is not always constant and has individual differences. It is assumed that this is due to the influence of individual differences in body shape, such as skeletal shape and flesh of the seated person, and individual differences in sitting posture, but the mechanism has not been clarified by analyses including these factors. From the above, it is considered that the comfortable pressure distribution cannot be explained only by the mechanical state. In this study, we focused on the pressure sensitivity of thighs and buttocks and performed an analysis assuming seating in an automobile seat. We determined the exponent of Steven’s power law for seat pressure by measuring local perceived pressure load that felt the same pressure feeling at the reference load point, and the sensitivity distribution of 29 participants were measured and classified them into 4 types. The comfortable pressure distribution of five participants was measured using the experimental seat and converted into a perceived pressure distribution using the sensitivity distribution. The results show measured pressure distribution is not the same as perceived. Analysis of the perceived pressure distribution suggests that the comfortable perceived pressure distribution is a uniform distribution that falls within a certain range for the minimum pressure.

Clinical features of neck and shoulder pain (Katakori) in Japanese hospital workers

Background:

Non-specific pain or discomfort in the neck and shoulder girdle, called katakori in Japanese, is a common, chronic musculoskeletal condition worldwide. However, its various clinical features are incompletely characterized, even among medical professionals. We aimed to clarify factors affecting katakori and to investigate objectively the associated neck muscle stiffness and skeletal muscle volume.

Methods:

All staff members at our private hospital were surveyed about their lifestyle, physical and mental status, and katakori symptoms, using a self-administered questionnaire. Multiple logistic regression analysis was used to explore possible katakori risk factors. On secondary assessment, ultrasound elastography of the trapezius muscle as well as limb/trunk muscle mass were compared between subjects with severe symptoms and subjects without katakori, using propensity score matching.

Results:

Of 359 participants enrolled, nearly 75% had katakori to some degree. Spending time on a computer during work (adjusted odds ratio [aOR]: 1.82 for 3-6 hours, aOR: 2.48 for > 6 hours), being female (aOR: 3.75), and having unsatisfactory sleep (aOR: 2.92) were potential risk factors for katakori. Comparison of 13 matched pairs showed a significantly stiffer trapezius in subjects with severe katakori symptoms, but no apparent differences in limb/trunk muscle mass.

Conclusions:

Katakori was particularly prevalent in our hospital staff. Possible risk factors for disabling katakori were doing long-term computer work, being female, and having unsatisfactory sleep. Symptoms seem to be associated with elevated neck muscle stiffness. These findings could guide working condition improvements to mitigate katakori.

Assessing Car Seat Posture through Comfort and User Experience

The vehicular market is undergoing a profound transformation that includes a trend toward fully automated driving. When travelling in automated systems, the main task is no longer driving. Therefore, the interior design of automated vehicles requires a renovation to adapt to new use cases. With this motivation, the use case of sleeping while travelling was chosen for this user study, in which different seat configuration conditions were evaluated. The three preselected seat positions for this research included the upright, reclined and flat seat positions. To the best of our knowledge, this study is the first to examine the comfort of different seat angles in meeting the need to sleep in a moving vehicle. Since the physical experience of the occupants with a high-fidelity seat prototype is essential to evaluate the new interior concept of the vehicle of the future, in this study, the experimental participants were asked about their perception of comfort and overall user experience while travelling by car under close-to-real test conditions. Therefore, the primary objective of this evaluation was to explore different seat configurations and find the most suitable seat position for the use case of sleeping in a car while moving. Our findings suggest that users prefer reclining and flat seats in short-/medium- and long-term use cases, respectively.

A Statistical Model to Determine Biomechanical Limits for Physically Safe Interactions With Collaborative Robots

Collaborative robots (cobots) provide a wide range of opportunities to improve the ergonomics and efficiency of manual work stations. ISO/TS 15066 defines power and force limiting (PFL) as one of four safeguarding modes for these robots. PFL specifies biomechanical limits for hazardous impacts and pinching contacts that a cobot must not exceed to protect humans from serious injuries. Most of the limits in ISO/TS 15066 are preliminary, since they are based on unverified data from a literature survey. This article presents a human-subject study that provides new and experimentally verified limits for biomechanically safe interactions between humans and cobots. The new limits are specifically tailored to impact and pinching transferred through blunt and semi-sharp surfaces as they can occur in the event of human error or technical failures. Altogether 112 subjects participated in the study and were subjected to tests with emulated impact and pinching loads at 28 different body locations. During the experiments, the contact force was gradually increased until the load evoked a slightly painful feeling on the subject’s body location under test. The results confirm that the pain thresholds of males and females are different in specific body regions. Therefore, when defining biomechanical limits, the gender difference must be taken into account. A regression model was utilized to incorporate the gender effect as a covariate into a conventional statistical distribution model that can be used to calculate individual limits, precisely fitted to a specific percentile of a mixed group of male and female workers which interacting with cobots.

Taking the strain: An examination of upper back musculoskeletal tissue sensitivity in relation to upper back pain and breast size. A cross-sectional study

BACKGROUND

The physiological basis for upper back pain experienced by women with large breasts is unclear but could relate to sensitivity of musculoskeletal tissues strained from the postural adaptations to large breasts. The aim of this cross-sectional study was to examine if upper back pain and breast size were associated with greater localised sensitivity of upper back musculoskeletal tissues.

METHODS

119 healthy postmenopausal women (mean age 61 years) had their upper back pain (numerical rating scale), breast size (breast size score), and upper back tissue sensitivity (pressure pain thresholds (digital algometry, kPa)) assessed. The pressure pain thresholds of six skeletal sites (T2, T4, T6, T8, T10 and T12) and six muscular sites (pectoralis major, levator scapulae, sternocleidomastoid, and upper, middle, and lower trapezius muscles) were examined. Linear mixed models with random subject effects were used to evaluate differences in sensitivity at each anatomical site between participants grouped by upper back pain (nil-mild, moderate-severe) and breast size (small, large).

FINDINGS

For most sites, the differences in sensitivity between upper back pain groups were highly significant (P < 0.002) with significantly lower pressure pain thresholds (Mean difference (MD): 74.6 to 151.1 kPa) recorded for participants with moderate-severe upper back pain. There were no differences in sensitivity between breast size groups.

INTERPRETATION

Increased upper back musculoskeletal sensitivity is related to perceived upper back pain but not to breast size. It remains unclear if and how structural or mechanical factors related to breast size contribute to upper back pain in women with large breasts.

The influence of sex and level of physical activity on maximum tolerance to mechanical pain

Background

A difference in maximum tolerance to mechanical pain (MTMP) between the sexes is widely studied but there is still no consensus on whether the level of physical activity (PA) influences pain.

Objectives

To compare the MTMP between men and women with different levels of PA.

Methods

Sixty five individuals were divided in female (n = 35) and male group (n = 30). The main outcome measures were PA level and MTMP by pressure algometry. Pressure was applied three times on both sides at the following points: cervical (5^th and 7^th) and lumbar (3^th and 5^th) vertebrae; trapezius, rhomboid, gluteus, gastrocnemius, pectoralis major, tibialis anterior, and deltoid muscles, elbow, hand, knee, and ankle.

Results

It was observed that the PA level has little influence on the MTMP at all the assessed points and that men have greater MTMP than women.

Conclusion

Sex, not the PA level, influences the MTMP.

Exploring multidimensional characteristics in cervicogenic headache: Relations between pain processing, lifestyle, and psychosocial factors

OBJECTIVE

Although multidimensional interventions including physiotherapy, psychology, and education are generally recommended in managing headache, and to prevent chronification, such approach is lacking in cervicogenic headache (CeH). Therefore, exploring CeH within a biopsychosocial framework is deemed an essential first step.

METHODS

Non-randomized cross-sectional design to compare pain processing, lifestyle, and psychosocial characteristics between 18 participants with CeH (CeH group) (40.2 ± 10.9 years) and 18 matched controls (control group) (39.2 ± 13.1 years). Pain processing characteristics included degree of central sensitization (Central Sensitization Inventory), and (extra)-cephalic pressure pain thresholds (kPa/cm²/s). Lifestyle characteristics included sleep quality (Pittsburgh Sleep Quality Index), physical activity, screen time, and sedentary time (hours a week). Psychosocial characteristics included degree of depression, anxiety and stress (Depression Anxiety Stress Scale-21), and quality of life (Headache Impact Test-6).

RESULTS

Pain processing characteristics: More (p = .04) participants in the CeH group showed higher degrees of central sensitization compared to the control group. Lower (p < .05) (extra)-cephalic pressure pain thresholds were revealed in the CeH group compared to the control group for each muscle. Lifestyle and psychosocial characteristics: Compared to the control group, sleep quality and headache-related quality of life were worse (p < .0001) in the CeH group. Severe to extreme stress was experienced by more participants in the CeH group (p = .02). Further, significant relations between pain processing and (1) lifestyle characteristics and (2) psychosocial characteristics were seen in the CeH group.

CONCLUSION

Exploring multidimensional characteristics in CeH exposed relations between pain processing, lifestyle, and psychosocial characteristics. These novel findings fill a gap in the current scientific literature, and highlight the need for outcome research targeting lifestyle and psychosocial factors.

Menthol-Based Topical Analgesic Induces Similar Upper and Lower Body Pain Pressure Threshold Values: A Randomized Trial

CONTEXT

Both health professionals and consumers use menthol-based topical analgesics extensively for the temporary relief of pain from musculoskeletal ailments or injury. However, there are no reports of differences in the pain pressure threshold (PPT) or the relative effectiveness of topical analgesics to reduce pain in the upper and lower body muscles and tendons. The objective of this study was to investigate whether differences existed in PPT and relative pain attenuation associated with a menthol-based topical analgesic over a variety of upper and lower body muscles and tendons.

DESIGN

Randomized allocation, controlled, intervention study.

METHODS

Sixteen participants (10 females and 6 males) were tested on their dominant or nondominant side. The order of specific muscle/tendon testing was also randomized, which included upper body (middle deltoid, biceps brachii, and lateral epicondylar tendon) and lower body locations (quadriceps, hamstrings, gastrocnemius, lumbosacral erector spinae muscles, and patellar and Achilles tendons). The PPT was monitored before and 15 minutes following the application of a menthol-based topical analgesic.

RESULTS

A menthol-based topical analgesic increased PPT (decreased pain sensitivity) overall (P = .05; 11.6% [2.4%]; d = 1.05) and PPT was higher (P < .0001; 31.5%-44.2%; d = 1.03-1.8) for lower versus upper body locations.

CONCLUSIONS

Health professionals and the public can be assured of similar reductions in pain sensitivity independent of the location of application of a menthol-based topical analgesic.

Effects of neural mobilizations through movement representation techniques for the improvement of neural mechanosensitivity of the median nerve region: a randomized controlled trial

PURPOSE

The main objective was to compare the effects of neural mobilization (NM), NM performed through mirror therapy (MT), NM performed through action observation (AO) training and finally classic rehabilitation program (mobility and strength) exercises on neural mechanosensitivity, widespread of proximal and distal pain and pressure pain thresholds (PPT). The second objective was to assess the effects of these interventions on handgrip strength, conditioned pain modulation, motor imagery ability and temporal summation.

MATERIALS AND METHODS

Single-blinded randomized controlled trial. Fifty-four healthy subjects were randomly assigned to each group. Neural mechanosensitivity, widespread pain and PPT were the main variables. The secondary variables included handgrip strength, conditioned pain modulation, motor imagery ability and temporal summation.

RESULTS

All groups showed significant differences in time*factor for neural mechanosensitivity (p = 0.001), PPT in the dermatome of the median nerve (p = 0.007), PPT at carpal tunnel (p < 0.05) and proximal widespread (p = 0.01). No differences were found for distal widespread, conditioned pain modulation, handgrip strength motor imagery ability or temporal summation (p > 0.05). There is an absence of statistically significant differences between groups.

CONCLUSIONS

NM through movement representation techniques can reduce mechanosensitivity and mechanical hyperalgesia in the median nerve dermatome and forearm, although no differences were found between groups.

Impact of Neck and Shoulder Pain on Health-Related Quality of Life in a Middle-Aged Community-Living Population

Purpose

Neck and shoulder pain (NSP) is very common in the general population. However, scarce information exists on the relationship between NSP and health-related quality of life (HRQOL) outcomes in this population. The present study described NSP prevalence and its impact on the HRQOL of middle-aged and older persons undergoing a routine medical checkup.

Methods

This study recruited 318 subjects (125 males and 193 females; average age, 63.4 years) in good health, collected underwent anthropometric measurements, physical function examinations, and blood testing. This study defined NSP as the presence of muscle tension, stiffness, pressure, or dull pain in areas between the neck and the arch of the scapular. Study subjects were divided into two groups (NSP (+) and NSP (-) groups). The subjects completed questions on the Medical Outcomes Study 36-item short-form health survey (SF-36) and the EuroQol 5-dimension, 5-level version (EQ-5D-5L) tool.

Results

Of the patients, 150 and 168 were NSP (+) and NSP (-), respectively. The NSP complaint rate was 47.2%. The NSP (+) group had younger and more female participants than the NSP (-) group. In the multivariate regression analysis, the NSP (+) group had lower physical QOL based on the SF-36 physical component summary (odds ratio (OR), 2.45) and lower mental QOL based on the SF-36 mental component summary (OR, 2.05). Overall, the NSP (+) group had a higher risk of having low QOL scores (EQ-5D-5L index; OR, 1.76).

Conclusions

The NSP (+) rate in healthy middle-aged and older persons was 47.2%. Furthermore, NSP (+) status was directly related poor HRQOL. NSP is a predictor of suboptimal physical and mental QOL. Therefore, NSP prevention or intervention for NSP may improve middle-aged and older adults' QOL.

Sensory, Motor, and Psychosocial Characteristics of Individuals With Chronic Neck Pain: A Case-Control Study

OBJECTIVE

Given the complex and unclear etiology of neck pain, it is important to understand the differences in central sensitization as well as psychosocial factors in individuals with chronic neck pain and healthy controls. The purpose of this study was to benchmark differences in central sensitization, psychosocial factors, and range of motion between people with nonspecific chronic neck pain and healthy controls and to analyze the correlation between pain intensity, neck disability, and psychosocial factors in people with chronic neck pain.

METHODS

Thirty individuals with chronic neck pain and 30 healthy controls were included in this case-control study. Outcome measures were as follows: central sensitization (pressure pain threshold, temporal summation, and conditioned pain modulation), psychosocial factors (depressive symptoms, pain catastrophizing, and quality of life), and active cervical range of motion.

RESULTS

People with neck pain had lower local pressure pain threshold, a decrease in conditioned pain modulation, more depressive symptoms, greater pain catastrophizing, lower quality of life, and reduced range of motion for neck rotation when compared with healthy controls. In people with neck pain, moderate correlations were observed between pain intensity and quality of life (ρ = -0.479), disability and pain catastrophizing (ρ = 0.379), and disability and quality of life (ρ = -0.456).

CONCLUSIONS

People with neck pain have local hyperalgesia, impaired conditioning pain modulation, depressive symptoms, pain catastrophizing, low quality of life, and reduced active range of motion during neck rotation, which should be taken into account during assessment and treatment.

IMPACT

This study shows that important outcomes, such as central sensitization and psychosocial factors, should be considered during assessment and treatment of individuals with nonspecific chronic neck pain. In addition, pain intensity and neck disability are correlated with psychosocial factors.

A Cumulative Impact of Psychological and Sensitization Risk Factors on Pain-Related Outcomes

OBJECTIVE

Risk constructs based on psychological risk factors (eg, pain catastrophizing, PC) and sensitization risk factors (eg, pressure pain threshold, PPT) are important in research and clinical practice. Most research looks at individual constructs but does not consider how different constructs might interact within the same individual. An evaluation of the cumulative impact of psychological and sensitization risk factors on pain-related outcomes may help guide us in the risk assessment of patients with pain conditions. The aim of this study is to evaluate the cumulative impact of these psychological (PC) and sensitization (PPT) risk factors on pain-related outcomes (activity avoidance, pain severity, and disability) considering covariates.

METHODS

We included 109 participants (70.60% women; mean ± SD age 53.6 ± 12.3 years) with chronic musculoskeletal pain for data analysis, who completed all measures of this study. Participants completed a single testing session that included measures of risk factors (PC and PPT) and pain-related outcomes (self-reported avoidance, functional avoidance, disability, and pain severity). Subgroups were constructed by dichotomizing of PC and PPT scores, resulting in four groups: (1) low catastrophizing and low sensitivity (N = 26), (2) high catastrophizing and low sensitivity (N = 27), (3) low catastrophizing and high sensitivity (N = 25), and (4) high catastrophizing and high sensitivity (N = 31).

RESULTS

One-way analysis of variance (ANOVA) revealed significant group differences (P < 0.05, η²  = 0.08 to 0.14) in all outcomes of this study (except functional avoidance), and post hoc analysis indicated the significant differences are between group 1 and 4. A cumulative impact is reflected by large effect sizes between group 1 and 4 (d = 0.8 to 1). The group 2 and 3 (one risk dimension groups: either high-PC or high-PPT) represent 47% of the total participants.

CONCLUSIONS

The study suggests both higher level of PC and pressure sensitivity have a cumulative impact on risk screening for pain-related outcomes, considering gender in functional avoidance (task-related outcome). A clinical presentation with high-PC (one dimension of risk) is not associated with high-PPT (another dimension of risk). This finding has important clinical and theoretical implications.

Age and Gender as Factors of Pressure Sensitivity of Pain-Free Persons: Are They Meaningful?

Purpose

Prior findings suggest that women and elderly persons are more sensitive to pressure than men and younger persons; however, the magnitudes of these differences are substantially inconsistent. We answered the question whether the higher sensitivity of women and elderly persons is quantitatively meaningful. Specifically, we investigated if it is large enough to hamper the diagnosis, classification and follow-up of pain conditions by clinicians.

Materials and Methods

From each age stratum (18–20, 21–30, 31–40, 41–50, 51–60, 61–70, 71–80, and >80 years), 40 pain-free women and 40 pain-free men were recruited. They rated the intensity of pressure of ten Newtons over ten seconds on an analogue zero to ten rating scale. The pressure was applied on their middle fingers and ear lobes with a threshold algometer. Centile curves visualized the sex- and age-dependent fluctuation of pressure sensitivity.

Results

Over the entire age range from 20 to 80 years, the median curves fluctuated within the interval of less than two points. The distance between the median curves of men and women was also less than two points. On the average, the median difference was half a point on the finger (p = 0.249) and the ear lobe (p = 0.083).

Conclusion

Less than two points is below the minimal clinically important difference for a zero to ten analogue pain rating scale; differences smaller than one point are even below the resolution of the scale. Sex differences and age fluctuations of pressure sensitivity are negligible.

Automated driving: A biomechanical approach for sleeping positions

Occupants of autonomous vehicle have frequently indicated the desire to sleep or rest while driving, yet little has been known regarding the suitable design criteria for a biomechanically reasoned in-vehicle sleeping position. This study was aimed at evaluating the biomechanical quality of different backrest and seat pan angle combinations, and at predicting the most favourable sleeping positions based on vehicle restriction. More specifically, the interface pressure distribution and subjective suitability rating of 23 subjects was assessed in a total of nine (3 × 3) combinations of seat pan (20°, 30°, 40°) and backrest (145°, 155°, 165°) angles. Biomechanical quality was evaluated with an interface pressure score (IPS) based on sensitivity weighted pressures and the total contact area. Two-way repeated measures ANOVA revealed that IPS significantly improves with increasing seat pan angle whereas backrest angles of 155° or 165° lead to significant better IPS compared to flatter ones (145°). The overall highest IPS was observed for a 40°-seat pan angle in combination with a 155°-backrest angle. Subjective suitability rating revealed that people prefer a combination of 165° backrest angle with a seat pan of 20°; however, eight of nine combinations can be considered as suitable for sleeping. Therefore, the combination of a 40°-seat pan angle and 155° backrest is recommended by the present study for an in-vehicle sleeping position due to the increased biomechanical quality.

Absolute and relative reliability of pain sensitivity and functional outcomes of the affected shoulder among women with pain after breast cancer treatment

OBJECTIVE

Breast cancer survivors (BCS) are often characterized by decreased pressure pain thresholds (PPT), range of motion (ROM) and strength in and around the shoulder affected by the treatment. This intra-rater reliability study was to establish the relative and absolute reliability of PPT's, active ROM and maximal isokinetic muscle strength (MIMS) of the affected shoulder in BCS with persistent pain after treatment.

METHODS

Twenty-one BCS participated in the study. The PPTs of 17 locations and pain intensity were assessed using a pressure algometer and a numeric rating scale. The ROM was measured using a universal goniometer and MIMS was measured using an isokinetic dynamometer. Relative reliability was estimated using intra class correlation coefficient (ICC), and absolute reliability using standard error of measurement (SEM). Minimum detectable change (MDC) was calculated from SEM.

RESULTS

The ICCs for PPTs ranged from 0.88-0.97, with SEM values ranging from 12.0 to 28.2 kPa and MDC ranging from 33.2 to 78.2 kPa. The ICCs for ROM ranged from 0.66-0.97, with SEM values ranging from 3.0 to 7.5° and MDC ranging from 8.4 to 20.8°. Finally, ICCs for MIMS ranged from 0.62-0.92, with SEM values ranging from 0.03 to 0.07 Nm/Kg FFM and MDC ranging from 0.09 to 0.19 Nm/kg FFM.

CONCLUSION

The results of this study indicate that PPTs, ROM and MIMS can be measured reliably on the affected shoulder in BCS with pain after treatment. This offer the possibility of using these measures to assess the effectiveness of interventions in this population.

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.

Topographical Pressure Pain Sensitivity Maps of the Feet Reveal Bilateral Pain Sensitivity in Patients With Unilateral Plantar Heel Pain

BACKGROUND

Plantar heel pain is one of the most common foot pain conditions treated by health care providers.

OBJECTIVES

To investigate differences in topographical pressure pain sensitivity maps of the feet between patients with unilateral plantar heel pain and healthy individuals, and to determine the relationship between topographical pressure maps, pain intensity, disability, and fascia thickness.

METHODS

Thirty-five patients with unilateral plantar heel pain and 35 matched healthy controls participated in this cross-sectional, case-control study. Pressure pain thresholds (PPTs) were assessed over 7 plantar locations on each foot. Topographical pressure pain sensitivity maps of the plantar region were generated using the averaged PPT of each assessed point. Pain and related disability were assessed with a numeric pain-rating scale (0-10) and the Foot and Ankle Ability Measure, respectively. Plantar fascia thickness was measured via ultrasound. All outcomes were obtained by an assessor blinded to the participants' condition.

RESULTS

Topographical pressure sensitivity maps revealed lower bilateral PPTs in patients with plantar heel pain compared to healthy controls, and a higher PPT on the calcaneus bone (P<.01). Women had lower PPTs than men in all areas (P<.001). Individuals with plantar heel pain also had thicker fascia, but only on the affected side, compared to healthy controls. Higher pressure pain sensitivity in the foot was associated with higher pain intensity at first step in the morning and thicker fascia at the calcaneus bone.

CONCLUSION

People with unilateral plantar heel pain had generalized bilateral pressure pain sensitivity in the plantar region of the foot. Greater pain intensity and fascia thickness were associated with higher pressure pain sensitivity in people with plantar heel pain.

LEVEL OF EVIDENCE

Case-control study, level 4. J Orthop Sports Phys Ther 2019;49(9):640-646. Epub 26 Mar 2019. doi:10.2519/jospt.2019.8813.

Local and Widespread Pressure Pain Hyperalgesia Is Not Side Specific in Females with Unilateral Neck Pain that Can Be Reproduced during Passive Neck Rotation

Current evidence for widespread hyperalgesia in non-specific neck pain (NSNP) is unclear. It is currently recommended to group NSNP patients according to pain-provoking movements. The aim of this study was to investigate local and widespread pain sensitivity in females with unilateral NSNP that is reproducible during passive neck rotation compared with matched controls, and to compare the side specific effect of pain location on pressure pain sensitivity among females with unilateral NSNP. Thirty-six females with unilateral NSNP evoked during passive ipsilateral (n = 20) or contralateral (n = 16) rotation toward the painful side were compared with 20 controls. Participants reported their pain intensity at rest and during passive neck rotation and completed the Neck Disability Index. Pressure pain thresholds (PPTs) were assessed bilaterally over the anterior scalene; the sternocleidomastoid; the levator scapulae; lateral to the spinous process of C6; the median, ulnar, and radial nerves; and the tibialis anterior. The ANOVA revealed lower PPTs in females with unilateral NSNP compared with the controls (all at p < 0.001), but no differences were found between the sides, nor was there any Group × side interaction. Among females with NSNP, those with higher pain intensity during ipsilateral rotation toward the painful side showed lower PPTs over the anterior scalene, median nerve, ulnar nerve, and tibialis anterior (all, p < 0.05) than females with higher pain intensity during contralateral rotation toward the painful side. These findings demonstrated bilateral local and widespread pressure pain hyperalgesia in females with unilateral NSNP that was reproducible during passive neck rotation compared with controls. There was no side specific effect of pain location on PPTs among females with unilateral NSNP.

Differential modulation of pressure pain threshold in response to transcutaneous spinal direct current stimulation with physical activity level

This study investigated the interaction between physical activity level and responses to transcutaneous spinal direct current stimulation (tsDCS) as reflected in changes in pressure pain threshold (PPT) in the lower extremity. Participants (n = 35, 15 males) consisted of physically active young adults. PPTs were determined at three sites (thigh, leg and foot) on the dominant leg before and after 20-min of anodal tsDCS applied at mid-thoracic level. Based on a questionnaire, participants were assigned to either a low-moderately active (n = 21) or highly active group (n = 14). At baseline, participants in the two activity groups exhibited comparable PPTs. After the intervention, PPTs were significantly elevated at all sites at 5-min and 30-min post-tsDCS. An interaction was found between activity groups and tsDCS-induced changes at the thigh site owing to a larger elevation in PPTs in the highly active group. These results corroborate previous findings regarding antalgic effects of tsDCS and point to the role of physical activity level as a potential factor susceptible to modulate responses to tsDCS interventions.

Frequency of reported pain in adult males with muscular dystrophy

INTRODUCTION

The purpose of this study was to present and compare pain between adult males with Duchenne (DMD), Becker's (BMD), Limb-Girdle (LGMD) Facioscapulohumeral (FSHD) forms of Muscular Dystrophy (MD), and healthy controls (CTRL), using three different methods of assessment.

METHODS

Pain was assessed using 1) a whole body visual analogue scale (VAS) of pain, 2) a generalised body map and 3) a localised body map.

RESULTS

All types of MD reported more VAS pain than CTRL, with 97% of all MD participants reporting pain; however, no differences were reported between types of MD. The generalised body map approach identified more frequent pain in the shoulders of FSHD (93%) than other groups (13-43%), hips of DMD (87%) and LGMD (75%) than other groups (0-29%), and legs of all MD (64-78%) than CTRL (25%). The localised body map approach identified common areas of frequent pain across types of MD, posterior distal leg and distal back, as well as condition specific regions of frequent pain, for example posterior trapezius in FSHD, and anterior hip pain in DMD and LGMD.

CONCLUSIONS

Using a single pain value (VAS), increased pain was reported by adults with MD compared to CTRL, with no clear differences between different MD groups, suggesting pain is symptomatic of MD. The use of the generalised body map approach, and to an even greater extent the localised body map approach, identified specific areas of frequent pain relevant to each individual condition. These results indicate that whist the commonly used generalised approach can be used to identify broad anatomical regions, the localised approach provides a more comprehensive understanding of pain, reflective of clinical assessment, and should be utilised in future research.

Evaluating the novel added value of neurophysiological pain sensitivity within the fear-avoidance model of pain

BACKGROUND

The fear-avoidance model (FAM) is a leading theoretical paradigm for explaining persistent pain following musculoskeletal injury. The model suggests that as injuries heal, pain-related outcomes are increasingly determined by psychological, rather than physiological factors. Increasing literature, however, suggests that neurophysiological processes related to pain sensitivity also play an important role in chronicity. To date, there has been limited research that has specifically explored the role of pain sensitivity within the FAM. This study addresses this gap by evaluating whether clinical measures of pain sensitivity help explain FAM-related outcomes, beyond model-relevant psychological predictors.

METHODS

The study sample consisted of 80 adults with chronic and widespread musculoskeletal pain. Participants completed a single testing session that included measures of all of the major constructs of the FAM, including pain catastrophizing, pain-related fear, activity avoidance (self-report and functional measures), pain-related disability, depression and pain severity, as well as a battery of quantitative sensory testing that included measures of pressure pain threshold and temporal summation of mechanical pain across eight body sites.

RESULTS

A series of hierarchical regression analyses revealed that after controlling for the psychological predictors of the FAM, indices of pain sensitivity significantly predicted 4 of the 5 FAM-related outcomes (p < 0.05). Depression was the only outcome not significantly predicted by pain sensitivity. Interestingly, measures of pain sensitivity, but not FAM psychological factors, predicted the functional measure of activity avoidance.

CONCLUSIONS

These findings provide further evidence for the importance of neurophysiological factors within the FAM and have important clinical and theoretical implications.

SIGNIFICANCE

This study provides evidence for the unique and added value of neurophysiological factors within the Fear Avoidance Model of pain and for the importance of integrating both sensory and psychological factors within both theoretical paradigms and clinical management strategies.

Assessment of the impact of Hold-Relax and Contract-Relax techniques on the compression pain threshold in patients with lateral humeral epicondylitis

Background. The method of proprioceptive neuromuscular paving (PNF) is unique in that it has its own principles of working with the patient. The overriding therapeutic goal during PNF therapy is to work on a lost function that is important for the patient. Objective. The aim of the study was to assess the impact of Hold-Relax and Contract-Relax techniques on the compression pain threshold in patients with lateral humeral epicondylitis. Material and method. The study involved 60 patients aged 47.8 ± 4.3 with inflammation of the lateral humeral epicondyle. There were 35 women and 25 men in the study group. In each examined person it was the first incident of lateral humeral epicondylitis. In each of the probands, subjective and physical physiotherapeutic examination was carried out. 41 left and 19 right limbs were tested. Measurements were made under standard conditions. Among the physiotherapeutic tests performed were: examination of the range of motion, assessment of the compression pain threshold using an algometer, and pain assessment during extension and radial deviation of the wrist with a load. The study of the range of movement was carried out using an electronic goniometer. Then, the subjects were randomly divided into two groups: group "A" in which the Hold-Relax technique was performed on the muscle group that extends and radially deviates the wrist and group "B" in which Contract-Relax was applied to the same muscle group. The therapy lasted 30 minutes and was continued for the next 10 days. In each group, apart from the mentioned techniques, physiotherapy treatments were applied as indicated. After the therapy, the tests that preceded the therapies were repeated. The obtained results were placed in the database and subjected to statistical analysis using the Statistica program. Results. The mean extent of the extension movement in the radiocarpal joint before the therapy in group "A" was 45.7 ± 4.7 while in group "B" it was 40.1 ± 3.79. After treatment, the mean range of motion increased in the "A" group to 67.46 ± 8.69 and in the "B" group to 71.6 ± 8.3. In both groups, changes were observed at the statistically significant level p = 0. Conclusion. 1. The use of both the Hold-Relax and Contract-Relax techniques had an impact on the change of the compression pain threshold.2. The use of Hold Relax and Contract Relax techniques has an impact on increasing the range of motion in patients with lateral epicondylitis.

Impact of classic massage on the pressure pain threshold- a preliminary study

Background: The pressure pain threshold (PPT) differs by muscle, depends on sex, age, and health status, and alters under the influence of disease. It is interesting to ask how and whether tissue sensitivity changes after the application of therapy. Aim of the study: The purpose of this study was to assess in healthy individuals the pressure sensitivity of muscles in the torso following a classic massage. Material and methods: A measurement of the pressure sensitivity of certain muscles of the back (the latissimus dorsi, the trapezius, and the spinal erector) was performed using an algometer before classic back massage and immediately after the procedure. A classic back massage was given to 60 healthy volunteers aged 20–47 years. The massage lasted 20 minutes and the major techniques were performed on selected superficial and deep muscles of the back. Results: The pressure sensitivity of the muscles decreased after the classic massage. Statistically significant changes were observed in the right (p < 0.001) and left (p = 0.002) spinal erectors; in the transverse part on both sides (p < 0.001), and in the descending part on both sides (p < 0.001) of the trapezius muscle; and in the right (p = 0.008) and left (p = 0.004) of the latissimus dorsi muscle. Conclusions: Classic massage alleviates tissue sensitivity to pressure in healthy individuals. It can be effective in cases of increased resting muscle tone accompanied by increased tissue sensitivity.

Gua Sha therapy for chronic low back pain: A randomized controlled trial

OBJECTIVE

To test the efficacy of Gua Sha therapy in patients with chronic low back pain.

METHODS

50 patients with chronic low back pain (78% female, 49.7 ± 10.0 years) were randomized to two Gua Sha treatments (n = 25) or waitlist control (n = 25). Primary outcome was current pain intensity (100-mm visual analog scale); secondary outcome measures included function (Oswestry Disability Index), pain on movement (Pain on Movement Questionnaire), perceived change in health status, pressure pain threshold, mechanical detection threshold, and vibration detection threshold.

RESULTS

After treatment, patients in the Gua Sha group reported lower pain intensity (p < 0.001) and better overall health status (p = 0.002) compared to the waitlist group. No further group differences were found. No serious adverse events occurred.

CONCLUSIONS

Gua Sha appears to be an acceptable, safe, and effective treatment for patients with chronic low back pain. Further rigorous studies are needed to confirm and extend these results.

Assessment of the influence of ischemic compression and clavitherapy on compression pain threshold measured on the lumbar spine rectifier muscle

Background. The British physician, Balfour, at the beginning of the nineteenth century was one of the first to describe thickened nodules and bumps in tissue, which could be painful under pressure. This pressure often also caused pain in other distant parts of the body. The above characteristics perfectly reflected what is now referred to as the trigger point. Objective. The aim of this study was to assess the impact of ischemic compression using clavitherapy on the level of compression pain threshold measured with an algometer on the muscle of the lumbar region spine extender. The following research questions were posed: Materials and methods. The research involved 40 patients with pain in the paraspinal muscles who were attending the Physio-Wysz Rehabilitation Center. In each subject, pain threshold was assessed using an algometer, 5 points before and after therapy. Each subject was then subjected to ischemic compression for each of the 5 points. The obtained results were entered into an Excel™ database and then analyzed using the Statistica program. Results. The mean value of the pain threshold for the L1 point before therapy was 114.4 ±17.22 N/cm2 and for P1 was 113.24±18.85 N/cm2. Immediately after therapy, the compression pain threshold decreased to 84.15±10.79 N/cm2 and 84.89 ±10.11 N/cm2 for the L1 and P1 points, respectively. Conclusions. There was a reduction in the mean compression pain threshold immediately after clavicle therapy. There were no significant differences when measuring the pressure pain threshold after therapy.

Topographic mapping of pain sensitivity of the lower back – a comparison of healthy controls and patients with chronic non-specific low back pain

Background and aims

The choice of testing site for quantitative sensory testing (QST) of pain sensitivity is important and previous studies have demonstrated patterns in pain sensitivity within discrete areas in different body regions. Some areas are characterized by a relatively high degree of spatial pain discrimination and recognizable patterns of pain referral, whilst others are not. The lumbar region is likely to have relatively low pain acuity and overlapping of pain referral. The current study was conducted to determine whether patterns of pain sensitivity (detection thresholds) could be identified in the lower back, whether differences in such patterns exist between different groups and whether such patterns could help identify a clinical source of pain and localized increased pain sensitivity.

Methods

Twenty-one patients with non-specific chronic low back pain and 21 healthy controls were tested for pressure and heat pain thresholds on 30 pre-defined locations over the mid and lower back. Topographical maps of mean pain thresholds and variability were produced, inspected visually and analyzed statistically. Between group differences in pain threshold were analyzed statistically as an indicator of widespread increased pain sensitivity. Evidence of segmental increased pain sensitivity was examined by group statistical comparison of mid-line lower range.

Results

A clear pattern of higher pain thresholds in the mid-line was evident in both groups and for both pain modalities. No discernible patterns were evident for variability within groups, but marked differences were seen between groups: variability for pressure pain thresholds appeared similar between groups, however for heat pain threshold, variability was uniformly low in the control group and uniformly high in the patient group. A highly significant (p<0.0001) difference in pain thresholds for pressure and heat was found with patients exhibiting lower thresholds than controls. No between group difference was found for mid-line lower range for either modality (p>0.05).

Conclusions

The current study supports previous findings of widespread, increased pain sensitivity in chronic non-specific low-back pain patients. It also indicates that there are discernible and similar topographical patterns of pain sensitivity in the dorsal area in both groups, but that this pattern is related to the lateral position of the test site and not the segmental level. Specific segments with increased pain sensitivity could not be identified in the patient group, which casts doubt on the utility of pressure and heat pain thresholds as indicators of the clinical source of spinal pain – at least in a population of chronic non-specific low-back pain.

Implications

In a cohort of chronic non-specific low-back pain patients and with the chosen methodology, topographical QST mapping in the lumbar region does not appear useful for identifying the spinal segment responsible for clinical pain, but it does demonstrate widespread group differences in pain sensitivity.

Spotlight on topographical pressure pain sensitivity maps: a review

Mechanical hyperalgesia defined as decreased pressure pain thresholds (PPTs) is commonly associated with pain. In this narrative review, we report the current state of the art within topographical pressure sensitivity maps. Such maps are based on multiple PPT assessments. The PPTs are assessed by an a priori defined grid with special focus on both spatial and temporal summation issues. The grid covers the muscle or the body region of interest using absolute or relative values determined from anatomical landmarks or anthropometric values. The collected PPTs are interpolated by Shepard or Franke and Nielson interpolation methods to create topographical pressure sensitivity maps. This new imaging technique has proven to be valuable in various disciplines including exercise physiology, neurology, physical therapy, occupational medicine, oncology, orthopedics, and sport sciences. The reviewed papers have targeted different body regions like the scalp, low back, neck-shoulder, and upper and lower extremities. The maps have delineated spatial heterogeneity in the pressure pain sensitivity underlining the different extents of pressure pain hyperalgesia in both experimentally induced and disease-associated pain conditions. Furthermore, various intervention studies have proven the utility of topographical pressure pain sensitivity maps. Topographical pressure pain sensitivity maps have contributed to revealing the efficacy of therapeutic, ergonomic, or training interventions that aim at reducing pain.

Effects of a Worksite Supervised Adapted Physical Activity Program on Trunk Muscle Endurance, Flexibility, and Pain Sensitivity Among Vineyard Workers

OBJECTIVES

In viticulture, the prevalence of low back pain is particularly high among vineyard workers exposed to sustained and awkward postures. One promising setting for low back pain prevention resides in the implementation of workplace physical activity.

METHODS

This nonrandomized pilot study aims at evaluating the effects of a worksite supervised adapted physical activity program among 17 vineyard workers volunteered to enter either an intervention group (n = 10) or a control group (n = 7).The intervention group followed a physical activity program for 8 weeks involving (1) 15 minutes of warm-up every working day and (2) two weekly 1-hour adapted physical activity sessions targeting trunk muscle endurance and flexibility. The control group was advised to continue normal physical activity. Evaluations were carried out at weeks 0, 4, 8, and 12. Physical capacity was assessed using flexibility tests for the trunk, along with trunk muscle flexor and extensor endurance tests. Finally, pain sensitivity was evaluated by assessing pressure pain thresholds over 14 anatomical locations in the low back region.

RESULTS

For the intervention group, the endurance of the trunk extensor and flexor significantly increased from baseline to week 8 as well as the pressure pain thresholds. No change was observed for the control group over the same period.

CONCLUSIONS

These encouraging results in combination with the high adherence rate set interesting foundations for the promotion of worksite supervised adapted physical activity and, most likely, offer a new promising approach to prevent low back pain among vineyard workers.

[Characteristic of the normal values of the pain threshold values in the dorsal region of the young women obtained by the pressure algometry method under different condition]

The application of modern techniques for different types of massage and manual therapy is associated with the exposure of the paravetrebral points. The knowledge of pain threshold values at these points is of great practical significance.

AIM

The objective of the present study was to obtain the statistical characteristics of the individual pressure pain threshold (PPT) for the healthy women and patients presenting with minor disturbances of spinal motion segments (SMS) at the trigger points on the back. The secondary objective was to estimate the dependence of the PPT parameters on a variety of conditions.

MATERIAL AND METHODS

Two groups of female volunteers (students of the South Ural State Humanitarian Pedagogical University aged 19-21 years) were formed, one composed of the girls in the quiescent state (group 1, n=45), the other comprised of the girls in the state of emotional agitation and prepared for physical activity (group 2, n=105). Each group was split into two sub-groups depending on the presence or absence of complaints about the state of the SMS. PPT was evaluated in terms of kg/cm2 with the use of the Wagner FPX algometer (USA) at 3 paired paravertebral points localized at different levels: the second and third lumbar vertebrae (LII-LIII); the ninth-to-tenth thoracic vertebrae (DIХ-DХ), the seventh cervical, and first thoracic vertebrae (CVII-DI); as well as in pairs on the trapezius muscles in their upper parts. The height, weight, and body mass index of the participants in the study were measured.

RESULTS

The PPTs values at the selected points on the back were log-normally distributed. The minimum values were measured on the trapezoidal muscles (about 2 kg/cm2) and the maximum ones in the lumbar spineregion (up to 7 kg/cm2). Complaints about the condition of SMS in group 1 were associated with the decrease of the PPT values at the paravertebral points on the neck and the lower back. No decrease of the PPT values in connection with the complaints was documented in the patients of group 2. The PPT values determined in the women of group 2 were statistically higher than in those of group 1 at all points studied and in all the subgroups; the differences ranged from 20% to 40%. The PPTs values at different points of the back correlated significantly between each other (Spearman correlation coefficient 0.6-0.9, p<0.001). In all the groups statistically significant asymmetry of the PPT values was documented (Kruskal-Wallis test, p<0.05); the right-side PPT values were lower than the left-side ones, with the difference amounting to 2-8%.

CONCLUSION

The conditions of PPT measurements at the paravertebral points have a significant impact on the resultant values, being higher when the subject is ready for performing the physical exercises. The complaints about the state of the SMS are associated with the decrease in the PPT values that are lower on the right side of the body than on its left side.

Sensitivity of the human back and buttocks: The missing link in comfort seat design

PURPOSE

The purpose of this study is to examine the differences in pressure sensitivity for areas of the human body in contact with the seat pan and backrest of a vehicle seat. These could provide a theoretical base for adapting the softness of the foam or the flexibility components used in seat design.

METHODS

Sensitivity was recorded at 32 points touching the seat pan and backrest by pushing a cylinder with a diameter of 20 mm into the seat until the participant reported that they were no longer comfortable. The force at which discomfort was reported was recorded using an advanced force gauge.

RESULTS AND CONCLUSIONS

The area of the body having contact with the front of the seat pan was more sensitive than the rest of those parts touching the seat pan. The area of the seat touching the shoulders was significantly more sensitive than the area in between the shoulders and lower down the back. Translating these findings directly into seat design should be done with care. Tests are still needed to confirm the assumed relationship between sensitivity and foam softness. Further information is also needed regarding the complete use of a seat, including analysis of vibrations while driving and comfort during ingress and egress.

Learning Curves Observed in Establishing Targeted Rate of Force Application in Pressure Pain Algometry

Purpose: To determine whether learning curves can be observed with deliberate practice when the goal is to apply a consistent rate of force at 5 N/second during pressure pain threshold (PPT) testing in healthy volunteers. Methods: In this prospective study, 17 clinician participants completed PPT targeted rate-of-application testing with healthy volunteers using three different feedback paradigms. The resultant performances of ramp rate during 36 trials were plotted on a graph and examined to determine whether learning curves were observed. Results: Clinicians were not consistent in the rate of force applied. None demonstrated a learning curve over the course of 36 trials and three testing paradigms. Conclusion: The results of this study indicate that applying a consistent 5 N/second of force is difficult for practising clinicians. The lack of learning curves observed suggests that educational strategies for clinicians using PPT may need to change.

Intra-session absolute and relative reliability of pressure pain thresholds in the low back region of vine-workers: ffect of the number of trials

BACKGROUND

Pressure pain thresholds (PPT) are commonly used to quantify mechanical pain sensitivity of deep structures. Excellent PPT reliability has been previously reported among the low back of healthy subjects. However, there is a lack of studies assessing PPT over the low back of workers exposed to biomechanical risk factors of low back pain. Thus, the purpose of this study was threefold: (1) to evaluate the intra-session absolute and relative reliability as well as minimal detectable change (MDC) values of PPT within 14 locations covering the low back region of vine-workers and (2) to determine the number of trial required to ensure reliable PPT assessments and (3) to assess the effect of modifier factors such as gender, age, body mass index (BMI) and pain intensity on PPT reliability.

METHODS

Twenty-nine vine-workers voluntarily participated in this study. Twenty-two reported low intensity of low-back pain while seven were pain-free. PPTs were assessed among 14 anatomical locations in the lower back region. Three trials were performed on each location with an interval time of at least one minute. Reliability was assessed computing intraclass correlation coefficients (ICC), standard error of measurement (SEM) for all possible combinations between trials. Bland-Altman plots were also generated to assess potential bias in the dataset. Finally, a repeated measure analysis of variance (RM-ANOVA) with the number of trials used as within subject factor was performed on (1) PPT, (2) ICC and (3) SEM values.

RESULTS

ICC ranged from 0.86 to 0.99 for all anatomical locations and for all possible combinations between trials. SEM for comparison between trial 1-2, 2-3, 1-3 and, 1-2-3 ranged from respectively, 36.7-77.5, 27.8-77.7, 50-95.2 and, 39.3-80.8 kPa. ICC and SEM remained similar to the ones obtained for the entire population when taking modifier factors in consideration. The visual analysis of Bland-Altman plots suggested small measurement errors for all anatomical locations and for all possible combinations between trials.

CONCLUSIONS

The assessment of PPTs of the lower back among vine-workers was found to have excellent relative and absolute reliability. Moreover, reliable measurements can be equally achieved when using the mean of three PPT measurement or with the first one.

Is One Trial Sufficient to Obtain Excellent Pressure Pain Threshold Reliability in the Low Back of Asymptomatic Individuals? A Test-Retest Study

The assessment of pressure pain threshold (PPT) provides a quantitative value related to the mechanical sensitivity to pain of deep structures. Although excellent reliability of PPT has been reported in numerous anatomical locations, its absolute and relative reliability in the lower back region remains to be determined. Because of the high prevalence of low back pain in the general population and because low back pain is one of the leading causes of disability in industrialized countries, assessing pressure pain thresholds over the low back is particularly of interest. The purpose of this study study was (1) to evaluate the intra- and inter- absolute and relative reliability of PPT within 14 locations covering the low back region of asymptomatic individuals and (2) to determine the number of trial required to ensure reliable PPT measurements. Fifteen asymptomatic subjects were included in this study. PPTs were assessed among 14 anatomical locations in the low back region over two sessions separated by one hour interval. For the two sessions, three PPT assessments were performed on each location. Reliability was assessed computing intraclass correlation coefficients (ICC), standard error of measurement (SEM) and minimum detectable change (MDC) for all possible combinations between trials and sessions. Bland-Altman plots were also generated to assess potential bias in the dataset. Relative reliability for both intra- and inter- session was almost perfect with ICC ranged from 0.85 to 0.99. With respect to the intra-session, no statistical difference was reported for ICCs and SEM regardless of the conducted comparisons between trials. Conversely, for inter-session, ICCs and SEM values were significantly larger when two consecutive PPT measurements were used for data analysis. No significant difference was observed for the comparison between two consecutive measurements and three measurements. Excellent relative and absolute reliabilities were reported for both intra- and inter-session. Reliable measurements can be equally achieved when using the mean of two or three consecutive PPT measurements, as usually proposed in the literature, or with only the first one. Although reliability was almost perfect regardless of the conducted comparison between PPT assessments, our results suggest using two consecutive measurements to obtain higher short term absolute reliability.