Intraexaminer and Interexaminer Reliability of Manual Palpation and Pressure Algometry of the Lower Limb Nerves in Asymptomatic Subjects

Proposal for Manual Osteopathic Treatment of the Phrenic Nerve

The article reviews the anatomical path of the phrenic nerve and its anastomoses, with the most up-to-date knowledge reported in the literature. We have briefly reviewed the possible phrenic dysfunctions, with the final aim of presenting an osteopathic manual approach for the treatment of the most superficial portion of the nerve, using a gentle technique. The approach we propose is, therefore, a theory based on clinical experience and the rationale that we can extrapolate from the literature. We hope that the article will be a stimulus for further experimental investigations using the technique illustrated in the article. To the authors' knowledge, this is the first article that takes into consideration the hypothesis of an osteopathic treatment with gentle techniques for the phrenic nerve.

Effects of the Three-Direction Movement Control Focus Complex Pain Program and Neurodynamic Focus Complex Pain Program on Pain, Mechanosensitivity, and Body Function in Taekwondo Athletes with Non-Specific Low Back Pain: A Preliminary Study

We aimed to determine the effects of three-direction movement control focus complex pain program (3D-MCE) and neurodynamic focus complex pain program (NDT) on pain, mechanosensitivity, and body function in Taekwondo athletes with non-specific low back pain. This study used a two-group pretest-posttest design and was conducted at a university physiotherapy lab and training center. It included 21 Taekwondo athletes with non-specific low back pain from a Taekwondo studio and a University in Busan. Participants were divided into a 3D-MCE group (n = 10) and an NDT group (n = 10). The numerical rating pain scale (NRPS), pain pressure threshold (PPT), movement analysis, and Oswestry Disability Index (ODI) were measured before and after the intervention. The intervention was performed for 45 min twice a week for 4 weeks. Each group performed movement control exercises and neurodynamic techniques. The NRPS, motion analysis, and ODI were significantly changed after the intervention in the 3-DMCE group. The NRPS, PPT, and ODI changed significantly after the intervention in the NDT group. Moreover, the PPT and motion analysis showed significant differences between the two groups. For Taekwondo athletes with non-specific low back pain, 3D-MCE improved the stability control ability of the lumbar spine. It was confirmed that neurodynamic techniques reduce muscle and nerve mechanosensitivity.

Measurement of pressure discomfort threshold in auricular concha for in-ear wearables design

In an effort to mitigate the homogenization of in-ear wearables, designers have been focusing on finding new solutions to enhance user comfort. While the concept of pressure discomfort thresholds (PDT) in humans has been applied to product design, research on the auricular concha remains scarce. In this study, we conducted an experiment to measure the PDT at six points in the auricular concha of 80 participants. Our results showed that the tragus was the most sensitive area and that gender, symmetry, and Body Mass Index (BMI)had no significant effect on PDT. Based on these findings, we generated pressure sensitivity maps of the auricular concha to aid in the optimization of in-ear wearable design.

Accuracy of Pain Tolerance Self-assessment Versus Objective Pressure Sensitivity

INTRODUCTION

Effective treatment of postoperative pain after elective surgery remains elusive, and the experience of pain can be variable for patients. The patient's intrinsic pain tolerance may contribute to this variability. We sought to identify whether there was a correlation between subjective report of intrinsic pain tolerance and objective measurement of pressure dolorimetry (PD). We also sought to identify whether a correlation existed between PD and Patient Reported Outcome Measurement Information System (PROMIS) scores of pain intensity, physical function, and mood. PD is a validated, objective method to assess pain tolerance. Markers of general mental and physical health are correlated with pain sensitization and may also be linked to pain tolerance.

METHODS

PROMIS scores, dolorimetry measurements, and survey data were collected on 40 consecutive orthopaedic foot and ankle surgery patients at the initial clinic visit. Patients were included if they had normal sensation on the plantar foot and no prior surgery or plantar heel source of pain.

RESULTS

Objective dolorimetry data reflecting 5/10 pain for the patients were 24 N/cm2 (±8.9). Patients estimated their pain threshold as 7.3/10 (±2.1). No correlation was found between objective and subjective pain threshold identified. A moderate negative correlation of R = -0.44 was observed regarding PROMIS-M with dolorimetry data (P < -0.05). PROMIS-M score >60 had a significant decrease in pain threshold to 15.9 ± 8.5 N/cm2 compared with 25.7 ± 8.9 N/cm2 for those who were less depressed with a PROMIS<60 (P < 0.05).

CONCLUSION

Subjective pain tolerance is not correlated with the patient's own objective pain threshold or markers of mental health and should not be used to assist clinical decision making. PROMIS-M is inversely correlated with objective pain. Higher PROMIS-M scores are associated with a lower objective pain threshold.

LEVEL OF EVIDENCE

Level II-Lesser Quality Randomized Controlled Trial or Prospective Comparative Study.

Analyzing the Interaction between Clinical, Neurophysiological and Psychological Outcomes Underlying Chronic Plantar Heel Pain: A Network Analysis Study

Plantar heel pain (PHP) is one of the most common foot pain conditions in adults. Several biological and psychological factors could be involved in chronic PHP in a complex matrix. However, reciprocal interactions between these factors are unknown. The aim of the present study was to use network analysis to quantify potential multivariate relationships between pain-related, function, clinical, mechanosensitivity, psychological, and health-related variables in individuals with PHP. Demographic (age, gender), pain-related (pain intensity), function, clinical (myofascial trigger points [TrPs]), mechanosensitivity (pressure pain thresholds), psychological (Beck Depression Inventory), and health-related variables (EQ-5D-5L) were collected in 81 PHP patients. Network connectivity analysis was conducted to quantify the adjusted correlations between the modeled variables and to assess their centrality indices. The connectivity network showed local associations between pain-related variables, foot function, and mechanosensitivity. Additionally, associations between quality of life, depression, and pain-related variables were found, while TrPs was associated with quality of life and mechanosensitivity. The node with the highest strength centrality was the worst pain intensity, while mechanosensitivity and worst pain intensity showed the highest closeness and betweenness centrality. This is the first study to apply network modeling to understand the connections between pain-related, function, clinical, mechanosensitivity, psychological, and health-related variables in PHP. The role of pain severity and mechanosensitivity is highlighted and supported by the network. Thus, this study reveals potential factors that could be the target in the management of PHP, promoting a comprehensive and effective therapeutic approach.

Pain threshold in selected trigger points of superficial muscles of the back in young adults

BACKGROUND

Monitoring of pain threshold is the basis for verification of the effectiveness of therapy or assessment of the patient's condition. This study aimed to determine the pain threshold of selected superficial muscles of the back taking into account trigger point activity in young and healthy males and females, with the evaluation of intrarater reliability of algometric measurements.

MATERIAL AND METHODS

The study examined 30 young adult participants (15 males and 15 females) aged 26.23 ± 3.21, and BMI of 23.80 ± 3.43. The Pain Test FPX Algometer (Wagner) was used for the study. Trigger points on the levator scapulae and trapezius muscles (superior and inferior portion) on both sides were examined. It was also verified whether the trigger points studied are active or inactive. Furthermore, an author's survey questionnaire was used.

RESULTS

Within the trigger points of the right (p = 0.04) and left (p = 0.02) superior trapezius muscle and the left (p = 0.04) levator scapulae muscle, the pain threshold values were higher in the male group. There was a statistically significantly higher number of active trigger points in the female group compared to that in the male group (2.49 ± 1.51 vs. 1.07 ± 1.16, respectively), p = 0.01. For all muscles tested, mean pain threshold values were significantly higher for inactive trigger points. A greater number of active trigger points is associated with lower pain thresholds at these points (left: the superior trapezius, r = -0.597, the inferior trapezius, r = -0.609; the levator scapulae, r = -0.746; right: the superior trapezius, r = -0.610, the inferior trapezius, r = -0.604; the levator scapulae, r = -0.747). The evaluation of the intrarater reliability showed excellent agreement between the first and second measurements, ICC > 0.987 for all examined trigger points.

CONCLUSIONS

(1) Women who reported pain more than once a week in the studied muscles showed a greater number of active trigger points. (2) A greater number of active trigger points in female is related to a lower pain threshold (which is associated with greater pain sensitivity) in female than in male. (3) A sample size of 30 people seems sufficient to detect variations in the pain threshold at active and inactive trigger points of selected back muscles, especially when the frequency of occurrence of both types of points is comparable.

Assessment of pressure sensitivity in the head region for Chinese adults

Measurement of pressure threshold has found its applications in the fields of medical sciences and product design. Hence it has been a profound area of research interest for several decades. However, hardly any detailed investigation has been undertaken to measure the pressure threshold in the head region. In this study, Pressure Discomfort Threshold (PDT) and Pressure Pain Threshold (PPT) were measured for two hundred eighteen healthy Chinese adults at seventy-six anatomical locations, and further statistical analyses were performed on the acquired data to understand the relationship between different demographic parameters. The results suggest that the pressure sensitivity is low in the vertex region, moderate in the forehead and temporal area, and high in the facial and nasal region. From this study, pressure sensitivity maps were developed for PDT and PPT for Chinese adults. The measured pressure threshold data showed no significant relationship with age and Body Mass Index (BMI).

Intra-Rater and Inter-Rater Reliability of Pressure Pain Algometry of the Sural and Tibial Nerves in Asymptomatic Elite Youth Footballers

Ankle injuries are highly prevalent in elite youth footballers and increase the mechanosensitivity of the local neural tissue, which may predispose athletes to re-injury and prolong rehabilitation periods. Increased neural mechanosensitivity presents clinically as altered pain pressure thresholds (PPTs) which are measured with pressure algometry. The purpose of this study was to determine the intra-rater and inter-rater reliability of PPTs of the ankle neural tissue in asymptomatic elite youth football players. Three raters utilised a digital algometer to evaluate the PPTs of the Sural and Tibial nervous tissue at the ankle of elite youth male footballers. Intraclass correlation coefficients (ICCs) with 95% confidence intervals (CI) were calculated to assess intra-rater and inter-rater reliability and Bland-Altman figures were plotted to enable visual evaluation of measurement error with a significance level of p < 0.05. Thirty-four players (16-18 years old) were assessed. Excellent intra-rater (Tibial ICC 0.88 (0.76-0.94); Sural ICC 0.89 (0.79-0.95)) and good inter-rater reliability (Tibial ICC 0.66 (0.40-0.82); Sural 0.71 (0.50-0.85)) was demonstrated. Bland-Altman plots demonstrated low levels of measurement error. Pressure algometry can be utilised clinically to accurately evaluate the PPTs of the Tibial and Sural nervous tissue at the ankle in asymptomatic elite male youth footballers.

Neuromuscular Mechanosensitivity in Subjects with Chronic Ankle Sprain: A Cross-Sectional Study

BACKGROUND

Ankle sprain is one of the most common musculoskeletal injuries in sports, at work, and at home. Subjects who suffer from this injury may develop ankle instability. Functional instability has been associated with a high rate of resprain and impaired neuromuscular control in patients with ankle instability.

OBJECTIVE

Measurement of neural and muscular mechanosensitivity after ankle sprain injury and establishment of the relationship between these variables.

METHODS

A cross-sectional case-control study was performed with a sample of 58 students from Alcalá de Henares University (21 males and 37 females, mean age ± SD = 21 ± 3.7 years). Subjects were divided into two groups: a case group (N = 29, subjects with unstable ankle) and a control group (N = 29, healthy subjects). The pressure pain threshold (PPT) of the tibialis anterior, peroneus longus, and peroneus brevis muscles and mechanosensitivity of the common peroneus and tibial nerves were evaluated in all subjects through a manual mechanical algometer.

RESULTS

Neuromuscular PPTs showed significant differences (P < 0.05) between both groups, such that, compared with the control group, the case group exhibited significantly lower PPT levels. In the case group, a strong positive correlation was observed between neural and muscular homolateral mechanosensitivity in both lower limbs.

CONCLUSIONS

Participants with chronic ankle instability showed higher neuromuscular mechanosensitivity in muscles and nerves surrounding the ankle joint than healthy subjects. These findings indicate that low PPT values may be associated with symptoms that characterize this disease.

Methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system: a systematic review

ABSTRACT

Mechanism-based classification of pain has been advocated widely to aid tailoring of interventions for individuals experiencing persistent musculoskeletal pain. Three pain mechanism categories (PMCs) are defined by the International Association for the Study of Pain: nociceptive, neuropathic, and nociplastic pain. Discrimination between them remains challenging. This study aimed to build on a framework developed to converge the diverse literature of PMCs to systematically review methods purported to discriminate between them; synthesise and thematically analyse these methods to identify the convergence and divergence of opinion; and report validation, psychometric properties, and strengths/weaknesses of these methods. The search strategy identified articles discussing methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system. Studies that assessed the validity of methods to discriminate between categories were assessed for quality. Extraction and thematic analysis were undertaken on 184 articles. Data synthesis identified 200 methods in 5 themes: clinical examination, quantitative sensory testing, imaging, diagnostic and laboratory testing, and pain-type questionnaires. Few methods have been validated for discrimination between PMCs. There was general convergence but some disagreement regarding findings that discriminate between PMCs. A combination of features and methods, rather than a single method, was generally recommended to discriminate between PMCs. Two major limitations were identified: an overlap of findings of methods between categories due to mixed presentations and many methods considered discrimination between 2 PMCs but not others. The results of this review provide a foundation to refine methods to differentiate mechanisms for musculoskeletal pain.

Sonographic measures and sensory threshold of the normal sciatic nerve and hamstring muscles

PURPOSE

The sciatic nerve innervates the hamstring muscles. Occasionally, the sciatic nerve is injured along with a hamstring muscle. Detailed biomechanical and sensory thresholds of these structures are not well-characterized. Therefore, we designed a prospective study that explored high-resolution ultrasound (US) at multiple sites to evaluate properties of the sciatic nerve, including cross-sectional area (CSA) and shear-wave elastography (SWE). We also assessed SWE of each hamstring muscle at multiple sites. Mechanical algometry was obtained from the sciatic nerve and hamstring muscles to assess multi-site pressure pain threshold (PPT).

METHODS

Seventy-nine asymptomatic sciatic nerves and 147 hamstring muscles (25 males, 24 females) aged 18-50 years were evaluated. One chiropractic radiologist with 4.5 years of US experience performed the evaluations. Sciatic nerves were sampled along the posterior thigh at four sites obtaining CSA, SWE, and algometry. All three hamstring muscles were sampled at two sites utilizing SWE and algometry. Descriptive statistics, two-way ANOVA, and rater reliability were assessed for data analysis with p ≤ 0.05.

RESULTS

A significant decrease in sciatic CSA from proximal to distal was correlated with increasing BMI (p < 0.001). Intra-rater and inter-rater reliability for CSA was moderate and poor, respectively. Elastographic values significantly increased from proximal to distal with significant differences in gender and BMI (p = 0.002). Sciatic PPT significantly decreased between sites 1 and 2, 1 and 3, and 1 and 4. Significant correlation between gender and PPT was noted as well as BMI (p < 0.001). Hamstring muscle elastographic values significantly differed between biceps femoris and semitendinosus (p < 0.001) and biceps femoris and semimembranosus (p < 0.001). All three hamstring muscles demonstrated increased PPT in males compared to females (p < 0.001). In addition, PPT of the biceps femoris correlated with BMI (p = 0.02).

CONCLUSION

High-resolution US provided useful metrics of sciatic nerve size and biomechanical properties. PPT for the normal sciatic nerve and hamstring muscles was obtained for future clinical application.

Inadequacies of the Lasègue test, and how the Slump and Bowstring tests are useful for the diagnosis of sciatica

Diagnosis of sciatica mainly relies on pain reproduction by stretching of the lumbar roots since neurological examination and medical history are usually not sufficient to guarantee diagnosis. The Lasègue test is the most popular method, which starts with the straight leg-raising test (SLR). However it is not perfect, and is not always well performed or interpreted. Passive ankle dorsiflexion at the end of the SLR (Bragard test) is more sensitive, but can also remain normal in some cases of sciatica. Other stretching tests can help to recognise lumbar root damage in patients with poorly defined pain in a lower extremity: firstly, the Christodoulides test, i.e. reproduction of L5 sciatic pain by a femoral stretch test; secondly, the Slump test, performed on a patient in a sitting position, by slowly extending their painful leg then passively bending their neck (or the opposite); and thirdly, the Bowstring test, which requires, at the end of the Lasègue test, once the knee has been slightly flexed, pressing on the course of the peroneal and/or tibial nerves in the popliteal fossea to try and reproduce the exact pain felt by the patient. The combination of all these tests takes less than 2minutes, and could improve both the sensitivity and specificity of the physical examination for the diagnosis of sciatica. This article is a review of the limitations of the Lasègue/SLR tests and of the efficacy of these other tests for stretching the lumbar roots.

Inter- and Intra-Rater Reliability of Soft Tissue Palpation Scoring in the Equine Thoracic Epaxial Region

Back pain is a significant factor for horses and is challenging for professionals to diagnose, with assessment frequently using subjective tools such as manual palpation. Reliable and valid objective measures are required and use of a pressure algometer (PA) has been investigated as an assessment tool; however, it has limitations, and other more realistic methods may be better suited for the task. The aim of the study was to establish inter- and intra-rater reliability for PA, FlexiForce Sensor (FFS), and manual palpation for equine epaxial soft tissue, measuring mechanical nociception threshold responses. In group 1, 10 horses underwent three repeated tests with PA and FFS, and once for manual palpation, with three Association of Chartered Physiotherapists in Animal Therapy (ACPAT) Chartered Physiotherapists in the right thoracic epaxial region. Group 2 followed the same protocol using one ACPAT Chartered Physiotherapist and 22 horses. The order of palpation was randomly applied for each test and each experimenter. Manual palpation showed excellent interrater reliability with no significant differences between scores (P = .64; intraclass correlation coefficient [ICC] 90.0%). PA (P = .002) and FFS (P = .025) scores significantly differed between experimenters. Intrarater testing showed significant differences (P = .014) with horses increasing sensitivity over repeated PA measures. The FFS showed no significant differences (P = .347; ICC 94.7%) in repeated measures with excellent reliability and consistency. The PA showed a lack of consistency in intrarater reliability conflicting with previous research findings, whereas the FFS showed greater reliability in comparison; however, it proved difficult to use in clinical practice. Manual palpation by physiotherapists was shown to have excellent interrater reliability when using a categorical scoring system.

Pressure pain sensitivity over nerve trunk areas and physical performance in amateur male soccer players with and without chronic ankle instability

OBJECTIVE

Chronic ankle instability (CAI) is reported after ankle sprain. Our aim was to assess differences in mechanical pain sensitivity of lower extremity nerve trunks and physical performance between amateur soccer players with and without CAI.

DESIGN

A cross-sectional case-control study.

SETTING

Amateur soccer teams.

PARTICIPANTS

Fifty-five male soccer players, 28 with and 27 without CAI participated.

MAIN OUTCOME MEASURES

The perceived instability was assessed with the Cumberland Ankle Instability Tool (CAIT). Pressure pain thresholds (PPTs) on the common peroneal and tibialis nerve trunks, vertical jump, lateral step-down test and joint position sense of the knee were assessed by a blinded assessor.

RESULTS

Soccer players with CAI showed lower PPTs over the common peroneal nerve than those without CAI (between-groups mean difference: 1.0 ± 0.8 kg/cm², P < 0.001). No differences for PPT over the tibialis posterior (P = 0.078) or any physical performance outcome (knee joint positioning sense [P = 0.798], lateral step-down test [P = 0.580] and vertical jump variables [all, P > 0.310]) were found. PPT over the common peroneal nerve exhibited a significant moderate correlation with the CAIT score (r = 0.528, P < 0.001).

CONCLUSION

Amateur soccer players with CAI have higher pressure pain sensitivity over the common peroneal nerve but exhibit similar physical performance to amateur soccer players without CAI.

Ultrasound-guided dry needling decreases pain in patients with piriformis syndrome

INTRODUCTION

Piriformis muscle syndrome (PMS) is a disorder that can lead to symptoms of buttock pain and limited hip-joint mobility, and may have an impact on quality of life.

METHODS

Thirty-two patients with PMS were randomized to the treatment group, which included three sessions of ultrasound-guided dry needling (DN) of the piriformis muscle (n = 16), or a waitlist control group (n = 16). The primary outcome was pain intensity measured on the visual analog scale recorded at baseline and then at 72 hours and 1 week after treatment.

RESULTS

At 1-week follow-up, pain intensity was significantly less in the DN group than in the waitlist control group (-2.16 [-1.01 to -3.32], P = .007) by an amount consistent with clinically meaningful improvement.

DISCUSSION

The findings suggest that DN resulted in clinically meaningful short-term improvement in pain intensity of patients with PMS.

Widespread Pressure Pain Sensitivity over Nerve Trunk Areas in Women with Frequent Episodic Tension-Type Headache as a Sign of Central Sensitization

Objective

Previous studies reported the presence of widespread pressure pain sensitivity in patients with tension-type headache. However, most of the studies assessed pressure pain sensitivity over muscle tissue. Our aim was to investigate the difference in pressure pain sensitivity over musculoskeletal and nerve symptomatic and distant areas between women with frequent episodic tension-type headache (FETTH) and healthy subjects.

Methods

Thirty-two women with FETTH and 32 matched healthy women participated. Pressure pain threshold (PPT) was bilaterally assessed over several nerve trunks (greater occipital, median, radial, ulnar, common peroneal, tibialis posterior) and musculoskeletal structures (temporalis muscle, C5/C6 joint, tibialis anterior) by an assessor blinded to the subject’s condition. A four-week headache diary was used to collect the intensity, frequency, and duration of headache. The Hospital Anxiety and Depression Scale was used to determine anxiety and depressive levels.

Results

Analysis of covariance found lower widespread and bilateral PPTs over all nerve trunks and musculoskeletal structures in women with FETTH pain (P &lt; 0.001). No significant effect of anxiety and depressive levels on PPTs was found (all P &gt; 0.222). PPT over the temporalis muscle was significantly negatively correlated with headache intensity.

Conclusions

This study found widespread pressure pain hypersensitivity over both nerve trunks and musculoskeletal structures in women with FETTH, suggesting that the presence of central altered nociceptive processing is not just restricted to musculoskeletal areas, for example, muscles, but also pain evoked from directly provoking the nerve trunks by pressure. It is also possible that nerve tissue treatment could lead to a decrease in central sensitization and headache features.

Reliability of pain pressure threshold algometry in persons with conservatively managed wrist fractures

OBJECTIVE

Wrist fracture is a common injury in Norway. Pressure algometry is widely used to quantify patients' pain threshold in various anatomical locations. The aim of this study was to explore the reliability of pain pressure threshold (PPT) algometry in persons with conservatively managed distal radius fractures.

METHODS

In this cross-sectional study, three raters (A, B, and C) tested the PPT of participants (18-97 years of age) with a unilateral distal radius fracture after removal of the cast. The raters conducted two measurements of both wrists. Intrarater reliability was examined in 75, 50, and 25 participants by Raters A, B, and C, respectively. Interrater reliability was tested in 50 and 25 participants by Rater Pairs A-B and A-C, respectively. Relative reliability was calculated with intraclass correlation coefficient (ICC_1.1 ) and absolute reliability using within-subject standard deviation (S_w ).

RESULTS

There was a significant difference in the PPT between the participants' injured and noninjured wrists (p < .0001). The mean PPT was 29% lower in the injured than in the noninjured wrists, 175 kPa (SD ± 62) versus 248 kPa (SD ± 83). Intrarater reliability (A) of PPT algometry was better in injured wrists than in noninjured wrists (ICC_1.1  = 0.825 vs. 0.765 and S_w  = 27 vs. 43 kPa). Similarly, interrater reliability of PPT algometry was better in injured wrists than in noninjured wrists. In injured wrists, the interrater reliability of PPT algometry between Raters A and B was 0.617 (ICC_1.1 ) and S_w was 51 kPa, and between Raters A and C, the interrater reliability was 0.706 (ICC_1.1 ) and S_w was 48 kPa.

CONCLUSION

PPT algometry is a useful measurement tool with acceptable reliability and thus suitable for monitoring and quantifying pain in persons with conservatively managed wrist fractures. To be more certain that a change has occurred, the same rater should perform the measurements.

Neural gliding and neural tensioning differently impact flexibility, heat and pressure pain thresholds in asymptomatic subjects: A randomized, parallel and double-blind study

OBJECTIVE

To compare the effect of neural gliding and tensioning on hamstring flexibility, nerve function (heat and cold thresholds) and pain sensitivity (pain intensity and pressure pain threshold) of the mobilized and non-mobilized lower limbs at post-intervention and 24 h follow up.

DESIGN

Randomized, parallel and double blinded trial.

SETTING/PARTICIPANTS

Forty-eight asymptomatic participants.

INTERVENTION(S)

Participants received neural gliding (n = 23) or tensioning (n = 25). Main Outcome Measures - Straight leg raising (SLR; in degrees), heat and cold threshold (ºC), pressure pain threshold (PPT; in Kgf) and pain intensity (visual analogue scale), taken at baseline, post-intervention and at 24 h follow up.

RESULTS

There was a significant interaction between time, intervention and limb for SLR (F2,45 = 3.83; p = 0.029). A significant interaction between time and intervention for PPT (F2,45 = 3.59; p = 0.036) and heat threshold (F2,45 = 5.10; p = 0.01). A significant effect of time (F2,45 = 9.42; p < 0.001) and of limb (F1,46 = 4.78; p = 0.035) for pain intensity during SLR, and a significant effect of time (F2,45 = 3.65; p = 0.034) for pain intensity during PPT.

CONCLUSION

Gliding and tensioning had similar and positive effects for flexibility in the mobilized limb, but tensioning was superior for the non-mobilized limb. Gliding was superior to tensioning for pressure pain and heat thresholds.

Tarsal Tunnel Mechanosensitivity Is Increased in Patients with Asthma: A Case-Control Study

Background: Based on changes in lung function and musculoskeletal disorders in patients with asthma, this study aimed to compare the tarsal tunnel and fibular bone pressure pain thresholds (PPTs) of patients with asthma and healthy matched-paired controls. Methods: A case-control study was performed. One hundred participants were recruited: 50 asthma patients and 50 healthy matched-paired controls. Bilaterally, tarsal tunnel and fibula bone PPTs were registered. Results: Statistically significant differences (p < 0.01) were shown bilaterally for tarsal tunnel PPT. With the exception of fibula PPT (p > 0.05), asthma patients presented less tarsal tunnel PPT than healthy participants. Statistically significant differences (p < 0.05) were shown for two linear regression prediction models of the right (R² = 0.279) and left (R² = 0.249) tarsal tunnels PPTs as dependent variables, and based on sex, group, contralateral tarsal tunnel PPT and ipsilateral fibula PPT as independent variables. Conclusions: The study findings showed that a bilateral tarsal tunnel mechanosensitivity increase is exhibited in patients diagnosed with asthma. The presence of asthma may bilaterally predict the PPT of tarsal tunnel. These findings may suggest the presence of central sensitization in asthma patients, which could clinically predispose them to musculoskeletal disorders, such as tarsal tunnel syndrome.

Widespread Pressure Pain Hypersensitivity in Musculoskeletal and Nerve Trunk Areas as a Sign of Altered Nociceptive Processing in Unilateral Plantar Heel Pain

Our aim was to investigate the differences in pressure sensitivity over musculoskeletal and nerve symptomatic and distant areas between individuals with plantar heel pain and healthy subjects and to determine the relationship between sensitivity to pressure pain, foot pain, and fascia thickness. Thirty-five patients with unilateral chronic plantar heel pain and 35 matched healthy controls participated. Pressure pain thresholds (PPTs) were assessed bilaterally over several nerve trunks (median, radial, ulnar, common peroneal, tibial, and sural nerve trunks) and musculoskeletal structures (calcaneus, medial gastrocnemius, tibialis anterior, and second metacarpal) by an assessor blinded to the subject's condition. Pain was assessed with a numerical pain rating scale (0-10), impact of foot pain was assessed with the Foot Function Index, and plantar fascia thickness was measured via ultrasound imaging. Analysis of covariance revealed lower widespread and bilateral PPTs over both nerve trunks and musculoskeletal structures in individuals with plantar heel pain (P < .001). Female patients showed lower PPT than male patients in almost all points (P < .001). PPT over the peripheral nerve trunks of the lower extremity were significantly associated with the intensity of pain at first step in the morning and with the foot function disability scale of the Foot Function Index (P < .05). This study found widespread pressure pain hypersensitivity over both nerve trunks and musculoskeletal structures in individuals with unilateral chronic plantar heel pain, suggesting the presence of a central altered central nociceptive pain processing. Pressure hypersensitivity over nerve trunks on the lower extremity was associated with higher pain intensity and related disability. PERSPECTIVES: This study found widespread pressure hypersensitivity over both nerve trunks and musculoskeletal structures in individuals with unilateral chronic plantar heel pain, as a manifestation of a centrally altered central nociceptive pain processing.

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.

Pain Threshold Tests in Patients With Heel Pain Syndrome

BACKGROUND

Pressure pain threshold (PPT) is a useful tool for evaluating mechanical sensitivity in patients suffering from various musculoskeletal disorders. However, no previous study has investigated PPT in the heel of patients experiencing plantar heel pain syndrome (PHPS). The aim of this study was to compare PPT levels and topographic presentation of sensitivity in the heel of patients with PHPS and in healthy controls.

METHODS

The reliability of PPT testing in patients with PHPS was assessed for intra- and interrater recordings. The PPT levels of 40 feet in each group were then assessed on 5 predetermined sites in the heel using a standardized measurement protocol. Patient functional status (FS) as measured by the Foot & Ankle Computerized Adaptive Test was employed as an external reference.

RESULTS

Multivariate analysis of covariance revealed no group differences for PPTs at all sites (P = .406). Age (P = .099) or BMI (P = .510) did not affect PPT values, although there was an effect on gender (P = .006). The analysis revealed significant differences between sites (P < .001) demonstrating a diverse topographic distribution. In the PHPS group, PPT levels at the anterior/medial, posterior/medial and central sites were significantly lower than at the posterior/lateral and anterior/lateral sites (P < .05). For the control group, PPT levels at the anterior/medial site were significantly lower than all other sites (P < .001).

CONCLUSION

No significant differences were found between PPT of the PHPS patients and controls, therefore, PPT cannot be recommended as an assessment tool for these patients. The topographic distribution indicated low PPT levels at the anterior/medial area of the heel in patients with PHPS and controls.

LEVEL OF EVIDENCE

Level II, comparative study.

Pressure algometry with a rotational fanning probe improves the detection of experimental muscle hyperalgesia

OBJECTIVE

Muscle hyperalgesia is typically evaluated by pressure algometry applying linear stimulation. Combining linear pressure stimulation with additional minor variations of the pressure in different directions may optimize the detection of pain sensitivity in hyperalgesic muscle.

METHODS

Pressure pain thresholds (PPTs) to linear pressure stimulations were assessed on the extensor carpi radialis brevis (ECRB) muscle in 18 healthy subjects with a computer-controlled pressure algometer. During constant pressure stimulation (5 seconds) equal to the PPT, rotational (45 to 180°), linear vibrational (15 to 50 Hz), or radial vibrational (5 to 25 Hz) stimulations were applied via regular and fanning rounded probes (1 cm2). The pressure pain intensity was rated on an electronic visual analogue scale (VAS). Muscle hyperalgesia was induced in nine subjects by injections of nerve growth factor (NGF) into the ECRB muscle, and isotonic saline was injected as a control condition in other nine subjects on day 0. The PPT and related pressure pain sensitivity were assessed on day -1, day +1, and day +4.

RESULTS

The PPT at day +1 was decreased in the NGF group compared with day -1 and the controls (P < 0.01). Preinjection (day -1) analysis showed that VAS scores were increased for rotation compared with linear stimulation alone (P < 0.001). During NGF-induced muscle, hyperalgesia linear pressure stimulation with rotation of the fanning probe induced higher VAS scores than with the regular probe within the NGF group as well as between NGF and control groups (P < 0.02).

CONCLUSIONS

Rotational stimulation together with pressure stimulation was more efficient than classical pressure algometry in detecting muscle hyperalgesia.

Vibration and rotation during biaxial pressure algometry is related with decreased and increased pain sensations

OBJECTIVE

During palpation, the pressure intensity and direction include minor deviations suggesting that standardized variations of the pressure intensity during pressure algometry may optimize the stimulus efficacy. This study examined the perceived pain outcome and reliability of a biaxial (bidirectional) algometer exerting rotational and vibratory stimulation on top of the basic pressure.

METHODS

In 24 healthy subjects, pressure pain thresholds (PPTs) were recorded with a linear pressure gradient (30 kPa/s) applied by a 1-cm(2) probe bilaterally on the tibialis anterior muscle via biaxial and handheld algometers. During constant pressure stimulation (5 seconds, 75%, 100%, 125% PPT), rotational (45°, 90°, and 180°), linear vibrational (15, 25, and 50 Hz), and radial vibrational stimulations (5, 15, and 25 Hz) were applied randomly via regular and fanning rounded probes (1 cm(2)). Subjects rated perceived pain on a 10-cm visual analogue scale on two occasions separated by 1 week period.

RESULTS

Repeated measures analysis of variance revealed enhanced effect of rotation angle (P < 0.001), probe (P < 0.001), and radial vibration frequency (P < 0.02), and suppressing effect of axial vibration frequency (P < 0.03) on pain perception, relative to basic pressure alone. PPT reliability of biaxial and handheld algometers showed averaged intraclass correlation coefficient of 0.94 and 0.945, and coefficient of variations of 15.4 and 13.5%, respectively.

CONCLUSIONS

PPT assessment and multidirectional stimulations can be exerted reliably via biaxial algometer. Linear vibrational stimulation effect on pressure pain perception verified the inhibitory interaction between simultaneous pressure stimulation of low-threshold mechanoreceptors and nociceptors, while radial vibration and rotational stimulation showed facilitatory effects.