Increased resistance towards fatigability in patients with facioscapulohumeral muscular dystrophy.

PURPOSE: In facioscapulohumeral muscular dystrophy (FSHD) fatigue is a major complaint. We aimed to investigate whether during isometric sustained elbow flexions, performance fatigability indexes differ in patients with FSHD with respect to healthy controls. METHODS: Seventeen patients with FSHD and seventeen healthy controls performed two isometric flexions of the dominant biceps brachii at 20% of their maximal voluntary contraction (MVC) for 2 min and then at 60% MVC until exhaustion. Muscle weakness was characterized as a percentage of predicted values. Maximal voluntary strength, endurance time and performance fatigability indices (mean frequency of the power spectrum (MNF), muscle fiber conduction velocity (CV) and fractal dimension (FD)), extracted from the surface electromyogram signal (sEMG) were compared between the two groups. RESULTS: In patients with FSHD, maximal voluntary strength was 68.7% of predicted value (p < 0.01). Compared to healthy controls, FSHD patients showed reduced MVC (p < 0.001; r = 0.62) and lower levels of performance fatigability, characterized by reduced rate of changes in MNF (p < 0.01; r = 0.56), CV (p < 0.05; 0.37) and FD (p < 0.001; r = 0.51) and increased endurance time (p < 0.001; r = 0.63), during the isometric contraction at 60% MVC. CONCLUSION: A decreased reduction in the slopes of all the considered sEMG parameters during sustained isometric elbow flexions suggests that patients with FSHD experience lower levels of performance fatigability compared to healthy controls.

Sphincter muscle activity before and after delivery: Does it depend on the type of birth?

AIM: There are ongoing discussions whether cesarean section is the safest mode of childbirth to prevent pelvic floor disorders. Pelvic floor electromyography (EMG) allows the analysis of external anal sphincter (EAS) function during voluntary contractions. The primary objective of this study was the evaluation of EMG amplitude of external anal sphincter in women who had vaginal delivery, compared to women who had cesarean section. The secondary objective was to evaluate the anal incontinence score changes before and after delivery between the groups, and to look for any relationship between the clinical and EMG findings. METHODS: Multichannel surface EMG was detected during maximal contractions in three sessions: (i) during pregnancy, (ii) 6 weeks after delivery and (iii) 1 year after delivery. Women were divided into two groups: cesarean section and vaginal delivery. RESULTS: External anal sphincter EMG amplitude decreases 6 weeks after vaginal deliveries from 10.1 to 8.6 µV with effect size of 0.4, but returns to baseline after 1 year. No differences were observed between groups in all other variables. CONCLUSION: No differences were observed after 1 year in EMG activity between the two groups; however, a slight decrease of sphincter muscle amplitude was noted 6 weeks after vaginal delivery. The delivery mode does not have effect on the EAS amplitude 1 year after delivery. Incontinence score slightly increased in both groups after delivery, with no significant differences between the two groups. No association was observed between the increase of incontinence score and the decrease of EMG signal amplitude.

Digital pain drawings are a useful and reliable tool for assessing patients with temporomandibular disorders.

BACKGROUND: Temporomandibular disorders (TMD) are characterised by complex symptomatology and their assessment can be enhanced using pain drawings (PD). OBJECTIVES: To evaluate the location and extent of pain in people TMD using digital PD, and to explore their association with clinical features. Reliability of pain extent and pain location using PD was also assessed. METHODS: Forty volunteers with TMD completed two consecutive digital PDs. Clinical features were captured from self-reported questionnaire. Additionally, secondary hyperalgesia was measured using the pressure pain threshold (PPT). The correlation between pain extent and clinical features was investigated using Spearman rank correlation coefficients. Reliability of pain extent was evaluated using intraclass correlation coefficient (ICC) and Bland-Altman plots. The Jaccard index was computed to assess the reliability of pain location. RESULTS: Analysis of the PDs indicated that people with TMD commonly experience pain in other body regions including the neck, the shoulder and the low back. Except for PPT and pain catastrophising, all other clinical features were significantly correlated with pain extent. The ICCs of pain extent for all body charts were very high (ICCs 95% CI from 0.73 to 0.96), and Bland-Altman plots showed mean biases close to zero with narrow limits of agreement. The reliability of pain location was also supported by Jaccard index mean scores above 0.68. CONCLUSIONS: People with TMD showed widespread pain, and pain extent was associated with pain intensity, neck and headache-related disability, depression, anxiety, hyperventilation and central sensitivity. The reliability of measuring pain extent and pain location was confirmed.

Influence of Clinical, Psychological, and Psychophysical Variables on Long-term Treatment Outcomes in Carpal Tunnel Syndrome: Evidence From a Randomized Clinical Trial.

OBJECTIVE: To assess the influence of clinical, psychological, and psychophysical variables on long-term clinical outcomes after the application of either physical therapy or surgery in women presenting with carpal tunnel syndrome (CTS). METHODS: A secondary analysis of a randomized trial investigating the efficacy of manual therapy including desensitization maneuvers of the central nervous system against surgery in 120 women with CTS was performed. Clinical outcomes including pain intensity, function, or symptom severity were assessed at 6 and 12 months post-intervention. Participants completed at baseline several clinical (pain intensity, function, and symptom severity), psychological (depression), and psychophysical (pressure pain thresholds and pain extent) variables, which were included as predictors. Multiple regression analyses were conducted to assess the relationship between baseline variables and clinical outcomes at 6 and 12 months post-intervention. RESULTS: The regression models indicated that higher scores of each clinical outcome (ie, intensity of pain or symptom severity) at baseline predicted better outcomes at 6 and 12 months post-intervention (from 15% to 65% of variance) in both groups. Lower pressure pain thresholds over the carpal tunnel at baseline predicted poorer clinical outcomes at 6 and 12 months post-intervention (from 5% to 20% of variance) in the physical therapy group, whereas higher depressive symptoms at baseline contributed to poorer outcomes at 6 and 12 months post-intervention (from 5% to 15% of the variance) within the surgery group. CONCLUSION: This study found that baseline localized pressure pain sensitivity and depression were predictive of long-term clinical outcomes in women with CTS following physical therapy or surgery, respectively.

Could the correct side of mediolateral episiotomy be determined according to anal sphincter EMG?

INTRODUCTION AND HYPOTHESIS: Mediolateral episiotomy is one of the most frequent surgical interventions performed in obstetrics. There is conflicting evidence as to whether mediolateral episiotomy reduces the risk of obstetric anal sphincter injuries (OASI). Recent studies suggest that functional asymmetry of pelvic floor innervation exists in healthy women and is strongly associated with postpartum incontinence when the trauma occurs on the dominant side of innervation. Mediolateral episiotomy is the most common cause of perineal trauma during delivery, and the surgical incision is usually performed on the mediolateral right side. Surface electromyography (EMG) has been recently applied in obstetrics for detecting electrical activity of the external anal sphincter (EAS). METHODS: Two hundred and forty-five pregnant nulliparous women at their second and third trimester of pregnancy were recruited, and EMG signals were detected using a multichannel cylindric anal probe. Measurements were repeated and compared 6-8 weeks after delivery on a subgroup of 167 women who were divided in two groups according to EMG amplitude asymmetry before delivery and two subgroups according to type of delivery: (1A) asymmetric left, episiotomy right; (1B) asymmetric left, other types of deliveries; (2A) asymmetric right, episiotomy right; (2B) asymmetric right, other type of deliveries. RESULTS: The reduction of EMG amplitude after right episiotomy was larger in women with right asymmetric sphincter compared with women with left asymmetry and women with other types of delivery. CONCLUSIONS: Prenatal EMG may be used to predict the impact of right-sided mediolateral episiotomy on EAS and perhaps also function following delivery.

Test-retest reliability of echo intensity parameters in healthy Achilles tendons using a semi-automatic tracing procedure.

OBJECTIVE: To evaluate the test-retest reliability of the ultrasound echo intensity parameters on healthy Achilles tendon using a semi-automatic tracing procedure. MATERIALS AND METHODS: Eighteen healthy volunteers participated. B-mode images were acquired in the transverse plane (mid-tendon; insertion) and used to analyze tendon echogenicity. Grayscale distribution of the pixels within the selected ROIs was represented as a histogram. Descriptive statistics of the grayscale distribution (mean, variance, skewness, kurtosis, and entropy) and parameters from the co-occurrence matrix (contrast, energy, and homogeneity) were calculated. RESULTS: Reliability of echo intensity parameters of the mid-Achilles tendon ranged from high to very high with an ICC2.k of 0.94 for echogenicity, 0.87 for variance, 0.80 for skewness, 0.72 for kurtosis, 0.89 for entropy, 0.90 for contrast, 0.91 for energy, and 0.93 for homogeneity, while for tendon insertion they ranged from moderate to high with an ICC2.k of 0.74 for echogenicity, 0.88 for variance, 0.75 for skewness, 0.55 for kurtosis, 0.87 for entropy, 0.70 for contrast, 0.77 for energy, and 0.56 for homogeneity. CONCLUSION: Ultrasound echo intensity is a reliable technique to characterize the internal structure of the Achilles tendon.

The effect of local skin cooling before a sustained, submaximal isometric contraction on fatigue and isometric quadriceps femoris performance: A randomized controlled trial.

The central- and peripheral mechanisms by which heat strain limits physical performance are not fully elucidated. Nevertheless, pre-cooling is often used in an attempt to improve subsequent performance. This study compared the effects of pre-cooling vs. a pre-thermoneutral application on central- and peripheral fatigue during 60% of isometric maximum voluntary contraction (MVC) of the right quadriceps femoris muscle. Furthermore, the effects between a pre-cooling and a pre-thermoneutral application on isometric MVC of the right quadriceps femoris muscle and subjective ratings of perceived exertion (RPE) were investigated. In this randomized controlled trial, 18 healthy adults voluntarily participated. The participants received either a cold (experimental) application (+8°C) or a thermoneutral (control) application (+32°C) for 20min on their right thigh (one cuff). After the application, central (fractal dimension - FD) and peripheral (muscle fiber conduction velocity - CV) fatigue was estimated using sEMG parameters during 60% of isometric MVC. Surface EMG signals were detected from the vastus medialis and lateralis using bidimensional arrays. Immediately after the submaximal contraction, isometric MVC and RPE were assessed. Participants receiving the cold application were able to maintain a 60% isometric MVC significantly longer when compared to the thermoneutral group (mean time: 78 vs. 46s; p=0.04). The thermoneutral application had no significant impact on central fatigue (p>0.05) compared to the cold application (p=0.03). However, signs of peripheral fatigue were significantly higher in the cold group compared to the thermoneutral group (p=0.008). Pre-cooling had no effect on isometric MVC of the right quadriceps muscle and ratings of perceived exertion. Pre-cooling attenuated central fatigue and led to significantly longer submaximal contraction times compared to the pre-thermoneutral application. These findings support the use of pre-cooling procedures prior to submaximal exercises of the quadriceps muscle compared to pre-thermoneutral applications.

Test-retest Reliability in Reporting the Pain Induced by a Pain Provocation Test: Further Validation of a Novel Approach for Pain Drawing Acquisition and Analysis.

BACKGROUND: Pain drawings (PD) are frequently used in research to illustrate the pain response to pain provocation tests. However, there is a lack of data on the reliability in defining the extent and location of pain. We investigated the test-retest reliability in reporting an acute painful sensation induced by a pain provocation test using a novel approach for PD acquisition and analysis in healthy volunteers. METHODS: Forty healthy volunteers participated. Each participant underwent 2 upper limb neurodynamic tests 1 (ULNT1), once to the point of pain onset (PO) and once until the point of submaximal pain (SP). After each ULNT1, participants completed 2 consecutive PD with an interval of 1 minute. Custom software was used to quantify the pain extent and analyze the pain overlap. The test-retest reliability of pain extent was examined using Intraclass Correlation Coefficient (ICC 2,1 ) and Bland-Altman plots. Pain location reliability was examined using the Jaccard similarity coefficient (JSC). RESULTS: The ICC values for PO and SP were 0.98 (95% CI: 0.96-0.99) and 0.97 (95% CI: 0.95-0.98), respectively. The mean difference and 95% limits of agreement (± 1.96 SD) in the Bland-Altman plots were 14 pixels (-1080;1110) for PO, and 145 (-1610;1900) for SP. The median JSCs (Q1;Q3) were 0.73 (0.64;0.80) for PO and 0.76 (0.65;0.79) for SP. CONCLUSIONS: Pain drawings is a reliable instrument to investigate pain extent and pain location in healthy individuals experiencing an acute painful sensation induced by a pain provocation test.

Real-time sonoelastography using an external reference material: test-retest reliability of healthy Achilles tendons.

OBJECTIVE: To establish the test-retest reliability of sonoelastography (SE) on healthy Achilles tendons in contracted and relaxed states using an external reference system. MATERIALS AND METHODS: Forty-eight Achilles tendons from 24 healthy volunteers were assessed using ultrasound and real-time SE with an external reference material. Tendons were analyzed under relaxed and contracted conditions. Strain ratios between the tendons and the reference material were calculated. The intraclass correlation coefficient (ICC2.k) and Bland-Altman plot were used to assess test-retest reliability. RESULTS: The reliability of SE measurements under relaxed conditions ranged from high to very high, with an ICC2.k of 0.84 (95 % CI: 0.64-0.92) for reference material, 0.91 (95 % CI: 0.83-0.95) for Achilles tendons and 0.95 (95 % CI: 0.91-0.97) for Kager fat pads (KFP). The ICC2.k value for skin was 0.30 (95 % CI: -0.26 to 0.61). Reliability for measurements in the contracted state ranged from high to very high, with an ICC2.k of 0.93 (95 % CI: 0.87-0.96) for reference material, 0.72 (95 % CI: 0.50-0.84) for skin, 0.93 (95 % CI: 0.87-0.96) for Achilles tendons, and 0.81 (95 % CI: 0.66-0.89) for KFP. Reliability of the strain ratio (tendon/reference) under relaxed conditions was high with an ICC2.k of 0.87 (95 % CI: 0.75-0.93), and in the contracted state, it was very high with an ICC2.k of 0.94 (95 % CI: 0.90-0.97). CONCLUSION: Sonoelastography using an external reference material is a reliable and simple technique for the assessment of the elasticity of healthy Achilles tendons. The use of an external material as a reference, along with strain ratios, could provide a quantitative measure of elasticity.

Effect of vaginal delivery on the external anal sphincter muscle innervation pattern evaluated by multichannel surface EMG: results of the multicentre study TASI-2.

INTRODUCTION AND HYPOTHESIS: A correlation exists between external anal sphincter (EAS) damage during birth and the subsequent development of fecal incontinence. This study evaluated the effect of delivery-related trauma on EAS innervation by means of intra-anal EMG performed with a rectal probe with 16 silver electrodes equally spaced along the circumference, before and after delivery. METHODS: Pre-partum EMG measurements were performed on 511 women, by nine clinical partners from five European countries at the 28th to 34th gestational weeks and the 6th to 8th post-delivery weeks; 331 women returned, after delivery, for the second test. The innervation zones (IZ) of EAS single motor units were identified by means of an EMG decomposition algorithm. RESULTS: The subjects were divided into four groups according to the delivery mode (Caesarean, vaginal with no evident damage, spontaneous lacerations and episiotomies). The number of IZs before and after delivery was compared. In the 82 women who underwent right mediolateral episiotomy, a statistically significant reduction of IZs was observed, after delivery, in the right ventral quadrant of the EAS (side of the episiotomy). Women who had Caesarean section, spontaneous lacerations or lack of evident damage did not present any significant change in the innervation pattern. CONCLUSIONS: Right episiotomy reduces the number of IZs on the right-ventral side of the EAS. The fast and reliable test proposed indicates the sphincter innervation pattern before delivery and helps obstetricians to evaluate the risks and to choose the preferred side of the episiotomy, if deemed necessary at the time of delivery.

Characterization of the motor units of the external anal sphincter in pregnant women with multichannel surface EMG.

INTRODUCTION AND HYPOTHESIS: Locating the innervation zones (IZs) of the external anal sphincter (EAS) is helpful to obstetricians to identify areas particularly vulnerable to episiotomy in pregnant women. The aim was to investigate the motor unit (MU) properties of the EAS during voluntary contractions. METHODS: Electromyographic signals were detected, from 478 pregnant women, by means of an intra-anal cylindrical probe carrying a circumferential array of 16 electrodes. The signals were decomposed into the constituent MU action potential trains and 5,947 templates were extracted and analyzed in order to identify the IZ position. RESULTS: MUs innervated at one end are concentrated in the dorsal portion of the sphincter, while MUs innervated in the middle are distributed symmetrically in the left and right portions of the EAS. The angular propagation velocity was estimated for each MU resulting in 260 ± 45 rad/s, corresponding to 1.8 m/s on the probe surface and to about 4 m/s at a radial depth of 10 mm from the probe surface. CONCLUSIONS: A novel method for identification and classification of MUs of the EAS is proposed and applied to a large-scale study. It is possible to distinguish MUs of the EAS in a minimally invasive way and identify their IZs. This information should be used to plan episiotomies and minimize risks of EAS denervation.

Reporting the Location and Extent of Pain in Adolescents: A Test-Retest Reliability Study.

BACKGROUND: A pain drawing is a self-administered assessment that requires the patient to shade in on a body chart the areas in which he or she experiences pain, regardless of the intensity. Pain drawings have already been validated in several adult populations. OBJECTIVES: The aim of this study is to establish adolescents' test-retest reliability in reporting the extent and location of their pain using a paper-based pain drawing. STUDY DESIGN: A one-day test-retest reliability study was set up. SETTING: The study took place in 2 separate locations-a pediatric hospital and a private physiotherapy practice in Ticino, in the southern part of Switzerland. This reliability study was approved by the local ethics committee of Ticino (2021-00492 CE 3832). METHODS: Adolescents with musculoskeletal pain (aged 11-16 years) were included. All participants were asked to shade the areas in which they experienced pain over the previous week. After the administration of a questionnaire and the acquisition of further personal data, the pain drawing was administered again. The pain drawings were then scanned and analyzed using a digital platform, which allowed the extraction of pain extent and location values. The test-retest reliability was evaluated on these data. The intraclass correlation coefficient and Bland-Altman analysis were used to assess the reliability of the reporting of the pain extent, whereas the Jaccard similarity coefficient was used to calculate the reliability of the reporting of the pain location. RESULTS: The reporting of the pain extent was observed to have excellent test-retest reliability: ICC2,1: 0.959 (95% CI: 0.925-0.978). The Bland-Altman analysis showed a mean difference close to 0: -0.010% (limits of agreements -0.962 to 0.942). The reliability of the reporting of pain location was also supported by the Jaccard index mean score of 0.82 (± 0.19). LIMITATIONS: Reliability of reporting may vary depending on the nature of the pain, its duration, or the type of disorder and body areas involved. CONCLUSIONS: Adolescents complaining musculoskeletal pain showed reliability in reporting pain extent and location using pain drawings.

Changes in Multiple Aspects of Pain Outcomes After Rehabilitation: Analysis of Pain Data in a Randomized Controlled Trial Evaluating the Effects of Adding Sensorimotor Training to Manual Therapy and Exercise for Chronic Neck Pain.

OBJECTIVES: To examine changes in pain outcomes to fully evaluate the effect of adding sensorimotor training to manual therapy and exercise in patients with chronic neck pain and sensorimotor deficits. Concordance was examined between pain distribution and pain intensity and patient-reported outcomes. METHODS: Participants (n=152) were randomly allocated into 4 intervention groups: One group received local neck treatment (NT) comprising manual therapy and exercise and the other 3 groups received additional sensorimotor training (either joint position sense/oculomotor exercises, balance exercises or both). Treatment was delivered twice a week for 6 weeks. Pain and patient-reported outcomes were measured at baseline, posttreatment, and 3-, 6- and 12-month follow-ups. RESULTS: There were greater changes in pain location, extent, and intensity at 6- and 12-month follow-ups in the sensorimotor training groups compared with the NT group ( P <0.05). A greater number of patients in the sensorimotor training groups gained ≥50% reduction in pain extent and intensity relative to the NT group at 6 and 12 months ( P <0.05). Clinical improvement in pain extent was concordant with pain intensity (adjusted kappa=056 to 0.66, %agreement=78.3 to 82.9, P <0.001) and disability (adjusted kappa=0.47 to 0.58, % agreement=73.7 to 79.0, P <0.01) at 3-, 6- and 12-month follow-ups, but not with function and well-being. The concordance tended to decline with time. DISCUSSION: Multiple aspects of the pain experience improved in the longer term by adding sensorimotor training to NT for patients with neck pain and sensorimotor deficits. The concordance between pain and patient-reported outcomes was not always evident and varied over time, suggesting the need for multidimensional assessments of pain.

Reliability of the Pen-on-Paper Pain Drawing Analysis Using Different Scanning Procedures.

INTRODUCTION: Pen-on-paper pain drawing are an easily administered self-reported measure that enables patients to report the spatial distribution of their pain. The digitalization of pain drawings has facilitated the extraction of quantitative metrics, such as pain extent and location. This study aimed to assess the reliability of pen-on-paper pain drawing analysis conducted by an automated pain-spot recognition algorithm using various scanning procedures. METHODS: One hundred pain drawings, completed by patients experiencing somatic pain, were repeatedly scanned using diverse technologies and devices. Seven datasets were created, enabling reliability assessments including inter-device, inter-scanner, inter-mobile, inter-software, intra- and inter-operator. Subsequently, the automated pain-spot recognition algorithm estimated pain extent and location values for each digitized pain drawing. The relative reliability of pain extent analysis was determined using the intraclass correlation coefficient, while absolute reliability was evaluated through the standard error of measurement and minimum detectable change. The reliability of pain location analysis was computed using the Jaccard similarity index. RESULTS: The reliability analysis of pain extent consistently yielded intraclass correlation coefficient values above 0.90 for all scanning procedures, with standard error of measurement ranging from 0.03% to 0.13% and minimum detectable change from 0.08% to 0.38%. The mean Jaccard index scores across all dataset comparisons exceeded 0.90. CONCLUSIONS: The analysis of pen-on-paper pain drawings demonstrated excellent reliability, suggesting that the automated pain-spot recognition algorithm is unaffected by scanning procedures. These findings support the algorithm's applicability in both research and clinical practice.

Automated Pain Spots Recognition Algorithm Provided by a Web Service-Based Platform: Instrument Validation Study.

Background: Understanding the causes and mechanisms underlying musculoskeletal pain is crucial for developing effective treatments and improving patient outcomes. Self-report measures, such as the Pain Drawing Scale, involve individuals rating their level of pain on a scale. In this technique, individuals color the area where they experience pain, and the resulting picture is rated based on the depicted pain intensity. Analyzing pain drawings (PDs) typically involves measuring the size of the pain region. There are several studies focusing on assessing the clinical use of PDs, and now, with the introduction of digital PDs, the usability and reliability of these platforms need validation. Comparative studies between traditional and digital PDs have shown good agreement and reliability. The evolution of PD acquisition over the last 2 decades mirrors the commercialization of digital technologies. However, the pen-on-paper approach seems to be more accepted by patients, but there is currently no standardized method for scanning PDs. Objective: The objective of this study was to evaluate the accuracy of PD analysis performed by a web platform using various digital scanners. The primary goal was to demonstrate that simple and affordable mobile devices can be used to acquire PDs without losing important information. Methods: Two sets of PDs were generated: one with the addition of 216 colored circles and another composed of various red shapes distributed randomly on a frontal view body chart of an adult male. These drawings were then printed in color on A4 sheets, including QR codes at the corners in order to allow automatic alignment, and subsequently scanned using different devices and apps. The scanners used were flatbed scanners of different sizes and prices (professional, portable flatbed, and home printer or scanner), smartphones with varying price ranges, and 6 virtual scanner apps. The acquisitions were made under normal light conditions by the same operator. Results: High-saturation colors, such as red, cyan, magenta, and yellow, were accurately identified by all devices. The percentage error for small, medium, and large pain spots was consistently below 20% for all devices, with smaller values associated with larger areas. In addition, a significant negative correlation was observed between the percentage of error and spot size (R=-0.237; P=.04). The proposed platform proved to be robust and reliable for acquiring paper PDs via a wide range of scanning devices. Conclusions: This study demonstrates that a web platform can accurately analyze PDs acquired through various digital scanners. The findings support the use of simple and cost-effective mobile devices for PD acquisition without compromising the quality of data. Standardizing the scanning process using the proposed platform can contribute to more efficient and consistent PD analysis in clinical and research settings.

Bilateral and multiple cavitation sounds during upper cervical thrust manipulation.

BACKGROUND: The popping produced during high-velocity, low-amplitude (HVLA) thrust manipulation is a common sound; however to our knowledge, no study has previously investigated the location of cavitation sounds during manipulation of the upper cervical spine. The primary purpose was to determine which side of the spine cavitates during C1-2 rotatory HVLA thrust manipulation. Secondary aims were to calculate the average number of pops, the duration of upper cervical thrust manipulation, and the duration of a single cavitation. METHODS: Nineteen asymptomatic participants received two upper cervical thrust manipulations targeting the right and left C1-2 articulation, respectively. Skin mounted microphones were secured bilaterally over the transverse process of C1, and sound wave signals were recorded. Identification of the side, duration, and number of popping sounds were determined by simultaneous analysis of spectrograms with audio feedback using custom software developed in Matlab. RESULTS: Bilateral popping sounds were detected in 34 (91.9%) of 37 manipulations while unilateral popping sounds were detected in just 3 (8.1%) manipulations; that is, cavitation was significantly (P < 0.001) more likely to occur bilaterally than unilaterally. Of the 132 total cavitations, 72 occurred ipsilateral and 60 occurred contralateral to the targeted C1-2 articulation. In other words, cavitation was no more likely to occur on the ipsilateral than the contralateral side (P = 0.294). The mean number of pops per C1-2 rotatory HVLA thrust manipulation was 3.57 (95% CI: 3.19, 3.94) and the mean number of pops per subject following both right and left C1-2 thrust manipulations was 6.95 (95% CI: 6.11, 7.79). The mean duration of a single audible pop was 5.66 ms (95% CI: 5.36, 5.96) and the mean duration of a single manipulation was 96.95 ms (95% CI: 57.20, 136.71). CONCLUSIONS: Cavitation was significantly more likely to occur bilaterally than unilaterally during upper cervical HVLA thrust manipulation. Most subjects produced 3-4 pops during a single rotatory HVLA thrust manipulation targeting the right or left C1-2 articulation; therefore, practitioners of spinal manipulative therapy should expect multiple popping sounds when performing upper cervical thrust manipulation to the atlanto-axial joint. Furthermore, the traditional manual therapy approach of targeting a single ipsilateral or contralateral facet joint in the upper cervical spine may not be realistic.

Myofascial trigger points and innervation zone locations in upper trapezius muscles.

BACKGROUND: Myofascial trigger points (MTrPs) are hyperirritable spots located in taut bands of muscle fibres. Electrophysiological studies indicate that abnormal electrical activity is detectable near MTrPs. This phenomenon has been described as endplate noise and it has been purported to be associated MTrP pathophysiology. Thus, it is suggested that MTrPs will be overlap the innervation zone (IZ). The purpose of this work was to describe the location of MTrPs and the IZ in the right upper trapezius. METHODS: We screened 71 individuals and eventually enrolled 24 subjects with neck pain and active MTrPs and 24 neck pain-free subjects with latent MTrPs. Surface electromyography (sEMG) signals were detected using an electrode matrix during isometric contraction of the upper trapezius. A physiotherapist subsequently examined the subject's trapezius to confirm the presence of MTrPs and establish their location. IZ locations were identified by visual analysis of sEMG signals. IZ and MTrPs locations were described using an anatomical coordinate system (ACS), with the skin area covered by the matrix divided into four quadrants. RESULTS: No significant difference was observed between active and latent MTrPs locations (P = 0.6). Forty-five MTrPs were in the third quadrant of the ACS, and 3 were included in second quadrant. IZs were located approximately midway between the seventh cervical vertebrae and the acromial angle in a limited area in the second and third quadrants. The mean distance between MTrP and IZ was 10.4 ± 5.8 mm. CONCLUSIONS: According to the acquired results, we conclude that IZ and MTrPs are located in well-defined areas in upper trapezius muscle. Moreover, MTrPs in upper trapezius are proximally located to the IZ but not overlapped.

Shear Wave Tensiometry Can Detect Loading Differences Between Operated and Unaffected Achilles Tendon.

BACKGROUND: The clinically relevant healing process of a ruptured and repaired Achilles tendon (AT) can last more than a year. The purpose of this cross-sectional study was to test if shear wave tensiometry is able to detect AT loading changes between a surgically managed AT rupture versus the unaffected contralateral tendon. Our secondary aims were to evaluate differences in mechanical properties when measured with myotonometry and morphological properties of the tendons measured with ultrasonographic imaging. METHODS: Twenty-one patients with surgically treated AT ruptures were investigated 12-37 months after surgery. Tendon load was measured using a shear wave tensiometer composed of an array of 4 accelerometers fixed on the tendon. Shear wave speed along the Achilles tendon was evaluated at different levels of ankle torque for both the operated and the unaffected side. Mechanical properties of the tendons were evaluated using MyotonPRO and morphological properties using ultrasonographic imaging. Friedman test was used to assess differences in AT wave speed, stiffness, thickness, and cross-sectional area between the operated and the unaffected tendon. RESULTS: We found a significant shear wave speed difference between sides at every ankle joint torque (P < .05) with a large effect size for the lowest ankle torque and small to medium effect sizes for higher ankle torque. Stiffness, thickness, and cross-sectional area of the operated tendon remained significantly higher compared to the unaffected side. CONCLUSION: In this cohort, we found that shear wave tensiometry can detect differences between operated and unaffected AT during a standardized loading procedure. The shear wave speed along the operated tendon, as well as the mechanical and morphologic properties, remains higher for 1-3 years after a rupture. LEVEL OF EVIDENCE: Level III, case-control study.

Intra-rater reliability of an experienced physiotherapist in locating myofascial trigger points in upper trapezius muscle.

OBJECTIVES: Myofascial trigger points (MTrPs) are considered the principal clinical feature of myofascial pain syndrome (MPS). An MTrP consists of spot tenderness within a taut band of muscle fibers and its stimulation can produce both local and referred pain. The clinical diagnosis of MPS depends on correct history taking and a physical examination aimed at identifying the presence of MTrP. The purpose of this study was to investigate the intra-rater reliability of a palpation protocol used for locating an MTrP in the upper trapezius muscle. METHODS: Twenty-four subjects with MTrP in the upper trapezius muscle were examined by an experienced physiotherapist. During each of eight experimental sessions, subjects were examined twice in randomized order using a palpation protocol. An anatomical landmark system was defined and the MTrP location established using X and Y values. RESULTS: The intraclass correlation coefficient ICC(1,1) values were 0.62 (95% CI: 0.30-0.81) for X and 0.81 (95% CI: 0.61-0.91) for Y. The Bland-Altman plots for X and Y showed a mean of difference of 0.04 and -0.2 mm, respectively. Limits of agreement for X ranged from -26.3 to 26.2 mm and for Y from -27 to 26.4 mm. DISCUSSION: The ICC(1,1) for the observed values revealed a moderate to high correlation and the Bland-Altman analysis showed means of difference very close to zero with narrow limits of agreement. An experienced physiotherapist can reliably identify MTrP locations in upper trapezius muscle using a palpation protocol.