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Purpose The aim of this randomized placebo-controlled crossover study was to compare the acute effect on young athletes of a single session of roller massager (RM) with that obtained from passive static stretching (PSS) and a placebo intervention (PL) on hamstring flexibility and on strength. Methods Twenty-nine (23 male, 6 female) young athletes completed the study. Maximal voluntary contraction (MVC) and two-leg sit-and-reach test were performed before and immediately after PL, PSS and RM on three different days. Results Results showed that all three interventions increased the flexibility of the hamstring muscles compared to the pre-test measurements (Wilcoxon signed-rank test, p Conclusions RM can be considered as an effective alternative to stretching to increase the flexibility of the hamstring. This could be meaningful when stretching is contraindicated or evokes pain.

Objectives Changes in mechanical loading as well as pathology can modify the Achilles tendon mechanical properties and therefore detection of these changes is relevant for the diagnosis and management of Achilles tendinopathy. The aim of this study was to evaluate strain and shear wave sonoelastography for their ability to detect changes in the Achilles tendon mechanical properties during a series of isometric contractions. Methods Longitudinal sonoelastography images of the Achilles tendon were acquired from 20 healthy participants using four different ultrasound devices; two implementing strain sonoelastography technology (SE1, SE2) and two, shear wave elastography technology (SWE1, SWE2). Results SE1 measured a decreasing strain ratio (tendon become harder) during the different contraction levels from 1.51 (0.92) to 0.33 (0.16) whereas SE2 mesaured a decreasing strain ratio from 1.08 (0.76) to 0.50 (0.32). SWE1 measured decreasing tendon stiffness during contractions of increasing intensity from 33.40 (19.61) to 16.19 (2.68) whereas SWE2 revealed increasing tendon stiffness between the first two contraction levels from 428.65 (131.5) kPa to 487.9 (121.5) kPa followed by decreasing stiffness for the higher contraction levels from 459.35 (113.48) kPa to 293.5 (91.18) kPa. Conclusions Strain elastography used with a reference material was able to detect elasticity changes between the different contraction levels whereas shear wave elastography was less able to detect changes in Achilles tendon stiffness when under load. Inconsistent results between the two technologies should be further investigated.

In literature, it is commonly reported that the progress of performance fatigability may be indirectly assessed through the changes in the features of the surface electromyogram (sEMG) signal. In particular, during isometric constant force contractions, changes in the sEMG signal are caused by several physiological factors, such as a decay in muscle fibers conduction velocity (CV), an increase of the degree of synchronization between the firing times of simultaneously active motor units (MUs), by the central nervous system, and a reduction of the recruitment threshold and a modulation of MUs firing rate. Amplitude and spectral parameters may be used to characterize the global contributions to performance fatigability, such as MU control properties and fiber membrane properties, or central and peripheral factors, respectively. In addition, being CV a physiological parameter, its estimation is of marked interest to the study of fatigue both in physiological and in presence of neuromuscular diseases.

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.

Sensitization mechanisms are thought to play a role in the perception of pain in people with cluster headache. No study has investigated the relation between the spatial extent of pain in cluster headache and measures of sensitization or other clinical features.Our aim was to investigate if the size of the painful area in people with cluster headache relates to widespread pressure sensitivity, headache features, and psychological outcomes.Forty men with episodic cluster headache reported their symptoms on a digital body chart and pain extent was calculated. Pressure pain thresholds were assessed locally over the temporalis muscle and the C5-C6 joint and at a remote site over the tibialis anterior to assess widespread pressure sensitivity. Clinical features of headache attacks, and anxiety/depressive levels were also assessed. Patients were assessed during a period of remission 6 months after their last pain attack and after treatment discontinuation.Thirty-two (80%) and thirty (75%) patients reported their headaches in the orbital and the frontal areas, respectively. No significant associations (rho values ranging from -0.228 to 0.187,Pain extent in the trigemino-cervical area was not related to the degree of pressure pain sensitivity or headache features in men with episodic cluster headache during a period of remission.

The purpose of the present study was to evaluate the Pearson correlations between hemodynamic parameters obtained with near infrared spectroscopy (NIRS), namely total hemoglobin (tHb) and tissue oxygen index (TOI %), as indicators of blood flow and oxygen extraction, and myoelectric parameters obtained with surface multichannel electromyography (sEMG), namely fractal dimension (FD) and conduction velocity (CV) slopes, as descriptors of central and peripheral fatigue, during sustained high level isometric contractions at 60% maximal voluntary contraction (MVC), in elderly subjects. Ten recreationally healthy elderly subjects (age 67.7 ± 4.6 years), 5 males and 5 females, performed one isometric contraction of the elbow flexors at 120° joint angle at 60% of MVC until exhaustion in two subsequent trials 1 week apart, one for the sEMG and the other one for NIRS recordings from the biceps brachii. A negative strong Pearson’s correlation between TOI % slope in the functional hyperemic phase (HP) of contraction and a positive correlation between the slope of TOI % recorded during the ischemic phase (IP) and the CV slope were found (r = − 0.76, P

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.

The shoulder complex (SC) consists of joints with little congruence and its active and passive structures ensure its stability. Stability of the SC rotation centre during upper arm movements can be estimated through the analysis of Helical Axes (HAs) dispersion. The aim of this study was to describe shoulder HAs dispersion during upper limb movements performed with dominant and non-dominant arms by young and elderly subjects. Forty subjects participated in the study (20 young: age 24.8 ± 2.8 years and 20 elderly: age 71.7 ± 6.3 years). Subjects were asked to perform four cycles of 15 rotations, flexions, elevations and abductions with one arm at a time at constant speed. Reflective markers were placed on participants' arms and trunk in order to detect movements and the HAs dispersion with an optoelectronic system. Mean Distance (MD) from the HAs barycenter and Mean Angle (MA) were used as HAs dispersion indexes. Young subjects showed significant lower MD compared to the elderly during all motion ranges of rotation, flexion and elevation (p 0.001). Moreover, the MD was lower in the dominant arm compared to the contralateral for rotation (p = 0.049) and flexion (p = 0.019). The results may be due to joint degeneration described in elderly subjects and differences in neuromuscular control of SC stability.

Background Mechanical and morphological properties of the Achilles tendon are altered in disease and in response to changes in mechanical loading. In the last few years different ultrasound based technologies have been used to detect tendon mechanical properties changes mainly in resting condition. Therefore the aim of this study was to evaluate if strain sonoelastography can identify changes in Achilles tendon elasticity during isometric contractions of increasing intensity. Methods This cross-sectional study enrolled 37 healthy volunteers (19 women) with mean (±SD) age of 27.1 (±7.0) years between January and June 2017. Strain sonoelastography images of the Achilles tendon were acquired during an isometric ramp force (0 kg, 0.5 kg, 1 kg, 2 kg, 5 kg and, 10 kg). An external reference material was used to provide a comparison between the examined tissue and a material of constant elasticity. Friedman test with post hoc pairwise comparison were used to determine the correlation between the difference contraction levels. Results The median and interquartile range (IQR) values for the strain ratio were 1.61 (1.5–2.9) in a relaxed state and 1.30 (1.07–2.02), 1.00 (0.76–1.66), 0.81 (0.70–1.19), 0.47 (0.39–0.73) and 0.33 (0.28–0.40) for 0.5 kg, 1 kg, 2 kg, 5 kg and 10 kg, respectively revealing increased tendon hardness with increasing contraction intensities. Friedman test revealed significant differences (p

A majority of patients with facioscapulohumeral muscular dystrophy (FSHD) report severe fatigue. The aim of this study was to explore whether fatigability during a performance task is related to the main clinical features of the disease in mildly affected patients. A total of 19 individuals with a molecular genetic-based diagnosis of FSHD (median D4Z4 deletion length of 27 kb) 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. Fatigability indices (average rectified value, mean frequency, conduction velocity, and fractal dimension) were extracted from the surface electromyogram (sEMG) signal, and their correlations with age, age at onset, disease duration, D4Z4 contraction length, perceived fatigability, and clinical disability score were analyzed. The conduction velocity during the low level contraction showed a significant negative correlation with the age at onset (p < 0.05). This finding suggest the assessment of conduction velocity at low isometric contraction intensities, as a potential useful tool to highlight differences in muscle involvement in FSHD patients.

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.

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 p r = 0.62) and lower levels of performance fatigability, characterized by reduced rate of changes in MNF (p r = 0.56), CV (p p r = 0.51) and increased endurance time (p 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.

Background Ultrasound imaging techniques have been used to assess the characteristics of skeletal muscles and tendons. Such techniques (gray scale analysis) allow qualitative evaluation and have been used recently to assess the internal structure of muscles and tendons by computer-aided gray scale analysis. We hypothesized that changes in the internal structure of the Achilles and patellar tendons after a ski mountaineering race competition could be detected with ultrasound. Methods Twenty athletes were recruited during the 19th Millet Tour du Rutor extreme, a three-day ski mountaineering competition. Ultrasound measurements of the Achilles and patellar tendons were carried out before the first race and immediately after each of the three competition days. Tendon thickness, cross-sectional area (CSA), and ultrasound gray scale analysis were calculated. Results Significant differences (p p Conclusions Achilles and patellar tendons of healthy athletes are highly responsive to an acute increase in mechanical load. Those changes can be detected from classical (thickness and CSA) and innovative (gray scale) ultrasound-based parameters. Trial registration This study was approved by the Azienda USL Valle d’Aosta Ethics Committee (protocol no. 23/03/2018.0026243.I).

To evaluate the test-retest reliability of the ultrasound echo intensity parameters on healthy Achilles tendon using a semi-automatic tracing procedure. 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. 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. Ultrasound echo intensity is a reliable technique to characterize the internal structure of the Achilles tendon.

Objective to examine potential association between mediolateral episiotomy and reduced incidence of obstetrical anal sphincter injuries (OASIS) diagnosed by endoanal ultrasound. Design prospective cohort study. Setting tertiary referral university hospital. Participants sixty nulliparous women at 28–33 weeks of gestation with singleton pregnancies were included between 2010 and 2012. Measurements and findings participants were examined with endoanal ultrasound at 28–33 weeks gestation and at 6–7 weeks post-partum. At both visits, symptoms of anal incontinence were assessed using Cleveland Clinic (Wexner) faecal incontinence scoring system. Mann Whitney U -test and χ 2 test was used to compare groups with vs. without episiotomy and groups with vs. without OASIS diagnosed by ultrasound. χ 2 test was used to assess correlation between OASIS and anal incontinence symptoms ( p ≤0.05 considered significant). None of the women included had sphincter injury or anal incontinence before childbirth. All delivered vaginally. Mediolateral episiotomy was performed in 33 (55%) cases. Six (10%) had OASIS on endoanal ultrasound (two were also diagnosed clinically), and 11 had symptoms of anal incontinence post-partum. No significant differences were seen in clinical characteristics between groups with vs. without episiotomy. No significant differences were seen in episiotomy rate ( p =0.14), angle ( p =0.42) and length ( p =0.14) between groups with vs. without OASIS on ultrasound. Correlation between anal incontinence symptoms and sonographically diagnosed OASIS was statistically significant ( p =0.04). Key conclusions mediolateral episiotomy does not seem to be protective against clinically or sonographically diagnosed OASIS even when episiotomy technique is considered. Endoanal ultrasound allows a significantly better detection of symptomatic OASIS compared to clinical examination alone. Implications for practice mediolateral episiotomy should be considered only when shortening the second stage of labour is indicated due to foetal distress, and not as a means of OASIS prevention.

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 20 min 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. 46 s; 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.

This study aimed to investigate the variation in muscle activity and movement in the lumbar and lumbothoracic region during a singular mono-planar lifting task, and how this is altered in individuals experiencing low back pain (LBP). Muscle activity from the lumbar and lumbothoracic erector spinae of 14 control and 11 LBP participants was recorded using four 13 × 5 high-density surface electromyography (HDEMG) grids. Root mean squared HDEMG signals were used to create spatial maps of the distribution of muscle activity. Three-dimensional kinematic data were recorded focusing on the relationship between lumbar and thoracic movements. In the task, participants lifted a 5 kg box from knee height to sternal height, and then returned the box to the starting position. The center of muscle activity for LBP participants was found to be systematically more cranial throughout the task compared to the control participants (P < 0.05). Participants with LBP also had lower signal entropy (P < 0.05) and lower absolute root mean squared values (P < 0.05). However, there were no differences between groups in kinematic variables, with no difference in contributions between lumbar and thoracic motion segments (P > 0.05). These results indicate that participants with LBP utilize an altered motor control strategy to complete a singular lifting task which is not reflected in their movement strategy. While no differences were identified between groups in the motion between lumbar and thoracic motion segments, participants with LBP utilized a less homogenous, less diffuse and more cranially focussed contraction of their erector spinae to complete the lifting movement. These results may have relevance for the persistence of LBP symptoms and the development of new treatments focussing on muscle retraining in LBP.

Background: Tecar therapy (TT) is an endogenous thermotherapy used to generate warming up of superficial and deep tissues. TT capability to affect the blood flow is commonly considered to be the primary mechanism to promote tissue healing processes. Despite some preliminary evidence about its clinical efficacy, knowledge on the physiologic responses induced by TT is lacking. Objective: The aim of this quantitative randomized pilot study was to determinate if TT, delivered in two modes (resistive and capacitive), affects the perfusion of the skin microcirculation (PSMC) and intramuscular blood flow (IMBF). Design: A randomized controlled pilot feasibility study. Subjects: Ten healthy volunteers (n = 4 females, n = 6 males; mean age 35.9 ± 10.7 years) from a university population were recruited and completed the study. Intervention: All subjects received three different TT applications (resistive, capacitive, and placebo) for a period of 8 min. Outcome measures: PSMC, IMBF, and the skin temperature (ST) were measured pre- and post-TT application using power Doppler sonography, laser speckle contrast imaging (LSCI), and infrared thermography. Results: Compared with placebo application, statistically significant differences in PSMC resulted after both the resistive (p = 0.0001) and the capacitive (p = 0.0001) TT applications, while only the resistive modality compared with the placebo was capable to induce a significant change of IMBF (p = 0.013) and ST (p = 0.0001). Conclusions: The use of power Doppler sonography and LSCI enabled us to evaluate differences in PSMC and IMBF induced by TT application.

AIM To apply topographical mapping of the electromyography (EMG) amplitude recorded from the upper trapezius muscle to evaluate the distribution of activity and the location of peak activity during a shoulder elevation task in participants with and without myofascial pain and myofascial trigger points (MTrP) and compare this location with the site of the MTrP. MATERIALS AND METHODS Thirteen participants with myofascial pain and MTrP in the upper trapezius muscle and 12 asymptomatic individuals participated. High-density surface EMG was recorded from the upper trapezius muscle using a matrix of 64 surface electrodes aligned with an anatomic landmark system (ALS). Each participant performed a shoulder elevation task consisting of a series of 30 s ramped contractions to 15% or 60% of their maximal voluntary contraction (MVC) force. Topographical maps of the EMG average rectified value were computed and the peak EMG amplitude during the ramped contractions was identified and its location determined with respect to the ALS. The location of the MTrP was also determined relative to the ALS and Spearman correlation coefficients were used to examine the relationship between MTrP and peak EMG amplitude location. RESULTS The location of the peak EMG amplitude was significantly (P

An increased fatigability associated with anterior cruciate ligament (ACL) injury may persist several months after surgery. The purpose of this study was to investigate the behavior of muscle fiber conduction velocity (CV) as a descriptor of myoelectric fatigue, at different stages after rehabilitation, post-ACL reconstruction. Nineteen subjects acted as control group (CG), 10 patients had undergone surgery within 12 months (R12), and 23 patients were more than 24 months post-surgery (R24+). Surface electromyography (EMG) signals were detected from the quadriceps femoris using bidimensional arrays during isometric contractions at 20% and 60% maximal voluntary contraction (MVC). We observed a lower fatigability in the R24+ group during the 60% MVC contraction, with respect to the other groups. Lower fatigability of quadriceps muscle after ACL reconstruction in the long term may be linked to a recovery from a transitory altered motor unit recruitment strategy due to surgery, observed in the R12 group. Therefore, the findings of this study do not suggest an impaired fatigability of the quadriceps muscle during sustained isometric contractions in active patients in the long term.

Shoulder complex control of motion is influenced by neuromuscular function and can be quantified through the analysis of helical axes (HAs) dispersion. Muscle fatigue is a variable able to influence neuromuscular control, altering muscle activation timing and proprioception. The aim of the study was to describe shoulder complex HAs dispersion after muscle fatigue during upper limb movements of young healthy subjects. Thirty healthy right-handed volunteers (age 23.2 ± 2.6 years) were asked to perform a test made up of 15 humerothoracic flexion and rotation movements using both upper limbs in two different recording sessions. After each session, muscles of the tested movement were fatigued in isometric condition at dominant side. After fatigue, subjects repeated the test. Kinematics was recorded by an optoelectronic system and HAs dispersion was computed using Mean Distance (MD) and Mean Angle (MA) for the entire Range of Motion (RoM) and in portions of RoM. After fatigue of shoulder flexion muscles, greater MD (p = 0.001) and MA (p = 0.019) were found on the dominant side. After fatigue of shoulder rotation muscles, greater MD and MA were found on the dominant (p = 0.002 for MD; p = 0.047 for MA) and non-dominant (p = 0.038 for MD; p = 0.019 for MA) sides. Independently of fatigue, greater MA was found in portions of RoM with higher external resistance torque in flexion and rotation tasks. Muscle fatigue increases shoulder complex HAs dispersion, probably due to alteration in neuromuscular control. This data should be considered when exercise involving upper arms are proposed to subjects undergoing fatigue.

People with acute neck pain commonly present with restricted neck movement. However, it is unknown whether the presence of acute pain affects the quality of neck movement; specifically neck movement variability. We examined the effects of acute neck muscle soreness induced via eccentric exercise in healthy volunteers, on the variability of neck movement by examining changes in parameters of the helical axis during active neck movements. An experimental, single-arm repeated measures study recruited 32 healthy participants, male and female, aged between 18 to 55. Repetitive active neck movements (flexion-extension, bilateral lateral flexion and bilateral rotation) were performed at different speeds, either at full range of motion (RoM) or restricted to 45° RoM at baseline pre-exercise (T0), immediately following eccentric neck exercise (T1), 24 hours (T2) and 48 hours post-exercise (T3). The mean distance (MD) and mean angle (MA) parameters of the helical axis were extracted to quantify movement variability. MD, measured during movements performed at full RoM, reduced significantly at T2 compared to T0 (P = 0.001) regardless of direction or speed of movement. MA was significantly lower at T2 and T3 compared to T1 (P = 0.029 and P = 0.033, respectively). When RoM was restricted to 45°, significantly lower MD values were observed at T3 compared to T1 (P = 0.034), and significantly lower MA values were measured at T3 compared to T0, T1 and T2 (all P This study uniquely demonstrates that neck movement variability is reduced immediately after, 24 hours and 48 hours after eccentric exercise, indicating that acute neck muscle soreness modifies the quality of neck movement.

The current scoping review aimed to map current literature investigating the relationship between pain extent extracted from pain drawings with clinical, psychological, and psycho-physiological patient-reported outcome measures in people with pain. Electronic databases were searched for cross-sectional cohort studies that collected pain drawings using digital technology or a pen-on-paper approach and assessed for correlations between pain extent and clinical, psychological or psycho-physical outcomes. Data were extracted by two different reviewers. The methodological quality of studies was assessed using the Newcastle&ndash, Ottawa Quality Assessment Scale. Mapping of the results included: 1, description of included studies, 2, summary of results, and 3, identification of gaps in the existing literature. Eleven cross-sectional cohort studies were included. The pain disorders considered were heterogeneous, ranging from musculoskeletal to neuropathic conditions, and from localized to generalized pain conditions. All studies included pain and/or pain-related disability as clinical outcomes. Psychological outcomes included depression and anxiety, kinesiophobia and catastrophism. Psycho-physical measures included pressure or thermal pain thresholds. Ten studies were considered of high methodological quality. There was heterogeneity in the associations between pain extent and patient-reported outcome measures depending on the pain condition. This scoping review found that pain extent is associated with patient-reported outcome measures more so in patients presenting with musculoskeletal pain, e.g., neck pain or osteoarthritis, rather than for those with neuropathic pain or headache.

Knee joint rotation center displacement can be estimated in vivo through the analysis of helical axis (HAs) dispersion. HAs can be analyzed during walking, providing information on joint stability. The study aim was to describe knee HAs dispersion during walking in dominant and non-dominant legs of young and elderly healthy subjects. Twenty young (YG: age 23.3 ± 2.4 years) and twenty elderly (EG: age 69.3 ± 4.6 years) healthy subjects were asked to walk on a treadmill at a self-selected speed with reflective markers placed bilaterally on thighs and shanks to detect HAs dispersion and knee kinematics with an optoelectronic system. HAs dispersion was described during the following four phases of gait cycle: (1) flexion from 95% of the previous gait cycle to 10% of the subsequent gait cycle, (2) extension from 10% to 40%, (3) flexion from 40% to 75% and (4) extension from 75% to 95% of the gait cycle. Mean Distance (MD) and Mean Angle (MA) were used as HAs dispersion indexes during each gait phase. Participants showed greater MD and MA in sagittal and frontal planes during the first and second phases. EG revealed higher MD (p = 0.001) and MA (p < 0.001) during the first phase and higher MA (p = 0.001) during the fourth phase in both dominant and non-dominant legs on the sagittal plane. HAs dispersion could be related to the amount of forces acting on knee (first two phases) and knee degeneration (elderly). These results may be used as reference data in further studies on HAs dispersion in presence of knee pathologies or after knee surgery or rehabilitation.

To counteract muscle mass, muscle strength and power loss during aging, and to study age-related change of neuromuscular manifestation of fatigue in relation to nutritional supplementation.randomized controlled double-blind study.Twice-daily consumption for 12 weeks of an Essential Amino Acids (EAA)-based multi-ingredient nutritional supplement containing EAA, creatine, vitamin D and Muscle Restore Complex®.38 healthy elderly subjects (8 male, 30 female; age: 68.91±4.60 years; body weight: 69.40±15.58 kg; height: 1.60±0.09 m) were randomized and allocated in supplement (SUPP) or placebo (PLA) group. Mean Measurements: Vitamin D blood level; Appendicular Lean Mass (ALM); Visceral Adipose Tissue (VAT); Maximal Voluntary Contraction (MVC) and Peak Power (PP); myoelectric descriptors of fatigue: Fractal Dimension and Conduction Velocity initial values (FD iv, CV iv), their rates of change (FD slopes, CV slopes) and the Time to perform the Task (TtT). Mean Results: Significant changes were found in SUPP compared to baseline: Vitamin D (+8.73 ng/ml; p0.001); ALM (+0.34 kg; p0.001); VAT (-76.25 g; p0.001); MVC (+0.52 kg; p0.001); PP (+4.82 W; p0.001). Between group analysis (SUPP Vs. PLA) showed improvements: vitamin D blood levels (+11,72 ng/ml; p0.001); Legs FFM (+443.7 g; p0.05); ALM (+0.53 kg; p0.05); MVC (+1.38 kg; p0.05); PP (+9.87 W; p0.05). No statistical changes were found for FD iv, CV iv, FD and CV slopes and TtT, either compared to baseline or between groups. Significant correlations between mean differences in SUPP group were also found.The study demonstrates that in healthy elderly subjects an EAA-based multi-ingredient nutritional supplementation of 12 weeks is not effective to change myoelectric manifestation of fatigue and TtT failure but can positively affect muscle mass, muscle strength, muscle power and VAT, counterbalancing more than one year of age-related loss of muscle mass and strength.

Objective: Fatigue experienced by people with multiple sclerosis (pwMS) is multidimensional, consisting of different components, such as perceived, physical and cognitive fatigue and performance fatigability. At present, there is no gold standard to assess performance fatigability in pwMS; therefore, we aimed to determine whether, during a fatiguing task, average rectified value (ARV), mean frequency of the power spectrum (MNF), muscle fiber conduction velocity (CV) and fractal dimension (FD) of surface electromyography (sEMG) may be used as indirect indices of performance fatigability. Moreover, we analyzed whether a three-week rehabilitation program impacts on performance fatigability in pwMS, and whether a relationship between sEMG parameters and trait levels of perceived fatigability, before and after rehabilitation, does exist. Approach: Twenty-one pwMS performed a 20% maximal voluntary contraction (MVC) of 1 min, and afterwards a 60% MVC held until exhaustion. sEMG signals were detected from the biceps brachii, vastus medialis and vastus lateralis. Performance fatigability was determined at entry to (t 0) and discharge from (t 1) rehabilitation. Perceived fatigability was measured at t 0 and t 2, one month after rehabilitation. Main results: ARV, MNF, CV and FD rates of change showed significant changes at t 0 and t 1 (p t 0 and t 2, were found. Significance: Our findings suggest that the sEMG parameters are useful for indirectly assessing performance fatigability in pwMS during sub-maximal fatiguing contractions, particularly in the biceps brachii.

Background Conduit arteries, especially the aorta, play a major role in ensuring efficient cardiac function and optimal microvascular flow due to their viscoelastic properties. Studies in animals and on isolated arteries show that acute systemic inflammation can cause aortic stiffening which affects hemodynamic efficiency. Carotid-femoral pulse wave velocity, a measure of aortic stiffness, may be useful as a bedside investigational method in patients with early sepsis admitted to intensive care, as circulatory changes can lead to multiple organ failure and increased mortality. This study aims to investigate arterial stiffness in early sepsis and its association with clinical outcomes. Methods This prospective observational study included adult patients with severe sepsis or septic shock admitted to our intensive care unit (n = 45). Their carotid-femoral pulse wave velocity was measured within 24 h of admission. We assessed the progression of multiple organ as well as cardiovascular failure by sequential SOFA scores. Prediction models for the progression of multiple organ and cardiovascular failure were constructed using multivariate logistic regression with pulse wave velocity and vasopressor use as predictors. A Cox proportional hazards model was used to examine the relationship between pulse wave velocity and survival time. Results The median pulse wave velocity for the cohort was 14.6 (8.1–24.7) m/s. There was no association between pulse wave velocity and the progression of multiple organ failure, before or after adjustment for vasopressor use. No association was found between pulse wave velocity and subsequent improvement in cardiovascular failure in the subgroup of patients who had cardiovascular instability at baseline. Cox regression and survival analyses with age, APACHE II, and baseline SOFA as confounders showed a shorter hospital survival time for patients with pulse wave velocity > 24.7 m/s (HR = 9.45, 95% CI 1.24–72.2; P = 0.03). Conclusions Patients with severe sepsis and septic shock admitted to intensive care have higher arterial stiffness than in the general population. No convincing association was found between pulse wave velocity at admission and the progression of multiple organ or cardiovascular failure, although the group with pulse wave velocity > 24.7 m/s had shorter survival time. Electronic supplementary material The online version of this article (10.1186/s40635-019-0252-3) contains supplementary material, which is available to authorized users.

Background: The purpose of this study was to investigate the acute effects of a single oral administration of an essential amino acids enriched mixture (EAA) on myoelectric descriptors of fatigue and maximal force production after a resistance exercise protocol (REP).Methods: Twenty adult males (age: 27 ± 6 years; body mass: 72.7 ± 7.50 kg; height: 1.76 ± 0.06 m) were enrolled in a double-blind crossover placebo-controlled study. Subjects were randomized to receive EAA mix (0.15 g/kg BM) or a placebo (PLA) in two successive trials 7 days apart. In both trials subjects completed a REP 2 h after the ingestion of the EAA mix or PLA. Before ingestion and after REP subjects performed isometric contractions of the dominant upper limb with the elbow joint at 120 degrees: (1) two maximal voluntary contractions (MVCs) for 2–3 s; (2) at 20% MVC for 90 s; (3) at 60% MVC until exhaustion. Mean values of MVC, conduction velocity initial values (CV), fractal dimension initial values (FD), their rates of change (CV slopes, FD slopes) and the Time to perform the Task (TtT) were obtained from a multichannel surface electromyography (sEMG) recording technique. Basal blood lactate (BL) and BL after REP were measured.Results: Following REP a significant decrease of MVC was observed in PLA (P < 0.05), while no statistical differences were found in EAA between pre-REP and post-REP. After REP, although a significant increase in BL was found in both groups (P < 0.0001) a higher BL Δ% was observed in PLA compared to EAA (P < 0.05). After REP, at 60% MVC a significant increase of CV rate of change (P < 0.05) was observed in PLA but not in EAA. At the same force level TtT was longer in EAA compared to PLA, with a significant TtT Δ% between groups (P < 0.001).Conclusion: Acute EAA enriched mix administration may prevent the loss of force-generating capacity during MVC following a REP. During isometric contraction at 60% MVC after REP the EAA mix may maintain CV rate of change values with a delay in the TtT failure.

Background Recent work described parameters of the helical axis in asymptomatic people with potential for investigating kinematic changes in the cervical region. This approach could provide novel information on movement variability in people with neck pain, however this has never been investigated. This study aimed to investigate movement variability during active neck movements performed at different speeds in people with and without chronic neck pain. Methods This observational case-control study examined 18 participants with chronic neck pain of either idiopathic or traumatic origin and 18 gender-matched asymptomatic participants. Cervical kinematics were captured with 3D motion capture as people with and without chronic neck pain performed flexion-extension, bilateral lateral flexion and bilateral rotation at different speeds (natural, slow, and fast). The mean distance and mean angle parameters of the helical axis were extracted to describe 3D motion and quantify movement variability. Findings A smaller mean distance was observed in those with neck pain compared to the asymptomatic participants during flexion-extension (P = 0.019) and rotation movements (P = 0.007). The neck pain group displayed smaller values for the mean angle during rotation movements with different speeds (P = 0.01). These findings indicate less variable movement for those with neck pain relative to the asymptomatic participants. No difference in the mean angle was observed between groups for flexion-extension and lateral flexion. Interpretation The findings reiterate the importance of data derived from kinematic measures, and its potential for providing clinicians with further insight into the quality of active neck movements in people with chronic neck pain.

We read with interest the study by Bocardi et al.1 aimed to evaluate the impact of aging on female pelvic floor function (PFF). For this purpose, the authors assessed PFF in 70 healthy nulliparous ...

Purpose: To evaluate Achilles tendon stiffness using strain sonoelastography with an external reference material during an isometric ramp contraction. Methods and Materials: Ultrasound and strain sonoelastography examinations were performed on 37 healthy participants using a commercially available ultrasound system (MyLab ClassC, Esaote, Genoa, Italy) with a linear transducer (LA533) in the frequency range 3–13 MHz. Strain sonoelastography, using an external reference material made with Zerdine® (CIRS, Norfolk, VA, USA) with known elasticity properties, was performed in the longitudinal plane at the level of the medial malleolus. The experimental protocol was tested and validated in previously published work. The external reference material was used to provide a comparison between the examined tissue and a material with a known elasticity. Stiffness was computed according to the sonoelastography color scale as the strain ratios between the tendon and reference material. Sonoelastography images were captured during rest and during a series of isometric contractions of the gastrocnemius muscle at different force levels (0.5kg, 1kg, 2kg, 5kg, 10kg.) The mean and standard deviation of the strain ratios for all subjects across the different conditions were calculated and the Friedman test with post hoc pairwise comparison were used to determine the correlation between the different contraction levels. Results: No significant differences were found for Achilles tendon stiffness between men and women (p=0.6) or between the left and right Achilles tendon (p=0.5), therefore the data were pooled for further analysis. The mean (±SD) values for the strain ratio was 1.98 (±1.09) in a relaxed state and 1.32 (±0.63), 1.07 (±0.55), 0.83 (±0.37), 0.49 (±0.19) and 0.33 (±0.10) for the contractions with 0.5 kg, 1 kg, 2 kg, 5 kg and 10 kg respectively. Friedman test for related samples showed significance (p=0.000) and the post hoc pairwise comparison revealed significant differences (p

A method to detect automatically the location of innervation zones (IZs) from 16-channel surface EMG (sEMG) recordings from the external anal sphincter (EAS) muscle is presented in order to guide episiotomy during child delivery. The new algorithm (2DCorr) is applied to individual motor unit action potential (MUAP) templates and is based on bidimensional cross correlation between the interpolated image of each MUAP template and two images obtained by flipping upside-down (around a horizontal axis) and left-right (around a vertical axis) the original one. The method was tested on 640 simulated MUAP templates of the sphincter muscle and compared with previously developed algorithms (Radon Transform, RT; Template Match, TM). Experimental signals were detected from the EAS of 150 subjects using an intra-anal probe with 16 equally spaced circumferential electrodes. The results of the three algorithms were compared with the actual IZ location (simulated signal) and with IZ location provided by visual analysis (VA) (experimental signals). For simulated signals, the inter quartile error range (IQR) between the estimated and the actual locations of the IZ was 0.20, 0.23, 0.42, and 2.32 interelectrode distances (IED) for the VA, 2DCorr, RT and TM methods respectively.

Convex hull area (CHA) and mean angle (MA) have been proposed to describe the behaviour of the helical axis during joint kinematics. This study investigates the intra- and inter-session reliability of CHA and MA during active movements of the cervical spine. Twenty-seven healthy volunteers (19 women) aged 23 ± 2.8 years participated. Each volunteer was tested on two sessions. All participants were instructed to perform the following active movements of the cervical spine: rotation, flexion/extension and lateral bending, each performed to full range and repeated ten consecutive times. Cervical movements were registered with an electromagnetic tracking system. For each participant, each movement and each session, range of motion (ROM), CHA and MA were extracted. ROM showed high intra- and inter-session reliability during all cervical spine movements using this method. Overall, the intra- and inter-session reliability of the helical axis parameters varied depending on the movement direction and ranged from fair to almost perfect. The intra- and inter-session reliability of CHA and MA were almost perfect during rotation whereas the intra- and inter-session reliability of CHA was substantial during lateral bending and intra- and inter-session reliability of MA ranged from fair to substantial during flexion/extension and lateral bending. This is the first study to evaluate the reliability of helical axis measures during active movements of the cervical spine. The results show that CHA and MA are promising descriptors of cervical kinematics which could be applied in future studies to evaluate neck function in patients with cervical spine disorders.

Widespread pain is considered a sign of central sensitization in people with chronic pain. Our aim was to examine whether pain extent, assessed from the pain drawing, relates to measures from quantitative sensory testing in fibromyalgia syndrome (FMS). Thirty women with FMS and no other co-morbid conditions completed pain drawings (dorsal and ventral views) and clinical and related disability questionnaires. Pain extent and pain frequency maps were obtained from the pain drawings using a novel customized software. Pressure pain thresholds were assessed over the 18 tender points considered by the 1990 American College of Rheumatology criteria for FMS diagnosis and over two additional standardized points. Heat and cold pain thresholds were also assessed on the dorsal aspect of the neck, the dorsal aspect of the wrist, and the tibialis anterior. Spearman's correlation coefficients were used to assess the relationship between pain extent and quantitative sensory testing outcomes as well as clinical symptoms. Larger extent of pain was associated with a higher pain intensity (dorsal area: r s = 0.461, P = 0.010; total area: r s = 0.593, P = 0.001), younger age (ventral area: r s = -0.544, P = 0.002; total area: r s = -0.409, P = 0.025), shorter history of pain (ventral area: r s = -0.367, P = 0.046), and higher cold pain thresholds over the tibialis anterior muscle (r s = -0.406, P = 0.001). No significant association was observed between pain extent and the remaining outcomes. Pain drawings constitute an easy and accurate approach to quantify widespread pain. Larger pain extent is associated with pain intensity but not with signs of central sensitization in women with FMS.

Although elbow extensors (EE) have a great role in cross-country skiing (XC) propulsion, previous studies on neuromuscular fatigue in long-distance XC have investigated only knee extensor (KE) muscles. In order to investigate the origin and effects of fatigue induced by long-distance XC race, 16 well-trained XC skiers were tested before and after a 56-km classical technique race. Maximal voluntary isometric contraction (MVC) and rate of force development (RFD) were measured for both KE and EE. Furthermore, electrically evoked double twitch during MVC and at rest were measured. MVC decreased more in KE (−13%) than in EE (−6%, P = 0.016), whereas the peak RFD decreased only in EE (−26%, P = 0.02) but not in KE. The two muscles showed similar decrease in voluntary activation (KE −5.0%, EE −4.8%, P = 0.61) and of double twitch amplitude (KE −5%, EE −6%, P = 0.44). A long-distance XC race differently affected the neuromuscular function of lower and upper limbs muscles. Specifically, although the strength loss was greater for lower limbs, the capacity to produce force in short time was more affected in the upper limbs. Nevertheless, both KE and EE showed central and peripheral fatigue, suggesting that the origins of the strength impairments were multifactorial for the two muscles.

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 two 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 two consecutive PD with an interval of one minute. Custom software was used to quantify the pain extent and analyse 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: PD 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.

Purpose The purpose of the present study was to evaluate inter-arm and inter-gender differences in fractal dimension (FD) and conduction velocity (CV) obtained from multichannel surface electromyographic (sEMG) recordings during sustained fatiguing contractions of the biceps brachii. Methods A total of 20 recreationally active males (24±6 years) and 18 recreationally active females (22±9 years) performed two isometric contractions at 120 degrees elbow joint angle: (1) at 20% maximal voluntary contraction (MVC) for 90 s, and (2) at 60% MVC until exhaustion the time to perform the task has been measured. Signals from sEMG were detected from the biceps brachii using bidimensional arrays of 64 electrodes and initial values and rate of change of CV and FD of the sEMG signal were calculated. Results No difference between left and right sides and no statistically significant interaction effect of sides with gender were found for all parameters measured. A significant inter-gender difference was found for MVC (p0.05). During the sustained 60% MVC no statistical correlation was found between MVC and CV or FD initial estimates nor between MVC and CV or FD slopes both in males and females whereas. A significant positive correlation between CV and FD slopes was found in both genders (males: r = 0,61; females: r = 0,55). Conclusions Fatigue determines changes in FD and CV values in biceps brachii during sustained contractions at 60% MVC. In particular males show greater increase in the rate of change of CV and FD than females whereas no difference in percentage change of these sEMG descriptors of fatigue was found. A significant correlation between FD and CV slopes found in both genders highlights that central and peripheral myoelectric components of fatigue may interact during submaximal isometric contractions.

To establish the test–retest reliability of sonoelastography (SE) on healthy Achilles tendons in contracted and relaxed states using an external reference system. 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. 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). 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.

Purpose The purpose of the study was the non-invasive investigation of the innervation zone (IZ) location of the gracilis muscle of both thighs by means of surface electromyography (EMG). Materials and methods Multichannel EMG signals were detected by means of a flexible array of 16 equally spaced silver bar electrodes. Tests were performed on both gracilis muscles on 15 subjects. Motor unit (MU) action potentials were visually identified and extracted. The locations of the IZs of the recognized MUs were statistically analyzed to find significant differences between the subjects and between the right and left muscle of each subject. Results and conclusions A statistically significant difference was found between the gracilis IZ position in the two sides, with more proximal IZs on the left side. This difference suggests a possible role of surface EMG in preoperative evaluation of patients prepared for the dynamic graciloplasty procedure. This test would provide an objective criterion for the choice of the gracilis muscle to be transposed with the highest probability of success.

Background. Myalgia frequently affects the upper trapezius muscle, and patients typically complain of dull pain and stiffness. Evidence suggests a correlation between repetitive movements, awkward posture, and the development of neck-shoulder muscle pain. However the mechanisms underlying these associations remain unclear. Purpose. To investigate the effect of experimentally induced upper trapezius muscle pain on the distribution of upper trapezius muscle activity during a repetitive task. It was hypothesized that pain would change the distribution of muscle activity resulting in activation of upper trapezius muscle regions which would not normally be active during the task. Methods. Ten healthy male (age: 26.2 ± 3.1 years) volunteers participated. Subjects lifted a 1 kg box between shelves positioned at hip and shoulder height with a cycle time of 3 s for 50 cycles. The task was repeated: 1. baseline, 2. following injection of 0.4 ml isotonic saline (0.9%) into the right upper trapezius muscle, 3. following injection of 0.4 ml hypertonic saline (5.8%) into the right upper trapezius muscle and 4. 15 mins after the last injection. Pain intensity ratings were obtained immediately following the injection and every 30 s until pain was no longer reported. Surface electromyography (EMG) was recorded from the upper trapezius muscle using a grid of 64 electrodes and 4 uniaxial accelerometers were mounted on the box to obtain the start and end points of the cyclic movement. The EMG root mean square (RMS) was computed for each location of the electrode grid to form a map of the EMG amplitude distribution.The following EMG variables were extracted from the RMS maps: mean RMS, entropy, and y- (cranial-caudal) and x-axis (medio-lateral) coordinates of the centroid of the RMS map. The EMG variables were then averaged across the 50 cycles for each epoch of the cycle. Results. Peak pain intensity was greater following the injection of hypertonic (4.7 ± 1.9/10) compared to isotonic saline (0.8 ± 1.1, P 0.05). Conclusions. The results indicate that nociceptive stimulation of the upper trapezius during a repetitive task changes the distribution of upper trapezius muscle activity and its amplitude. Implications. The described alterations of muscle activity may have an important role in the perpetuation of pain during repetitive activity.

Background: Body charts are a useful tool to assess pain in clinical practice. Patients report their complaints by drawing on body chart the location and the extent of pain. Reporting pain or symptoms over a body chart is a complex task as it involves subjective body spatial cognition and also recognition over a standard two-dimensional template that does not take into account body structures variability. Several methods, paper-based or digital, for completing and analyzing pain drawings have been proposed, and their good test-retest or inter-examiner reliability were described. However, subjects’ spatial acuity in reporting two successive identical stimulus over a body chart has never been investigated. Purpose: The aim of the present study is to assess spatial acuity in reporting two successive identical stimulus over a digital body chart in a group of healthy subjects. Moreover, we investigated if spatial acuity is influenced by the size and the location of the stimulus. Methods: Fifty healthy subjects participated in the study. All subjects received in well defined body parts twenty pressure stimulations, randomly distributed all over the body. Pressure stimulations involved points (1cm2) or larger areas (60cm2) over the body and were applied respectively by an algometer of 1,5 Kg and a flat weight of 2 kg. Each stimulus was performed twice, in a randomized sequence and exactly in the same body location. After each of the forty stimulations, participants were requested to represent the perceived stimulation on a digital body chart. To investigate spatial acuity in reporting perceived stimulus, an appropriate software compared each couple of drawings (D1 and D2) representing the identical stimulations. For the point-like drawings, the distance in pixel between D1 and D2 whereas for drawings of larger areas, the not overlapping area between D1 and D2 were calculated. Results: The median of distance between point-like drawings was 8.8 pixel (IQR: 12.06), the median of not-overlapping area was 48.67% (IQR: 36.34) of the total area (D1+D2). Friedman Test showed a significant change in accuracy of point-like drawings in different body regions: the lower distance (5.9 pixels) between D1 and D2 has been found in the anterior part of the arm, the larger distance (16.1 pixels) in the anterior part of the thigh. Overlapping of reported areas was not significantly different in different body regions. Conclusion The results of the present study showed that the two identical pressure stimuli were reported over a digital body chart in non-identical locations. Moreover, this phenomena has resulted different among different body parts. Implications: It will be interesting to analyze if the same spatial acuity could be observed in patients with pain, in order to evaluate if pain is responsible of an alteration of this variable. Consequently, it will be also possible to assess more precisely pain drawings reliability.

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. 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. 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. 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.

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.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.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.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.

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.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.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.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.

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.