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Objective: The study aimed to investigate the effects of the level of contraction during isometric shoulder abduction at different abduction angles on muscle thickness and stiffness of the shoulder girdle in asymptomatic individuals. Design: Measurement properties study. Setting: Biomechanics and motion analysis lab. Participants: Twenty individuals volunteered to participate in this study. Main Outcome Measure: The subjects were tested for morphological and mechanical properties, expressed by thickness and stiffness of the supraspinatus tendon and muscle, and upper trapezius muscle. Moreover, acromiohumeral distance was also evaluated using B-mode ultrasound and shear-wave elastography. Intervention: The thickness and stiffness of the supraspinatus and upper trapezius muscle were assessed at 3 angles of abduction (0°, 60°, and 90°) and 3 levels of contraction (0%, 10%, and 20% of the maximal voluntary isometric contraction) using ultrasonography with shear-wave imaging. Moreover, the acromiohumeral distance was measured to establish the occupation ratio during passive movement. Results: The supraspinatus and upper trapezius muscle thickness and stiffness were significantly greater at 60° shoulder abduction compared with 0°, and 90° compared with 60°, as well as significantly greater at 20% maximal voluntary isometric contraction compared with 0% and 10% maximal voluntary isometric contraction. Thickness and stiffness were significantly greater in the supraspinatus compared with the upper trapezius muscle at all 3 angles of shoulder abduction for all 3 level of contractions. The acromiohumeral distance decreased significantly from 0° to 60° and from 60° to 90°. Conclusion: Morphological and mechanical properties of the supraspinatus and upper trapezius muscles depended on the relative level of muscle contraction and the angle of shoulder abduction. [ABSTRACT FROM AUTHOR]

Clinical Scenario: The fascial relationship between scapular muscles and abdominal muscles has been documented from previous studies. However, it is not yet clear whether voluntary abdominal contraction has a beneficial effect on scapular muscle activity during shoulder exercises. Clinical Question: Do scapulothoracic muscle activation levels increase if shoulder exercises are performed with voluntary abdominal activation? Summary of Key Finding: After the literature review, 4 cross-sectional studies met the inclusion criteria and were included in this critically appraised topic. Clinical Bottom Line: There is moderate evidence to support dynamic shoulder exercises with voluntary abdominal contraction can increase trapezius and serratus anterior muscle activation level in asymptomatic shoulders. Strength and Recommendation: Findings from 4 cross-sectional trials indicate that there is moderate evidence supporting that dynamic shoulder exercises performed with voluntary abdominal contraction can increase scapular muscle activity. [ABSTRACT FROM AUTHOR]

Shoulder pain is a complex, prevalent problem that is multifactorial in nature. While there are many potential causes, one common suspect is the rotator cuff musculature. The purpose of the present study was to induce pain in the supraspinatus muscle of healthy subjects and observe the resulting changes in muscle activity. Eight muscles on 23 subjects were assessed using electromyography: anterior, middle, and posterior deltoid; pectoralis major; upper trapezius; latissimus dorsi; serratus anterior; supraspinatus; and infraspinatus. It was hypothesized that the rotator cuff muscles would display reduced activity during pain, and that reductions in activity would remain after the pain had dissipated. Both of the rotator cuff muscles measured did indeed display reduced activity in a majority of the dynamic, isometric, and maximal contractions. Many of those reductions remained after the pain had subsided. [ABSTRACT FROM AUTHOR]

Purpose: To verify whether training the iron cross (IC) with assistive devices (herdos; HIC) and added external load (LHIC) to equate the moments of force developed on the rings could be considered an intermediate step between the nonoverloaded herdos situation (HIC) and the IC performed on the rings. Methods: Relative levels of surface electromyography (sEMG) activity were normalized with respect to a standing IC before comparing gymnasts who can perform the IC on the rings (achievers) and gymnast who cannot (nonachievers) in the 2 herdos conditions (HIC and LHIC). Seven muscles were chosen for sEMG analysis, namely, pectoralis major (PM), latissimus dorsi, teres major, lower trapezius, serratus anterior, biceps brachii (BB), and triceps brachii. Additionally, 3 indices were calculated to measure levels of coactivation: Elbowidx, Scapulaidx, and Shoulderidx. Results: The bigger magnitude of differences in sEMG activity among situations was found for the PM and BB (F ≥ 30.7; P <.001). When comparing the global and the PM, teres major, BB, and triceps brachii activity across groups, nonachievers activated their musculature to a greater extent than the achievers independently of the herdos situation (P ≤.046). Achievers' Elbowidx was the only index that was significantly higher (P ≤.005) in the IC in comparison to LHIC and HIC. Conclusion: sEMG activity of PM and BB was particularly sensitive between situations, independently of the level of achievement. We recommend training the IC by adding external load in the herdos situation to increase muscle activity to levels closer to the rings situation but avoiding the potential factor of injuries. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the contribution of splenius capitis, sternocleidomastoid, and upper fibers of trapezius activation to the gains in rate of force development (RFD) of the head and neck during maximum voluntary ballistic contractions. Methods: RFD gain was facilitated by a single-session intervention for maximum voluntary ballistic contractions in the anterior direction, oriented at 45° to the midsagittal plane, which require active restraint of axial rotation. Muscle activation for the agonist (sternocleidomastoid) and 2 antagonists (splenius capitis and upper fibers of trapezius) was evaluated. The study sample included 12 physically active men (mean age, 22.6 y). RFD (N·m·s−1; 0–100 ms) and integrated muscle activity (50 ms before and 100 ms after force onset) were measured at 10 minutes, 20 minutes, and 2 days postintervention, relative to baseline. Muscle activation predictive of RFD gains was evaluated by linear regression analysis. RFD reproducibility was evaluated using the coefficient of variation of the typical error. Results: The intervention yielded a 1.95- to 2.39-fold RFD gain (P ≤.05), with greater RFD gain for participants with a lower peak moment of force (<10.9 N·m) than those with a higher peak moment (≥10.9 N·m) at baseline (P ≤.002). For the low group, 65% to 74% of the RFD gain was predicted by ipsilateral sternocleidomastoid activation, with ipsilateral splenius capitis activation predicting 77% to 92% of RFD gain for the high group. Absolute peak and impulse of static force were greater for the high than for the low group (P ≤.04). RFD reproducibility was high (coefficient of variation of the typical error ≤ 14.4%). Conclusions: The agonist- and antagonist-focused synergies might reflect different functional priorities, higher RFD gain compared with higher head–neck force. [ABSTRACT FROM AUTHOR]

ABSTRACT We examined the feasibility of using the neofunctional deep breathing (NDB) technique to reduce the allostatic load following the Trier Social Stress Test (TSST). Forty‐four healthy subjects were randomised into experimental and control groups. Following the TSST procedure, participants underwent either a single session of NDB or an attention control intervention. The Procomp Infinity Biofeedback system measured breath per minute (BPM), respiratory amplitude, HRV linear domains, skin conductance, and trapezius muscle electromyographic activity. Cortisol and cytokine salivary concentrations, perceived stress, and anxiety levels were also assessed. These parameters were combined into an allostatic load index (ALI) to measure the intervention's effect. This pilot RCT demonstrated the feasibility of the study design and practicality of the intervention. The NDB group showed reduced ALI, increased respiratory abdominal amplitude, decreased BPM, increased HRV indicating parasympathetic activation, and decreased cortisol and inflammatory cytokines. This study highlighted the feasibility of testing the NDB technique in reducing allostatic load through a neurobiological and anti‐inflammatory response after exposure to psychosocial stress. This protocol can represent a non‐invasive therapeutic adjutant in disorders related to a dysregulation of the HPA axis or to an inflammatory state.Trial Registration: NCT04102813 [ABSTRACT FROM AUTHOR]

AbstractThis study analyzed the residue depletion kinetics of ivermectin (IVM) in Nelore and crossbred (Nelore x Angus) cattle aiming to compare the profiles between the breeds and evaluate the residue levels at the injection site. IVM 1%, at a dose of 0.2 mg/kg, was administered via the subcutaneous route, and tissue samples were collected on different days post administration for analysis by LC–MS/MS. The results revealed that the detection of the marker residue in conventional matrices such as the liver, perirenal fat, and trapezius muscle (injection site) had relatively high residue concentrations. The maximum residue limit (MRL) was exceeded at the injection site at 21- and 35-days post administration in crossbred and Nelore animals, respectively, with significant variations between animals. This study highlighted significant challenges in accurately determining the pharmacokinetic profile and withdrawal periods of IVM in cattle due to high variability in tissue residue data, particularly at injection sites. The comparison of IVM concentrations between cattle breeds was hindered by high standard errors, emphasizing the need for more rigorous sampling protocols. The results suggest that current guidelines may not adequately account for the erratic depletion kinetics of injectable formulations like IVM, especially at injection sites. Therefore, improving sampling techniques and revising guidelines are essential for accurate residue monitoring and withdrawal period determination. [ABSTRACT FROM AUTHOR]

Objective: A recent study was designed to ascertain the impact of extracorporeal shock wave therapy on upper trapezius trigger points in cervicogenic headaches patients. Design: A double-blinded randomized controlled trial study, in which 50 participants (11 male and 39 female) aged between 20–40 with cervicogenic headache were subdivided with randomization to group (A), which received traditional physical therapy and sham shock wave therapy, and group (B), which received traditional physical therapy and actual shock wave therapy. All assessments were performed by a therapist before and after the treatment program (4 wks). Results: There was a significant difference of headache disability index, visual analog scale scores, and upper trapezius electromyographic characteristics with P value <0.05 in both groups, in favor of the shock wave group. Conclusions: Extracorporeal shock wave therapy could be used for clinical and research concerns because its positive effects on pain suppression, reduction of headache intensity, and restoration of muscle regular activity in cervicogenic headache patients. [ABSTRACT FROM AUTHOR]

This study aimed to observe human trapezius muscle (TpzM) development during early fetal period and apply diffusion tensor imaging (DTI) analysis to describe the muscle architecture that leads to physiological functions. Human embryonic and early fetal specimens were selected for this study. TpzM was first detected at Carnegie stage 20. The position of the TpzM changed with the formation of the scapula, clavicle, and vertebrae, which are its insertions and origins. DTI revealed the fiber orientation from each vertebral level to dissect each muscle. Fiber orientation in the ventral view gradually changed from the cervical to thoracic vertebrae, except for the middle part at which the insertions changed, which was almost similar in all early fetal specimens. The TpzM volume increased from C1 to C7 in the upper part, reached local maxima at C6 and C7 in the middle, and then decreased. These muscles can be categorized into three parts according to their insertions and presented with the features of each part. The fiber orientation and distribution of the three parts at the vertebral level were almost constant during the early fetal period. The border between the upper and middle parts was mainly located around the C6 and C7 vertebral levels, whereas the middle and lower parts were between the Th1 and Th2 vertebral levels. A three‐dimensional change in the fiber orientation in the upper part of the TpzM according to the vertebral level was noticeable. Our data will help to elucidate the developmental processes of TpzM. [ABSTRACT FROM AUTHOR]

Background Repetitive application of high forces to the shoulder and scapular musculature during the pitching motion over the course of a collegiate baseball season may lead to changes in strength and increased fatigue, potentially predisposing pitching athletes to injury. The purpose of this study was to investigate periscapular strength profiles of Division I collegiate baseball players over the course of a season. Methods This study was a retrospective data analysis of 18 Division I baseball pitchers. Isometric scapular plane abduction (scaption), external rotator, internal rotator, middle trapezius, and lower trapezius isometric strength was measured on throwing arm of each subject using a MicroFET 2 handheld dynamometer. Data were collected in a single session at the preseason, midseason, and postseason of the college baseball season, which spanned a five-month period. A repeated measures ANOVA was utilized to determine if there was a significant change in periscapular strength across the baseball season. Results Over the three time-points, all strength values decreased for each muscle group, with decreases ranging from 3-14%. Changes in scaption strength values were statistically significant (p=0.018, partial eta squared =0.284) with an 8% reduction over the entire season, specifically with a 5% decline from mid-season to post-season. While external rotator, internal rotator, middle trapezius, and lower trapezius strength values all decreased over the course of the season (range 0.02kg to 1.8kg), these differences were not statistically significant. However, the middle trapezius strength value change (1.3kg loss) exceeded the minimal detectible change. Conclusion Periscapular muscles in baseball pitchers diminish in strength over the course of a collegiate baseball season. Understanding strength changes over the course of a season may influence training and therapeutic interventions. Level of Evidence 3b [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of lumbar stabilization on muscle activity, muscle onset time, and scapular kinematics in individuals with scapular dyskinesis. Fourteen participants with scapular dyskinesis were recruited. Scapular muscle activity and activation onset time were measured by electromyography (EMG), and scapular upward rotation was measured by two-dimensional (2-D) Kinovia software, under two conditions: with and without abdominal bracing. There was a significant increase in the activity of the serratus anterior, middle trapezius, and inferior trapezius muscles between the conditions (p < 0.001, p = 0.045, and p < 0.001, respectively). During abdominal bracing, the activation onset time of the serratus anterior and lower trapezius was noticeably shorter (p = 0.041 and p = 0.011, respectively). Scapular upward rotation at 30°, 60°, 90°, and 120° of shoulder abduction was significantly greater (p = 0.027, p = 0.003, p = 0.003, and p = 0.030, respectively). Increased scapular muscle activation, early activation onset time, and increased scapular upward rotation were also noted. These changes have an impact on the scapulohumeral rhythm. [ABSTRACT FROM AUTHOR]

Cervical aggressive fibromatosis is a rare intermediate tumor characterized by invasive growth. Aggressive fibromatosis (AF), also referred to as desmoid-type fibrosarcoma or grade I fibrosarcoma, is a clonal proliferative lesion of fibroblasts located in deep soft tissues. While many cases have been reported, there are relatively few involving aggressive fibromatosis in the anterior inferior margin muscle space of the neck trapezius muscle. We present a case of pathologically confirmed left cervical aggressive fibromatosis, admitted to the Fourth Affiliated Hospital of Zhejiang University. The initial ultrasound and magnetic resonance imaging (MRI) scan of the patient revealed a mass in the left cervical dorsal muscle space, which slowly increased after one year. An enhanced MRI scan initially diagnosed the mass as a left cervical schwannoma. The patient underwent neck soft tissue lesion resection surgery, with postoperative confirmation of cervical aggressive fibromatosis. Our case suggests that fibromatosis cannot be ruled out, and the low-signal cord-like non-enhanced areas, representing collagen fiber characteristics after enhanced scanning, are significant imaging features in diagnosing cervical fibromatosis. Based on the available literature, we have conducted preliminary research on the clinical presentation, imaging manifestations, diagnosis, and differential diagnosis of cervical aggressive fibromatosis to improve clinical understanding and ensure timely clinical treatment. [ABSTRACT FROM AUTHOR]

The increased weight of multifunction and intelligent helmet systems can cause an exacerbation of the neck workload. Further, increased weight of the helmet can reduce the wearing comfort, and prolonged use may cause neck fatigue and even neck injury. This study evaluates the fatigue of neck muscles caused by wearing a helmet in motion using electromyography (EMG) measurement. Additionally, a comprehensive evaluation model for neck fatigue was established effectively. Twenty healthy subjects were selected to run for 10 min continuously in each task by wearing two different helmets, respectively, during which the EMG signals of different neck muscles and subjective scores were recorded and analyzed. Two-way repeated measures analysis of variance (ANOVA) and Pearson correlation analysis were used to obtain indicators of neck fatigue, based on which the support vector machine (SVM) was used to construct a classification model of neck fatigue. By using integral EMG (IEMG) and root mean square (RMS) for assessing the neck injury in sternocleidomastoideus and trapezius muscles, it was observed that the mean power frequency (MPF) and median frequency (MF) in trapezius and splenius capitis could be used as effective evaluation indicators of neck fatigue. The EMG activity in trapezius was the highly sensitivity to fatigue when wearing helmets in motion. The classifier for distinguishing three different neck fatigue levels was 91.67% accurate. This study demonstrates the feasibility of an EMG-based method to evaluate the neck fatigue caused by wearing a helmet in motion, and also provides an evaluation method for the optimal design of helmets in the future. [ABSTRACT FROM AUTHOR]

Background: Myofascial trigger points found along taut bands of muscle fibers are a common cause of pain among nursing professionals. Instrument-assisted soft-tissue mobilization (IASTM) and myofascial release (MFR) are two techniques to relieve pain and disability. This study aimed to compare the effects of IASTM and MFR on pain, range of motion, and functional disability on upper trapezius trigger points (UTTPs) in nursing professionals. Materials and Methods: Thirty nursing professionals with UTTPs were allotted to two groups (n = 15 each). The IASTM group received IASTM plus a home exercise program, whereas the MFR group received myofascial release plus a home exercise program. Both groups received two sessions per week for three weeks. Patients were assessed for pain, range of motion, and functional disability at baseline and after 3 weeks. Results: The results indicated statistically significant differences between the IASTM group and the MFR group for pain, disability, and range of motion, except for active cervical rotation on the left side. Within each group, all the variables showed significant improvement. Conclusion: Although both groups had significant improvements in all variables, participants treated with IASTM had better results in reducing pain, improving range of motion, and improving functional status. [ABSTRACT FROM AUTHOR]

Workers are driven to work faster in the industrial work environment to meet high productivity targets. An increased work pace leads to increased muscle activation. However, the effect of work pace on bilateral upper trapezius muscles during sewing machine operation in an industrial work environment has not been thoroughly investigated in experimental studies. Therefore, this research aims to conduct an experimental study to analyze the bilateral upper trapezius muscle activity of industrial sewing machine operators at different levels of work pace. Thirty subjects (15 males, and 15 females) continuously performed the sewing operation for two hours in an industrial work environment. Experiments were conducted for two levels of work pace i.e. low pace (100% of standard cycle time) and high pace (120% of standard cycle time). Electromyographic signals were recorded from the bilateral upper trapezius muscles. The EMG amplitude (RMS) among the muscles was computed. A statistically significant (p < 0.05) increase in muscle activity was observed with an increased work pace. In this study, right upper trapezius muscle activity increased by 30.4% during high work pace tasks compared to low pace, while the left upper trapezius showed a 24.12% increase. The right upper trapezius showed a mean difference of 0.696 (%MVC), and the left upper trapezius showed 0.399 (%MVC), both indicating greater activity during high-pace tasks. The increase in muscle activity with time indicated the presence of muscle fatigue among sewing machine operators. Furthermore, higher muscular activity was observed among females than males. This research highlights the critical need to balance productivity goals with the health and safety of workers, reducing the risk of muscle fatigue and associated work-related musculoskeletal disorders. [ABSTRACT FROM AUTHOR]

Background: Pain is a common non-motor symptom in patients with cervical dystonia (CD), severely impacting their quality of life. The pathophysiology of CD is incompletely understood but it involves altered processing of proprioceptive and pain signals. Objectives: The purpose of this proof-of-concept study was to determine if vibro-tactile stimulation (VTS)—a non-invasive form of neuromodulation targeting the somatosensory system—can modulate neck pain in people with CD. Methods: In a multi-center study, 44 CD patients received VTS to sternocleidomastoid and/or trapezius muscles for up to 45 min under 9 different stimulation conditions that either targeted a single or a pair of muscles. The primary outcome measure was a perceived pain score (PPS) rated by participants on a 100-point analogue scale. Results: During VTS, 29/44 (66%) of participants experienced a reduction in PPS of at least 10% with 17/44 (39%) reporting a reduction in pain of 50% or higher. After VTS cessation, 57% of participants still reported a 10% or higher reduction in PPS. Effects were significant at the group level and persisted for up to 20 min post-treatment. No distinct optimal stimulation profiles were identified for specific CD phenotypes. Clinical markers of disease severity or duration did not predict the degree of VTS-induced pain reduction. Conclusion: This proof-of-concept study demonstrates the potential of VTS as a new non-invasive therapeutic option for treating neck pain associated with CD. Further research needs to delineate optimal dosage and long-term effects. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate the effects of a head/neck supporting exoskeleton (HNSE) on the electromyographic fatigue threshold (EMGFT) of the neck and shoulder muscles during a simulated overhead work task. Background: Overhead work is a well-known risk factor for neck and shoulder musculoskeletal disorders due to the excessive strain imposed on the muscles and joints in these regions. Method: Fourteen healthy males performed a repetitive overhead nut fastening/unfastening task to exhaustion while wearing and not wearing the HNSE at two neck extension angles (40% and 80% of neck maximum range of motion). Electromyographic signals were continuously recorded from the right and left sternocleidomastoid (SCMR, SCML), splenius capitis (SCR, SCL), upper trapezius (UTR, UTL), and anterior deltoid (ADR, ADL) muscles. The normalized electromyographic amplitude (nEMG) data was time normalized, and a bisegmental linear regression was applied to determine the muscle fatigue break point. Results: The results showed a significant increase in fatigue threshold time in the SCMR (p <.001), SCML (p =.002), and UTR (p =.037) muscles when the HNSE was used. However, the EMGFT times for the right and left deltoid and left trapezius muscles showed a nonsignificant reduction due to the head/neck support exoskeleton use. In addition, the neck extension angle did not reveal a significant effect on muscles' EMGFT time. Conclusion: Overall, the findings confirmed a significant delay in fatigue onset in sternocleidomastoid muscles, as measured by the electromyographic fatigue threshold. This finding suggests that the HNSE can be an effective ergonomic intervention for reducing the risk of musculoskeletal disorders in overhead workers. However, further studies are needed to investigate the effect of the HNSE at other neck extension angles and more realistic tasks to ensure the generalizability of our results. Application: The present findings emphasize the application of the fatigue onset time to evaluate the effectiveness of ergonomic interventions, including exoskeletons, which can subsequently be utilized to alleviate postural demands and reduce the risk of musculoskeletal disorders. [ABSTRACT FROM AUTHOR]

Background: Fatty infiltration (FI) of the supraspinatus is commonly seen in chronic large-to-massive rotator cuff tears. Evaluating FI in patients with severe muscle atrophy can be confusing. Purpose/Hypothesis: The purpose of this study was to investigate the anatomic relationship between the suprascapular artery and supraspinatus muscle on magnetic resonance imaging (MRI) to provide a method for defining the border of the supraspinatus muscle on Y-view MRI. It was hypothesized that the branches of the suprascapular artery would encircle the supraspinatus muscle on Y-view and adjacent MRI slices and could be used for defining the supraspinatus outline on oblique sagittal images. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: A total of 172 shoulders that had undergone arthroscopic repair for large-to-massive rotator cuff tears were retrospectively included. Two methods, one based on the supraspinous fossa and trapezius (SF method) and the other based on the region bounded by the branches of the suprascapular artery (SA method), were used for defining the supraspinatus outline on Y-view MRI for the assessment of FI. Preoperative supraspinatus FI grade and tangent sign and postoperative tendon integrity were evaluated. Shoulder function was assessed using the American Shoulder and Elbow Surgeons (ASES) score and active range of motion. Results: The branches of the suprascapular artery encircled the supraspinatus in all shoulders, with the diameter of the branches ranging from 0.5 to 3 mm. The agreement in supraspinatus FI grading between the SF and SA methods was 65.12%. When limited to the 61 shoulders with a positive tangent sign, the agreement dropped to 22.95% (κ = 0.032). The group (FI grade 2 by SA method and ≥3 by SF method) showed no significant difference in postoperative outcomes compared with the 2-vs-2 group but had significantly better postoperative ASES scores (P =.001) and active range of motion in forward elevation (P =.020) compared with the ≥3-vs-≥3 group. The tangent sign was positive in 92.16% of the 2-vs-≥3 group. Conclusion: The suprascapular artery is a reliable reference for the evaluation of supraspinatus FI. When a positive tangent sign presents, supraspinatus FI is likely to be overestimated if the hyperintensity outside the region bounded by the branches of the suprascapular artery is mistaken as FI. [ABSTRACT FROM AUTHOR]

Prolonged standing in surgery has been linked to an increased risk of musculoskeletal disorders. The aim of this study was to determine whether sitting could serve as an alternative work posture in laparoscopic procedures. Twenty medical students in their third and fourth years were recruited. Sitting and standing were compared at two task complexity levels on a laparoscopic surgery simulator. Measured variables included user posture preferences, perceived discomfort, performance and biomechanics. Electromyography data from the upper trapezius and erector spinae muscles were analysed. Results showed that posture did not affect surgical performance and erector spinae muscle activation. Sitting showed higher muscle activation at the trapezius muscles; however, perceived discomfort was unaffected. Most participants preferred sitting for the difficult task and standing for the easy task. Findings showed that sitting, with appropriate seat design considerations, could serve as an alternative or even as a preferred work posture for simulated laparoscopic procedures. Practitioner Summary: Prolonged standing in surgery has been linked to increased musculoskeletal disorder risks. This study investigated sitting as a potential alternative work posture to standing. Both postures were tested during simulated laparoscopic procedures. Results showed that sitting can serve as an alternative or even preferred work posture for simulated laparoscopic surgery. [ABSTRACT FROM AUTHOR]

Background: Vago-glossopharyngeal neuralgia (VGN) is a rare condition characterized by neuropathic pain in the areas innervated by the glossopharyngeal and vagus nerve. Diagnosis can be challenging due to its rarity and the need to differentiate it from other sources of pain. Neurovascular conflicts involving the glossopharyngeal nerve and surrounding vasculature are often implicated in the development of VGN. Surgical interventions, such as microvascular decompression, have shown promise in relieving symptoms, but long-term outcomes remain poorly understood. This case report presents a unique manifestation of VGN accompanied by unilateral accessory nerve palsy and syncope, shedding light on the complexities involved in diagnosis and management. Case presentation: The presented case involves a 42-year-old patient without comorbidities with a 1-year history of syncope, dysphonia, cough, oropharyngeal pain, dysphagia, right periaricular pain, and weakness of the right sternocleidomastoid and trapezius muscle. After an initial evaluation, compression of the right cranial nerves IX, X, and XI by the posterior inferior cerebellar artery (PICA) was identified as the cause. The patient underwent microvascular decompression, which provided 3 years of symptom relief. However, symptoms recurred with additional manifestations, including left periauricular pain and increased syncopal episodes of cardiogenic origin. A follow-up brain MRI revealed compression of the left cranial nerves IX and X. A second surgical intervention targeting the left side resulted in partial improvement but symptom reappearance after 1 year. Finally, a third surgery involving the left side was performed, and along with isolating the affected cranial nerves, two superior rootlets of the vagus nerve were rhizotomized. Postoperative recovery was successful, with complete resolution of symptoms and no recurring issues during follow-up examinations. Conclusion: This case underscores the complexity of diagnosing and managing neurovascular conflicts associated with VGN pain syndrome. While initial microvascular decompression provided relief, the recurrence of symptoms and emergence of new manifestations highlight the challenges in managing this condition. Precise identification of nerve compression and targeted surgical interventions, such as sectioning the superior roots of the vagus nerve, offer potential efficacy in refractory cases. Further studies and long-term follow-up are necessary to gain comprehensive insights into the progression and outcomes of these interventions. [ABSTRACT FROM AUTHOR]

Background: We describe techniques for safe resection of a Type 3 foramen magnum meningioma with dorsal displacement of the accessory nerve rootlets and vertebral artery which limits ventral access to the tumor. Method: Partial sectioning of the accessory nerve rootlets may help create larger working space. Topical lidocaine placement on the rootlets of the spinal accessory nerve may mitigate trapezius muscle contraction and facilitates further progress throughout tumor resection. Conclusion: Creating safe working corridors between the lower cranial nerves through mobilization or partial sectioning of rootlets in the case of CN XI facilitates tumor resection through a far lateral approach. [ABSTRACT FROM AUTHOR]

Introduction: Massage is an effective treatment for reducing pain, swelling, stiffness, and improving muscle mobility. Although self-reported benefits on muscle stiffness and pain are well-known, studies measuring muscle stiffness objectively are scarce. Methods: A randomized controlled trial involving 30 recreationally active young women (22.3 ± 0.4 years) was conducted. The participants were randomly assigned to either the control group or the intervention group which received a series of five 30-min whole back therapeutic massage sessions over 5 weeks. Shear wave elastography was used to assess muscle stiffness (erector spinae (ESp) and upper trapezius (UT) muscles) before and after the intervention and at 3-week follow-up. Results: For ESp, there was no statistically significant time x group interaction (F =2.908; p = 0.063). However, there was a statistically significant and large time x group interaction for UT (F =13.533; p = 0.006; η² = 0.19). Post-hoc testing for time indicated that the shear modulus in the intervention group was reduced at follow-up (p = 0.005; d = 1.02), while the difference between baseline and post-intervention measurements were not statistically significant (p = 0.053; d =0.75). Conclusion: In conclusion, massage significantly reduced proximal UT stiffness both 3 days and 3 weeks after the intervention. However, it had no significant effect on the distal part of UT or the ESp muscle. [ABSTRACT FROM AUTHOR]

BACKGROUND: There are no data on the additional contribution of dry needling (DN) for trigger points (TPs) accompanying patients with cervical spondylosis (CS). OBJECTIVE: To analyse the contribution of DN applied to concomitant active TPs in the upper trapezius muscle on the treatment outcomes of physiotherapy in CS. METHODS: In this prospective randomized controlled study, 70 patients with CS and active TPs in the upper trapezius muscle were included. The first group received physiotherapy for 5 days per week for 3 weeks. The second group received DN with the same program. All participants were evaluated before treatment (day 0) and at the end of treatment (day 21) in terms of pain, functional status, quality of life, anxiety/depression scores, and number of TPs. RESULTS: 33 patients in the first group and 32 patients in the second group completed the study. While the change over time was found significant in all variables, the change was not different between groups. The group-time interaction effect was not found to be statistically significant in any variable. Percentage changes of all variables were similar between the groups. CONCLUSION: DN treatment added to the physiotherapy did not contribute to recovery in patients with CS. [ABSTRACT FROM AUTHOR]

Background: Massive irreparable rotator cuff tears (MIRCTs) remain a challenging treatment paradigm, particularly for nonelderly patients without pseudoparalysis or arthritis. Purpose: To use a network meta-analysis to analyze comparative studies of surgical treatment options for MIRCTs in patients <70 years of age for several patient-reported outcomes, range of motion (ROM), and acromiohumeral distance (AHD). Study Design: Network meta-analysis of comparative studies; Level of evidence, 3. Methods: A systematic review of the literature, using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, of the MEDLINE, Embase, and Cochrane Library databases was conducted from 2017 to 2022. Inclusion criteria were (1) clinical comparative studies of MIRCTs (with several study-specific criteria); (2) ≥1 outcome of interest reported on, with standard deviations; (3) minimum 1-year follow-up; and (4) mean age of <70 years for both cohorts, without arthritis or pseudoparalysis. There were 8 treatment arms compared. Outcomes of interest were the American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score, visual analog scale for pain, AHD, and forward flexion and external rotation ROM. A frequentist approach to network meta-analysis with a random-effects model was performed using the netmeta package Version 0.9-6 in R. Results: A total of 23 studies met the inclusion criteria, with 1178 patients included in the network meta-analysis. There was a mean weighted age of 62.8 years, 568 (48.2%) men, with a mean follow-up of 28.9 months. There were no significant differences between groups in regard to sex (P =.732) or age (P =.469). For the ASES score, InSpace balloon arthroplasty (mean difference [MD], 12.34; 95% CI, 2.18 to 22.50; P =.017), arthroscopic bridging graft (aBG) (MD, 7.07; 95% CI, 0.28 to 13.85; P =.041), and long head of biceps augmented superior capsular reconstruction (BSCR) (MD, 5.16; 95% CI, 1.10 to 9.22; P =.013) resulted in the highest P-scores. For the Constant-Murley score, debridement (MD, 21.03; 95% CI, 8.98 to 33.08; P <.001) and aBG (MD, 6.97; 95% CI, 1.88 to 12.05; P =.007) resulted in the highest P-scores. For AHD, BSCR resulted in the highest P-score (MD, 1.46; 95% CI, 0.45 to 2.48; P =.005). For forward flexion ROM, debridement (MD, 45.77; 95% CI, 25.41 to 66.13; P <.001) resulted in the highest P-score, while RSA resulted in the lowest P-score (MD, –16.70; 95% CI, −31.20 to −2.20; P =.024). Conclusion: For patients <70 years with MIRCT without significant arthritis or pseudoparalysis, it appears that graft interposition repair techniques, superior capsular reconstruction using the long head of the biceps tendon, arthroscopic debridement, and balloon arthroplasty provide superiority in various outcome domains, while RSA provides the least benefit in forward flexion. [ABSTRACT FROM AUTHOR]

Botulinum toxin can be used for various purposes to enhance neck aesthetics, addressing concerns such as platysmal bands, optimizing the cervicomental angle, preventing worsening of horizontal neckline and decolletage lines during aging, submandibular gland hypertrophy, and hypertrophied superior trapezius muscle. Understanding the anatomy of muscles such as the trapezius, platysma, and submandibular gland is crucial for achieving desirable outcomes with botulinum toxin administration. Techniques for injecting botulinum toxin into these muscles are discussed, emphasizing safety and efficacy. Specific injection points and methods are detailed for treating platysmal bands, optimizing the cervicomental angle, addressing submandibular gland hypertrophy, and managing hypertrophied superior trapezius muscle. Careful consideration of anatomical landmarks and potential complications is essential for successful botulinum toxin injections in these areas. [ABSTRACT FROM AUTHOR]

Myositis ossificans (MO) is a benign, self-limiting, and nonneoplastic lesion involving the skeletal muscle or soft tissue, rarely occurring in the head and neck. It is relatively rare in clinical practice, and it is difficult to distinguish specific cases from musculoskeletal conditions, which poses unique challenges for clinical diagnosis and treatment. We reported that a 9-year-old boy suffered from local and nontraumatic MO of the trapezius muscle. Given the rarity of this case, the present article detailed the diagnosis and treatment of this rare case and reviewed the relevant literature on MO, focusing on the clinical, pathological, and radiographic characteristics of MO. Notably, these investigations aimed to enhance clinicians' understanding of the disease and improve diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Postherpetic neuralgia results from varicella-zoster virus reactivation post--chickenpox infection, manifesting as persistent and severe pain lasting a minimum of 3-mo post--herpes zoster onset. Traditional postherpetic neuralgia management comprises antiviral, analgesic medications, corticosteroids, and various agents. Ultrasound-guided nerve blocks have recently emerged as a promising postherpetic neuralgia treatment. In a case involving a 58-year-old man with severe thoracic herpes zoster lesions, the serratus posterior superior intercostal plane block was employed under ultrasound guidance, significantly reducing pain scores and enhancing quality of recovery. This study underscores serratus posterior superior intercostal plane block's secure, effective role in managing thoracic herpes zoster, and mitigating postherpetic neuralgia risk. This case report represents the pioneering application of serratus posterior superior intercostal plane block for postherpetic neuralgia, offering a promising avenue for relieving patients suffering from this condition. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study is to evaluate whether the application of an interfascial injection with dextrose water could result in reduced pain and improved shoulder function and range of motion. Design: This is a double-blind randomized controlled trial. Thirty-five patients with chronic shoulder pain were randomly assigned to receive either an interfascial injection of 10 mL of 10% dextrose water guided by ultrasound or a sham injection of 0.5 mL of 10% dextrose water into the subcutaneous layer. All patients received education on a home program of self-massage and self-stretching. Shoulder pain, shoulder range of motion, and neck and shoulder function were measured before injection and at 4 and 12 wks after injection. Results: Both groups showed significant improvements in visual analog scale scores at 12-wk follow-up. The interfascial injection group exhibited a significant pain reduction compared with the sham group at the 12-wks follow-up. No between-group differences were observed in shoulder range of motion, pain threshold, and neck and shoulder function. Conclusions: Interfascial injection is effective in decreasing pain in patients with myofascial pain syndrome. [ABSTRACT FROM AUTHOR]

Introduction: In the presented research, we characterized the contralateral effect after applying capacitive and resistive transfer of energy (TECAR) in the treatment of active myofascial trigger point (MTrP). In order to assess the contralateral effect, we used the infrared thermovision method. We hypothesize that by means of thermal imaging studies, we will be able to present and confirm the contralateral effect which can be important in establishing the MTrP treatment protocol with the use of TECAR. Material and methods: In the study, thermographic imaging was performed on a group of 6 volunteers with an age range [25-45] years (mean age: 32.3 years ± 9.83 years) who were randomly selected for the study from among people practicing recreational sports and showing the clinical presence of active MTrP in the upper trapezius muscle (UT). Results: On both sides, the reference area (side untreated) and the target area (side treated), there was an increase in the percentage changes of isotherms. These results indicate the presence of a contralateral effect. The use of TECAR therapy ipsilaterally in the treatment of MTrP in UT results in an increase of temperature on the symmetrical body part and it may be connected with the presence of vascular contralateral effect on the untreated side. Conclusions: These changes were investigated by IR which, as our research shows, can be an effective form of assessing the therapeutic effects of TECAR in MTrP treatment. [ABSTRACT FROM AUTHOR]

Abstract Background The investigation aimed to assess the impacts of magnesium sulphate (MgSO4) iontophoresis and high-power pain-threshold ultrasound (HPPT-US) on pain, range of motion (ROM), and functional activity in physical therapy students suffering from mechanical cervical pain. Methods Typically, 75 males aged 19 to 30 years suffering from mechanical neck pain were enrolled in this investigation. Participants were divided at random into three groups. Group A received iontophoresis plus conventional physical therapy program, Group B received HPPTUS along with conventional therapy, and Group C received conventional therapy only. The outcomes were pain evaluated by visual analog scale (VAS) and Digital Electronic Pressure Algometer, cervical range of motion measured by Myrin gravity reference goniometer, and Arabic Neck disability index (ANDI) evaluate neck function. Results The differences within and between groups were detected utilizing a mixed-design multivariate analysis of variance (MANOVA). The within- and between-group analysis of all outcome measures revealed that there were statistically significant differences at post-intervention between high-power ultrasound and conventional group at all variables and also between iontophoresis and conventional group, but there was no statistically significant variation between high-power ultrasound and iontophoresis. Conclusion MgSO4 iontophoresis and HPPT-US are effective in decreasing pain, improving neck function, and improving neck ROM in subjects with mechanical neck pain who have active myofascial trigger points (MTrPs) on the upper fibers of the trapezius with no superiority of one over the other. Trail registration The study was registered in the Clinical Trials Registry (registration no: NCT05474898) 26/7/2022.

Context: This study evaluated the diagnostic accuracy of repetitive nerve stimulation (RNS) compared with single-fiber electromyography (SF-EMG) in generalized myasthenia gravis (MG). Aims: The aim of the study was to determine the diagnostic sensitivity of RNS in various muscles and assess the effect of varying decrement cutoff values on diagnostic efficacy. Setting and Design: This was a prospective study of 34 confirmed generalized MG patients. Subjects and Methods: RNS was performed on five muscles. Clinical features, autoantibody presence, and SF-EMG jitter rates recorded from the frontalis muscle were analyzed. Patients were classified according to the MG Foundation of America classification. Statistical Analysis: SPSS version 23 was used for descriptive statistics, comparisons of categorical and quantitative data, and correlation analysis, with the significance level set at P < 0.05. Results: Among the patients (58.8% males and mean age = 59.47 ± 13.37 years), SF-EMG detected increased jitter in 91.2%, whereas RNS identified a significant decrease of 50% across at least one muscle. The decremental response was >10% in the abductor digiti minimi (ADM), trapezius, nasalis, abductor pollicis brevis, and extensor indicis proprius muscles in 5.9%, 26.5%, 29.4%, 11.8%, and 29.4% of patients, respectively. A sensitivity improvement at lower decrement values was observed only in the ADM muscle. A significant correlation was found between decreases in the trapezius muscle and seropositivity. Conclusions: Optimal muscle selection improves RNS diagnostic accuracy in MGs. The study recommends incorporating the spinal accessory and radial nerves in RNS due to their high sensitivity, although modifying the decrement cutoff value has a limited overall effect.

Botulinum toxin can be used for various purposes to enhance neck aesthetics, addressing concerns such as platysmal bands, optimizing the cervicomental angle, preventing worsening of horizontal neckline and decolletage lines during aging, submandibular gland hypertrophy, and hypertrophied superior trapezius muscle. Understanding the anatomy of muscles such as the trapezius, platysma, and submandibular gland is crucial for achieving desirable outcomes with botulinum toxin administration. Techniques for injecting botulinum toxin into these muscles are discussed, emphasizing safety and efficacy. Specific injection points and methods are detailed for treating platysmal bands, optimizing the cervicomental angle, addressing submandibular gland hypertrophy, and managing hypertrophied superior trapezius muscle. Careful consideration of anatomical landmarks and potential complications is essential for successful botulinum toxin injections in these areas.

Background: Temporomandibular joint has biomechanical and neurological interactions with cervical region in a complex functioning that is addressed as cranio-cervical mandibular system. Subjects and methods: In a prospective cohort study of 67 patients, their mean age 24.3 ± 5.6 years of both genders with temporomandibular disorder "bruxism," patients had fulfilled a questionnaire regarding bruxism manifestations. Pain pressure algometer was used to assess pain pressure threshold for trigger point in masseter, temporalis, sternocleidomastoid, and trapezius, and bubble inclinometer was used to assess cervical proprioception for all cervical ranges. Results: There was a statistical significant indirect weak correlation between proprioception error of cervical flexion and pain pressure threshold of masseter (r = − 0.333) (p = 0.006), between proprioception error of cervical flexion and pain pressure threshold of trapezius (r = − 0.363) (p = 0.003), and also between proprioception error of cervical left-side bending and pain pressure threshold of trapezius (r − 0.298; p 0.014), while there was significant direct weak correlation between proprioception error of cervical left rotation and cervical bending to left (r 0.315; p 0.009), where the p-value was < 0.05. Conclusion: The study proved that temporomandibular joint pain was correlated with impaired neck proprioception in whom with bruxism. Trial registration: NCT05657353. Registered 28 November 2022 — prospectively registered, https://register.clinicaltrials.gov/prs/app/action/LoginUser?ts=1&cx=-jg9qo4. [ABSTRACT FROM AUTHOR]

Skeletal muscles of the head and trunk originate in distinct lineages with divergent regulatory programmes converging on activation of myogenic determination factors. Branchiomeric head and neck muscles share a common origin with cardiac progenitor cells in cardiopharyngeal mesoderm (CPM). The retinoic acid (RA) signalling pathway is required during a defined early time window for normal deployment of cells from posterior CPM to the heart. Here, we show that blocking RA signalling in the early mouse embryo also results in selective loss of the trapezius neck muscle, without affecting other skeletal muscles. RA signalling is required for robust expression of myogenic determination factors in posterior CPM and subsequent expansion of the trapezius primordium. Lineage-specific activation of a dominant-negative RA receptor reveals that trapezius development is not regulated by direct RA signalling to myogenic progenitor cells in CPM, or through neural crest cells, but indirectly through the somitic lineage, closely apposed with posterior CPM in the early embryo. These findings suggest that trapezius development is dependent on precise spatiotemporal interactions between cranial and somitic mesoderm at the head/trunk interface. [ABSTRACT FROM AUTHOR]

AbstractObjectiveStudy designMethodsResultsConclusionThe main objective of this study is to test the reliability of a non-invasive objective method for the measurement of biomechanical parameters of cervicofacial muscle groups, with the purpose of diagnosis and evaluation of voice disorders’ treatments, especially focused on muscle tension dysphonia.Prospective study.The device used is a handheld myotonometer (MyotonPRO) that measures biomechanical and viscoelastic properties in superficial soft tissues frequency, stiffness, elasticity, relaxation time and creep. It is used in the field of medicine, sport and research. This pilot study includes 10 subjects, who have been measured in the masseter, sternocleidomastoid, orbicularis oris, semispinalis capitis, suprahyoid, infrahyoid and trapezius muscles on each side. Measurements were performed by 2 evaluators to assess inter-evaluator reliability. Subsequently, one of them repeated the measurements to assess intra-evaluator reliability.The results revealed good to excellent inter-rater reliability for the masseter, sternocleidomastoid, trapezius and suprahyoid muscles, with lower ICCs for the stiffness and creep properties. Intra-rater reliability was good to excellent for the masseter, sternocleidomastoid, semispinalis capitis and suprahyoid muscles. The lowest ICCs were found in the stiffness and creep properties.The use of a myotonometer to measure the mechanical properties of selected cervical and orofacial muscles is a reliable and reproducible method. Future research is needed to establish an association between the properties of these muscles and their role in voice disorders, as well as to determine whether this tool can aid diagnosis with quantifiable and objectifiable indicators, and for monitoring and treatment efficacy. [ABSTRACT FROM AUTHOR]

Purpose: Understanding of rare or unknown anatomical variations of the vasculature of the neck is critical to reduce the risk of complications during surgeries and other invasive procedures in the neck and shoulder regions. Methods: Bilateral dissection of the neck and muscles of the back of an 87-year-old Caucasian male donor was performed to demonstrate the origin, course and termination of the arteries that arise in the neck. Results: Several anatomical variations were noted on the right side of the neck of the donor body – (i) only inferior thyroid and ascending cervical arteries originated from the thyrocervical trunk (TCT), from the first part of the subclavian artery (SA), whereas the transverse cervical (TCA) and suprascapular (SSA) arteries were entirely absent, (ii) Dorsal scapular artery (DSA) emerged normally from the third part of the SA. However, after supplying the rhomboids and levator scapulae muscles, DSA provided two additional branches to the trapezius muscle and a branch to the supraspinatus muscle. Interestingly, the branches to the trapezius muscle from the DSA were the only sources of blood supply to the muscle. Conclusion: We report a unique anatomical variation involving the absence of the TCA and SSA from the TCT. The unilateral absence of these major vessels and the branches of DSA supplying the trapezius and supraspinatus muscles have not been reported previously in the literature in a single case report. This case study may provide useful information for head and neck reconstruction and shoulder repair surgeries. [ABSTRACT FROM AUTHOR]

Background: Tension-type headache (TTH) is the most prevalent primary headache. Pressure pain thresholds (PPTs) reflect the pressure pain sensitivity of the tissues. Women with TTH have showed greater pressure hypersensitivity in some muscles compared to men. The aim of this study was to compare the PPTs from myofascial trigger points in cervical and cranial muscles which might contribute to headaches between men and women with TTH. Methods: An observational and correlation cross-sectional study was performed. PPTs were evaluated bilaterally and compared between men and women in the following muscles: upper trapezius, splenius capitis and cervicis, semispinalis, rectus capitis posterior major, obliquus capitis superior and inferior, occipitofrontalis posterior and anterior, temporalis, masseter, clavicular and sternal head of sternocleidomastoid, zygomaticus major, and levator scapulae. The mean PPT was calculated as well. Results: Significant differences showing lower PPTs in women compared to men were found in the mean PPT (p = 0.000) and in all the points except in the left clavicular head of the sternocleidomastoid (p = 0.093) and in the left masseter (p = 0.069). Conclusions: Lower PPTs from myofascial trigger points in cervical and cranial muscles, which might contribute to headaches, were observed in women compared to men with TTH. The mean PPT was also lower in women than in men, suggesting the need for gender-specific approaches in the treatment of TTH. [ABSTRACT FROM AUTHOR]

The main aim of this study was to investigate the efficacy of a dual task protocol in people with episodic migraine with respect to both active exercises only and cognitive task only treatments, concerning some neurophysiological and clinical outcomes. A randomized control trial was adopted in people with episodic migraine without aura. Some neurophysiological and clinical outcomes were collected (t0): resting motor threshold (rMT), short intracortical inhibition (SICI) and facilitation (ICF), pressure pain threshold (PPT), trail making test (TMT), frontal assessment battery (FAB), headache-related disability (MIDAS) and headache parameters. Then, participants were randomized into three groups: active exercise only (n = 10), cognitive task only (n = 10) and dual task protocol (n = 10). After 3 months of each treatment and after 1-month follow-up the same neurophysiological and clinical outcomes were revaluated. A significant time x group effect was only found for the trapezius muscle (p = 0.012, pη2 = 0.210), suggesting that PPT increased significantly only in active exercise and dual task protocol groups. A significant time effect was found for rMT (p < 0.001, pη2 = 0.473), MIDAS (p < 0.001, pη2 = 0.426), TMT (p < 0.001, pη2 = 0.338) and FAB (p < 0.001, pη2 = 0.462). A repeated measures ANOVA for SICI at 3 ms highlighted a statistically significant time effect for the dual task group (p < 0.001, pη2 = 0.629), but not for the active exercises group (p = 0.565, pη2 = 0.061), and for the cognitive training (p = 0.357, pη2 = 0.108). The dual task protocol seems to have a more evident effect on both habituation and sensitization outcomes than the two monotherapies taken alone in people with migraine. [ABSTRACT FROM AUTHOR]

Background: Central and peripheral sensitization are characterized by widespread hyperalgesia that is manifested by larger pain extent area and reduction in pressure pain threshold (PPT). PPT decreases in patients with migraine not only over the trigeminal cervical complex but also throughout the body. Methods: A cross-sectional study was adopted to assess the local and widespread hyperalgesia in chronic and episodic migraine patients respect to healthy controls. The guidelines of Andersen's were used to evaluate the PPT bilaterally over 3 muscles in the trigemino-cervical complex (temporalis, sub-occipitalis, trapezius) and over 1 muscle far from this area (tensor fasciae latae). Results: Thirty subjects with episodic migraine (35.8 ± 2.82 years), 30 with chronic migraine (53.03 ± 19.79 years), and 30 healthy controls (29.06 ± 14.03 years) were enrolled. The interaction effect was present for the trapezius muscle with a significant difference between the right and the left side in episodic group (p = 0.003). A group effect was highlighted in all four muscles analyzed such as suboccipital (p < 0.001), temporalis (p > 0.001), trapezius (p < 0.001), and TFL (p < 0.001). PPT was usually higher in the control group than in the episodic group which in turn was characterized by higher PPT values than the chronic group. Conclusions: People with chronic and episodic migraine presented lower PPT than healthy controls both in the trigeminal and in the extra-trigeminal area. People with chronic migraine presented lower PPT than episodic migraine only in the trigeminal area. Temporalis and sub-occipitalis are the most sensitive muscles in people with chronic and episodic migraine. [ABSTRACT FROM AUTHOR]

In order to better design handling-assisted exoskeletons, it is necessary to analyze the biomechanics of human hand movements. In this study, Anybody Modeling System (AMS) simulation was used to analyze the movement state of muscles during human handling. Combined with surface electromyography (sEMG) experiments, specific analysis and verification were carried out to obtain the position of muscles that the human body needs to assist during handling. In this study, the simulation and experiment were carried out for the manual handling process. A treatment group and an experimental group were set up. This study found that the vastus medialis muscle, vastus lateralis muscle, latissimus dorsi muscle, trapezius muscle, deltoid muscle and triceps brachii muscle require more energy in the process of handling, and it is reasonable and effective to combine sEMG signals with the simulation of the musculoskeletal model to analyze the muscle condition of human movement. [ABSTRACT FROM AUTHOR]

Background: Accumulated training shots throughout a session may induce changes in electromyography (EMG) parameters of the primary muscles involved in movement in archery athletes. Thus, the aim of this study was two-fold: (i) analyze the impact of 50 and 100 archery shots on a single session on the EMG parameters of trained archery athletes; and (ii) explore the effects of training routines of the athletes to cope with fatigue induced by the accumulated shots on the EMG parameters. Methods: They were divided into two groups: those who regularly performed ≤100 shots per training session (n = 13) and those who performed >100 shots per session (n = 7). The participants were exposed to a condition involving 100 archery shots, with measurements taken at baseline, after 50, and after 100 shots. EMG was used to measure the electric potential of the deltoid (middle and posterior), trapezius (upper, middle, and lower), and infraspinatus during isometric contraction. The collected outcomes included the mean and maximal amplitude of EMG root mean square (EMGRMS, µV) and the median frequency of the raw surface EMG signal power spectrum (EMGMED, Hz). Results: The results showed significant differences for most of the analyzed muscles analyzed, specifically in the deltoid, infraspinatus, and trapezius (p < 0.05). Conclusions: Our study suggests that in most of the muscles analyzed, EMG parameters—particularly mean and maximal EMGRMS—tend to increase from baseline to 50 shots, with significant declines observed after 100 shots, indicating muscle fatigue. The training routines of the athletes do not appear to significantly influence their response to fatigue conditions. [ABSTRACT FROM AUTHOR]

To determine the effects of blood flow restriction (BFR) on the mean firing rate (MFR) and motor unit action potential amplitude (MUAPAMP) VS. recruitment threshold (RT) relationships during fatiguing isometric elbow flexions. Ten men (24.5 ± 4.0 years) performed isometric trapezoidal contractions at 50% maximum voluntary contraction to task failure with or without BFR, on 2 separate days. For BFR, a cuff was inflated to 60% of the pressure required for full brachial artery occlusion at rest. During both visits, surface electromyography was recorded from the biceps brachii of the dominant limb and the signal was decomposed. A paired-samples t test was used to determine the number of repetitions completed between BFR and CON. ANOVAS (repetition [first, last] × condition [BFR, CON]) were used to determine differences in MFR vs. RT and MUAPAMP VS. RT relationships. Subjects completed more repetitions during CON (12 ± 4) than BFR (9 ± 2; p = 0.012). There was no significant interaction (p > 0.05) between the slopes and y-intercepts during the repetition X condition interaction for MUAPAMP VS. MFR. However, there was a main effect of repetition for the slopes of the MUAPAMP VS. RT (p = 0.041) but not the y-intercept (p = 0.964). Post hoc analysis (collapsed across condition) indicated that the slopes of the MUAPAMP VS. RT during the first repetition was less than the last repetition (first: 0.022 ± 0.003 mv/%MVC; last: 0.028 ± 0.004 mv/%MVC; p = 0.041). Blood flow restriction resulted in the same amount of higher threshold MU recruitment in approximately 75% of the repetitions. Furthermore, there was no change in MFR for either condition, even when taken to task failure. Thus, BFR training may create similar MU responses with less total work completed than training without BFR. [ABSTRACT FROM AUTHOR]

Pexa, BS, Johnston, CD, Elder, EE, Ford, KR, Patterson, MQ, and Myers, JB. Pool-based surfboard elicits activation of posterior shoulder muscles during a surfing stroke. J Strength Cond Res 38(7): 1300–1304, 2024—Surfboard paddling may activate posterior shoulder muscles, which are critical to baseball pitchers’ injury risk and performance. The purpose of this study was to measure posterior shoulder muscle activation during different phases of the surf stroke (propulsion vs. recovery) on a pool-based surfboard. Twenty healthy active adult subjects completed a familiarization and testing session with the pool-based surfboard. During the testing session, electromyography (EMG) sensors were placed on 6 posterior shoulder muscles: latissimus dorsi, infraspinatus, posterior deltoid, upper trapezius, middle trapezius, and lower trapezius. Subjects completed 4 laps in a pool at 3 separate resistances (low, moderate, and heavy) in a randomized order. The peak EMG signal during each phase (propulsion and recovery) was recorded. A 2-way within subject ANOVA (resistance-by-phase) with post hoc Bonferroni’s corrections was used to identify differences in EMG activation. There was a significant main effect of phase for the latissimus dorsi (F 5 91.3, p, 0.001), upper trapezius (F 5 36.5, p, 0.001), middle trapezius (F 5 33.8, p, 0.001), and lower trapezius (F 5 21.6, p, 0.001). The latissimus dorsi demonstrated higher activation during the propulsion phase (p, 0.001), and all trapezius muscles demonstrated higher activation during the recovery phase (p, 0.001). There was a significant main effect of resistance for the posterior deltoid (F 5 3.4, p 5 0.043), with higher muscle activation in the low resistance trials compared with the heavy resistance trials (p 5 0.036). Recreationally active individuals demonstrate activation of the posterior shoulder when using a pool-based surfboard. This poolbased surfboard may be beneficial to activate the posterior musculature and may be more accessible than standard surfing to baseball athletes. [ABSTRACT FROM AUTHOR]

BACKGROUND: The normal value of the scapular muscle activity ratio during arm elevation is not clear. OBJECTIVE: To obtain normal values of the scapular muscle activity ratio during arm elevation in healthy individuals. METHODS: This cross-sectional study enrolled 47 healthy people. The participants performed shoulder flexion and lowered task with 90-degree movements every 2 seconds. Muscle activities of scapular muscles were measured. For normalization, the maximum isometric contraction of the shoulder flexion was measured at 90∘ (reference contraction). The integrated electromyographic value (IEMG) obtained during the task was normalized by IEMG during the reference contraction and the relative IEMG value was calculated. Then, the scapular muscle activity ratio was computed. The relationship between muscle strength and other factors was also investigated. RESULTS: The median values for upper trapezius/serratus anterior and upper trapezius/lower trapezius were often approximately 1, and that for upper trapezius/middle trapezius was often between 1 and 2. The shoulder flexion isometric strength and scapular muscle activity ratio showed significant negative correlations in multiple phases. CONCLUSION: Normal values for upper trapezius/serratus anterior and upper trapezius/lower trapezius during arm elevation and lowering were generally 1. Low muscle strength may contribute to an abnormal scapular muscle activity balance. [ABSTRACT FROM AUTHOR]

Background A strong body of literature has been published outlining muscle activity differences during sports performance in groups of overhead athletes. However, there are limited studies that have directly compared the muscle activity in overhead athletes with and without history of shoulder injury during functional everyday tasks. Purpose This study aimed to identify muscle activities across fourteen upper extremity and core muscles during three functional everyday movements in athletes with and without history of shoulder injury. Study Design Cross-Sectional Study Methods Thirty-two male overhead throwing athletes (fifteen healthy and seventeen injured) were recruited and completed three everyday functional movements of high elevation, low elevation, and rotation, using their dominant arm to move an object between two fixed positions. Electromyography (EMG) was recorded for fourteen muscles including: biceps brachii, deltoids (anterior, medial, and posterior), trapezius (upper and lower), pectoralis major, latissimus dorsi, serratus anterior, infraspinatus, external obliques, and gluteus maximus (all surface electrodes) and supraspinatus (fine wire electrode). Mixed model repeated measures ANOVA and post-hoc analysis assessed mean muscle activity (%MVC) between groups and each movement phase. Results Upper trapezius elicited higher mean activity in healthy athletes during both phases of the arm rotation task (p < 0.05). No differences between groups were evident for arm elevation tasks. Qualitative analysis of muscle patterns during functional tasks reflected a temporal shift in muscle activation timings and magnitudes between athlete groups, suggesting potential compensatory mechanisms in injured athletes. [ABSTRACT FROM AUTHOR]

Background: The shoulder complex relies on scapular movement controlled by periscapular muscles for optimal arm function. However, minimal research has explored scapular muscle activation ratios during functional tasks, nor how they might be influenced by biological sex. This investigation aims to characterize how sex impacts scapular muscle activation ratios during functional tasks. Methods: Twenty participants (ten females, ten males) were assessed with surface electromyography (EMG) and motion tracking during seven functional tasks. Activation ratios were calculated from normalized EMG for the three trapezius muscles and serratus anterior. Scapular angles were calculated using a YXZ Euler sequence. Two-way mixed methods ANOVAs (p <.05) were used to assess the effects of sex and humeral elevation level on ratios and angles. Results: Sex-based differences were present in the Tie Apron task, with males exhibiting higher upper trapezius/lower trapezius and upper trapezius/middle trapezius ratios than females. Males also demonstrated decreased internal rotation in this task. Other tasks showcased significant sex-based differences in scapular upward rotation but not in activation ratios. Humeral elevation generally demonstrated an inverse relationship with scapular muscle activation ratios. Conclusions: This study highlights sex-based differences in scapular muscle activation ratios during specific functional tasks, emphasizing the need to consider sex in analyses of shoulder movements. Normative activation ratios for functional tasks were provided, offering a foundation for future comparisons with non-normative groups. Further research is warranted to confirm and explore additional influencing factors, advancing our understanding of shoulder activation and movement in diverse populations. [ABSTRACT FROM AUTHOR]

The relaxation of trapezius muscles is widely believed to alleviate fatigue or injury of the trapezius muscles and reduce the risk of shoulder and neck pain. This study aims to examine the effects of different muscle relaxation techniques on the physical properties of the trapezius muscle and to explore how changes in the physical properties of the upper trapezius muscle affect those of the middle trapezius muscle. Twenty-four healthy males (mean age: 23.08 ± 0.97 years; height: 172.42 ± 4.61 cm; weight: 66.38 ± 6.68 kg; and body mass index: 22.30 ± 1.81 kg/m2), randomly divided into four groups: stretching relaxation group (ST, n = 6), mechanical vibration massage (MV, n = 6), pulse massage (PU, n = 6), and control (CO, n = 6). Measurements using the Myoton digital muscle assessment system were conducted daily over 2 weeks. The experimental groups demonstrated a notable decrease in tension and stiffness, accompanied by heightened elasticity in the upper trapezius muscles. Conversely, the control group exhibited contrasting trends. Although no significant variances were detected among the relaxation techniques, all proved efficacious compared to the control group (P < 0.05). Moreover, relaxation of the upper trapezius muscles significantly influenced the middle trapezius muscles (P < 0.05). Various relaxation methods positively influenced trapezius muscle attributes over 2 weeks, with inter-regional effects noted. [ABSTRACT FROM AUTHOR]

Objectives: To compare the efficacy of dry needling (DN) and cold‐spray‐stretching treatments using surface electromyography (sEMG) and ultrasound (US) in the treatment of patients with myofascial pain syndrome (MPS) with active trigger point (ATrP) in the upper trapezius muscle. Methods: This prospective randomized single‐blind study included 60 MPS patients aged 18–65 years who have ATrP in the upper trapezius muscle. Patients were randomized into two treatment groups as DN and cold spray stretching. Both treatment groups received 1 treatment per week and totally 3 sessions. Evaluation parameters were pain level assessed by Numeric Rating Scale and algometer, neck range of motion angles, neck disability index (NDI). The effects of the treatments on ATrP were evaluated by sEMG and US histogram. All parameters were evaluated at the beginning of the treatment and at the end. Algometer and sEMG were performed also before and after the first and third sessions. Results: There was no significant difference between the two groups regarding demographic data. The mean age of the participants was 39.7 ± 11.6 years. Fifty‐one patients were female. Significant improvement in terms of pain level, functionality, sEMG, and US histogram were achieved in both groups (P <.05). When comparing the two groups, algometer scores and the NDI score were statistically higher in the cold‐spray‐stretching group than in the DN group (P <.008 and P <.028, respectively). Conclusion: Both treatment options should be preferred. The efficacy of both treatments was observed via sEMG and US histograms. [ABSTRACT FROM AUTHOR]

This study recruited 30 young participants (15 men and 15 women) to examine the smartphone usage patterns in three postures (standing, supported sitting, and unsupported sitting) and at five head angle (HA) positions (0°-40°). Cervical erector spinae (CES) and upper trapezius (UTZ) muscle activity, neck flexion (NF), gaze angle (GA), viewing distance (VD), and discomfort scores were collected. Results showed that HA and posture almost affected all responses, while CES muscle activity, NF, and VD differed between sexes. Strain in the neck and shoulder region increased with HA increase. Particularly, when the HA exceeded 20°, the discomfort scores considerably increased. Unsupported sitting should be avoided during smartphone use because of relatively poor responses in all variables. However, both standing and supported sitting have their respective benefits. Sex-related differences were typically observed in the standing position, with women tending to have lower NF but higher CES muscle activity compared with men. Practitioner summary: Although smartphones have become daily necessities, the overall quantitative neck and shoulder strain of using smartphones in different postures is rarely evaluated. We suggest that maintaining the HA within 20° is recommended because of relatively low load on the neck and shoulders. An unsupported sitting should be avoided during smartphone use. [ABSTRACT FROM AUTHOR]

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