Human trapezius muscle development during the early fetal period.

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.

Close relationships between neck and upper-back stiffness and transverse cervical artery flow velocity.

PURPOSE: Neck and upper-back stiffness is encountered in daily life, with symptoms appearing as dullness or aches predominantly in the trapezius muscle (TM). Our previous study demonstrated that TM hardness as measured with a muscle hardness meter correlates well with transverse cervical artery (TCA) flow supplying the TM. Muscle hardness meters, however, cannot measure hardness in the TM alone. Meanwhile, recent advances in ultrasound elastography have enabled the evaluation of localized hardness in targeted tissues. The present study, therefore, aimed to clarify the relationship between TM hardness as measured by elastography and TCA hemodynamics as measured on Doppler sonography, with reference to daily symptoms of upper-back stiffness. METHODS: The study population comprised 66 healthy young adults (32 males, 34 females; mean age, 21 ± 1 years). Relationships were evaluated between TM hardness as a negative correlate of strain ratio from elastography and TCA hemodynamics on Doppler sonography. Hemodynamics in the TCA were evaluated according to the frequency of neck and upper-back stiffness. RESULTS: TM strain ratio correlated with peak systolic velocity (PSV) in the TCA (r = 0.273, p = 0.036), particularly in symptomatic subjects (r = 0.417, p = 0.022). PSV in the TCA decreased with increasing frequency of daily symptoms (p = 0.045). CONCLUSION: TCA hemodynamics correlated with muscle hardness when evaluating localized TM hardness. This relationship and low PSV in the TCA were evident in symptomatic subjects. These results suggest that PSV in the TCA is associated with neck and upper-back stiffness.

Effects of the open Latarjet procedure on shoulder kinematics and periscapular muscle activity 3 months postoperatively.

BACKGROUND: The debate surrounding the influence of the open Latarjet procedure on postoperative scapular motions persists, and there is no evidence regarding its effects on periscapular muscle activation. This study aimed to assess the short-term influence of the open Latarjet procedure on scapular kinematics and periscapular muscle activity during arm raising and lowering based on comparisons between patients and healthy athletes. METHODS: 22 healthy male athletes and 22 male athletes scheduled for glenohumeral stabilization surgery by the open Latarjet procedure were included. Scapular kinematics, periscapular muscle activities, and shoulder-related quality of life were recorded before surgery and 3 months postoperatively for the Latarjet group. For the healthy group, same assessments were performed 3 months apart. Bilateral differences in both scapular kinematics and periscapular muscle activation ratios and the Western Ontario Shoulder Instability (WOSI) index were defined as dependent variables. RESULTS: Scapular kinematics of the operated shoulder, namely scapular upward/downward rotation, internal/external rotation, and anterior/posterior tilt recorded between 20° and 120° of humerothoracic elevation, showed no alterations 3 months after surgery (P > .05) and did not differ from those observed in healthy athletes (P > .05). Similarly, all periscapular muscle activations were not different within time and between groups (P > .05). The WOSI index of the operated shoulder was significantly improved postoperatively (871.9 ± 443.7 vs. 1346.3 ± 552.3) but remained higher than the WOSI indices of the nonoperated shoulder or those of the healthy group (52.7 ± 75.6). CONCLUSIONS: This study emphasizes the short-term effects of the open Latarjet procedure, demonstrating an improvement in the shoulder-related quality of life 3 months after surgery. Notably, during this period, both kinematics and periscapular muscle activity remained consistent and similar to the patterns observed for healthy athletes.

Spinal accessory nerve anatomy in the posterior cervical triangle: A systematic review with meta-analysis.

This study aimed to investigate the anatomy of the spinal accessory nerve (SAN) in the posterior cervical triangle, especially in relation to adjacent anatomical landmarks, along with a systematic review of the current literature with a meta-analysis of the data. Overall, 22 cadaveric and three prospective intraoperative studies, with a total of 1346 heminecks, were included in the analysis. The major landmarks relevant to the entry of the SAN at the posterior border of the SCM muscle (PBSCM) were found to be the mastoid apex, the great auricular point (GAP), the nerve point (NP), and the point where the PBSCM meets the upper border of the clavicle. The SAN was reported to enter the posterior cervical triangle above GAP in 100% of cases and above NP in most cases (97.5%). The mean length of the SAN along its course from the entry point to its exit point from the posterior triangle of the neck was 4.07 ± 1.13 cm. The SAN mainly gave off 1 or 2 branches (32.5% and 31%, respectively) and received either no branches or one branch in most cases (58% and 23%, respectively) from the cervical plexus during its course in the posterior cervical triangle. The major landmarks relevant to the entry of the SAN at the anterior border of the TPZ muscle (ABTPZ) were found to be the point where the ABTPZ meets the upper border of the clavicle and the midpoint of the clavicle, along with the mastoid apex, the acromion, and the transverse distance of the SAN exit point to the PBSCM. The results of the present meta-analysis will be helpful to surgeons operating in the posterior cervical triangle, aiding the avoidance of the iatrogenic injury of the SAN.

Immunohistochemical properties of motoneurons supplying the porcine trapezius muscle.

The trapezius muscle (TRAP) belongs to the scapulothoracic group of muscles, which play a crucial role in the integrity and strength of the upper limb, trunk, head, and neck movements and, thus, in maintaining balance. Combined retrograde tracing (using fluorescent tracer Fast Blue, FB) and double-labelling immunohistochemistry were applied to investigate the chemical coding of motoneurons projecting to the porcine TRAP. FB-positive (FB+) motoneurons supplying the cervical (c-TRAP) and thoracic part (th-TRAP) of the right (injected with the tracer) TRAP were located within the IX-th Rexed lamina in the ipsilateral ventral horn of the grey matter of the spinal medulla. Immunohistochemistry revealed that nearly all the neurons were cholinergic in nature [choline acetyltransferase (CHAT)- or vesicular acetylcholine transporter (VACHT)-positive]. Many retrogradelly labelled neurons displayed also immunoreactivity to calcitonin gene-related peptide (CGRP; approximately 68% of FB+ neurons). The smaller number of nerve cells (5%, 3%, 2% or 1%, respectively) stained for nitric oxide synthase (n-NOS), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and substance P (SP). The retrogradely labelled neurons were closely apposed by nerve fibres expressing immunoreactivity to CHAT, VACHT, CGRP, SP, DßH, VIP, n-NOS, NPY, GAL, Leu-Enk and Met-Enk. Taking into account the clinical relevance of TRAP, the present results may be useful in designing further research aimed at the management of various dysfunctions of the muscle.

Epidemic Myalgia Presenting as Cervical Pain: A Case Report.

A 53-year-old female visited our hospital because of cervical and abdominal pain preceding fever and upper respiratory symptoms. Severe tenderness was noted over the bilateral sternocleidomastoid muscles, the superior portion of the trapezius muscle, and the umbilical region of the abdomen. The patient reported exacerbation of posterior neck pain in the supine position and during the transition from sitting to the supine position. The diagnosis of epidemic myalgia was finally made. This case highlights the presence of the cervical variant of epidemic myalgia.

Local alternating heat and cold stimulation affects hemodynamics and oxygenation in fatigued muscle tissue and autonomic nervous activity: a single-arm interventional study.

BACKGROUND: Local alternating heat and cold stimulation as an alternative to contrast bath may cause intermittent vasoconstriction and vasodilation, inducing a vascular pumping effect and consequently promoting increased tissue blood flow and oxygenation. This study aimed to examine the effects of local alternating heat and cold stimulation, using a wearable thermal device, on the hemodynamics of fatigued muscle tissue and autonomic nervous activity. METHODS: Twenty healthy individuals experienced fatigue in the periarticular muscles of the shoulder joint due to a typing task. Local alternating heat and cold stimulations were then applied to the upper trapezius muscle. Muscle hardness was measured using a muscle hardness meter, and muscle tissue hemodynamics and oxygenation were evaluated using near-infrared spectroscopy before and after the stimulation. Autonomic nervous activity was also evaluated using heart rate variability. RESULTS: Alternating heat and cold stimulation decreased muscle hardness of the fatigued trapezius muscle from 1.38 ± 0.15 to 1.31 ± 0.14 N (P < 0.01). The concentration of total hemoglobin in the trapezius muscle tissue increased from - 0.21 ± 1.36 to 2.29 ± 3.42 µmol/l (P < 0.01), and the tissue hemoglobin oxygen saturation also increased from 70.1 ± 5.4 to 71.1 ± 6.0% (P < 0.05). Additionally, the heart rate variability parameter, which is an index of sympathetic nervous activity, increased from 3.82 ± 2.96 to 6.86 ± 3.49 (P < 0.01). A correlation was found between increased tissue hemoglobin oxygen saturation and increased parameters of sympathetic nervous activity (r = 0.50, P < 0.05). CONCLUSIONS: Local alternating heat and cold stimulation affected the hemodynamic response in fatigued muscle tissue and autonomic nervous activity. This stimulation is more efficient than conventional contrast baths in terms of mobility and temperature control and has potential as a new versatile therapeutic intervention for muscle fatigue. TRIAL REGISTRATION: UMIN-CTR (UMIN000040087: registered on April 7, 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000045710 . UMIN000040620: registered on June 1, 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046359 ).

Paraspinal Muscle Morphology in Proximal Cervical Spondylotic Amyotrophy.

STUDY DESIGN AND OBJECTIVE: This is a retrospective analysis of prospectively collected single-center observational data. The aim is to evaluate atrophy and fatty degeneration rates of cervical spinal muscles in proximal cervical spondylotic amyotrophy (PCSA). OVERVIEW OF LITERATURE: Proximal cervical spondylotic amyotrophy affects muscles in the upper extremities. In cases that lack improvement with conservative treatment, surgery is recommended. However, preoperative factors associated with poor outcomes remain unclear. We hypothesized that assessing fatty degeneration of the cervical spinal muscles and examining its relationship with functional impairment would help predict postoperative improvement in neurological function. METHODS: This study included 18 patients who underwent PCSA surgery. We performed selective laminoplasty and foraminotomy. Preoperative paraspinal muscle cross-sectional area and fatty degeneration were quantified and correlated with neurological function. RESULTS: Neurological improvement based on manual muscle testing was observed in 12/18 patients, comparing preoperative, perioperative, and over 12-month postoperative statuses. On the affected side, at the C4/5 level, fatty degeneration was more significant in the trapezius, whereas at the C5/6 level, fatty degeneration was more significant in the splenius capitis and trapezius. The fatty degeneration of the C4/5 and C5/6 trapezius was significantly correlated with preoperative muscle strength and postoperative muscle strength improvement. CONCLUSIONS: The degree of fat infiltration of the muscle correlated with pre- and postoperative muscle strength at the lesion level. Thus, our results suggest a relationship between cervical muscle morphology and the clinical manifestations of PCSA. The marked increase in trapezius fatty infiltration at the C4/5 and C5/6 levels may be a valuable indicator to predict poor improvements in postoperative muscle strength.

Ultrasound-Guided Combined Greater Occipital Nerve Block at the C2 Level with Trapezius Trigger Point Injection and Supraorbital-Supratrochlear Nerve Block: More Effective on Allodynia and Disability in Chronic Migraine.

Background: Chronic migraine (CM) patients with cutaneous allodynia (CA) show a poor response to treatment. Long-term studies have yet to be conducted to demonstrate the efficacy of blocks on CA. This study evaluated the improvement in allodynia and disability in CM treated with ultrasound (US)-guided blocks. Methods: In this prospective, non-randomized comparative study, 60 CM patients with CA were evaluated for the clinical effectiveness of the therapy using the numeric rating scale (NRS), headache impact test-6 (HIT-6), brush allodynia test, and allodynia symptom checklist (ASC-12). At the first visit, tenderness in the nerve or trapezius muscle was confirmed in the intervention group. US-guided greater occipital nerve block (GONB), GONB, and trapezius muscle injection (TPI), or GONB, TPI, and peripheral trigeminal nerve block (PTNB), respectively, were performed four times once a week for a month. Initial and third-month assessments were performed. Results: The ASC-12 scores decreased in the GONB+TPI+PTNB and GONB groups more than the GONB+TPI group (mean rank, respectively, 26.86, 27.40, 38.39; P = 0.018). The decrease in HIT-6 scores was greater in the GONB+TPI+PTNB group than in the GONB group (mean rank, respectively, 21.98, 39.95, P < 0.017) in the first month. In the third month, the GONB+TPI+PTNB group scored HIT-6 significantly lower than GONB and GONB+TPI (mean rank: 18.84, 38.73, 35.61; P < 0.001). Conclusions: GONB+TPI+PTNB was more successful in alleviating allodynia and disability.

Demonstration of kinesio taping effect by ultrasonography in neck pain

SUMMARY OBJECTIVE: This study aimed to demonstrate the effectiveness of kinesio taping in nonspecific neck pain and to assess whether ultrasonographic parameters of the upper trapezius muscle can be used in the follow-up of kinesio taping treatment. METHODS: This was a single-blind, prospective, randomized controlled trial study involving 60 participants with nonspecific neck pain. The participants were randomly assigned into two groups. Kinesio taping group (n=29) received a 4-week neck exercise program, with kinesio taping applied twice a week for a total of four times, and the exercise group (n=28) received a 4-week neck exercise program. Participants were evaluated according to pain intensity (Visual Analog Scale), cervical range of motion, and disability (Neck Disability Index). Also, trigger point diameter and upper trapezius muscle thickness were evaluated with ultrasonography. Before and after the therapy, as well as the first month, all measures were taken by an investigator other than the practitioner of the treatment program. RESULTS: The results showed that the Visual Analog Scale and Neck Disability Index scores in the kinesio taping group were statistically significantly improved when compared to the exercise group (p<0.05). In addition, the thickness of the upper trapezius muscle and the diameter of the trapezius muscle trigger point were statistically significantly improved in the kinesio taping group compared to the exercise group (p<0.05). In the kinesio taping group, there was no statistical significance in cervical range of motion as compared to the exercise group. CONCLUSION: The combination of kinesio taping and exercise therapy was effective in reducing nonspecific neck pain and neck disability. Also, this study showed that ultrasonographic evaluation of the trapezius muscle could be used in the follow-up of kinesio taping therapy.

Pain intensity and cervical range of motion in women with myofascial pain treated with acupuncture and electroacupuncture: a double-blinded, randomized clinical trial

BACKGROUND: Acupuncture stimulates points on the body, influencing the perception of myofascial pain or altering physiologic functions. OBJECTIVE: The aim was to evaluate the effect of electroacupuncture (EAC) and acupuncture (AC) for myofascial pain of the upper trapezius and cervical range of motion, using SHAM acupuncture as control. METHOD: Sixty women presenting at least one trigger point at the upper trapezius and local or referred pain for more than six months were randomized into EAC, AC, and SHAM groups. Eight sessions were scheduled and a follow-up was conducted after 28 days. The Visual Analog Scale assessed the intensity of local and general pain. A fleximeter assessed cervical movements. Data were analyzed using paired t or Wilcoxon's tests, ANOVA or Friedman or Kruskal-Wallis tests and Pearson's correlation (α=0.05). RESULTS: There was reduction in general pain in the EAC and AC groups after eight sessions (P<0.001). A significant decrease in pain intensity occurred for the right trapezius in all groups and for the left trapezius in the EAC and AC groups. Intergroup comparisons showed improvement in general pain in the EAC and AC groups and in local pain intensity in the EAC group (P<0.05), which showed an increase in left rotation (P=0.049). The AC group showed increases in inclination (P=0.005) sustained until follow-up and rotation to the right (P=0.032). CONCLUSION : EAC and AC were effective in reducing the pain intensity compared with SHAM. EAC was better than AC for local pain relief. These treatments can assist in increasing cervical range of motion, albeit subtly. .

Anatomical basis of the myofascial trigger points of the trapezius muscle / Bases anatómicas de los puntos de gatillo miofasciales del músculo trapecio

This study aimed to bring the trapezius muscle, knowledge of the locations where the accessory nerve branches enter the muscle belly to reach the motor endplates and find myofascial trigger points (MTPs). Although anatomoclinical correlations represent a major feature of MTP, no previous reports describing the distribution of the accessory nerve branches and their anatomical relationship with MTP are found in the literature. Both trapezius muscles from twelve adult cadavers were carefully dissected by the authors (anatomy professors and medical graduate students) to observe the exact point where the branches of the spinal accessory nerve entered the muscle belly. Dissection was performed through stratigraphic layers to preserve the motor innervation of the trapezius muscle, which is located deep in the muscle. Eight points were identified: In all cases, these locations corresponded to clinically described MTPs. The eight points where common in these twelve cadavers. This type of clinical correlation between spinal accessory nerve branching and MPT is useful to achieve a better understanding of the anatomical correlation of MTP and the physiopathology of these disorders and may provide a scientific basis for their treatment, providing useful additional information to therapists to achieve better diagnoses and improve therapeutic approaches.

El objetivo de este estudio fue correlacionar los sitios de entrada de los ramos del nervio accesorio en el músculo trapecio con placas motoras y los puntos de gatillo miofasciales. A pesar de las correlaciones anatomoclínicas se constituyeren en la principal característica de los puntos de gatillo, no hay informes en la literatura describiendo sobre la distribución de los ramos del nervio accesorio y su relación anatómica con los puntos de gatillo. Ambos músculos trapecio de doce cadáveres adultos fueron disecados por los autores (profesores de anatomía y estudiantes de postgrado en Medicina) para observar el punto exacto donde los ramos del nervio accesorio espinal penetraban en el vientre muscular. La disección se llevó a cabo respetando las capas estratigráficas para preservar la inervación del músculo ubicada profundamente a éste. Ocho puntos fueron identificados: En todos los casos correspondieron a la descripción clínica de los puntos gatillo miofasciales y eran comunes a todos los cadáveres. Esta correlación anatomoclínica entre la ramificación del nervio espinal accesorio y los puntos de gatillo miofascial es útil para una mejor comprensión de la fisiopatología de los puntos gatillo y puede proporcionar una base para un abordaje diagnóstico y terapéutico racional para estos trastornos.

Tratamento do estresse psicológico pela acupuntura, avaliado pela eletromiografia do músculo trapézio / Psychological stress treated by acupuncture and evaluated by trapezius muscle electromyography

JUSTIFICATIVA E OBJETIVOS: O estresse é considerado um fenômeno da vida moderna, que pode estar presente na vida de todas as pessoas, independente de idade, sexo, classe social ou profissão. Esta pesquisa foi realizada visando propor um tratamento alternativo para o estresse, pelo tratamento com acupuntura, avaliando eletromiograficamente o músculo trapézio, direito e esquerdo, de indivíduos portadores de estresse psicológico, uma semana antes das avaliações e após a acupuntura. MÉTODO: Para a realização deste estudo foram selecionados 10 voluntários, submetidos a um questionário que avaliou os sinais de estresse psicológico. O músculo estudado foi o trapézio por refletir melhor os sinais de estresse. Este foi estudado bilateralmente e a ação muscular foi captada no repouso e durante atividade isométrica, realizando-se movimentos de elevação e abaixamento. Em cada uma das 10 sessões de acupuntura foi realizado o agulhamento do ponto C7; pontos obtidos a partir de um pentagrama e pontuar pontos de confluência do meridiano distinto afetado no pentagrama. RESULTADOS: Os valores de RMS, quando comparados antes e após o tratamento com acupuntura, no repouso e em elevação da escápula foram estatisticamente significativos (p < 0,01). CONCLUSÃO: Os músculos apresentaram menor atividade eletromiográfica após o tratamento, mostrando assim a eficácia da acupuntura em indivíduos portadores de estresse psicológico.

BACKGROUND AND OBJECTIVES: Stress is a modern life phenomenon and may be present in the lives of anyone, regardless of age, gender, social class or profession. This research aimed at proposing an alternative treatment for stress with acupuncture, evaluating by electromyography right and left trapezius muscles of patients under psychological stress one week before evaluations and after acupuncture. METHOD: Participated in this study 10 volunteers submitted to a questionnaire to evaluate signs of psychological stress. The trapezius muscle was selected for best reflecting stress signs. The study was bilateral and muscle action was captured at rest and during isometric activities with raising and lowering movements. The following points were needled during each one of the 10 acupuncture sessions: C7 point, points obtained as from a pentagram and confluence points of the distinct meridian affected on the pentagram. RESULTS: RMS values, compared before and after acupuncture treatment, at rest and with elevation of the scapula were statistically significant (p < 0.01). CONCLUSION: Muscles have shown less electromyographic activity after treatment, thus showing the efficacy of acupuncture for patients under psychological stress.

Use of electromyography to assess pain in the upper trapezius and lower back muscles within a fatigue protocol / Uso da eletromiografia na análise de dor dos músculos trapézio superior e lombares durante protocolo de fadiga

OBJECTIVE: The aim of this study was to investigate whether muscle fatigue indices obtained using surface electromyography and calculated in the time and frequency domains would be capable of objectively diagnosing pain and discriminating between subjects with and without pain in the upper trapezius muscle and the lower back muscles. METHODS: Forty-seven individuals underwent a muscle fatigue test for thirty-five seconds at 80% of the maximal voluntary contraction (MVC), while EMG and muscle force data were recorded. The RMS value and the median frequency (MF) were calculated within consecutive one-second windows. Linear regression analysis was used to obtain the slope coefficients and the respective y-axis intercept values, which were considered to be localized muscle fatigue indices. RESULTS: In the frequency domain, the slope coefficients were negative for both muscles, while in the time domain, the coefficient for the upper trapezius was positive and the coefficient for the lower back muscles was negative (p<0.01). Significant differences were also found in the frequency domain between subjects with and without pain in the upper trapezius (p<0.01). The subjects with pain had significantly lower force values than the subjects without pain (p<0.05), in both the upper trapezius and the lower back muscles. CONCLUSION: The force values associated with the fatigue indices (MF slope and y-axis intercept) were able to predict the presence of pain in the upper trapezius (p<0.05), but not in the lower back muscles.

OBJETIVO: A proposta do estudo foi investigar se índices de fadiga, obtidos a partir de eletromiografia de superfície, calculados no domínio do tempo e da frequência, são capazes de diagnosticar a dor objetivamente, discriminando entre sujeitos com e sem dor no trapézio superior e nos músculos lombares. MÉTODOS: Quarenta e sete indivíduos foram submetidos a um teste de fadiga muscular por 35s a 80% da contração voluntária máxima (CVM), enquanto EMG e força muscular foram registradas. O valor RMS e a mediana da frequência (MF) foram calculados em janelas consecutivas de 1s. Análise de regressão linear foi utilizada para obter os coeficientes de inclinação e seus respectivos valores de interseção no eixo y, os quais foram considerados índices de fadiga muscular localizada. RESULTADOS: Os coeficientes de inclinação analisados no domínio da frequência apresentaram comportamento similar, sendo negativos para ambos os músculos, enquanto que, no domínio tempo, o trapézio superior apresentou coeficientes positivos, e músculos lombares, coeficientes negativos (p<0,01). Diferenças significativas também foram identificadas no domínio da frequência entre os sujeitos com e sem dor no trapézio superior (p<0,01). Os indivíduos com dor apresentaram valores de força significativamente menores que os sujeitos sem dor (p<0,05), tanto nos músculos lombares quanto no trapézio superior. CONCLUSÃO: Os valores de força associados aos índices de fadiga (inclinação da MF e intersecção do eixo y) foram hábeis para predizer a presença de dor no trapézio superior (p<0,05), mas não nos músculos lombares.

Temporomandibular joint dysfunction and trapezius muscle fatigability

INTRODUCTION: It has been suggested that pain increases trapezius muscle activation in patients with temporomandibular joint dysfunction (TMD). Changes in muscle activation might change muscle resistance to fatigue. The purpose of this study was to evaluate the fatigability of the trapezius muscle in patients with TMD. METHOD: Fourteen patients with TMD (clinically diagnosed and referred by a dentist) and eleven healthy subjects performed a fatigue test consisting of shoulder elevation performed at 70 percent of the maximal voluntary isometric contraction, which was maintained for 30 seconds. Electromyographic signals were obtained from the upper portion of the trapezius muscle (sampling frequency: 2000 Hz/channel). Consecutive segments of three seconds in duration each were extracted from the electromyographic signal and analyzed in the frequency domain using a Fast Fourier Transform algorithm. Linear regression analysis was applied to the consecutive median frequencies for each subject. The slope of the regression line was used to describe muscle fatigability. RESULTS: No changes were observed in fatigability between the right and left trapezius of either group or between the left trapezius of the healthy and TMD groups. The linear regression for median frequencies in the right trapezius of the TMD group showed a slope of -0.15 ± 0.33 (mean ± SD), which was smaller than the slope for the healthy group (-0.44 ± 0.46; p= 0.049). These results suggested that the fatigability of the right trapezius was lower in the TMD group than in the healthy group.

INTRODUÇÃO: Tem sido sugerido que a dor aumenta a ativação do músculo trapézio em pacientes com disfunção temporomandibular (TMD). Mudanças na ativação do músculo podem alterar a resistência à fadiga. O objetivo do estudo foi investigar a fatigabilidade do músculo trapézio em pacientes com TMJ. MÉTODOS: Quatorze indivíduos com TMD (diagnosticados clinicamente e encaminhados pelo especialista odontólogo) e onze indivíduos saudáveis realizaram um protocolo de fadiga que consistiu em uma contração isométrica submáxima de elevação do ombro, em um nível de 70 por cento da contração voluntária máxima, mantida por um período de 30 segundos. O sinal eletromiográfico (EMG) foi obtido da porção superior do músculo trapézio, (taxa de amostragem de 2000Hz/canal). Três segundos consecutivos do sinal EMG foram analisados no domínio da freqüência usando a Transformada Rápida de Fourier (FFT). Uma análise de regressão linear foi aplicada para valores consecutivos da freqüência mediana (MF) de cada sujeito, e a inclinação da regressão linear foi utilizada para descrever a fatigabilidade muscular. RESULTADOS: Nenhuma diferença foi observada na fatigabilidade do músculo trapézio direito e esquerdo para ambos os grupos e entre o trapézio esquerdo do grupo saudável e com TMD. A MF do músculo trapézio direito do grupo com disfunção apresentou valores de inclinação da reta de regressão linear de -0,15 ± 0,33 (média ± SD), os quais foram menores que os valores do grupo saudável (-0,44 ± 0,46; média ± SD; p= 0,049). Esses resultados sugerem que a fatigabilidade do trapézio direito é menor no grupo com TMD do que no grupo saudável.

Avaliação funcional do músculo trapézio e nervo espinhal pós-esvaziamento cervical através da eletroneuromiografia: estudo de 25 pacientes / Functional evaluation of trapezius muscle and spinal nerve after neck dissection through eletro-neuromiography: study of 25 patients

OBJETIVO: Foram estudados 25 pacientes portadores de neoplasias malignas da cabeça e pescoço (20 de vias aerodigestivas superiores e cinco da glândula tireóide), submetidos a esvaziamentos cervicais uni ou bilaterais (33 procedimentos), sendo 15 supra-omohióideos, 11 funcionais e sete em campos alargados. MÉTODO: Através da eletroneuromiografia (ENM), foram avaliados funcionalmente o músculo trapézio e o nervo espinhal após os diferentes procedimentos, aos 30 e 180 dias. RESULTADOS: Foram aferidos para as três formas de linfadenectomia 94 por cento de desnervação do músculo trapézio, severa em 68 por cento e moderada 32 por cento (p = 0,001), portanto valores significativos. Quanto à avaliação do tipo de lesão do nervo espinhal, após 30 dias observou-se lesão de axônio (axonotmese) em 31 dos 33 procedimentos. Com relação à reinervação, esta foi detectada após 180 dias, sendo boa (21 por cento), moderada (72 por cento) e ruim (7 por cento) para valores de p = 0,001 de significância estatística. CONCLUSÕES: A eletroneuromiografia foi um método efetivo na avaliação da unidade neuromuscular e o tipo de esvaziamento cervical conservador não foi determinante de alterações destas estruturas.

BACKGROUND: Twenty fire patients with malignant head and neck neoplasias (20 from superior aerodigestive tract and 5 from thyroid gland), were submitted to 33 unilateral or bilateral neck node dissection (15 supraomohyoid, 11 modified and 7 wide field), at the Head and Neck Service of Hospital Araújo Jorge, Goiânia, Goiás, Brazil. METHOD: Eletroneuromiography (ENM) of the trapezius muscle after spinal nerve dissection. RESULTS: In spite of surgical dissection, 94 percent of trapezius muscle desnervation were detected, being 38 percent severe and 62 percent moderate, (p = 0,001). The degree of lesion for spinal nerve after 30 days, showed axoniumtmese in 31 of 33 procedures, and after 180 days, 21 percent of severe, 72 percent of moderate and 7 percent of unsatisfactory reinervation were diagnosed (p = 0,001). CONCLUSIONS: ENM is an effective method of evaluation of neuromuscular unit (trapezius muscle/spinal nerve) and the type of neck node dissection was not determinant of structural nerve alteration.