Clinical Effectiveness and Tolerability of 2% Menthol in Musculoskeletal Pain : A Pilot Observational Real-world Evidence Study

Objective : To determine the efficacy and safety of 2% menthol in the management of musculoskeletal pain. Materials and Methods : 81 patients above the age of 18 years of either sex with any musculoskeletal pain were included in the study. Subjects were instructed to apply 2% menthol gel twice daily to the affected area for 7 to 10 days. A Visual Analog Scale (VAS) was used to assess the severity of the initial pain. Moreover, the level of muscle soreness on a 7-point Likert scale was also evaluated. The patients were assessed before the treatment and 7 to 10 days after the initiation of the treatment. Results : The VAS scores for pain significantly improved (P< 0.0001) in subjects after completion of the treatment. There was a 70% improvement (7.67 � 1.04 before treatment to 2.30 � 0.56 after treatment) in the VAS scores compared to baseline, and the mean Likert scale of muscle soreness was 2.04 � 0.25 at the end of the treatment. Moreover, no significant adverse events were observed in the patients during the study. Conclusion : The study showed that 2% menthol effectively improves musculoskeletal pain

Efeitos da dor experimental no desempenho dos músculos flexores do cotovelo após oito semanas de treinamento de força: um estudo piloto / Effects of experimental pain on elbow flexor muscles performance after eight weeks of strength training: a pilot study

INTRODUÇÃO: O treinamento de força tem sido recomendado na reabilitação clínica, bem como no condicionamento físico de atletas. Não é incomum, em ambos os casos, a presença de dor durante a prática; no entanto, até o momento, não há informação consensual em relação aos efeitos da dor muscular aguda nas adaptações ao treinamento de força. OBJETIVO: O objetivo deste estudo piloto foi avaliar os efeitos da dor induzida experimentalmente na adaptação da força muscular após um período de treinamento de 8 semanas. MÉTODO: O estudo incluiu cinco voluntários saudáveis do sexo masculino e não treinados. Os participantes foram submetidos a um protocolo de treinamento de força (3x/semana durante 8 semanas) para os músculos flexores do cotovelo. A dor muscular aguda foi induzida no início de cada sessão de treinamento, por meio de infusão intramuscular de 2,5 ml de solução salina hipertônica (6%) no ventre do músculo bíceps braquial. A força dinâmica máxima (1RM) e a contração isométrica voluntária máxima (CIVM) foram medidas antes e após quatro e oito semanas de treinamento. RESULTADOS: A força dinâmica máxima aumentou, em média, 37,3% e 78,4% após quatro e oito semanas, respectivamente. Entretanto, pouca ou nenhuma diferença foi encontrada na CIVM (-1,7% e -3,0% após quatro e oito semanas, respectivamente). CONCLUSÃO: Após 24 sessões de treinamento de força, com dor muscular aguda induzida a cada sessão, voluntários saudáveis aumentaram sua capacidade de produzir força dinâmica máxima em mais de 75%; entretanto, a força isométrica apresentou apenas pequenas variações negativas.

INTRODUCTION: Strength training has been recommended in clinical rehabilitation, as well as in the physical conditioning of athletes. It is not uncommon, in both cases, the presence of pain during practice; however, to date, there is no consensual information about the effects of acute muscle pain on strength training adaptations. OBJECTIVE: The aim of this pilot study was to evaluate the effects of experimentally induced pain on muscle strength adaptation after an 8-week training period. METHOD: The study included five untrained, healthy male volunteers. Participants were submitted to a strength training protocol (3x/week for 8 weeks) for the elbow flexor muscles. Acute muscle pain was induced at the beginning of each training session through an intramuscular infusion of 2.5 ml of hypertonic saline (6%) into the biceps brachii muscle belly. Maximal dynamic strength (1RM) and maximal voluntary isometric contraction (MVIC) were measured at pre- and after four and eight weeks of training. RESULTS: Maximal dynamic strength increased, on average, 37.3% and 78.4% after four and eight weeks, respectively. However, little, if any, difference was found in MVIC (-1.7% and ­ 3.0% after four and eight weeks, respectively). CONCLUSION: After 24 strength training sessions, with acute muscle pain induced every session, healthy volunteers increased their ability to produce maximal dynamic strength by more than 75%; however, isometric strength presented only small negative changes.

Muscle pain induced by static contraction is modulated by transient receptor potential vanilloid 1 and ankyrin 1 receptors

Abstract Molecular mechanisms involved in the development of muscle pain induced by static contraction are not completely elucidated. This study aimed to evaluate the involvement of the transient receptor potential vanilloid 1 (TRPV1) and the transient receptor potential ankyrin 1 (TRPA1) receptors expressed in peripheral and central terminals of primary afferents projected to gastrocnemius muscle and spinal cord in muscle pain induced by static contraction. An electrical stimulator provided the contraction of rat gastrocnemius muscle and mechanical muscle hyperalgesia was quantified through the pressure analgesimeter Randall-Selitto. AMG9810 and HC030031 were used. When administered in ipsilateral, but not contralateral gastrocnemius muscle, drugs prevented mechanical muscle hyperalgesia induced by static contraction. Similar results were obtained by intrathecal administrations. We propose that, in an inflammatory muscle pain, peripheral and central TRPV1 and TRPA1 work together to sensitize nociceptive afferent fibers, and that TRPV1 and TRPA1 receptors are potential target to control inflammatory muscle pain.

Perinuclear anti neutrophil cytoplasmic antibody vasculitis with nonspecific muscle pain

This is a case report describing p-ANCA vasculitis presenting with nonspecific muscle pain. It is a very uncommon finding seen in p-ANCA vasculitis patients which they usually present with palpable purpura alone. In this case, along with nonspecific muscle pain, renal involvement of the disease has been explained and there are no upper and lower respiratory tract complaints which favours more towards microscopic polyangitis.

Electroacupuncture and transcutaneous electrical acupoint stimulation with different intensities relieve muscular of inflammatory pain of the rats / 针刺研究

OBJECTIVE: To observe and compare the ameliorate effects of electroacupuncture (EA) and transcutaneous electrical acupoint stimulation (TEAS) with different intensities on inflammatory muscle pain, so as to confirm the role of different afferent nerve fibers in different layers (skin or muscle) in pain relief of acupuncture. METHODS: The intensities of the thresholds of A (Ta) and C (Tc) were selected for TEAS and EA. TEAS and EA were applied on the layer of skin and muscle of "Liangqiu" (ST34), respectively. Forty-eight rats were randomly divided into control, model, TEAS-Ta, TEAS-Tc, EA-Ta and EA-Tc groups (n=8 in each group). The inflammatory muscle pain model was established by complete Freund's adjuvant (CFA) injection into the right biceps femoris muscle. EA or TEAS was applied once a day for 3 days. The weight difference between the hind limbs and the abnormal electromyography (EMG) activities were observed as an index for pain of the rats. RESULTS: After modeling, the weight difference between the hind limbs was increased markedly in the model group relevant to the control group (P<0.01). Compared with the model group, the weight difference between the hind limbs in the TEAS-Tc, EA-Ta, and EA-Tc groups was significantly decreased (P<0.05, P<0.01). Compared with that before intervention, the area under the curve and discharge frequency of abnormal EMG of rats in the TEAS-Tc and EA-Ta groups were significantly reduced after intervention (P<0.01, P<0.05), while those in the EA-Tc group were significantly increased (P<0.05). After the intervention, compared with the TEAS-Ta group, the inhibition rate of the area under the curve and the discharge frequency of the abnormal EMG in the TEAS-Tc group increased significantly (P＜0.05); and those were also increased in the EA-Ta group when compared with the EA-Tc group (P<0.01). CONCLUSION: TEAS with Tc or EA with Ta in the muscle layer can alleviate the pain and inhibit the abnormal EMG in inflammatory muscle pain rats. It is indicated that local pain relief by acupuncture was related to the afferent nerve fiber in different layer with different intensities.

Migraña crónica sin aura, dolor referido a ATM: informe de caso / Cronic migrain without aura, referall pain in TMJ: Case report

Resumen Muchos pacientes presentan dolores de cabeza primarios que no son tomados en cuenta en la consulta diaria de odontología. Es común que los asocien a un dolor referido a la articulación témporomandibular, inclusive a un dolor dental de origen no odontogénico, donde se ve incluida esta estructura.

Abstract A lot of the patients present primary headaches and most of the time, they are not connected in the general practice of dentistry, it´s common that the patient relates the pain to the symptom of TMJ referral pain, or another dental pain non odontogenic, muscular or others.

Development of Smart Fruit Basket for Pineapple Harvesting

Abstract@#Introduction: Pineapple harvesting work contributes to the reporting of musculoskeletal symptoms (MSS) and ergonomic risks. Pineapples are harvested manually in some parts of Malaysia using rattan baskets and workers are exposed to excessive bending, pain and discomfort. This intervention study developed and tested a prototype of an ergonomic harvesting basket to potentially reduce discomfort and physiological workload during a simulation of harvesting activity. Methods: The development and testing of improved harvesting basket was performed in laboratory and workshop. The improved basket had adjustable cushion straps, foam back pad and an opening for unloading of fruits. Harvesting was simulated using improved and existing basket by human subjects and questionnaires were used to assess discomfort. Physiological workload was assessed by heart rate and energy expenditure. Results: A total of 12 male respondents with average age of 22.4 (2.2) years participated in harvesting simulation. Discomfort as measured in Likert scale (mean (standard deviation) for improved basket 4.13 (6.1) vs existing basket 12.26 (11.2); p<0.05) was significantly reduced. Average heart rate (94.13 beats/min vs 89.05 beats/min) and energy expenditure (6 kJ/min vs 5 kJ/min) improved. Conclusion: The use of improved basket was linked to reduction of discomfort and overall workload. Improving design of agricultural manual tools may be able to improve health of workers and prevent MSS. Future fabrication of the improved basket using lightweight materials has potential to be expanded into plantation sectors not limited to pineapples in Malaysia and across Asia.

Uso de la crioterapia en la fatiga muscular post esfuerzo en individuos que realizan práctica deportiva: revisión sistemática / Use of cryotherapy in post-effort muscle fatigue in individuals who practice sports: systematic review / Uso da crioterapia na fadiga muscular pós-esforço em indivíduos que realizam prática esportiva: revisão sistemática

Introducción. En la práctica deportiva, la fatiga muscular es un factor de riesgo para lesión muscular, constituyéndose en un problema que aparece cuando la carga mecánica a la cual se somete un músculo o grupo muscular es superior a la resistencia de este. Objetivo. Describir las intervenciones con crioterapia en Fatiga Muscular post esfuerzo, en individuos que realizan práctica deportiva, a través de una Revisión Sistemática. Método. Se realizó la búsqueda en bases de datos PUBMED/MEDLINE, EMBASE, LILACS, SCIELO, SCIENCE DIRECT, Registro Cochrane Central de Ensayos Controlados con la estrategia de búsqueda: Sports Medicine, Cryotherapy, Muscle Fatigue, Recovery of Function, Physical Exertion, Muscle Damage. La identificación y detección de las referencias fueron exportadas al gestor de referencias MENDELEY. La evaluación del Riesgo de Sesgo se realizó con el uso del software Review Manager y la calidad metodológica con lo reportado por la Base de Datos PEDro. Resultados. Se evaluaron 19 ensayos clínicos aleatorizados en los cuales se evidencia que la crioterapia reporta cambios en la fatiga muscular desde la disminución del dolor y biomarcadores. La inmersión en agua fría fue la modalidad más efectiva para acelerar la cinética de recuperación 72 horas después del ejercicio; demostró menor dolor y mayores niveles de recuperación, percibidos a lo largo de 24 a 48 horas después del ejercicio. Conclusión. De la totalidad de modalidades de crioterapia, la inmersión en agua fría es la que reporta mejores resultados en el proceso de recuperación de la fatiga muscular.

Introduction. In sports practice, muscle fatigue is a risk factor for muscle injury becoming a problem that appears when the mechanical load to which a muscle or muscle group is subjected is greater than its resistance. Objective. Describe post-effort Muscular Fatigue in active Men and Women who perform sports practice against interventions with cryotherapy, through a Systematic Review. Method. PUBMED / MEDLINE, EMBASE, LILACS, SCIELO, SCIENCE DIRECT, Central Cochrane Registry of Controlled Trials with the search strategy were searched: Sports Medicine, Cryotherapy, Muscle Fatigue, Recovery of Function, Physical Exertion, Muscle Damage The identification and detection of references were exported to the MENDELEY reference manager. The Bias Risk assessment was performed with the use of Review Manager software and methodological quality as reported by the PEDro Database. Results. 19 randomized clinical trials were evaluated in which it is evident that cryotherapy reports changes in muscle fatigue since the decrease in pain, and biomarkers. Cold water immersion was the most effective modality to accelerate recovery kinetics 72 hours after exercise; showed less pain and higher levels of recovery perceived over 24 to 48 hours after exercise. Conclusion. Of all the cryotherapy modalities, the immersion in cold water is the one that reports the best results in the process of recovery of muscular fatigue.

Introdução. Na prática esportiva, a fadiga muscular é um fator de risco para a lesão muscular, tornando- se um problema que ocorre quando a carga mecânica à qual um músculo ou grupo muscular é submetido é superior à resistência do músculo. Objetivo. Descrever as intervenções com crioterapia na fadiga muscular pós-esforço, em indivíduos que realizam prática esportiva, por meio de uma revisão sistemática. Método. Foi realizada uma busca nas bases de dados PUBMED/MEDLINE, EMBASE, LILACS, SCIELO, SCIENCE DIRECT, Registro Central Cochrane de Ensaios Controlados com a estratégia de busca: Medicina Esportiva, Crioterapia, Fadiga Muscular, Recuperação da Função, Esforço Físico, Dano Muscular. A identificação e detecção das referências foram exportadas para o gerenciador de referência do MENDELEY. A avaliação do risco de viés foi realizada com o uso do software Review Manager de revisão e qualidade metodológica com a relatada pelo banco de dados PEDro. Resultados. Dezenove ensaios clínicos randomizados foram avaliados nos quais se evidencia que a crioterapia relata alterações na fadiga muscular desde a diminuição da dor e dos biomarcadores. A imersão em água fria foi a modalidade mais eficaz para acelerar a cinética de recuperação 72 horas após o exercício; demonstrou menos dor e níveis mais altos de recuperação, percebidos entre 24 e 48 horas após o exercício. Conclusão. De todas as modalidades de crioterapia, a imersão em água fria é a que proporciona os melhores resultados no processo de recuperação da fadiga muscular.

Influence of acupuncture on the pain perception threshold of muscles submitted to repetitive strain / Influência da acupuntura no limiar de percepção dolorosa de musculatura submetida a esforço repetitivo

ABSTRACT BACKGROUND AND OBJECTIVES: Muscle pain is one of the causes of the leave of absence in physical activities, as well as limiting factor in sports performance. The objective of this study was to evaluate the early and late response to the pain perception threshold after acupuncture in a single application, in subjects submitted to repetitive strain. METHODS: Clinical-experimental quantitative trial, with control group and blind, with 47 healthy women, aged between 18 and 55 years (36.3±10.6), divided deterministically by sequential alternation to the groups: acupuncture (GACP n=16), Sham (Gsham n=16) and control (CGRT n=15). The repetitive strain was performed in the Reformer equipment of the Pilates method, before and after the intervention, with 0,25x40mm needles. The GACP received the needling at point ST36 (Zusanli). The Gsham received superficial needling out of the acupuncture point, and the CGRT only performed the exercise. All patients had the needles for 20 minutes, except for the CGRT who remained only at rest. A digital pressure algometer was used at point BL57 (Chengshan). The algometry was conducted before the intervention and the exercise, immediately after, and after 24 hours. RESULTS: The GACP showed a significant increase in the pain perception threshold when compared to Gsham (p =0.021) and to CGRT (p<0.001) and after 24 hours, with CGRT (p=0.006). The results were coherent with the acupuncture theoretical foundations, suggesting the release of opioid analgesics and applicability in the recovery of post-exercise sore muscles. CONCLUSION: A single acupuncture intervention was able to increase the Pain Perception Threshold immediately and after 24 hours.

RESUMO JUSTIFICATIVA E OBJETIVOS: A dor muscular é uma das causas de afastamento de práticas de atividades físicas e fator limitante no desempenho desportivo. O objetivo deste estudo foi avaliar a resposta imediata e tardia do limiar de percepção dolorosa após estímulo de acupuntura em uma única aplicação, em sujeitos submetidos a esforço repetitivo. MÉTODOS: Ensaio clínico-experimental, quantitativo, com grupo controle e encoberto, 47 mulheres sadias, com idades entre 18 e 55 anos (36,3±10,6), separadas por alocação determinista por alternância sequencial em grupos: acupuntura (GACP n=16), Sham (Gsham n=16) e controle (GCRT n=15). Realizou-se o esforço repetitivo no equipamento Reformer do método Pilates, antes e após a intervenção com agulhas 0,25x40mm. O GACP recebeu agulhamento no ponto E36 (Zusanli). O Gsham agulhamento superficial, fora do ponto de estímulo de acupuntura e o GCRT só realizou o exercício. Todos permaneceram 20 min com agulhas e o GCRT só em repouso. Utilizou-se um algômetro de pressão digital no ponto B57 (Chengshan). A algometria foi realizada antes da intervenção e do exercício, imediatamente após, e após 24 horas. RESULTADOS: O GACP teve aumento significativo do limiar de percepção dolorosa no momento imediato, quando comparado ao Gsham (p=0,021) e ao GCRT (p<0,001), e após 24 horas com o GCRT (p=0,006). Houve coerência dos resultados com as bases teóricas do estímulo da acupuntura, sugerindo liberação de opioides analgésicos e aplicabilidade em recuperação de dores musculares pós-exercícios. CONCLUSÃO: Uma única intervenção de acupuntura foi capaz de aumentar o limiar de percepção dolorosa de imediato e após 24 horas.

Trastornos musculoesqueléticos en recicladores que laboran en Lima Metropolitana / Musculoskeletal disorders among recyclers working in Metropolitan Lima

Introducción, Los recicladores en su mayoría desarrollan sus actividades en precarias condiciones sanitarias y de seguridad ocupacional. Los síntomas de los trastornos musculoesqueléticos (TME) es un problema que afecta a todos los sectores y ocupaciones, Objetivos, Conocer la percepción de síntomas de los TME, Diseño, Estudio descriptivo transversal. Lugar, Lima Metropolitana, Participantes, Recicladores de cualquier edad y género, Intervenciones, Aplicación del Cuestionario Nórdico, Principales medidas de resultados, Presencia de síntomas de TME por regiones anatómicas, Resultados, De los 131 participantes, 114 cumplieron con los criterios de inclusión, 58,8% (n=57) fueron varones y 41,2% (n=47) mujeres, con una media de 41,2 años (DE: 14,51; min: 18, máx: 77), La región anatómica con más síntomas lue la región lumbar, y lue la dolencia que más interferencia tuvo con las tareas de la casa o el trabajo, En el grupo etario de 20 a 39 años, los síntomas musculoesqueléticos más frecuentes se presentaron en la región cervical (p=0,012), mientras que en los mayores de 50 años se presentaron en las rodillas (p=0,040), Conclusiones, La percepción de síntomas de los TME en los recicladores se presentó predominantemente en la región lumbar y fue la dolencia que más interferencia tuvo con las tareas de casa o el trabajo

Introduction: Recyclers mostly operate in poor sanitary conditions and low occupational satety. The symptoms of musculoskeletal disorders (MSD) represent a problem affecting all the sectors and occupations. Objective, To determine the perception of MSD symptorns. Desiqn, Cross-sectional study, Setting, Metropolitan Lima, Participants, Recyclers of any age and gender, Interventions, Implementation of Nordic Queslionnaire. Main outcome measures, Presence of MSD symptoms according to anatomical reqions. Results, Out of 131 selected participants, 114 met the inclusion criteria of which 58,8% (n = 67) were male and 41.2% (n = 47) female with an average age of 41.2 years (SD: 14,51; min: 18, max: 77), The anatomical region where most of the symptoms occurred was the lumbar region where the disease interlered with most of the household chores or work. In the age group 20-39 years, the most frequent musculoskeletal symptoms occurred in the cervical region (p = 0,012), whereas among people older than 50 years they occurred in the knees (p = 0,040), Conclusions, The perception of the symptoms of musculoskeletal disorders among recyclers was predominantly present in the lumbar region and it was the disease that had the most interlerence with household chores or work.

Riesgo ergonómico asociado a sintomatología musculoesquelética en personal de enfermería / Ergonomic risk associated to musculoskeletal symptoms in nursing staff / Risco ergonómico associado à sintomatología musculoesquelética em pessoal de enfermagem

Objetivo: Asociar los trastornos musculoesqueléticos y los factores de riesgo ergonómicos en personal de enfermería de una clínica en la Costa Atlántica, 2014. Materiales y Métodos: Estudio descriptivo analítico realizado a 111 trabajadores de enfermería, se utilizaron los cuestionarios Condiciones Sociodemográficas, Nórdico (versión en español) y calificación del riesgo de acuerdo a la actividad física. Resultados: el 73,9% del personal de enfermería que labora en la institución es auxiliar de enfermería, son mujeres el 84,7%, 30 años es la edad promedio, el 42,3% lleva menos de un año laborando en la clínica, trabajan en promedio entre 41 a 60 horas (58,6%). El 49,5% del personal manifestó dolores musculares en los últimos 12 meses, siendo la espalda (37,8%) y el cuello (16,2%) las partes del cuerpo más afectadas. Durante la jornada, el 39,6% carga pesos mayores a los permitidos para hombres y mujeres. Existe asociación significativa (p < 0,05) entre la carga física laboral y el riesgo de presentar síntomas de espalda (p = 0,036) y mano-muñeca derecha (p = 0,014). Conclusiones: El dolor de espalda y en mano-muñeca derecha está asociado significativamente (p < 0,05) al riesgo de carga física.

Objective: To associate musculoskeletal disorders and ergonomic risk factors in nursing staff from a clinic in the Atlantic Coast, 2014. Materials and Methods: Descriptive-analytic study conducted with 111 nursing workers. The sociodemographic survey, Nordic (Spanish version) and a risk rating instrument according to physical activity were applied. Results: 73.9% of nursing staff in the institution are nursing assistants, 84.7% are women, with an average age of 30 years; 42.3% has been working at the clinic for less than a year and they work 41 to 60 hours a week on average (58.6%). 49.5% of nursing staff expressed muscular pains over the past 12 months, being back (37.8%) and neck (16.2%), the most affected parts of the body. During the working day, 39.6% carry weights higher than those permitted for men and women. There is significant association (p < 0.05) between the physical workload and the risk to show back symptoms (p = 0.036) or right hand-wrist troubles (p = 0.014). Conclusions: Back and right hand wrist pains are significantly associated (p < 0.05) to the physical workload risk.

Objetivo: Associar os distúrbios musculoesqueléticos e os fatores de risco ergonômicos em pessoal de enfermagem de uma clínica na Costa Atlântica, 2014. Materiais e Métodos: Estudo descritivo analítico realizado a 111 trabalhadores de enfermagem utilizaram se os questionários Condições Sociodemográficas, Nórdico (versão em espanhol) e qualificação do risco de acordo à atividade física. Resultados: o 73,9% do pessoal de enfermagem que trabalha na instituição é auxiliar de enfermagem, são mulheres o 84,7%, 30 anos é a idade media, o 42,3% leva menos de um ano trabalhando na clínica, trabalham em media entre 41 a 60 horas (58,6%). O 49,5% do pessoal manifestou dores musculares nos últimos 12 meses, sendo as costas (37,8%) e o pescoço (16,2%) as partes do corpo mais afetadas. Durante o dia de trabalho, o 39,6% carga pesos maiores aos permitidos para homens e mulheres. Existe associação significativa (p < 0,05) entre a carga física laboral e o risco de apresentar sintomas de costas (p = 0,036) e mão direita (p = 0,014).Conclusões: A dor de costas e em mão-pulso direita está associado significativamente (p < 0,05) ao risco de carga física.

The Relationship between Emotional Working Hour and Muscle Pain / 산업간호학회지

PURPOSE: The purpose of this study was to investigate muscle pains of emotional laborers and determine whether there were differences in their muscle pains depending on the hours spent on emotional labor. METHODS: This is a secondary analysis of the data collected from the 3rd (2011) Korean Working Conditions Survey. 50,032 participants responded to the study's questionnaire. Among them, 15,669 participants were emotional laborers who directly dealt with people such as customers, passengers, pupils, patients, etc. RESULTS: Thirty three percent of subjects had reported muscle pains. Muscle pains of subjects were positively related to the hours spent on emotional labor (p<.001). According to the logistic regression analysis, the adjusted odd ratio of the subjects who spent about almost all of the work hours on emotional labor was 1.32 (95% CI: 1.15~1.52), compared to the subjects who spent about a quarter of their work hours on emotional labor, when other factors were controlled. CONCLUSION: The study's findings indicate that engaging in emotional labor for longer hours increases the risks of muscle pains. Occupational nurses must pay closer attention to the management of muscle pains of emotional laborers.

Analgesic Effect of Intrathecal Gabapentin in a Rat Model of Persistent Muscle Pain

OBJECTIVE: To evaluate the analgesic effect of intrathecal gabapentin therapy on secondary hyperalgesia in a rat model of persistent muscle pain. METHODS: Intrathecal catheters were implanted into rats. Mechanical secondary hyperalgesia was induced by repeated intramuscular injections of acidic solution into the gastrocnemius muscle. Gabapentin was administrated intrathecally. Rats were allocated to control and experimental (gabapentin 30, 100, 300, and 1,000 microg) group. After gabapentin administration, mechanical withdrawal threshold was measured every 15 minutes and the motor function was measured 30 minutes later. RESULTS: Mechanical hyperalgesia was evoked after the second acidic buffer injection. There was a significant improvement on the mechanical threshold after administration of 100, 300, and 1,000 microg gabapentin compared to pre-injection and the control group. The analgesic effect continued for 105, 135, and 210 minutes, respectively. To discern side effects, motor function was measured. Motor function was preserved in both groups after gabapentin administration, except for rats who received 1,000 microg gabapentin. CONCLUSION: Intrathecal gabapentin administration produces dose-dependent improvements in mechanical hyperalgesia in a persistent muscle pain rat model. This implicates the central nervous system as having a strong influence on the development of persistent mechanical hyperalgesia. These results are helpful in understanding the pathophysiology of secondary hyperalgesia and in the treatment of patients with chronic muscle pain.

The Relationship between Emotional Working Hour and Muscle Pain / 한국직업건강간호학회지

PURPOSE: The purpose of this study was to investigate muscle pains of emotional laborers and determine whether there were differences in their muscle pains depending on the hours spent on emotional labor. METHODS: This is a secondary analysis of the data collected from the 3rd (2011) Korean Working Conditions Survey. 50,032 participants responded to the study's questionnaire. Among them, 15,669 participants were emotional laborers who directly dealt with people such as customers, passengers, pupils, patients, etc. RESULTS: Thirty three percent of subjects had reported muscle pains. Muscle pains of subjects were positively related to the hours spent on emotional labor (p<.001). According to the logistic regression analysis, the adjusted odd ratio of the subjects who spent about almost all of the work hours on emotional labor was 1.32 (95% CI: 1.15~1.52), compared to the subjects who spent about a quarter of their work hours on emotional labor, when other factors were controlled. CONCLUSION: The study's findings indicate that engaging in emotional labor for longer hours increases the risks of muscle pains. Occupational nurses must pay closer attention to the management of muscle pains of emotional laborers.

Temperomandibular Disorders - Orthodontics- Cause Or Cure - A Review.

There is a long time debate whether orthodontic treatment is the cause of Temperomandibular joint disorders ( TMD) or it is used to alleviate the symptoms associated with these disorders such as clicking joints, Muscular pains etc. This paper reviews different aspects of Temperomandibular disorders in relation to orthodontic treatment.

An Outbreak of Trichinosis with Molecular Identification of Trichinella sp. in Vietnam

The 5th outbreak of trichinosis occurred in a mountainous area of North Vietnam in 2012, involving 24 patients among 27 people who consumed raw pork together. Six of these patients visited several hospitals in Hanoi for treatment. Similar clinical symptoms appeared in these patients within 5-8 days after eating infected raw pork, which consisted of fever, muscle pain, difficult moving, edema, difficult swallowing, and difficult breathing. ELISA revealed all (6/6) positive reactions against Trichinella spiralis antigen and all cases showed positive biopsy results for Trichinella sp. larvae in the muscle. The larvae detected in the patients were identified as T. spiralis (Vietnamese strain) by the molecular analysis of the mitochondrial cytochrome c oxidase subunit III (cox3) gene.

Effects of 10 Hz Repetitive Transcranial Magnetic Stimulationin Acute Human Muscle Pain Model

OBJECTIVE: To investigate the analgesic effect of high frequency repetitive transcranial magnetic stimulation (rTMS) on the experimental human muscle pain and its underlying mechanism. METHOD: Twenty healthy Korean volunteers participated in this study. The acute muscle pain was induced by infusion of hypertonic saline (5%) into the left extensor carpi radialis longus (ECRL) muscle. During the hypertonic saline injection, 10 Hz rTMS were applied on the hot spot of left ECRL. The changes of visual analogue scale (VAS) of muscle pain and motor evoked potential (MEP) were measured from the start of saline injection to 70 minutes after the start of stimulation. At 90 minutes after the first stimulation, the subjects completed the Korean version of the McGill Pain Questionnaire (MPQ). The sham stimulation was applied with the same method as rTMS experiment. RESULTS: In rTMS, the VAS of muscle pain was significantly decreased from 2.5 minutes and continued until 3 minutes after the last rTMS. While the amplitude of MEP was significantly increased, the latency of MEP was significantly decreased after the start of rTMS and the effect on MEP continued until 5 minutes after the last rTMS. The quality of pain experiment by rTMS and sham stimulation showed no difference in MPQ. CONCLUSION: The present results suggested that 10 Hz rTMS over primary motor cortex decreased the perception of muscle pain and increased the excitability of corticospinal pathway.

Antinociceptive Effect of Botulinum Toxin A in Persistent Muscle Pain Rat Model

OBJECTIVE: To investigate the effects of botulinum toxin on the mechanical hyperalgesia, electrophysiology and motor functions in the persistent muscle pain rat model. METHOD: A secondary mechanical hyperalgesia in the bilateral hindpaws of Sprague-Dawley rats was produced by the repeated injections of acidic saline into gastrocnemius. Botulinum toxin A (BTX-A(4): 4 U/kg, BTX-A(7): 7 U/kg) was administrated into same muscle 24 hours after a second injection of saline. The mechanical hyperalgesia was measured with withdrawal threshold to von Frey filament. The grade of muscle paralysis was evaluated with electrophysiology and the locomotor performance using inclined plane board. RESULTS: The mechanical hyperalgesia was significantly decreased from 5 days to 2 weeks in BTX-A(7) group in the injected side. The dose-dependent decreased amplitude of compound muscle action potential and reduced prevalence of endplate noise from the first day of botulinum toxin injection lasted for 4 weeks in both gastrocnemius. The maximum angle maintained at initial position on the inclined plane board did not change. CONCLUSION: Local muscular injection of botulinum toxin A reduced ipsilateral hyperalgesia dose-dependently in persistent muscle pain rat model without motor deficit. The antinociceptive mechanism of botulinum toxin might act at a local or peripheral rather than a systemic or central effect due to ineffectiveness of contralateral hyperalgesia. Clinically, botulinum toxin A might be useful for the treatment of local and referred pain of muscle origins.

Effectiveness of the Royal Thai traditional massage for relief of muscle pain.

Objective: To determine the effectiveness of Thai traditional massage for muscle pain relief. Methods: Adults with muscle pain in the neck and/or shoulder and/or back without organic causes that needed specific treatment who attended the Ayuraved Clinic during April to May 2004 received royal Thai traditional massage performed by experienced personnel. An effectiveness of royal Thai traditional massage was determined by pain relief assessed by visual analog scale Results: There were 115 participants; 88 (76.5%) were females. The mean age of the participants was 47.9 years; 45.2% of them had shoulder pain, 40.9% back pain and 26.1% neck pain. The median duration of the symptom was 4 months. The mean pain scores of the participants before and after the royal Thai traditional massage were 7.0 and 3.2, respectively (p<0.001). The participants who had a pain score < 3 before and after the royal Thai traditional massage were 3.5% and 79.1%, respectively (p<0.001). Adverse effects of the massage were not observed. Conclusion: Royal Thai traditional massage is probably effective in relieving muscle pain of the neck, shoulder and back.

EFFECT OF EXPERIMENTAL MUSCLE PAIN INDUCED BY INTRAMUSCULAR INJECTION OF HYPERTONIC SALINE ON MUSCLE FATIGUE DURING SUSTAINED MAXIMAL VOLUNTARY CONTRACTION / 体力科学

It has recently demonstrated that central fatigue during sustained maximal voluntary contraction (MVC) progresses faster in the presence of delayed onset muscle soreness due to eccentric contractions than in normal states (Endoh et al., 2005). However, it remains to be clarified whether these findings are related to muscle damage or muscle pain induced by eccentric contractions. The present study investigated which factor plays a more critical role in the earlier onset of central fatigue during sustained MVC with muscle pain induced by injecting hypertonic saline. Ten healthy male right-handed subjects (age, 21~32 yrs.) were asked to perform brief MVCs (~3 sec) before and after injection of isotonic saline (0.9%, 1.0 ml, ISO) or hypertonic saline (5.25%, 1.0 ml, HYP) into the left biceps brachii. The subjects then performed 1 min MVC (fatigue test) with isometric elbow flexion was done in ISO or HYP condition or intact control condition (CON). During these contractions, transcranial magnetic stimulation was delivered to the contralateral motor cortex to evaluate voluntary activation (VA), the motor evoked potential (MEP) and electromyographic (EMG) silent period (SP). Ratio of root mean square of the EMG and elbow flexion force (EMGrms/F) was also measured.The peak pain induced by the injection of HYP was significantly higher than that of ISO (p<0.01). There was no significant difference in either the maximum size of the M response or the twitch force between ISO and HYP (p>0.05). However, during the brief MVCs, both maximal force (p<0.01) and VA (p<0.05) for HYP were significantly decreased compared to those for ISO. During the fatigue test, although MVC, VA, MEP and SP were significantly altered (p<0.05~0.01), there was no significant difference among CON, ISO and HYP (p>0.05). There was no significant difference in EMGrms during the fatigue test (p>0.05).These results suggest that peripheral force-producing capacity remained intact after the injection of ISO and HYP during sustained MVC, and that progression of central fatigue during sustained MVC was less affected by the increased group III and IV afferent activity induced by HYP.