Prevalence and factors associated with injuries in recreational runners: a cross-sectional study / Prevalência e fatores associados às lesões em corredores amadores: um estudo transversal / Prevalencia y factores asociados a lesiones en corredores aficionados: un estudio transversal

ABSTRACT Introduction The increased number of people who choose running as a form of exercise has been associated with a higher prevalence of musculoskeletal injuries. Objectives To determine the prevalence and the factors that could be correlated with injuries among amateur runners in Recife, in the State of Pernambuco (PE), Brazil. Methods An observational, cross-sectional study, in which 300 (three hundred) amateur runners answered a social demographic questionnaire, as well as questions about training characteristics, footstrike and landing pattern, and history of running injuries. The data were analyzed by descriptive statistics, the student-t test to compare means, and the Chi-squared to compare prevalences. Results The prevalence of injuries amongst runners in Recife-PE was 58.5% (n= 175), the knee being the most commonly injured site (37.3%). In both groups - runners with and without injuries - there was a higher number of male runners, with 72.4% and 72.6% respectively. There was no difference in relation to the weekly frequency of running between the groups (p<0.63). However, runners with a history of injuries ran around 7 kmh a week more than the runners without injuries (p<0.03). A neutral footstrike (F=0.87; p=0.99) and hindfoot landing (F=4.13; p=0.90) were the most reported running patterns in both groups. It was found that wear was the main criterion used for changing running shoes in both groups (F = 8.35, p = 0.4). Conclusion There was a high prevalence of musculoskeletal injuries among amateur runners in Recife-PE. Among the factors associated with the injuries, one variable was significant: a higher weekly volume of training. Level of evidence II; Study type: Cross-sectional study.

RESUMO Introdução O evidente aumento do número de pessoas que escolhem a corrida como forma de exercitar o corpo tem sido associado à maior prevalência de lesões musculoesqueléticas. Objetivos Verificar a prevalência e os fatores que possam estar associados às lesões em corredores amadores da cidade de Recife-PE. Métodos Estudo observacional do tipo transversal, no qual 300 corredores amadores responderam a um questionário sociodemográfico, além de questões sobre características do treinamento, tipo de pisada e aterrissagem e histórico de lesões relacionadas à corrida. Os dados foram analisados pela estatística descritiva; para a comparação entre médias, foi usado o Teste t de Student e para a comparação de prevalências, o teste do qui-quadrado. Resultados A prevalência de lesões em corredores amadores de Recife-PE foi de 58,5% (n = 175), sendo o joelho a região mais acometida (37,3%). Nos grupos corredores com lesão e sem lesão, a maioria dos participantes era do sexo masculino, respectivamente, 72,4% e 72,6%. Não houve diferença quanto à frequência semanal de treinamento entre os grupos (p < 0,63). Ao contrário, os corredores com histórico de lesão treinaram em média 7 quilômetros/semana a mais do que os corredores sem lesões (p < 0,03). O tipo de pisada neutra (F = 0,87; p = 0,99) e a aterrissagem com retropé (F = 4,13; p = 0,90) foram os mais referidos pelos corredores em ambos os grupos. Foi verificado que o desgaste foi o principal critério utilizado para trocar de tênis em ambos os grupos (F = 8,35; p = 0,4). Conclusões Houve alta prevalência de lesões musculoesqueléticas em corredores amadores de Recife-PE. Entre os fatores associados às lesões, uma variável mostrou-se significante: maior volume de treino semanal. Nível de Evidência: II; Tipo de Estudo: Transversal.

RESUMEN Introducción El evidente aumento en el número de personas que eligen la carrera como forma de ejercitar el cuerpo ha sido asociado con una mayor prevalencia de lesiones musculoesqueléticas. Objetivos Verificar la prevalencia y los factores que pueden estar asociados con lesiones en corredores aficionados en la ciudad de Recife-PE. Métodos Estudio transversal observacional, en el que 300 corredores aficionados respondieron un cuestionario sociodemográfico, además de cuestiones sobre características del entrenamiento, tipo de pisada y aterrizaje e historial de lesiones relacionadas con la carrera. Los datos se analizaron mediante estadística descriptiva; para la comparación entre promedios, se utilizó el test t de Student y para la comparación de prevalencia, la prueba de chi-cuadrado. Resultados La prevalencia de lesiones en corredores aficionados en Recife-PE fue de 58,5% (n = 175), siendo la rodilla la región más afectada (37,3%). En los grupos de corredores lesionados y no lesionados, la mayoría de los participantes eran del sexo masculino, respectivamente, 72,4% y 72,6%. No hubo diferencias con respecto a la frecuencia de entrenamiento semanal entre los grupos (p < 0,63). Por el contrario, los corredores con historial de lesiones entrenaron un promedio de 7 kilómetros/semana más que los corredores sin lesiones (p < 0,03). El tipo de pisada neutra (F = 0,87; p = 0,99) y el aterrizaje con retropié (F = 4,13; p = 0,90) fueron los más indicados por los corredores en ambos grupos. Se encontró que el desgaste fue el principal criterio utilizado para cambiar de zapatillas en ambos grupos (F = 8,35, p = 0,4). Conclusiones Hubo una alta prevalencia de lesiones musculoesqueléticas en corredores aficionados en Recife-PE. Entre los factores asociados con las lesiones, se encontró una variable significativa: el mayor volumen de entrenamiento semanal. Nivel de evidencia II; Tipo de Estudio: Transversal.

Short-term transcutaneous electrical nerve stimulation reduces pain and improves the masticatory muscle activity in temporomandibular disorder patients: a randomized controlled trial

Abstract Studies to assess the effects of therapies on pain and masticatory muscle function are scarce. Objective To investigate the short-term effect of transcutaneous electrical nerve stimulation (TENS) by examining pain intensity, pressure pain threshold (PPT) and electromyography (EMG) activity in patients with temporomandibular disorder (TMD). Material and Methods Forty patients with myofascial TMD were enrolled in this randomized placebo-controlled trial and were divided into two groups: active (n=20) and placebo (n=20) TENS. Outcome variables assessed at baseline (T0), immediately after (T2) and 48 hours after treatment (T1) were: pain intensity with the aid of a visual analogue scale (VAS); PPT of masticatory and cervical structures; EMG activity during mandibular rest position (MR), maximal voluntary contraction (MVC) and habitual chewing (HC). Two-way ANOVA for repeated measures was applied to the data and the significance level was set at 5%. Results There was a decrease in the VAS values at T1 and T2 when compared with T0 values in the active TENS group (p<0.050). The PPT between-group differences were significant at T1 assessment of the anterior temporalis and sternocleidomastoid (SCM) and T2 for the masseter and the SCM (p<0.050). A significant EMG activity reduction of the masseter and anterior temporalis was presented in the active TENS during MR at T1 assessment when compared with T0 (p<0.050). The EMG activity of the anterior temporalis was significantly higher in the active TENS during MVC at T1 and T2 when compared with placebo (p<0.050). The EMG activity of the masseter and anterior temporalis muscle was significantly higher in the active TENS during HC at T1 when compared with placebo (p<0.050). Conclusions The short-term therapeutic effects of TENS are superior to those of the placebo, because of reported facial pain, deep pain sensitivity and masticatory muscle EMG activity improvement.

Electromyography and asymmetry index of masticatory muscles in undergraduate students with temporomandibular disorders

Aim: To compare the electromyographic activity and the asymmetry index among degrees of severity of temporomandibular disorders (TMD). Methods: Surface electromyography (EMG) of the right and left masseter and temporalis muscles was performed in 126 undergraduate students at rest and at maximal voluntary contraction. Three measurements were performed for five seconds of maximal contraction and mandibular rest. The degree of temporomandibular dysfunction was identified according to the Fonseca anamnestic index. The analysis of the asymmetry index for two pairs of muscles during maximal voluntary contraction was based on the asymmetry index proposed by Naeije, McCarrol and Weijs (1989). Results: 48.41% of the sample had mild TMD, followed by volunteers without TMD (26.98%), moderate TMD (19.05%) and severe (5.56%). The survey results show absence of correlation between the Fonseca anamnestic index and electromyographic activity at rest and at maximal voluntary contraction in undergraduate students in both muscles (p>0.05) and the asymmetry index did not differ between the analyzed groups. Conclusions: For the population of undergraduate students, there is no evidence that the presence and severity of TMD influence the EMG activity of masseter and temporalis muscles and the muscle asymmetry index at rest and maximal voluntary contraction.