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OBJECTIVE: The purpose of this study was to compare the electromyographic pattern of core muscles during intermediate Pilates mat exercises between healthy people and those with low back pain. METHODS: We evaluated healthy participants (n = 19; mean ± standard deviation [SD]: age 28 ± 8 years, body mass 65 ± 10 kg, height 160.0 ± 9.1 cm) and a low back pain group (n = 13; mean ± SD: age 30 ± 9 years, body mass 67 ± 12 kg, height 170.0 ± 6.6 cm). Electromyographic analysis assessed the multifidus, external oblique, internal oblique, and rectus abdominis muscles during classical Pilates exercises (single leg stretch, criss-cross, and dead bug). We calculated the root mean square normalized by maximum voluntary contraction, and the time of peak activation was provided by a linear envelope and normalized by the total movement cycle. RESULTS: The criss-cross exercise presented the highest values of root mean square for trunk flexors (rectus abdominis and oblique) compared with the other exercises, followed by the single leg stretch and the dead bug, which had similar muscle activation. The single leg stretch presented more activation of the rectus abdominis and oblique, whereas the criss-cross and dead bug created more activation of the oblique compared with the multifidus and rectus. CONCLUSIONS: The Pilates exercises presented different muscle recruitment patterns, and allowed the activation of the lumbopelvic stabilizing muscles even in the first session for healthy individuals and those with chronic low back pain.

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OBJECTIVES: To investigate the relationships between the perception of comfort and biomechanical parameters (plantar pressure and ground reaction force) during running with four different types of cushioning technology in running shoes. DESIGN: Randomized repeated measures. METHODS: Twenty-two men, recreational runners (18-45 years) ran 12km/h with running shoes with four different cushioning systems. Outcome measures included nine items related to perception of comfort and 12 biomechanical measures related to the ground reaction forces and plantar pressures. Repeated measure ANOVAs, Pearson correlation coefficients, and step-wise multiple regression analyses were employed (p≤0.05). RESULTS: No significant correlations were found between the perception of comfort and the biomechanical parameters for the four types of investigated shoes. Regression analysis revealed that 56% of the perceived general comfort can be explained by the variables push-off rate and pressure integral over the forefoot (p=0.015) and that 33% of the perception of comfort over the forefoot can be explained by second peak force and push-off rate (p=0.016). CONCLUSIONS: The results did not demonstrate significant relationships between the perception of comfort and the biomechanical parameters for the three types of shoes investigated (Gel, Air, and ethylene-vinyl acetate). Only the shoe with Adiprene+ technology had its general comfort and cushioning perception predicted by the loads over the forefoot. Thus, in general, one cannot predict the perception of comfort of a running shoe through impact and plantar pressure received.

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This study compares surface electromyographic activity of the internal oblique, rectus abdominis, multifidus, iliocostalis, anterior deltoids during the pull-up on a lower and on a higher difficulty level. We assessed nine adults with previous experience in Pilates. The root mean square (RMS) values were normalized by maximum isometric contraction for each participant. During the ascent phase, the low spring position showed a significantly higher RMS than the high spring position of 8.9% for deltoid, 17.2% for internal oblique, 22.3% for rectus abdominis, 4.1% for iliocostalis, and 5.6% for multifidus, and in the descent phase, the RMS in the lower spring exceeded significantly the high spring position in 1.6% for the deltoid, 10% for internal oblique, 31.4% for rectus abdominis and 11.4% for iliocostalis. There was no predominance of abdominal muscles over the shoulder muscle in any spring position. The pull-up exercise can be a useful choice for the core and anterior deltoid muscles strengthening...

Este estudo compara a atividade eletromiográfica de superfície dos músculos oblíquo interno, reto abdominal, multífidos, iliocostal e deltóide anterior durante o pull-up em dois níveis de dificuldade (mola alta e mola baixa). Foram avaliadas nove adultos com experiência anterior em Pilates. Os valores RMS foram normalizados pela contração isométrica máxima. Durante a fase de subida, a posição de mola baixa mostrou RMS significativamente maiores em relação a alta de 8,9% para deltóide, 17,2% para o oblíquo interno, 22,3% para o reto abdominal, 4,1% para iliocostal, e 5,6% para o multífido, e na fase de descida, em 1,6% para o deltóide, 10% para oblíquo interno, 31,4% para o reto abdominal e 11,4% para o iliocostal. Não houve predomínio dos músculos abdominais sob o músculo do ombro em qualquer posição de mola. O exercício de pull-up pode ser ferramenta útil para o fortalecimento da musculatura do core e do músculo deltóide anterior...

Este estudio compara la EMG superficial de los músculos recto del abdomen, oblicuo interno, multifidos, ilio-costal y deltoides anterior durante el ejercicio pull-up en dos niveles de dificultad. Se evaluaron a nueve adultos experimentados en Pilates. Los valores de RMS se normalizaron por la contracción isométrica máxima. Durante la fase de ascenso, la posición baja del resorte mostró valores significativamente majores de RMS que la posición alta de 8,9% para lo deltoides, 17,2% para oblicuo interno, 22,3% para recto abdominal, 4,1% para ilio-costalis, y 5,6% para multifidos. En la fase de descenso, el RMS, en el muelle inferior, excede significativamente la posición alta del resorte en 1,6% para el deltoides, 10% para oblicuo interno, 31,4% para recto abdominal y 11,4% para ilio-costalis. No hubo predominio de los músculos abdominales bajo los deltoides anteriores. Pull-up puede ser una herramienta útil para el trabajo del core y para la fortificación del deltoides anterior...

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