Luis Mochizuki

NEUROMUSCULAR ACTIVITY DURING BENCH PRESS EXERCISE PERFORMED WITH AND WITHOUT THE PREEXHAUSTION METHOD

Brennecke, A, Guimarães, TM, Leone, R, Cadarci, M, Mochizuki, L, Simão, R, Amadio, AC, and Serrão, J. Neuromuscular activity during bench press exercise performed with and without the preexhaustion method. J Strength Cond Res 23(7): 1933-1940, 2009-The purpose of the present study was to investigate the effects of exercise order on the tonic and phasic characteristics of upper-body muscle activity during bench press exercise in trained subjects. The preexhaustion method involves working a muscle or a muscle group combining a single-joint exercise immediately followed by a multi-joint exercise (e.g., flying exercise followed by bench press exercise). Twelve subjects performed 1 set of bench press exercises with and without the preexhaustion method following 2 protocols (P1-flying before bench press; P2-bench press). Both exercises were performed at a load of 10 repetition maximum (10RM). Electromyography (EMG) sampled at 1 kHz was recorded from the pectoralis major (PM), anterior deltoid (DA), and triceps brachii (TB). Kinematic data (60 Hz) were synchronized to define upward and downward phases of exercise. No significant (p > 0.05) changes were seen in tonic control of PM and DA muscles between P1 and P2. However, TB tonic aspect of neurophysiologic behavior of motor units was significantly higher (p < 0.05) during P1. Moreover, phasic control of PM, DA, and TB muscles were not affected (p > 0.05). The kinematic pattern of movement changed as a result of muscular weakness in P1. Angular velocity of the right shoulder performed during the upward phase of the bench press exercise was significantly slower (p < 0.05) during P1. Our results suggest that the strategies set by the central nervous system to provide the performance required by the exercise are held constant throughout the exercise, but the tonic aspects of the central drive are increased so as to adapt to the progressive occurrence of the neuromuscular fatigue. Changes in tonic control as a result of the muscular weakness and fatigue can cause changes in movement techniques. These changes may be related to limited ability to control mechanical loads and mechanical energy transmission to joints and passive structures.

Anticipatory and compensatory postural adjustments in sitting in children with cerebral palsy

The aim of this study was to examine postural control in children with cerebral palsy performing a bilateral shoulder flexion to grasp a ball from a sitting posture. The participants were 12 typically developing children (control) without cerebral palsy and 12 children with cerebral palsy (CP). We analyzed the effect of ball mass (1 kg and 0.18 kg), postural adjustment (anticipatory, APA, and compensatory, CPA), and groups (control and CP) on the electrical activity of shoulder and trunk muscles with surface electromyography (EMG). Greater mean iEMG was seen in CPA, with heavy ball, and for posterior trunk muscles (p<.05). The children with CP presented the highest EMG and level of co-activation (p<.05). Linear regression indicated a positive relationship between EMG and aging for the control group, whereas that relationship was negative for participants with CP. We suggest that the main postural control strategy in children is based on corrections after the beginning of the movement. The linear relationship between EMG and aging suggests that postural control development is affected by central nervous disease which may lead to an increase in muscle co-activation.

The influence of anthropometric factors on postural balance: the relationship between body composition and posturographic measurements in young adults

OBJECTIVE: The aim of the present study was to evaluate the influence of anthropometric characteristics and gender on postural balance in adults. One hundred individuals were examined (50 males, 50 females; age range 20-40 years). METHODS: The following body composition measurements were collected (using bone densitometry measurements): fat percentage (% fat), tissue (g), fat (g), lean mass (g), bone mineral content (g), and bone mineral density (g/cm2). In addition, the following anthropometric measurements were collected: body mass (kg), height (cm), length of the trunk-cephalic region (cm), length of the lower limbs (cm) and length of the upper limbs (cm). The following indices were calculated: body mass index (kg/m2), waist-hip ratio and the support base (cm2). Also, a postural balance test was performed using posturography variables with open and closed eyes. RESULTS: The analysis revealed poor correlations between postural balance and the anthropometric variables. A multiple linear regression analysis demonstrated that the whole group (female and male) height explained 12% of the medial-lateral displacement, 10% of the speed of oscillation, and 11% of the displacement area. The length of the trunk-cephalic length explained 6% of the displacement in the anteroposterior direction. With eyes closed, the support base and height explained 18% of the medial displacement, and the lateral height explained 10% of the displacement speed and 5% of the scroll area. CONCLUSION: Measured using posturography, the postural balance was only slightly influenced by the anthropometric variables, both with open and closed eyes. Height was the anthropometric variable that most influenced postural balance, both in the whole group and separately for each gender. Postural balance was more influenced by anthropometric factors in males than females.

Biomechanical parameters of gait among transtibial amputees: a review

Rehabilitation for lower-limb amputees needs to focus on restoration of daily functions and independent locomotion. As gait is reestablished, reorganization of the motor pattern takes place in order to optimize the functions of the locomotor system. Biomechanics is a field of study that enables understanding of this reorganization. From such knowledge, appropriate strategies for recovering the autonomy of the means of locomotion can be established. Thus, this paper had the aim of reviewing the current status of the biomechanics of locomotion among unilateral transtibial amputees. To achieve this aim, papers written in English or Portuguese and published up to 2005 were selected from the Cochrane Library, PubMed, Scientific Electronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs) and Dedalus databases. In cases of transtibial amputation, the absence of plantar flexors negatively affects locomotion. Increased absorption and energy generation by the muscles that control the hip joint of the amputated leg can be considered to be the main compensatory strategy developed by unilateral transtibial amputees during gait. Factors associated with the characteristics of the amputation, prosthesis and experimental protocol used directly influence the results.

Relation between the Sensory and Anthropometric Variables in the Quiet Standing Postural Control: Is the Inverted Pendulum Important for the Static Balance Control?

The aim of this study was to evaluate the relation between the sensory and anthropometric variables in the quiet standing. Methods. One hundred individuals (50 men, 50 women; 20–40 years old) participated in this study. For all participants, the body composition (fat tissue, lean mass, bone mineral content, and bone mineral density) and body mass, height, trunk-head length, lower limb length, and upper limb length were measured. The center of pressure was measured during the quiet standing posture, the eyes opened and closed with a force platform. Correlation and regression analysis were run to analyze the relation among body composition, anthropometric data, and postural sway. Results. The correlation analysis showed low relation between postural sway and anthropometric variables. The multiple linear regression analyses showed that the height explained 12% of the mediolateral displacement and 11% of the center of pressure area. The length of the trunk head explained 6% of displacement in the anteroposterior postural sway. During eyes closed condition, the support basis and height explained 18% of mediolateral postural sway. Conclusion. The postural control depends on body composition and dimension. This relation is mediated by the sensory information. The height was the anthropometric variable that most influenced the postural sway.

O preparo bioético na graduação de Fisioterapia

O desenvolvimento da Fisioterapia, aliado as mudancas na educacao e na saude, faz com que a autonomia e os dilemas eticos do fisioterapeuta sejam maiores a cada dia, expandindo seu papel no cuidado do paciente. Para alem do Codigo de Etica, as nocoes de Bioetica sao centrais no preparo de graduandos para os desafios profissionais. Este estudo verificou a capacidade de tomar decisoes eticas de alunos no ultimo ano de Fisioterapia de duas universidades na cidade de Sao Paulo, das quais uma oferece no curriculo a disciplina Bioetica e a outra nao. Cinquenta alunos de cada universidade responderam a um questionario sobre dilemas eticos correspondentes a artigos do Codigo de Etica; cada questao oferecia tres alternativas de resposta: uma bioetica, outra referente ao Codigo e uma nao-etica. As respostas foram analisadas estatisticamente. Os resultados mostraram um bom preparo etico em pouco mais de metade dos alunos das duas universidades, sugerindo que ambas oferecem preparo etico similar aos graduandos, independente da diferenca curricular. No entanto, os alunos da universidade que oferece Bioetica tiveram resultados significantemente melhores nos quesitos referentes a relacao com outros profissionais da saude, sugerindo que essa disciplina oferece melhores condicoes para o relacionamento interprofissional, fator importante tanto na pratica clinica quanto para elevar o status da Fisioterapia.

Análise da atividade eletromiográfica de superfície de pontos gatilhos miofasciais

There are examples of common clinical conditions that clinical signals are related to alterations in muscle tone, including myofascial pain syndrome. OBJECTIVE: to discuss the application of surface EMG to detect effect of miofascial trigger point (MTP) on neuromuscular activity at rest and maximum voluntary contraction of the trapezoid muscle. METHODS: Fifty-six subjects participated in the study and were divided into two groups: Healthy group (n = 28), with subjects who necessarily did not present MTP, and PAIN group (n = 28), with subjects who necessarily had MTP. RESULTS: The EMG signal was significantly higher in the muscle portion containing MTP than in the healthy muscle portion in PAIN group and than Healthy group (26,56 ± 44,54, 5,39 ± 6,29 and 1,56 ± 0,76, respectively, p = 0,0001) during rest. In addition, a higher intensity of the EMG signal was observed in subjects with active MTP than in latent MTP (17,85 ± 30,25 versus 3,74 ± 1,52, p = 0,04. Besides, the subjects who presented autonomic phenomena had higher EMG signal than those who had no autonomic phenomena (16,78 ± 28,44 versus 3,51 ± 3,65. CONCLUSION: The surface EMG is reliable to measure the muscular activity of the MTP, mainly at rest condition.

Application of Pilates principles increases paraspinal muscle activation

OBJECTIVE To analyze the effect of Pilates principles on the EMG activity of abdominal and paraspinal muscles on stable and unstable surfaces. METHODS Surface EMG data about the rectus abdominis (RA), iliocostalis (IL) and lumbar multifidus (MU) of 19 participants were collected while performing three repetitions of a crunch exercise in the following conditions: 1) with no Pilates technique and stable surface (nP + S); 2) with no Pilates technique and unstable surface (nP + U); 3) with Pilates technique and stable surface (P + S); 4) with Pilates and unstable surface (P + U). The EMG Fanalysis was conducted using a custom-made Matlab(®) 10. RESULTS There was no condition effect in the RA iEMG with stable and unstable surfaces (F(1,290) = 0 p = 0.98) and with and without principles (F(1,290) = 1.2 p = 0.27). IL iEMG was higher for the stable surface condition (F(1,290) = 32.3 p < 0.001) with Pilates principles (F(1,290) = 21.9 p < 0.001). The MU iEMG was higher for the stable surface condition with and without Pilates principles (F(1,290) = 84.9 p < 0.001).

Influência da resolução e da distância da câmera nas medidas feitas pelo software de avaliação postural (sapo)

O erro na medida de um sistema de avaliacao da postura esta relacionado com a digitalizacao, a resolucao da câmera, a distância da câmera em relacao ao voluntario estudado, entre outros. Estes erros somam-se no procedimento metodologico e muitos deles nao sao possiveis evitar, porem devem ser conhecidos e quantificados. OBJETIVO: Quantificar o erro na medida realizada pelo SAPO (Software para avaliacao postural) em diferentes situacoes experimentais. METODOS: Foram realizadas 16 fotos de um manequim de 1,40m articulado nos planos anterior, posterior, lateral direita e lateral esquerda com câmeras de 3,2 e 12,0 megapixels, posicionadas a 3,0m e a 5,0m de distância do manequim. Para a quantificacao do erro, foram calculadas as diferencas das medidas obtidas por meio do SAPO com as medidas feitas diretamente no manequim. Apenas um avaliador realizou o registro das imagens, porem a digitalizacao no software dos pontos demarcados no manequim foi realizada por tres digitalizadores, sendo dois inexperientes e um experiente. RESULTADOS: Os valores medios das medidas horizontais, verticais, angulares e de distância sao proximos de zero, embora algumas variaveis angulares apresentem valores maiores, como nas medidas de ângulo Q direito e esquerdo. A câmera com resolucao de 3,2 megapixels posicionada a 3m apresentou o menor erro. CONCLUSAO: O SAPO e um metodo acurado para uso clinico; sao necessarios estudos para verificar a influencia do plano de posicionamento do voluntario em relacao a câmera, o efeito do reposicionamento e da palpacao nas medidas oferecidas pelo software.

Autoregulating Jump Performance to Induce Functional Overreaching

Abstract Claudino, JG, Cronin, JB, Mezêncio, B, Pinho, JP, Pereira, C, Mochizuki, L, Amadio, AC, and Serrão, JC. Autoregulating jump performance to induce functional overreaching. J Strength Cond Res 30(8): 2242–2249, 2016—The purpose of this study was to determine whether autoregulating jump performance using the minimal individual difference (MID) associated with countermovement jump (CMJ) height could be used to regulate and monitor a training phase that elicited functional overreaching and tapering in team sport athletes. The participants were familiarized with the jump and then the CMJ height reliability was quantified to determine the MID. Countermovement jump height was assessed in the pretesting session (T0), at the end of 4 weeks of intensified training (T1), and after 2 weeks of tapering (T2). Eighteen national level U17 male futsal players were randomly allocated into the regulated group (RG; n = 9) and the control group (CG; n = 9). The RG performed 6 weeks of training with the training load regulated by mean height of CMJ with MID, whereas the CG performed the preplanned training. The differences between groups and across time points were compared by a 2-way analysis of variance. In the RG, the MID loading was increased in weeks 3 and 4 (8.2 and 14.5%, respectively; p < 0.001) compared with the preplanned loading of the CG during the overreaching phase. In the jump results, the RG significantly (p ⩽ 0.05) reduced CMJ height during T1 (effect size [ES] = −0.31; 95% confidence interval [CI]: −0.58 to −0.02); however, there were no significant changes in the CG jump height at T1 and T2. At T2, the RG significantly increased CMJ height above baseline (ES = 0.30; 95% CI: 0.09 to 0.51). Researchers and practitioners could use this autoregulating method to regulate and monitor training load to achieve functional overreaching in youth futsal players.