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BACKGROUND: Increased foot pronation during walking has been associated with low back pain. This association may be due to the impact of increased pronation on pelvic motion. OBJECTIVE: To investigate the effects of increased bilateral foot pronation on pelvic kinematic in frontal and transverse planes during the loading response phase of gait. METHODS: Pelvic, hip, and foot angular positions of 20 participants were collected while they walked at fast speed wearing flat and medially inclined insoles inserted in the shoes. Pelvic motion in frontal and transverse planes was analyzed during the loading response phase. Foot eversion-inversion was analyzed during the complete stance phase to verify the insoles effectiveness in inducing increased pronation and to exclude excessive pronators. RESULTS: Inclined insoles were effective in inducing increased foot pronation. Pelvic and hip motion were altered in the increased pronation condition compared to the control condition. In the frontal plane, mean pelvic position was more inclined to the contralateral side (mean difference [MD]: 0.54°; 95%CI: 0.23, 0.86) and its range of motion (ROM) was reduced (MD: 0.50°; 95%CI: 0.20, 0.79). In the transverse plane, mean pelvic position was less rotated toward the contralateral leg (MD: 1.03°; 95%CI: 0.65, 1.60) without changes in ROM (MD: 0.04°; 95%CI: -0.17, 0.25). The hip was more internally rotated (MD: 1.37°; 95%CI: 0.76, 1.98) without changes in ROM (MD: 0.10°; 95%CI: -1.02, 1.23). CONCLUSION: Increased bilateral foot pronation changes pelvic motion during walking and should be assessed, as a contributing factor to possible pelvic and lower back disorders.

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BACKGROUND: Gait speed and metabolic cost are indicators of functional capacity in children with cerebral palsy. Uncovering their mechanisms helps guide therapeutic actions. OBJECTIVES: To investigate the contributions of energy-generating and energy-conserving mechanisms to gait speed and metabolic cost of children with unilateral cerebral palsy. METHODS: Data on eccentric and concentric muscle work, co-contraction, elastic torque and vertical stiffness of the affected-limb, forcing torque of the non-affected limb, gait speed and metabolic cost were collected from 14 children with unilateral cerebral palsy, aged 6-12 years. Analyses included two groups of multiple regression models. The first group of models tested the association between each dependent variable (i.e., speed and metabolic cost) and the independent variables that met the input criteria. The second group verified the contribution of the non-selected biomechanical variables on the predictors of the first model. RESULTS: Gait speed (R2=0.80) was predicted by elastic torque (ß=0.62; 95%CI: 0.60, 0.63), vertical stiffness (ß=-0.477; 95%CI: -0.479, -0.474) and knee co-contraction (ß=0.27; 95%CI: -1.96, 2.49). The production of eccentric work by the affected limb proved relevant in adjusting the vertical stiffness (R2=0.42; ß=-0.64; 95%CI: 0.86, -0.42); elastic torque of the affected-leg was associated with impulsive torque of the non-affected leg (R2=0.31; ß=0.55; 95%CI: 0.46, 0.64). Metabolic cost of gait (R2=0.48) was partially predicted by knee co-contraction (ß=0.69; 95%CI: 0.685, 0.694). CONCLUSIONS: The chain of associations revealed by the two steps models helped uncover the mechanisms involved in the locomotion of children with unilateral cerebral palsy. Intervention that changes specific energy conserving and generating mechanisms may improve gait of these children.

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There are extensive connections between the latissimus dorsi (LD) and gluteus maximus (GMax) muscles and the thoracolumbar fascia (TLF), which suggests a possible pathway for myofascial force transmission. The present study was designed to provide empirical evidence of myofascial force transmission from LD to contralateral GMax through TFL in vivo. To accomplish this goal, we evaluated whether active or passive tensioning of the LD results in increased passive tension of the contralateral GMax, indexed by changes in the hip resting position (RP) or passive stiffness. The hip RP was defined as the angular position in which the passive joint torque equals zero, and passive hip stiffness was calculated as the change in passive torque per change in joint angle. Thirty-seven subjects underwent an assessment of their passive hip torque against medial rotation by means of an isokinetic dynamometer. These measures were carried out under three test conditions: (1) control, (2) passive LD tensioning and (3) active LD tensioning. Electromyography was used to monitor the activity of the hip muscles and the LD under all conditions. Repeated measures analyses of variance demonstrated that passive LD tensioning shifted the hip RP towards lateral rotation (p=0.009) but did not change the passive hip stiffness (p>0.05). Active LD tensioning shifted the hip RP towards lateral rotation (p<0.001) and increased the passive hip stiffness (p≤0.004). The results demonstrated that manipulation of the LD tension modified the passive hip variables, providing evidence of myofascial force transmission in vivo.

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A eletromiografia (EMG) é uma técnica que permite o registro dos sinais elétricos gerados pelas células musculares, possibilitando a análise da atividade muscular durante o movimento. A compreensão de conceitos relativos a EMG é essencial para se assegurar a validade e confiabilidade desse instrumento de mensuração em pesquisas da área de reabilitação e na prática clínica de fisioterapeutas. Dessa forma, foi objetivo deste estudo discutir aspectos relevantes relacionados à coleta, processamento e análise de dados eletromiográficos de forma a facilitar a compreensão da instrumentação, aplicações e limitações da técnica. De acordo com a revisão realizada, diversos fatores que influenciam a qualidade dos dados coletados devem ser considerados, não apenas na utilização da técnica, mas também na interpretação e avaliação crítica de estudos que utilizam a EMG. Quando todos estes fatores são considerados, a EMG se torna uma ferramenta adequada para investigação da função muscular, tanto na pesquisa quanto na prática clínica de fisioterapeutas.

Electromyography (EMG) is a procedure used to register the electrical activity generated by muscle cells, allowing the analysis of muscle activity during movement. The comprehension of concepts relative to EMG is essential to assure the validity and reliability of this instrument in rehabilitation research and clinical practice of physiotherapists. Therefore, the objective of this study was to discuss relevant aspects related to the acquisition, processing and analysis of electromyographic data in order to assist the comprehension of the instrumentation, applications and limitations of the technique. According to the literature review, several factors that can influence the quality of the data collected should be considered not only for the utilization of the technique but also for the interpretation and critical appraisal of studies that use EMG. Provided that all this factors are considered, EMG is an adequate instrument for the investigation of muscle function either in research or in clinical practice of physical therapists.

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