Ajustes cinemáticos do complexo articular do tornozelo sobre diferentes superfícies instáveis / Kinematic adjustments of the ankle joint complex on different unstable surfaces

INTRODUÇÃO: Poucos estudos discutem as reações corporais de indivíduos saudáveis no momento em que os exercícios em superfícies instáveis estão sendo executados, embora os efeitos do treinamento ­ efeitos crônicos do exercício- sejam bastante estudados. OBJETIVO: Descrever a cinemática articular do tornozelo e retropé durante essa interação. MÉTODOS: Dezoito voluntários participaram do estudo. A posição articular da região do tornozelo foi estudada em três superfícies: Airex® Balance-pad, BOSU® e chão (controle). Para análise estatística, utilizou-se ANOVA e Pós-teste de Tuckey, considerando um nível de significância menor que 0,05. RESULTADOS: A posição articular da região tornozelo no plano sagital foi diferente no BOSU® em relação ao Airex® (p < 0.001) e ao chão (p < 0.001). O tornozelo ficou em posição mais próxima à neutra no AIREX® e no chão. Com o BOSU, a dorsiflexão foi acentuada. Não houve diferença da posição média no no plano frontal. A variabilidade da posição da região do tornozelo foi maior no BOSU® que no Airex® (p < 0.001) e no chão (p < 0.001), tanto no plano sagital, quanto no plano frontal. A frequência média de deslocamento da posição articular na região do tornozelo no plano sagital foi maior no BOSU® que no chão (p < 0.001); e no plano frontal, para o retropé, foi maior no BOSU® que no Airex® (p < 0.001) e chão (p < 0.001). CONCLUSÃO: Houve diferença no comportamento articular da região do tornozelo na condição BOSU® em relação às demais nas superfícies utilizadas, havendo um aumento das oscilações articulares no processo de controle postural em condições mais instáveis e maior dosiflexão no BOSU®. [AU]

INTRODUCTION: There are few studies approaching the bodily reactions of healthy individuals while performing exercises on unstable surfaces, although the training effects ­ exercise chronic effects - are well studied. OBJECTIVE: The goal of this study is to describe the ankle and rear foot region osteoarticular kinematic during this interaction. METHODS: Eighteen volunteers participated in the study. The ankle region osteoarticular displacement was studied in three different surfaces: AIREX® Balance-pad, BOSU® and Ground (control). Statistical analysis was performed using ANOVA and Tukey test, considering a significance level of 0.05. RESULTS: The position of the ankle joint in the sagittal plane was greater in the BOSU® than in the AIREX® (p < 0.001) and ground (p < 0.001). The ankle was close to the neutral position in the AIREX® and on the ground. With BOSU, the dorsiflexion was accentuated. Considering the frontal plane, there was no difference in the rear foot position. Moreover, the variability in the ankle region position in sagittal and frontal planes was higher in BOSU® than AIREX® (p < 0.001) and ground (p < 0.001). The mean frequency of the ankle position in the sagittal plane was greater in the BOSU® than on the ground (p < 0.001), and, in frontal plane, the rear foot frequency displacement was largest in the BOSU® than in the AIREX® (p < 0.001) and on the ground (p < 0.001). CONCLUSION: There were observed differences in ankle region postural control strategies in the BOSU® condition when compared with the other surfaces tested. The ankle and rear foot oscillations increase and there is a greater dorsiflexion for the postural control under the most unstable condition - BOSU. [AU]

30o inclination in handles of plastic boxes can reduce postural and muscular workload during handling

BACKGROUND: The handling of materials, which occurs in the industrial sector, is associated with lesions on the lumbar spine and in the upper limbs. Inserting handles in industrial boxes is a way to reduce work-related risks. Although the position and angle of the handles are significant factors in comfort and safety during handling, these factors have rarely been studied objectively. OBJECTIVE: To compare the handling of a commercial box and prototypes with handles and to evaluate the effects on upper limb posture, muscle electrical activity, and perceived acceptability using different grips while handling materials from different heights. METHOD: Thirty-seven healthy volunteers evaluated the handles of prototypes that allowed for changes in position (top and bottom) and angle (0°, 15°, and 30°). Wrist, elbow, and shoulder movements were evaluated using electrogoniometry and inclinometry. The muscle electrical activity in the wrist extensors, biceps brachii, and the upper portion of the trapezius was measured using a portable electromyographer. The recorded data on muscle movements and electrical activity were synchronized. Subjective evaluations of acceptability were evaluated using a visual analog scale. RESULTS AND CONCLUSIONS: The prototypes with handles at a 30° angle produced the highest acceptability ratings, more neutral wrist positions, lower levels of electromyographic activity for the upper trapezius, and lower elevation angles for the arms. The different measurement methods were complementary in evaluating the upper limbs during handling. .