Joint knee loads during squat with constant or variable resistance in males. A clinical trial.

BACKGROUND: In the squat movement, the use of constant resistance (CR) generates greater compression and shear forces close to 90° of knee flexion, increasing joint overload. However, when used variable resistance (VR) there is no consensus about the effect of knee joint load. The aim of this study was to compare knee torques using constant or variable resistance during the squat exercise. METHODS: Twenty-one healthy male subjects (mean age, 24 [SD, 3] years; height, 1.76 [SD, 0.04] m), who practice squats during strength training routine. Were simultaneously record data from the platform force and tridimensional kinematic to obtain torques around knee. 15 repetitions were performed up to maximum knee flexion with the use of variable (RV) or constant (CR) resistance in a single session. RESULTS: Significant differences regarding the angles only in the sagittal plane at the end of the ascending phase of the squat, with less knee extension in the VR condition. In the sagittal and frontal planes, lower values of extensor and abductor torque were found in the VR condition at the angles of greater knee flexion. CONCLUSION: The use of variable resistance compared to constant resistance seems to be an alternative to be considered when the objective is to minimize the internal loads on the knee joint in exercises such as the squat in amplitudes of greater flexion. This study indicated that VR helps subjects who are learning the squat movement, enabling the application of this knowledge in physical therapy or physical training clinics.

Center of pressure position in the touches of the star excursion balance test in healthy individuals.

BACKGROUND: The Star Excursion Balance Test (SEBT) is a clinical test that aims to assess postural control. Its interpretation is related to the understanding of the motor specificities required. Adjustments must be made to the center of pressure (COP) to maintain balance during testing movements. Comprehend the specifics of these adjustments for each direction can allow the development of more suitable exercises for balance training. The aim was to compare the positions of the COP on the different directions of the SEBT and correlate the reachs obtained in the SEBT with the distances from the COP to the borders of the base of support (BOS). METHODS: Sixteen healthy subjects participated in the study. Measurements were made by performing the SEBT over the force platform. The Kruskal-Wallis test followed by Bonferroni's post hoc test was used to compare directions. The Pearson correlation test was used to check the correlation of parametric variables and Spearman correlation test for the nonparametric ones. RESULTS: The position of the COP at the touch differs from the anterior direction to the other directions of the SEBT and the performance in this direction is correlated with the proximity of the COP to the anterior limit of the support base. The performances in the other directions did not correlate with the COP position. CONCLUSION: The requirements of the compensation mechanisms for postural control are different between the directions of the SEBT.

Avaliação do controle postural em praticantes de dança de salão / Evaluation of postural control in practitioners of ballroom dancing

Este estudo teve como objetivo analisar o efeito imediato da prática de dança de salão sobre o controle postural estático de seus praticantes, juntamente aos fatores que possam influenciá-lo. Optou-se por um estudo transversal de caráter observacional quantitativo em uma amostra por conveniência, constituída por 19 homens e 19 mulheres praticantes de dança de salão, que participaram de uma prática de dança de 120 minutos. Foram coletados os dados sociodemográficos, antropométricos e sintomas osteomusculares. Para a avaliação do centro de pressão (COP), foi utilizado uma plataforma de força antes e depois da prática. O único fator que demonstrou diferença significativa no controle postural antes da prática de dança foi o sexo, sendo os homens que apresentam maiores deslocamentos no COP. Comparando o efeito da prática de 120 minutos de dança, em todos os participantes, houve uma diminuição do deslocamento do COP na posição bipodal no COPap (p= 0.028) e COPvel (p= 0.003), na posição unipodal COPvel (p= 0.006) e na posição semi-tandem COPml (p= 0.026). O efeito imediato de uma prática de dança de salão contribui para o controle postural em ambos os sexos. (AU)

This study aimed to analyze the immediate effect of the practice ballroom dancing on the static postural control of its practitioners, along with factors that can influence it. We opted for a cross-sectional study of quantitative observational in a sample of convenience of 19 men and 19 women practitioner's ballroom dancing, who participated in a dance practice about 120 minutes. We collected sociodemographic data, anthropometric and musculoskeletal symptoms. For the evaluation of center of pressure (COP), was used a force platform before and after practice. The only factor that demonstrated a significant association with postural control prior to dance practice was the genre, men show greater displacements at the COP. Comparing the effect of the practice of 120 minutes of dance, in all participants, a decrease in COP displacement in the bipedal position in COPap (p = 0.028) and COPvel (p = 0.003), in the single-leg position COPvel (p = 0.006) and in the semi-tandem position COPml (p = 0.026). The immediate effect of a ballroom practice contributes to postural control in both sexes. (AU)

Influência da hidrocinesioterapia no equilíbrio postural de idosas institucionalizadas / Influence of hydrokinetic therapy in postural balance of institutionalized elderly people

O objetivo deste estudo foi avaliar a influência de um programa de hidrocinesioterapia em piscina rasa no equilíbrio postural de idosas institucionalizadas. Participaram do estudo 8 idosas institucionalizadas com média de idade de 62,95 ± 2,87 anos. O equilíbrio postural foi avaliado por meio de uma plataforma de força. Foram realizadas 3 tentativas em cada condição do teste de organização sensorial (TOS) previamente e posteriormente a intervenção de hidrocinesioterapia em piscina rasa. As variáveis analisadas foram: amplitude de deslocamento do centro de pressão (COP) na direção ântero-posterior, médio-lateral e velocidade de deslocamento do COP. Foi aplicado o teste Wilcoxon para a comparação entre as avaliações pré e pós a intervenção. Foi observada uma melhora no controle postural após a intervenção, visto que ocorreu diminuição do deslocamento do centro de pressão, principalmente na direção ântero-posterior. Para o grupo de idosas institucionalizadas participantes deste estudo, a hidrocinesioterapia realizada em piscina rasa foi capaz de melhorar o equilíbrio postural.

The purpose of the present study was to evaluate the influence that a hydrokinetic therapy program in shallow water has on postural balance of institutionalized elderly women. In this study 8 institutionalized elderly, with a mean age of 62.95 ± 2.87 years participated. The postural balance was evaluated through the force platform. 3 attempts in each sensory organization test (SOT) previously and subsequently the intervention of hydrokinetic therapy in shallow water were made. The variables analyzed were: displacement amplitude of the pressure center (COP) in the anteroposterior, mediolateral direction and displacement speed of the COP. An improvement in postural control after the intervention was observed, where a decrease on the displacement of the pressure center happened, especially in the anteroposterior direction. For the group of institutionalized elderly participants in this study, hydrokinetic therapy performed in shallow water was able to improve postural balance.

Análise do equilíbrio dinâmico de idosas institucionalizadas após hidrocinesioterapia / Analyze of balance before hydrotherapy intervention

OBJETIVO: O presente estudo teve como objetivo avaliar o equilíbrio dinâmico de idosas institucionalizadas pré e pós-intervenção com hidrocinesioterapia. MÉTODO: Para avaliação do equilíbrio foram utilizados dois testes: Escala de Equilíbrio de Berg (EEB) e Performance Oriented Mobility Assessment (POMA). As atividades aquáticas foram realizadas em piscina rasa, uma vez por semana, num total de 15 sessões. Foi aplicado o teste t Student para comparar as avaliações pré e pós-intervenção. RESULTADOS: Observou-se melhora na manutenção do equilíbrio corporal no período após a hidrocinesioterapia de forma estatisticamente significativa nas avaliações dos dois testes propostos (EEB p < 0,01 e POMA p < 0,05). CONCLUSÕES: O programa de hidrocinesioterapia demonstrou ser efetivo para a melhora do equilíbrio dinâmico e diminuição do risco de quedas de idosas institucionalizadas. Sendo assim, é um recurso fisioterapêutico que pode ser recomendado para prevenir quedas desta população.

OBJECTIVE: This study aimed to evaluate the dynamic balance in old women before and after hydrotherapy intervention. METHOD: To assess the balance, two tests were used: the Berg Balance Scale (BBS) and Performance Oriented Mobility Assessment (POMA).The water activities were conducted in shallow water once a week, totaling 15 sessions. The t Student test was applied to compare the previous and after evaluations. RESULTS: A better body balance after the hydrotherapy intervention was observed being statistically significant in both proposed tests (BBS p < 0.01 e POMA p < 0.05). CONCLUSIONS: The hydrotherapy program showed to be effective to the dynamic balance and reducing the risk of falls in older women. Therefore, it is a physiotherapy resource which can be recommended to prevent falls of these people.

Effect of low back pain on postural stability in younger women: influence of visual deprivation.

SUMMARY: This study investigated the effect of low back pain (LBP) on body balance during normal and visual deprivation during standing in a LBP group (10 women) and a control group (10 women). A 3-D force plate was used to measure the center of pressure (COP) anteroposterior and mediolateral displacements, and resultant velocity. ANOVA was used to compare situations. LPB group presented higher amplitudes of COP for anterioposterior direction (p<0.01) in conditions of open (3.07 ± 0.53 cm) and closed eyes (3.70 ± 0.71 cm) than healthy women (1.39 ± 0.17 cm and 1.75 ± 0.36 cm, for open and closed eyes, respectively). Similar results were found for COP involving mediolateralsway. The resultant COP velocity was larger for LBP group (p<0.05) when visual information was removed (3.03 ± 0.68 m/s and 3.63 ± 1.33 m/s for LBP and healthy women, respectively). LBP influenced the stability of young women during quiet standing, and the visual deprivation appears to reinforce LBP effects.

Equilíbrio corporal e exercícios físicos: uma revisão sistemática / Corporal balance and physical exercises: a systematic review

Declínios funcionais relacionados com a idade, a massa muscular ou os sistemas sensoriais contribuem para as instabilidades posturais. O objetivo dessa revisão foi investigar a influência de programas de exercícios físicos sobre o equilíbrio corporal. Para isso, foi feita uma busca por referências em língua Portuguesa e Inglesa, utilizando-se bases eletrônicas de dados: SciELO, Sciencedirect, Scopus, Pubmed Central e Pubmed. Foram considerados artigos originais que tratassem de forma clara e objetiva o assunto, e publicados entre 1995 e 2008. De modo geral, idosos são o público de maior interesse por parte dos estudiosos, e a modalidade de Tai-Chi é uma das mais utilizadas. A prática de exercícios físicos mostrou-se eficaz na redução das instabilidades posturais e diminuição do risco de quedas. A modalidade que se mostrou mais eficiente para isso é a combinação de fortalecimento, alongamento e coordenação, sendo que a referida melhoria ficou evidenciada a partir de 20 sessões.

Functional declines related with the age, the muscular mass or the sensorial systems contribute to the instability postural. The objective of this review was to investigate the influence of physical exercises programs in the corporal balance. Search engines used were: SciELO, Sciencedirect, Scopus, Pubmed Central e Pubmed. Original papers published from 1995 to 2008 were considered when the main subject of discussion was the topic of interest. In general, the elderly people are the public of larger interest of researchers and the Tai-Chi is one of the modality most used. The practice of physical exercises was shown effective in the reduction of the postural instabilities and decrease of the risk of falls. The modality that was shown more efficient for this is the combination of stretching, strengthening and coordination, and the referred improvement was evidenced starting from 20 sessions.

Effects of a program for trunk strength and stability on pain, low back and pelvis kinematics, and body balance: a pilot study.

The purpose of this pilot study was to investigate the effects of trunk strength and stability training on body balance and low back and pelvis kinematics during gait in females. Six subjects volunteered to do 20 sessions of training. Data collection involved a qualitative pain grade test, low back stabilization tests, low back and pelvis kinematics, and body balance assessment. Results indicate the absence or decrease in the low back pain, and also an increase in the stabilization and strength of low back and pelvis complex. The 3-D kinematics showed statistically significant differences (p<0.05) when compared pre- to post-training. The body balance was improved as well as the range of motion (ROM) was improved for trunk rotation, pelvis inclination and low back flexion. The results suggest the influence of trunk strength and stability on low back and pelvis pain and kinematics as well as on body balance. Further studies with a larger sample and/or a control group must be conducted in an attempt to confirm this hypothesis.

Influência do treinamento de estabilização central sobre a dor e estabilidade lombar / Influence of core stabilization training on low back pain and stability

O objetivo deste estudo foi verificar como um programa de exercícios de estabilização central influencia a estabilidade e a ocorrência de dor na região lombar da coluna vertebral. Este estudo contou com a participação de seis mulheres com idade média de 23 (+-1) anos. Foram realizadas 20 sessões de treinamento específico para estabilização central com uma frequência semanal de tres sessões com duração de 45 minutos, sendo a coleta de dados realizada antes e depois do período de treinamento, por meio da aplicação de uma escala qualitativa para dor lombar e testes de estabilidade lombar. Os resultados indicaram que após o período de tratamento ocorreu a ausência total ou decréscimo da dor na região lombar em todos os sujeitos, além de se observar também o aumento da força de estabilização do complexo lombo-pélvico. Os resultados indicaram que a aplicação de um treinamento com base em exercícios de estabilização central como tratamento de sujeitos com lombalgia foi efetivo já com 20 sessões, visto que acarretou diminuição da dor e aumento da força muscular em todos os sujeitos avaliados, sem a aplicação de qualquer droga ou terapia analgésica.