Gait biomechanics of forty male subjects was evaluated at normal and fast walking speeds. The forty subjects composed four groups based on their body mass index, with ten subjects in each of the groups: underweight, normal weight, overweight and obese. To our knowledge this is the first comprehensive 3-dimensional kinetic and kinematic gait analysis of all four groups based on body mass index. The obese subjects walked with significantly slower gait speed by taking shorter steps and strides, while having significantly higher step widths and longer gait cycle times than the other subjects. The obese subjects spent significantly less time in single support and more time in double support than their non-obese counterparts. These adjustments in temporal characteristics for the obese participants may be as a result of the gait compensation for the additional body weight in order to give them the most efficient, stable and balanced walking ability. Body mass index affected significantly the forces and moments at the ankle, knee and hip in the medial-lateral plane while speed effects were more prominent in the sagittal and transverse planes. These results suggest that an increase in the body weight would affect the gait stability while increasing the speed will affect the gait progression. Contrary to most researchers beliefs that an increase of the body weight would increase the forces and moments of the knee in all three planes, this study was able to prove that the actual forces and moments in the medial-lateral plane for the knee joint decrease while the ones in the sagittal plane increase. On the other hand, the hip joint in the medial-lateral plane displays the highest forces and moment for the obese subjects. These results are indicative of a gait compensation related to increasing body weight in the medial-lateral compartment of the lower extremity joints. Recommendations for further studies and follow up experiments are enclosed.

Made available in DSpace on 2016-12-06T17:07:17Z (GMT). No. of bitstreams: 1 PAMELA.pdf: 2668750 bytes, checksum: 96752be9e4cc22aee9368d301b2b09b4 (MD5) Previous issue date: 2008-09-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This is a descriptive search that has a general objective the evaluation of the clinic-functional and dynamic of the gait in elderly with knee osteoarthrosis. The specific objectives were to verify the clinic-functional characteristic of the knee in elderly with osteoarthrosis; verify the kinetics characteristics of the gait in elderly with knee osteoarthrosis; compare the kinetic characteristics of the vertical ground reaction forces with normal parameters and identify the morphologic characteristics of the ground reaction forces curve. Twelve elderly subjects with medical knee osteoarthrosis diagnosis were intentionally chosen. The clinic-functional and kinetics variables were measured through the Q angle of the knee, active and passive flexion and extension amplitude of the knee, habitual and maximal velocity of the gait and vertical ground reaction forces. The kinetics data were collected in habitual speed with frequency of sampling of 600Hz. The data were processed through SPSS 11.0 and SAD 32 programs. The statistic used was descriptive, with average, standard deviation and coefficient of variation. Analyzing the results, the observations were that the subjects showed high intensity of the pain (8,2 ± 1,5), obesity in 5/6 of the subjects, diminution of the active and passive amplitude of the flexion and extension of the knee, decreased velocity of the gait (2,7 ± 0,43 km/h), and postural varo and valgus deviation in . of the subjects. More than these, there were a significant increase in the median support force (87% ± 0,039 BW) and a diminution of the first peak of force (96% ± 0,03 BW), second peak of force (99% ± 0,02 BW) and in body weight acceptance tax (71° ± 3,4), suggesting that the subjects of this study do not have enough muscular and ligament forces to control the flexion (shock absorber) and stabilization of the knee during the stance phase of the gait. And the pain, must be doing by chronic repetitive movement occasioned by the articular dysfunction, altered alignments and obesity that accompanying these subjects. This paper demonstrates that the objective analysis of the gait in association with the clinic-functional parameters of the knee can be used to document the gait adaptations of the subjects with knee osteoarthrosis, and to plan best therapeutics interventions. / Esta e uma pesquisa descritiva que teve como objetivo geral avaliar as alterações clínico-funcionais e dinâmicas da marcha de idosos com osteoartrose de joelho. Os objetivos específicos foram verificar as características clínico-funcionais dos joelhos de idosos com osteoartrose de joelho; verificar as características cinéticas da marcha dos idosos com osteoartrose de joelhos; comparar as características cinéticas da componente vertical da força de reação do solo da marcha de indivíduos com osteoartrose de joelho, com valores normais de referência e analisar as características morfológicas da curva da força de reação do solo. Participaram da pesquisa 12 idosos com diagnóstico médico de osteoartrose de joelhos, escolhidos de forma não probabilística intencional. As variáveis de estudo foram medidas do angulo Q do joelho, amplitude articular ativa e passiva de extensão e flexão do joelho, velocidade habitual e máxima da marcha, e forças verticais de reação do solo. Os dados cinéticos foram coletados na velocidade habitual de cada sujeito com freqüência de amostragem de 600hz. O processamento dos dados foi no programa SPSS 11.0 e SAD 32. A estatística utilizada foi a descritiva, com média, desvio padrão e coeficiente de variação. Analisando os resultados pôde-se observar que os sujeitos apresentaram alta intensidade de dor (8,2 ± 1,5), obesidade em 5/6 dos sujeitos, diminuição da amplitude ativa e passiva de movimento articular de flexão e extensão do joelho, diminuição da velocidade habitual da marcha (2,7 ± 0,43), alteração postural em varo ou valgo em ¾ dos sujeitos. Além disso, houve um significativo aumento da média da força de suporte médio (87% ± 0,039 PC) e uma diminuição do primeiro pico de força (96% ± 0,03 PC), do segundo pico de força (99% ± 0,02 PC) e da taxa de aceitação do peso (71° ± 3,4), sugerindo que os indivíduos deste estudo apresentam disfunção articular dos joelhos e não apresentam força muscular e ligamentar suficiente para controlar a flexão (amortecimento) e estabilidade do joelho durante a fase de apoio. E ainda, que a dor pode estar sendo gerada pelas cargas crônicas de movimentos repetitivos ocasionadas pela disfunção articular, alteração postural e excesso de peso que acometem estes sujeitos. Este estudo demonstra que a análise objetiva da marcha associada aos parâmetros clínico-funcionais do joelho, pode ser usada para documentar as adaptações na marcha de idosos com osteoartrose de joelhos e para o planejamento de intervenções terapêuticas mais eficazes.