Aline A. Gomes

Lower limb electromygraphy and kinematics of neuropathic diabetic patients during real-life activities: Stair negotiation

In this study we investigate the influence of diabetic neuropathy (DN) on lower limb electromyography (EMG) and kinematics during stair negotiation.

Alinhamento frontal estático do joelho e cargas plantares durante a marcha de adultos jovens assintomáticos

Na pratica fisioterapeutica, pressupoe-se que alteracoes posturais do membro inferior influenciem a biomecânica e funcao dos demais complexos durante o movimento. No entanto, a literatura sobre a relacao entre desalinhamentos estaticos do joelho e possiveis alteracoes dinâmicas ainda e escassa e inconclusiva. Assim, buscou-se avaliar o efeito do alinhamento frontal estatico do joelho sobre a distribuicao da pressao plantar durante a marcha. Foram avaliados inicialmente 44 adultos jovens assintomaticos. Por fotogrametria digital, mediu-se o ângulo frontal do joelho, classificado como normal (170° a 175°), valgo 175°. Dado o baixo numero de valgos, foram analisados dois grupos: de joelhos normais (n=18) e de joelhos varos (n=23). A distribuicao da pressao plantar foi avaliada durante a marcha em cinco areas. Os grupos mostraram-se estatistica-mente semelhantes em todas as variaveis cineticas avaliadas em todas as areas plantares. Joelhos normais apresentaram significativa correlacao com o tempo de contato no antepe lateral e medio-pe; e os varos, correlacao com a area e tempo de contato em duas e tres areas plantares, e com a pressao integral no antepe lateral. Os resultados mostraram que o desalinhamento frontal de 3° do joelho, embora com moderada correlacao, nao influencia a distribuicao de cargas na superficie plantar durante a marcha. Sugere-se pois que a avaliacao clinica nao se limite a avaliacao articular estatica do joelho, mas inclua atividades dinâmicas.

Dynamic simulation of hip strategy of diabetic neuropathic individuals during gait

Patients suffering from diabetic neuropathy present disturbed kinetic, kinematic and electromyographic gait patterns. These disturbances have been experimentally related with plantar ulcerations. However, experimental data are limited because it is not possible to record certain muscle groups (e.g, illiopsoas). In this respect, computational simulations complement the experiments. Our aim is to simulate how the neuromusculoskeletal system of diabetic neuropathic individuals deals with a reduced distal muscle function during level gait. It was hypothesized that proximal muscle compensates the reduced distal muscle function. We used a seven segment planar musculoskeletal model of the body with 8 muscles in each leg. Normal gait muscle excitation patterns were used as reference input in forward dynamics simulations. In order to simulate the neuropathic gait condition, those reference excitations were modified according to functional changes found in diabetic gait. The tibialis anterior (3,75%) and gastrocnemius (15%) excitation reduction along with iliopsoas (11,25%) and hamstrings (7,5%) excitation increase during push-off, guaranteed larger pre-swing hip flexion and smaller hip extension during stance. This motion pattern was not observed when hamstrings excitation remained unchanged. Ankle plantar-flexion during push-off and ankle flexion during swing decreased as the gastrocnemius and tibialis were functionally reduced. The musculoskeletal model was able to represent the hip strategy possibly adopted by the diabetic neuropathic patients during gait as an adaptation to loss of function in distal muscles. The increase in hamstrings function is crucial to improve the model dynamic stability opening new approaches to therapeutic handling of these patients.

An Optimal Control Framework to Predict Gait Patterns Resulting from Changes in Musculoskeletal Properties

A musculoskeletal model allows the analysis of the human gait and may aid the investigation of different strategies employed by the human body to perform this important task. This study presents a planar multibody model of the musculoskeletal system and an optimal control approach to obtain the time history of motion and muscle activation during the gait. Passive joint moments and muscle properties of the model are modified to represent potential changes caused by different diseases, such as diabetic neuropathy. The system adaptation is predicted on the basis of an optimal control framework and the results show many global adaptations as a response to local changes in the properties of the musculoskeletal system and evidences the great potential of this framework to predict patient adaptations to disease, assistive devices or surgical interventions.