Investigation of the biomechanical effect of variable stiffness shoe on external knee adduction moment in various dynamic exercises

10.1186/1757-1146-6-39Journal of Foot and Ankle Research61

Modificações biomecânicas na marcha de indivíduos com osteoartrite medial do joelho Biomechanical changes in gait of subjects with medial knee osteoarthritis

OBJETIVO: Demonstrar a presença e magnitude de determinadas variáveis biomecânicas na marcha de pacientes com osteoartrite (OA) medial de joelho e suas relações com o carregamento deste. MÉTODOS: Vinte e um indivíduos diagnosticados com OA do compartimento medial do joelho foram submetidos à avaliação da marcha e comparados com grupo controle. RESULTADOS: O grupo com OA em relação ao grupo controle apresentou: menor velocidade da marcha (0,8±0,1 vs. 1,1±0,1m/s), maior pico precoce do momento adutor (2,6±1,2 vs. 0,3±1,4 Nm/kg), maior pico tardio do momento adutor (1,8±0,7 vs. 0,9±0,2 Nm/kg), maior pico do momento flexor (1,6±0,9 vs. 0,6±0,4 Nm/kg), elevado pico de varo dinâmico (11,5º±8,3 vs. 3º±3,9), maior pico de flexão (15,6º±8 vs. 9,3º±4,1), com tendência ao flexo (5,5º±8,5) na fase de apoio, menor pico de flexão (58,7º±13,3 vs. 67,5º±4,8) no balanço e elevados picos de rotação externa (25,5º±12,7 vs. 0,5º±12,4). Os picos de ângulos e de momentos ocorreram nas mesmas fases da marcha nos dois grupos. CONCLUSÃO: Pacientes com OA do compartimento medial do joelho apresentam modificações na marcha com aumento rotação externa, redução da velocidade, aumento do momento flexor e flexão no apoio, insuficientes para uma redução considerável do carregamento. Nível de Evidência III, Estudo caso-controle.<br>OBJETIVE: Demonstrate the presence and magnitude of biomechanical variables during gait in patients with medial knee osteoarthritis (OA) and the relationship with the knee loading. METHODS: Gait of 21 subjects diagnosed with medial knee OA was evaluated and compared to the control group. RESULTS: The group with OA showed: Lower gait speed (0.8 ± 0.1 vs. 1.1 ± 0.1m/s), higher peak early (2.6 ± 1.2 vs. 0.3 ± 1.4 Nm/Kg) and late peak of the adduction moment (1.8 ± 0.7 vs. 0.9 ± 0.2 Nm/Kg), higher peak flexor moment (1.6 ± 0.9 vs. 0.6 ± 0.4 Nm/Kg) , high dynamic peak varus (11.5 ± 8.3 vs. 3o ± 3.9), higher peak flexion (15.6o ± 8 vs. 9.3o to ± 4.1), with a flexion tendency (5.5 o ± 8.5) in the stance phase, smaller peak of flexion (58.7o ± 13.3 vs. 67.5 o ± 4.8) in the balance phase and and higher peaks of external rotation (25.5o ± 12.7 vs. 0.5o ± 22.4). CONCLUSION: Patients with medial knee OA show changes in gait with increased external rotation, speed reduction, increased flexor moment and flexion in the stance phase, insufficient for reduction of the load. Level of Evidence III, Case Control Study

Conservative biomechanical strategies for knee osteoarthritis

Knee osteoarthritis (OA) is one of the most prevalent forms of this disease, with the medial compartment most commonly affected. The direction of external forces and limb orientation during walking results in an adduction moment that acts around the knee, and this parameter is regarded as a surrogate measure of medial knee compression. The knee adduction moment is intimately linked with the development and progression of knee OA and is, therefore, a target for conservative biomechanical intervention strategies, which are the focus of this Review. We examine the evidence for walking barefoot and the use of lateral wedge insoles and thin-soled, flexible shoes to reduce the knee adduction moment in patients with OA. We review strategies that directly affect the gait, such as walking with the foot externally rotated ('toe-out gait'), using a cane, lateral trunk sway and gait retraining. Valgus knee braces and muscle strengthening are also discussed for their effect upon reducing the knee adduction moment.</p