scholarly journals Estimation of knee joint reaction force based on the plantar flexion resistance of an ankle-foot orthosis during gait

2018 ◽  
Vol 30 (8) ◽  
pp. 966-970 ◽  
Author(s):  
Masataka Yamamoto ◽  
Koji Shimatani ◽  
Masaki Hasegawa ◽  
Takuya Murata ◽  
Yuichi Kurita
Keyword(s):  
Knee Joint ◽  
Plantar Flexion ◽  
Reaction Force ◽  
Joint Reaction Force ◽  
Ankle Foot Orthosis ◽  
Foot Orthosis ◽  
Joint Reaction

scholarly journals Effects of plantar flexion resistive moment generated by an ankle-foot orthosis with an oil damper on the gait of stroke patients: a pilot study

2012 ◽  
Vol 37 (3) ◽  
pp. 212-221 ◽  
Author(s):  
Sumiko Yamamoto ◽  
Naoki Tomokiyo ◽  
Tadashi Yasui ◽  
Toshikazu Kawaguchi
Keyword(s):  
Plantar Flexion ◽  
Reaction Force ◽  
Three Dimensional ◽  
Chronic Phase ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Ankle Foot Orthosis ◽  
Paretic Limb ◽  
Gait Parameters ◽  
Foot Orthosis

Background: An ankle-foot orthosis with an oil damper was previously developed to assist the first rocker function during gait, but the effects of the amount of resistive moment generated on gait have not been clarified. Objectives: To measure the amount of resistive moment generated by the ankle-foot orthosis with an oil damper during gait and determine its effect on the gait of patients with stroke. Study Design: Preliminary cross-sectional study. Methods: The gait of four patients with stroke in the chronic phase was measured in four conditions: without an ankle-foot orthosis and with the ankle-foot orthosis with an oil damper generating three different amounts of resistive moment. Measurements were taken with a three-dimensional motion analysis system and a specially designed device to determine the resistive moment. Results: The resistive moment was observed in the former half in stance of the paretic limb, and its magnitude was less than 10 N m. Some gait parameters related to terminal stance and preswing were affected by the amount of resistive moment. The forward component of floor reaction force and the shank vertical angle showed peak values when the patients reported feeling most comfortable during gait. Conclusion: Although the resistive moment generated by the ankle-foot orthosis with an oil damper was small, it was sufficient to alter gait. Clinical relevance To maximize the effectiveness of ankle-foot orthoses, it is necessary to know the effects of resistive moment on the gait of patients with stroke. The ankle-foot orthosis with an oil damper assists the first rocker function in gait and also affects the gait in a later phase in stance. The peak values of some gait parameters coincided with patients reporting gait to be most comfortable. It is important to know that ankle-foot orthosis with an oil damper assistance in the first rocker alters the weight acceptance on the paretic limb and affects the gait parameters related to propulsion ability in stance.

scholarly journals Finite Element Analysis on Knee Joint with Leg Length Inequality

2018 ◽  
Vol 7 (4.30) ◽  
pp. 359
Author(s):  
N. F. Othman ◽  
M. N. A. Suhaimi ◽  
K. S. Basaruddin ◽  
M. H. Mat Som ◽  
W. M. R. Rusli
Keyword(s):  
Knee Joint ◽  
Reaction Force ◽  
Equivalent Stress ◽  
Static Condition ◽  
Von Mises Stress ◽  
Stress And Strain ◽  
Leg Length ◽  
Joint Reaction Force ◽  
Element Analysis ◽  
Joint Reaction

This study aims to investigate the effect of leg length discrepancy (LLD) on the joint reaction stress and strain of femur particularly in the knee joint. The knee joint model was developed using CATIA and imported into ANSYS to simulate the LLD case based on the value of the joint reaction force from the previous experimental study. The analysis was done under a linear static condition. The knee components were divided on three; bone (femur and tibia), cartilage (femoral cartilage and tibial plateau cartilage) and menisci. The effect of LLD on the knee joint was determined by observing the contour of equivalent stress and strain distribution on the knee joint components and the maximum equivalent von-Mises stress and strain. The result shows a higher value of stress and strain was found on the short leg compared to the long leg due to the LLD. The pattern of overall results shows that the magnitude of stress-strain is proportional to the level of increments in LLD. Since the short leg demonstrate the greater in stress and strain value, it is prone to experience failure in the future such as wear in cartilage.

Knee joint reaction force during tibial diaphyseal lengthening: a study on a rabbit model

2004 ◽  
Vol 37 (7) ◽  
pp. 1053-1059 ◽  
Author(s):  
Lang Yang ◽  
Gang Cai ◽  
Les Coulton ◽  
Michael Saleh
Keyword(s):  
Knee Joint ◽  
Reaction Force ◽  
Rabbit Model ◽  
Joint Reaction Force ◽  
Joint Reaction

scholarly journals Stiffness control in posterior-type plastic ankle-foot orthoses: Effect of ankle trimline Part 2: Orthosis characteristics and orthosis/patient matching

1996 ◽  
Vol 20 (2) ◽  
pp. 132-137 ◽  
Author(s):  
T. Sumiya ◽  
Y. Suzuki ◽  
T. Kasahara
Keyword(s):  
Plantar Flexion ◽  
Measuring Device ◽  
Ankle Foot Orthosis ◽  
Maximum Resistance ◽  
Severe Spasticity ◽  
Ankle Foot Orthoses ◽  
Final Adjustment ◽  
Flexion Strength ◽  
Foot Orthosis ◽  
Selection Of

The hingeless plastic ankle-foot orthosis (AFO) changes stiffness largely depending on how much plastic is trimmed around the ankle. To support proper selection of the orthosis and final adjustment of the orthotic stiffness, the correlation between the posterior upright width and the resistance to dorsi- and plantar flexion movements was measured in 30 posterior-type plastic AFOs. The posterior upright width was varied by regularly trimming around the ankle in nine stages. The resistance to dorsi- and plantar flexion movements was measured by bending the plastic AFOs 15d` with the measuring device described in Part 1. All the plastic AFOs decreased in their resistance to both movements in proportion to the reduction of the posterior upright width. The maximum resistance to plantar flexion movement was about 28 Nm, which was strong enough to assist dorsiflexion in patients with severe spasticity. On the other hand, the maximum resistance to dorsiflexion movement measured was about 10 Nm, which was insufficient to stabilise the ankle in patients who lacked in plantar flexion strength. These findings suggested that this type of plastic AFO should be prescribed for patients who predominantly require dorsiflexion assist, and that the orthotic stiffness could be finally adjusted by trimming to exactly meet individual requirements.

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