OPTIMIZATION OF HIP RESISTANCE SIMULATED ON DISARTICULATION PROSTHESIS BY PASSIVE SWING MODEL
OPTIMIZATION OF HIP RESISTANCE SIMULATED ON DISARTICULATION PROSTHESIS BY PASSIVE SWING MODEL
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被动摆动模型模拟离断假肢髋关节阻力的优化
DOI：
10.3951/biomechanisms.17.217
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
T. Mita
中科院分区：
文献类型：
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作者：
K. Aoki;N. Yamazaki;Takenobu Inoue;Nobuya Yamazaki;T. Mita
本文介绍了一种髋关节脱关节假体的髋关节特性优化。我们试图利用我们的被动行走模型来优化特征，以提高行走能力，该模型可以利用刚体部分的力学特性和关节阻力来行走。为了了解髋关节脱臼假体步态是如何进行的，我们采访了两位髋关节脱臼假体使用者。访谈表明，日常生活中的实际步态与训练阶段的步态是不同的。这两种步态分别被称为“实用步态”和“训练步态”。用户反映训练步态速度比实际步态慢。此外，在实际步态中，与训练步态相比，假体侧的脚跟接触更自然。步态测量显示，在训练步态中，与摆动假体相关的腰椎角模式具有快速扩展和侧向弯曲。尽管步态类型不同，但声音侧的步长是一致的。在实际步态中，声音侧步长与假体侧步长一致。与训练步态相比，受试者1的实际步态速度快28%，受试者2的实际步态速度快7%。因此，在实际步态中，由于两侧步长相同，通过摆动义肢可以提高步态速度。假体的运动不是通过健全的下肢实现的，而是通过腰椎的屈曲、伸展和侧屈来实现的。此外，实用步态尽可能减少腰椎运动，并减少腰部周围的肌肉力量。我们利用上述特点开发了一个被动摆动模型。该模型由八个刚性部分组成：上半身、骨盆、上肢、大腿、小腿。每个关节都有韧带的被动阻力。通过测量得到健全的髋关节和腰椎关节的肌肉活动力矩。实际步态的目标函数由以下参数定义：(1)各步长之差；(2)活动矩幅值；(3)步态模式与活动矩周期之差。在这些参数最小的情况下，记录段的姿态、平移速度、角速度和周期以及活动矩幅值。与受试者相比，假体侧计算的运动模式非常一致，因此该模型可用于估计髋关节特征。当该模型模拟当前髋关节弹性特性减弱一半的情况下，步态速度加快6%，腰椎侧弯弯矩幅度减小26%。因此，削弱髋关节周围的电流弹性特性可以很容易地控制假体的摆动。因此，调整髋部弹性特性可以提高行走能力。
This paper describes the optimization of hip joint characteristics of a hip disarticulation prosthesis. We attempted to optimize the characteristics for improved ability to walk using our passive walking model, which can walk by utilizing mechanical properties of rigid body segments and joint resistance.In order to understand how the hip disarticulation prosthesis gait is performed, we interviewed two hip disarticulation prosthesis users. The interviews showed that practical gait in daily life is different from the gait at a training stage. These two types of gaits were named “practical gait” and “training gait.” Users indicated that the training gait velocity was slower than that of the practical gait. Moreover, in the practical gait the heel contact on the prosthesis side was more natural in comparison with the training gait.Gait measurements showed that the lumbar angle pattern has rapid extension and lateral bending involving the swing prosthesis in training gait. Step length on the sound side is in agreement despite the different types of gait. In practical gait, step length on the sound side agrees with that on the prosthesis side. Gait velocity in practical gait compared with training gait was 28% faster with subject 1 and 7% faster with subject 2. Therefore, practical gait has an improved gait velocity by swinging the prosthesis, as step length on each side is the same. Motion of prosthesis is achieved not by sound lower extremities but by lumbar flexion, extension, and lateral bending. Furthermore, practical gait reduces lumbar motion as much as possible, and reduces muscle force around the lumbar area.We developed a passive swing model by applying the above characteristics. This model is composed of eight rigid segments: upper torso, pelvis, upper extremities, thigh, shank-foot. Each joint has passive resistance by ligament. The sound hip and lumbar joint have active moments by muscle, which were obtained from measurement. The objective function for practical gait is defined by the following parameters: (1) difference of each step length, (2) amplitude of active moments, (3) difference of cycles between gait patterns and active moments. As these parameters are minimized, postures of segments, translational velocity, angular velocities and cycle, and amplitude of active moment are recorded. In comparison of subjects, calculated motion patterns on the prosthesis side were well in agreement, so this model is available to estimate hip joint characteristics.When this model simulates a condition of the current hip elastic characteristic weakened by half, the gait velocity is 6% faster and amplitude of lumbar lateral bending moment is reduced 26%. For this reason, weakening current elastic characteristics around the hip joint can easily control the swing of the prosthesis. As a result, adjustment of the hip elastic characteristic can improve the walk capability.