TRANSLATIONAL AND ROTATIONAL POWER TERMS IN 6 DEGREE-OF-FREEDOM JOINT MODELING

六自由度关节建模中的平移和旋转幂项

• 批准号: 3770199
• 负责人: F L BUCZEK
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ARTHRITIS AND MUSCULOSKELETAL AND SKIN DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3770199
• 关键词: ankle; biological models; biomechanics; body movement; ergonomics; foot; gait; hip; human subject; joints; knee; model design /development

An engineering methodology called "inverse dynamics" provides the resultant forces & moments at major anatomical joints during walking. These "joint reactions" perform mechanical work, & consequently have power associated with them. Joint powers have been used to evaluate mechanical energy flows for individual joints. If added for all major joints of the body, the sum represents a mechanical energy cost for movement, which is an important parameter for estimation of mechanical efficiency. Traditionally, joint models have allowed only rotations at joints, without accounting for translations such as sliding & compression/distraction. Our immediate objective is to implement full six degree-of-freedom (DOF) joint models for the lower extremity, allowing for three rotational & three translational movements (DOFs). Traditional models assumed that translational powers canceled each other across a joint; our new methods include joint powers associated with the three translational DOFs. We believe this detailed model will provide more robust calculations for joint powers, improving reliability & accuracy in total mechanical power estimates. Lower extremity data are collected over full stride cycles for multiple walking trials. Ensemble averages & coefficients of variability are determined for each DOF. Results at the ankle joint for an intra-subject analysis (n=5) showed that X-axis rotational power (associated with ankle dorsi/plantarflexion) predominates, with a peak value of 360 W. The next largest peak in joint power was for the vertical translational DOF, and was less than 10% of the predominant peak. Positive work during push-off was significantly less (ps0.05) for the 6 DOF model (27.9 J) than for either 1 or 3 DOF models (30.3 & 29.9 J, respectively). Negative work during early stance was also significantly less for the 6 DOF model (-10.3 J) than for either 1 or 3 DOF models )-13.1 & -12.6 J, respectively). Inter-subject analyses (n=50) were conducted on joint power data, with similar results. Joint powers at the knee are currently being studied.

一种称为“逆动力学”的工程方法提供了 步行过程中主要解剖关节的作用力和力矩。 这些“联合反应”进行机械工作，因此 与它们相关的功率。 联合权力已用于评估 各个关节的机械能流。 如果添加到所有专业 人体的关节，总和代表机械能成本 运动，这是估计机械的重要参数 效率。 传统上，联合模型仅允许旋转 关节，不考虑诸如滑动＆的翻译 压缩/分心。 我们的直接目标是实施 下肢的六个自由度（DOF）联合模型， 允许三个旋转和三个翻译运动（DOF）。 传统模型假设翻译能力相互取消 穿过关节；我们的新方法包括与 三个翻译DOF。 我们相信这个详细的模型将提供 联合权力的更强大的计算，提高可靠性和 总机械功率估计的准确性。 下肢数据是 在全步循环上收集了多次步行试验。 合奏 为每个DOF确定可变性的平均值和系数。 在踝关节上进行受试者内分析（n = 5）的结果显示 X轴旋转功率（与踝背骨/plantarflexion相关） 主要为主为，峰值为360 w。关节的第二大峰 功率用于垂直翻译DOF，不到不到10％ 主要峰。 推下期间的积极工作非常明显 6 DOF模型（27.9 J）的（PS0.05）少于1或3 DOF 型号（分别为30.3和29.9 J）。 早期立场的负面工作 对于6 DOF模型（-10.3 J）也明显少于任何一个 1或3 DOF模型）-13.1＆-12.6 j，J）。 主体间 在关节功率数据上进行了分析（n = 50），结果相似。 目前正在研究膝盖的联合力量。