Schmalz Thomas, Altenburg Bjoern, Ernst Michael, Bellmann Malte, Rosenbaum Dieter
Otto Bock Healthcare GmbH, Hermann-Rein-Straße 2a, 37075, Göttingen, Germany.
Gait Posture. 2019 Feb;68:161-167. doi: 10.1016/j.gaitpost.2018.11.017. Epub 2018 Nov 16.
For demanding activities in daily life, such as negotiating stairs, ramps and uneven ground, the functionality of conventional prosthetic feet ("Daily Life Feet" - DLF) is often limited. With the introduction of microprocessor-controlled feet (MPF) it was expected that the functional limitations of DLF might be reduced. The purpose of the present study was to investigate biomechanical gait parameters with DLF and MPF when walking on a specifically designed ramp involving abruptly changing inclination angles as a scenario reflecting typical situations related to walking on uneven ground.
The specific aim of the study was to answer the research question if the advanced adaptability of MPF to different ground slopes would lead to more natural motion patterns and reduced joint loading compared with DLF feet.
A specifically designed ramp was installed within a gait lab. During downward motion on this ramp biomechanical parameters - ground reaction forces, joint moments and joint angles were obtained both with DLF and MPF used by four transtibial amputees. A control group of 10 non-amputees (NA) was measured with for comparison.
The NA group managed the ramp element with the abruptly changing inclination with a specific ankle joint adaptation. Compared to DLF the MPF considerably improved the ankle adaptation to the abruptly changing inclination which was reflected by a significantly increased stance phase dorsiflexion which was comparable to the NA group. The peak value of the knee extension moment on the prosthetic side was significantly increased with DLF, whereas it was almost normal with MPF (DLF: 0.71 ± 0.13 Nm/kg, MPF: 0.42 ± 0.12 Nm/kg, NA: 0.36 ± 0.07 Nm/kg, p < 0.05 and p < 0.01). The external knee adduction moment was generally reduced for the transtibial amputees and did not show differences between foot designs.
The adaptable ankle joint motion of the MPF is a crucial requirement for a more natural motion pattern and leads to a reduction of sagittal knee joint loading on the prosthetic side.
对于日常生活中的高要求活动，如上下楼梯、斜坡以及在不平整地面行走，传统假脚（“日常生活假脚” - DLF）的功能往往有限。随着微处理器控制假脚（MPF）的引入，人们期望能减少DLF的功能限制。本研究的目的是调查在一个专门设计的、具有突然变化倾斜角度的斜坡上行走时，使用DLF和MPF的生物力学步态参数，该斜坡场景反映了在不平整地面行走的典型情况。
本研究的具体目标是回答研究问题，即与DLF假脚相比，MPF对不同地面坡度的先进适应性是否会导致更自然的运动模式并减少关节负荷。
在步态实验室安装了一个专门设计的斜坡。在四名经胫截肢者使用DLF和MPF在该斜坡上向下行走时，获取生物力学参数 - 地面反作用力、关节力矩和关节角度。测量了一个由10名非截肢者组成的对照组（NA）以作比较。
NA组通过特定的踝关节适应性来应对倾斜角度突然变化的斜坡部分。与DLF相比，MPF显著改善了踝关节对突然变化倾斜的适应性，这表现为支撑相背屈显著增加，与NA组相当。使用DLF时，假肢侧膝关节伸展力矩的峰值显著增加，而使用MPF时几乎正常（DLF：0.71±0.13 Nm/kg，MPF：0.42±0.12 Nm/kg，NA：0.36±0.07 Nm/kg，p<0.05和p<0.01）。经胫截肢者的膝关节外展力矩总体上有所降低，且在不同假脚设计之间未显示出差异。
MPF可适应的踝关节运动是实现更自然运动模式的关键要求，并可减少假肢侧矢状面膝关节负荷。
