Gait termination in lower limb amputees

Gait termination can be challenging for balance-impaired populations, including lower limb amputees. As powered prosthetic ankle devices come to market, it is important to better understand gait termination timing in an unplanned situation. Timing patterns were examined in unplanned gait termination to determine a threshold for being able to terminate gait in 1 step. Time to terminate gait (TTG) was also examined, using both final heel strike and center of mass (COM) acceleration metrics. Fourteen able-bodied subjects walked over ground and terminated gait in response to a randomly-timed auditory stimulus. A lumbarmounted accelerometer and footswitches were used to assess timing of gait termination. Subjects were able to terminate gait in 1 step if the stimulus occurred at or before 19.8% of gait cycle. Later stimulus resulted in a 2-step stop pattern. The TTG using COM acceleration was greater than when using heel strike data. Motion of the COM was not fully arrested until 162 ± 38% of gait cycle. The stabilization phase between heel strike and COM motion arrest was greater for 1-step stops (1.41 ± 0.42 s) than 2-step stops (0.96 ± 0.33 s). These findings indicate gait termination timing should be calculated using COM motion, including the stabilization phase post heel strike.

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The role of enhanced plantar-surface sensory feedback on lower limb EMG during planned gait termination

Somatosensory & Motor Research ◽

10.1080/08990220.2021.1904870 ◽

2021 ◽

pp. 1-11

Author(s):

Kelly A. Robb ◽

Jordan D. Hyde ◽

Stephen D. Perry

Keyword(s):

Lower Limb ◽

Sensory Feedback ◽

Gait Termination ◽

Plantar Surface

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Adaptive Foot in Lower-Limb Prostheses

Journal of Robotics ◽

10.1155/2017/9618375 ◽

2017 ◽

Vol 2017 ◽

pp. 1-15 ◽

Cited By ~ 2

Author(s):

Thilina H. Weerakkody ◽

Thilina Dulantha Lalitharatne ◽

R. A. R. C. Gopura

Keyword(s):

Lower Limb ◽

Uneven Surface ◽

Design Concepts ◽

Human Foot ◽

Future Developments ◽

Adaptive Capabilities ◽

Adaptive Nature ◽

Lower Limb Amputees ◽

Artificial Prosthesis ◽

Lower Limb Prostheses

The human foot consists of complex sets of joints. The adaptive nature of the human foot enables it to be stable on any uneven surface. It is important to have such adaptive capabilities in the artificial prosthesis to achieve most of the essential movements for lower-limb amputees. However, many existing lower-limb prostheses lack the adaptive nature. This paper reviews lower-limb adaptive foot prostheses. In order to understand the design concepts of adaptive foot prostheses, the biomechanics of human foot have been explained. Additionally, the requirements and design challenges are investigated and presented. In this review, adaptive foot prostheses are classified according to actuation method. Furthermore, merits and demerits of present-day adaptive foot prostheses are presented based on the hardware construction. The hardware configurations of recent adaptive foot prostheses are analyzed and compared. At the end, potential future developments are highlighted.

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