The Effect of Stimulus Timing on Unplanned Gait Termination

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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Dysfunctional muscle activities and co-contraction in the lower-limb of lumbar disc herniation patients during walking

Scientific Reports ◽

10.1038/s41598-020-77150-7 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Wei Wang ◽

Hui Wei ◽

Runxiu Shi ◽

Leitong Lin ◽

Lechi Zhang ◽

...

Keyword(s):

Lumbar Disc Herniation ◽

Disc Herniation ◽

Lower Limb ◽

Gait Cycle ◽

Lumbar Disc ◽

Lower Limbs ◽

Heel Strike ◽

Control Group ◽

Double Support ◽

Support Phase

AbstractThis study aimed to investigate lower-limb muscle activities in gait phases and co-contraction of one gait cycle in patients with lumbar disc herniation (LDH). This study enrolled 17 LDH patients and 17 sex- and age-matched healthy individuals. Bilateral muscle activities of the rectus femoris (RF), biceps femoris long head (BL), tibialis anterior (TA), and lateral gastrocnemius (LG) during walking were recorded. The gait cycle was divided into four phases by the heel strike and top off according to the kinematics tracks. Root mean square (RMS), mean frequency (MF), and co-contraction of surface electromyography signals were calculated. The LDH patients showed enhanced BL RMS during the single support phase (SS), second double support phase, and swing phase (SW) as well as decreased MF of RF during SS and of TA and LG during SW (p < 0.05). The co-contraction of the TA-LG was increased in LDH patients than in the control group (p < 0.05). Positive correlations were observed between TA-LG co-contraction (affected side, r = 0.557, p = 0.020; contralateral side, r = 0.627, p = 0.007) and the Oswestry disability index scores in LDH patients. LDH patients have increased BL firing rate and insufficient motor unit recruitment in specific phases in the lower limbs during walking. Dysfunction in LDH patients was associated with immoderate intermuscular co-contraction of the TA-LG during walking.

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Gait termination in lower limb amputees

Gait & Posture ◽

10.1016/j.gaitpost.2007.02.004 ◽

2008 ◽

Vol 27 (1) ◽

pp. 82-90 ◽

Cited By ~ 25

Author(s):

A.H. Vrieling ◽

H.G. van Keeken ◽

T. Schoppen ◽

E. Otten ◽

J.P.K. Halbertsma ◽

...

Keyword(s):

Lower Limb ◽

Gait Termination ◽

Lower Limb Amputees

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Dual-task walking reduces lower limb range of motion in individuals with Parkinson’s disease and freezing of gait: But does it happen during what events through the gait cycle?

PLoS ONE ◽

10.1371/journal.pone.0243133 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243133

Author(s):

Camila Pinto ◽

Ana Paula Salazar ◽

Ewald Max Hennig ◽

Graham Kerr ◽

Aline Souza Pagnussat

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Range Of Motion ◽

Dual Task ◽

Lower Limb ◽

Gait Cycle ◽

Freezing Of Gait ◽

Heel Strike ◽

Discrete Analysis ◽

Flexion Extension

Background It is unclear how dual-task gait influences the lower limb range of motion (RoM) in people with Parkinson’s disease (PD) and freezing of gait (FOG). The lower limb kinematics during dual-task gait might differ from regular gait, but during what events in the gait cycle? Methods This is an observational within-subjects study. Thirty-two individuals with PD and FOG underwent a gait analysis. Single and dual-task gait was assessed by a 3D motion analysis system and the RoM data of the lower limb were extracted from hips, knees and ankles in the sagittal plane. Dual-task assignment was performed using word-color interference test. To compare both gait conditions, we used two different analyses: (1) common discrete analysis to provide lower limb RoM and (2) Statistical Parametric Mapping analysis (SPM) to provide lower limb joint kinematics. A correlation between lower limb RoM and spatiotemporal gait parameters was also performed for each gait condition. Results Common discrete analysis evidenced reductions in RoM of hips, knees and ankles during the dual task gait when compared to single gait. SPM analysis showed reductions in flexion-extension of hip, knees and ankles joints when dual task was compared to single task gait. These reductions were observed in specific gait events as toe off (for knees and ankles) and heel strike (for all joints). The reduction in lower limb RoM was positively correlated with the reduction in step length and gait speed. Conclusions Lower limb joints kinematics were reduced during toe off and heel strike in dual task gait when compared to single gait. These findings might help physiotherapists to understand the influence of dual and single walking in lower limb RoM throughout the gait cycle in people with PD and FOG.

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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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Feasibility assessment of transfer functions describing biomechanics of the human lower limb during the gait cycle

Biomedical Signal Processing and Control ◽

10.1016/j.bspc.2021.102776 ◽

2021 ◽

Vol 69 ◽

pp. 102776

Author(s):

Edric John Cruz Nacpil ◽

Somer Nacy ◽

George Youssef

Keyword(s):

Lower Limb ◽

Gait Cycle ◽

Transfer Functions ◽

Feasibility Assessment

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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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