Lower-Limb Biomechanical Characteristics Associated with Unplanned Gait Termination Under Different Walking Speeds

Author(s):  
Huiyu Zhou ◽  
Xuanzhen Cen ◽  
Yang Song ◽  
Ukadike C. Ugbolue ◽  
Yaodong Gu
2019 ◽  
Vol 185 (Supplement_1) ◽  
pp. 490-499 ◽  
Author(s):  
Krishan Bhakta ◽  
Jonathan Camargo ◽  
Pratik Kunapuli ◽  
Lee Childers ◽  
Aaron Young

ABSTRACT Introduction Powered prostheses are a promising new technology that may help people with lower-limb loss improve their ability to perform locomotion tasks. Developing active prostheses requires robust design methodologies and intelligent controllers to appropriately provide assistance to the user for varied tasks in different environments. The purpose of this study was to validate an impedance control strategy for a powered knee and ankle prosthesis using an embedded sensor suite of encoders and a six-axis load cell that would aid an individual in performing common locomotion tasks, such as level walking and ascending/descending slopes. Materials and Methods Three amputees walked on a treadmill and four amputees walked on a ramp circuit to test whether a dual powered knee and ankle prosthesis could generate appropriate device joint kinematics across users. Results Investigators found that tuning 2–3 subject-specific parameters per ambulation mode was necessary to render individualized assistance. Furthermore, the kinematic profiles demonstrate invariance to walking speeds ranging from 0.63 to 1.07 m/s and incline/decline angles ranging from 7.8° to 14°. Conclusion This work presents a strategy that requires minimal tuning for a powered knee & ankle prosthesis that scales across a nominal range of both walking speeds and ramp slopes.


Author(s):  
Smit Soni ◽  
Anouk Lamontagne

Abstract Background Conventional treadmills are widely used for gait retraining in rehabilitation setting. Their usefulness for training more complex locomotor tasks, however, remains limited given that they do not allow changing the speed nor the direction of walking which are essential walking adaptations for efficient and safe community ambulation. These drawbacks can be addressed by using a self-pace omnidirectional treadmill, as those recently developed by the gaming industry, which allows speed changes and locomotor movements in any direction. The extent to which these treadmills yield a walking pattern that is similar to overground walking, however, is yet to be determined. Methods The objective of this study was to compare spatiotemporal parameters, body kinematics and lower limb muscle activation of healthy young individuals walking at different speeds (slow, comfortable, fast) on a low-cost non-motorized omnidirectional treadmill with and without virtual reality (VR) vs. overground. Results Results obtained from 12 young healthy individuals (18–29 years) showed that participants achieved slower speed on the treadmill compared to overground. On the treadmill, faster walking speeds were achieved by a mere increase in cadence, as opposed to a combined increase in cadence and step length when walking overground. At matched speed, enhanced stance phase knee flexion, reduced late stance ankle plantarflexion, as well as enhanced activation amplitudes of hip extensors in late stance and hip extensors in early swing were observed. The addition of VR to treadmill walking had little or no effect of walking outcomes. Collectively, results show that the omnidirectional treadmill yields a different walking pattern and lead to different adaptations to speed compared to overground walking. We suggest that these alterations are mainly driven by the reduced shear forces between the weight bearing foot and supporting surface and a perceived threat to balance on the omnidirectional treadmill. Conclusion Since such treadmills are likely to be used for prolonged periods of time by gamers or patients undergoing physical rehabilitation, further research should aim at determining the impact of repeated exposure on gait biomechanics and lower limb musculoskeletal integrity.


2016 ◽  
Vol 49 ◽  
pp. 178-185 ◽  
Author(s):  
Sarah Trager Ridge ◽  
John Henley ◽  
Kurt Manal ◽  
Freeman Miller ◽  
James G. Richards

2016 ◽  
Vol 120 (1) ◽  
pp. 55-62 ◽  
Author(s):  
M. Petrovic ◽  
K. Deschamps ◽  
S. M. Verschueren ◽  
F. L. Bowling ◽  
C. N. Maganaris ◽  
...  

People with diabetes walk slower and display biomechanical gait alterations compared with controls, but it remains unknown whether the metabolic cost of walking (CoW) is elevated. The aim of this study was to investigate the CoW and the lower limb concentric joint work as a major determinant of the CoW, in patients with diabetes and diabetic peripheral neuropathy (DPN). Thirty-one nondiabetic controls (Ctrl), 22 diabetic patients without peripheral neuropathy (DM), and 14 patients with moderate/severe DPN underwent gait analysis using a motion analysis system and force plates and treadmill walking using a gas analyzer to measure oxygen uptake. The CoW was significantly higher particularly in the DPN group compared with controls and also in the DM group (at selected speeds only) compared with controls, across a range of matched walking speeds. Despite the higher CoW in patients with diabetes, concentric lower limb joint work was significantly lower in DM and DPN groups compared with controls. The higher CoW is likely due to energetic inefficiencies associated with diabetes and DPN reflecting physiological and biomechanical characteristics. The lower concentric joint work in patients with diabetes might be a consequence of kinematic gait alterations and may represent a natural strategy aimed at minimizing the CoW.


2016 ◽  
Vol 32 (4) ◽  
pp. 388-393
Author(s):  
Kelly Ohm ◽  
Michael E. Hahn

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.


2008 ◽  
Vol 27 (1) ◽  
pp. 82-90 ◽  
Author(s):  
A.H. Vrieling ◽  
H.G. van Keeken ◽  
T. Schoppen ◽  
E. Otten ◽  
J.P.K. Halbertsma ◽  
...  

2009 ◽  
Vol 23 (7) ◽  
pp. 659-671 ◽  
Author(s):  
Aline H Vrieling ◽  
Helco G van Keeken ◽  
Tanneke Schoppen ◽  
At L Hof ◽  
Bert Otten ◽  
...  

2013 ◽  
Vol 28 (3) ◽  
pp. 347-350 ◽  
Author(s):  
Hiroaki IWASE ◽  
Shin MURATA ◽  
Kunihiko ANAMI ◽  
Nana MATSUO ◽  
Tomohiko YONEYAMA ◽  
...  

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