3P2-D04 Analysis of Inertial Motion in Swing Phase of Human Gait and Its Application to Motion Generation of Transfemoral Prosthesis(Rehabilitation Robotics and Mechatronics)

2014 ◽  
Vol 2014 (0) ◽  
pp. _3P2-D04_1-_3P2-D04_4
Author(s):  
Hiroshi SANO ◽  
Takahiro WADA ◽  
Masahiro SEKIMOTO
Keyword(s):  
Swing Phase ◽  
Rehabilitation Robotics ◽  
Human Gait ◽  
Motion Generation ◽  
Inertial Motion ◽  
Transfemoral Prosthesis

A Computer Model to Simulate the Swing Phase of a Transfemoral Prosthesis

2004 ◽  
Vol 20 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Brendan Burkett ◽  
James Smeathers ◽  
Timothy M. Barker
Keyword(s):  
Walking Speed ◽  
Swing Phase ◽  
Prosthetic Knee ◽  
Energy Demands ◽  
Swing Time ◽  
Significant Difference ◽  
Prosthetic Knee Joint ◽  
Transfemoral Prosthesis ◽  
Everyday Task ◽  
Phase Motion

For amputees to perform an everyday task, or to participate in physical exercise, it is crucial that they have an appropriately designed and functional prosthesis. Past studies of transfemoral amputee gait have identified several limitations in the performance of amputees and in their prosthesis when compared with able-bodied walking, such as asymmetrical gait, slower walking speed, and higher energy demands. In particular the different inertial characteristics of the prosthesis relative to the sound limb results in a longer swing time for the prosthesis. The aim of this study was to determine whether this longer swing time could be addressed by modifying the alignment of the prosthesis. The following hypothesis was tested: Can the inertial characteristics of the prosthesis be improved by lowering the prosthetic knee joint, thereby producing a faster swing time? To test this hypothesis, a simple 2-D mathematical model was developed to simulate the swing-phase motion of the prosthetic leg. The model applies forward dynamics to the measured hip moment of the amputee in conjunction with the inertial characteristics of prosthetic components to predict the swing-phase motion. To evaluate the model and measure any change in prosthetic function, we conducted a kinematic analysis on four Paralympic runners as they ran. When evaluated, there was no significant difference (p > 0.05) between predicted and measured swing time. Of particular interest was how swing time was affected by changes in the position of the prosthetic knee axis. The model suggested that lowering the axis of the prosthetic knee could reduce the longer swing time. This hypothesis was confirmed when tested on the amputee runners.

scholarly journals Dynamic Optimization of Transfemoral Prosthesis during Swing Phase with Residual Limb Model

2010 ◽  
Vol 34 (4) ◽  
pp. 428-438 ◽  
Author(s):  
Yasuo Suzuki
Keyword(s):  
Dynamic Optimization ◽  
Musculoskeletal Model ◽  
Swing Phase ◽  
Metabolic Energy ◽  
Residual Limb ◽  
Limb Muscle ◽  
Joint Friction ◽  
The Subject ◽  
Transfemoral Prosthesis ◽  
Metabolic Energy Expenditure

A new simulation model was created with a transfemoral prosthesis including a residual limb muscle model during the swing phase. The optimal knee joint friction value was calculated to minimize muscle metabolic energy expenditure. Using this model to examine how an amputee could walk as fast as possible, the minimum swing duration was calculated. The obtained optimal joint friction value was close to the value the subject preferred when walking normally. The calculated minimum swing duration was close to the time the subject could achieve. The method of dynamic optimization with a musculoskeletal model used in this study indicated the possibility of obtaining optimal mechanical properties suited to each amputee' capability of mastering control of his/her residual limb.

On Transfemoral Prosthetic Knee Design for Natural Human Knee Motion

2020 ◽  
Vol 13 (1) ◽  
pp. 49-59
Author(s):  
Wen-Tzong Lee ◽  
Kevin Russell ◽  
Raj S. Sodhi
Keyword(s):  
Design Process ◽  
Knee Flexion ◽  
Gait Cycle ◽  
Design Method ◽  
Human Gait ◽  
Motion Generation ◽  
Knee Motion ◽  
Human Knee ◽  
Prosthetic Knee ◽  
Position Data

Background: A transfemoral prosthetic knee is an artificial knee used by above-the-knee amputees. There are two major categories of transfemoral prosthetic knee designs: pin joint-based and polycentric designs. While pin joint-based knee designs only allow pure rotation of the knee, polycentric knee designs allow a combination of rotational and translational knee motion which is exhibited in natural knee motion. Objective: This work presents both the recently-patented design process and the resulting design of a polycentric transfemoral prosthetic knee that approximates natural spatial human knee motion during flexion and extension. Methods: The design process includes tibial motion acquisition, Revolute-Revolute-Spherical-Spherical linkage (or RRSS) motion generation, RRSS linkage axode generation and circle fitting. The polycentric transfemoral prosthetic knee design produced from this process includes a gear joint with a specific spatial orientation to approximate natural spatial human knee motion. Results: Using the design process, a polycentric transfemoral prosthetic knee was designed to replicate a group of five tibial positions over 37.5° of knee flexion (the amount of knee flexion in a standard human gait cycle) with a minimal structural error. Conclusion: The circular gear-based knee design accurately replicated natural spatial knee motion over the tibial position data given for a standard human gait cycle. The knee design method must be implemented over a broader sampling of tibial position data to determine if a circular gear-based knee design is consistently accurate.

Gait acts as a gate for reflexes from the foot

2004 ◽  
Vol 82 (8-9) ◽  
pp. 715-722 ◽  
Author(s):  
J Duysens ◽  
C M Bastiaanse ◽  
B C.M Smits-Engelsman ◽  
V Dietz
Keyword(s):  
Electrical Stimulation ◽  
Tibialis Anterior ◽  
Stance Phase ◽  
Background Activity ◽  
Swing Phase ◽  
The Body ◽  
Human Gait ◽  
Step Cycle ◽  
Reflex Reversal ◽  
Stimulation Of

During human gait, electrical stimulation of the foot elicits facilitatory P2 (medium latency) responses in TA (tibialis anterior) at the onset of the swing phase, while the same stimuli cause suppressive responses at the end of swing phase, along with facilitatory responses in antagonists. This phenomenon is called phase-dependent reflex reversal. The suppressive responses can be evoked from a variety of skin sites in the leg and from stimulation of some muscles such as rectus femoris (RF). This paper reviews the data on reflex reversal and adds new data on this topic, using a split-belt paradigm. So far, the reflex reversal in TA could only be studied for the onset and end phases of the step cycle, simply because suppression can only be demonstrated when there is background activity. Normally there are only 2 TA bursts in the step cycle, whereas TA is normally silent during most of the stance phase. To know what happens in the stance phase, one needs to have a means to evoke some background activity during the stance phase. For this purpose, new experiments were carried out in which subjects were asked to walk on a treadmill with a split-belt. When the subject was walking with unequal leg speeds, the walking pattern was adapted to a gait pattern resembling limping. The TA then remained active throughout most of the stance phase of the slow-moving leg, which was used as the primary support. This activity was a result of coactivation of agonistic and antagonistic leg muscles in the supporting leg, and represented one of the ways to stabilize the body. Electrical stimulation was given to a cutaneous nerve (sural) at the ankle at twice the perception threshold. Nine of the 12 subjects showed increased TA activity during stance phase while walking on split-belts, and 5 of them showed pronounced suppressions during the first part of stance when stimuli were given on the slow side. It was concluded that a TA suppressive pathway remains open throughout most of the stance phase in the majority of subjects. The suggestion was made that the TA suppression increases loading of the ankle plantar flexors during the loading phase of stance.Key words: human gait, cutaneous reflexes, sural nerve, tibialis anterior, split belt, reflex reversal.

scholarly journals Impaired Transmission in the Corticospinal Tract and Gait Disability in Spinal Cord Injured Persons

2010 ◽  
Vol 104 (2) ◽  
pp. 1167-1176 ◽  
Author(s):  
Dorothy Barthélemy ◽  
Maria Willerslev-Olsen ◽  
Henrik Lundell ◽  
Bernard A. Conway ◽  
Hanne Knudsen ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Corticospinal Tract ◽  
Motor Evoked Potentials ◽  
Swing Phase ◽  
Spinal Cord Lesion ◽  
Foot Drop ◽  
Human Gait ◽  
Cord Injury ◽  
Spinal Cord Injured ◽  
Cord Lesion

Rehabilitation following spinal cord injury is likely to depend on recovery of corticospinal systems. Here we investigate whether transmission in the corticospinal tract may explain foot drop (inability to dorsiflex ankle) in persons with spinal cord lesion. The study was performed in 24 persons with incomplete spinal cord lesion (C1 to L1) and 15 healthy controls. Coherence in the 10- to 20-Hz frequency band between paired tibialis anterior muscle (TA) electromyographic recordings obtained in the swing phase of walking, which was taken as a measure of motor unit synchronization. It was significantly correlated with the degree of foot drop, as measured by toe elevation and ankle angle excursion in the first part of swing. Transcranial magnetic stimulation was used to elicit motor-evoked potentials (MEPs) in the TA. The amplitude of the MEPs at rest and their latency during contraction were correlated to the degree of foot drop. Spinal cord injured participants who exhibited a large foot drop had little or no MEP at rest in the TA muscle and had little or no coherence in the same muscle during walking. Gait speed was correlated to foot drop, and was the lowest in participants with no MEP at rest. The data confirm that transmission in the corticospinal tract is of importance for lifting the foot during the swing phase of human gait.

Amplitude modulation of the soleus H reflex in the human during active and passive stepping movements

1995 ◽  
Vol 73 (1) ◽  
pp. 102-111 ◽  
Author(s):  
J. D. Brooke ◽  
J. Cheng ◽  
J. E. Misiaszek ◽  
K. Lafferty
Keyword(s):  
Soleus Muscle ◽  
Body Position ◽  
Swing Phase ◽  
Passive Movement ◽  
H Reflex ◽  
The Body ◽  
Human Gait ◽  
Vertical Position ◽  
Flexion Extension ◽  
Full Flexion

1. It was hypothesized that passive movement of either the whole leg or its separate segments, in a manner mimicking human gait, leads to attenuation of the soleus H reflex. It was further hypothesized that this attenuation arises from presynaptic effects. Reflex amplitudes were observed in humans during natural bipedal and unipedal stepping on the spot, during passive stepping, during passive movement of the lower limb segments about the hip, knee, and ankle individually in a stepping fashion, and during passive movement with tonic contraction of the soleus muscle. 2. In natural stepping at a cadence of 54 steps/min, the reflex means were substantially depressed in the swing phase (P < 0.01). (Means, standing control 90.1%, unipedal 8.3%, bipedal 6.9%, of maximum M wave.) During the stance phase, reflex magnitudes were mildly and significantly elevated in four of six subjects, compared with standing controls (P < 0.05). 3. For passive stepping, subjects were dorsally tilted 20 and 90 degrees (lying supine) from the vertical position, to obtain quiet electromyograms (EMGs) in the postural muscles. Recorded during natural stepping, the right leg was manipulated to match the electrogoniometer traces of the three major joints. 4. At 20 degrees of tilt of the body, mean H reflexes were significantly lower, by 26.4%, compared with the supine position (P < 0.05). During passive stepping movement of the leg at 54 steps/min, the reflex was profoundly attenuated over the entire cycle (P < 0.01). The significantly attenuated reflexes during active stepping and during passive stepping movement of the whole leg were not significantly different at the point where the limb approached full flexion in the swing phase (P > 0.48). This was the case for measurements made at either body position, 20 degrees dorsal tilt or supine. 5. Passive flexion-extension, around either the hip or the knee, significantly inhibited the mean reflex magnitude close to full flexion, at either body position (P < 0.01). Such movement around the ankle resulted in significant inhibition of the reflex in two of the four subjects (P < 0.05). The numeric sum of the reflex depression arising from the flexion-extension of the individual joints was greater than that arising from movement of the whole limb. 6. With the ankle braced, the significant reflex attenuation remained when a tonic isometric contraction of the soleus muscle was introduced. This suggests premotoneuronal mechanisms for the inhibition.(ABSTRACT TRUNCATED AT 400 WORDS)

Sign in / Sign up

Export Citation Format

Share Document