Spatio-temporal parameters and intralimb coordination patterns describing hemiparetic locomotion at controlled speed

 I see nothing here that tells survivors EXACTLY how to recover walking. So more useless research. Damn, a lot of people supposedly working in stroke need to be fired.

Spatio-temporal parameters and intralimb coordination patterns describing hemiparetic locomotion at controlled speed

 
RESEARCH Open Access
Lucio A Rinaldi 1
and Vito Monaco 2*

Abstract

Background:
 

Comparison between healthy and hemiparetic gait is usually carried out while subjects walk overground at preferred speed. This generates bias due to the lack of uniformity across selected speeds because they reflect the great variability of the functional level of post-stroke patients. This study aimed at examining coordinative adaptations during walking in response to unilateral brain damage, while homologous participants walked at two fixed speeds.
Methods:
 

 Five patients with left and five with right chronic hemiparesis, characterized by similar level of motor functioning, were enrolled. Ten non-disabled volunteers were recruited as matched control group. Spatio-temporal parameters, and intralimb thigh-leg and leg-foot coordination patterns were used to compare groups while walking on a treadmill at 0.4 and 0.6 m/s. The likelihood of Continuous Relative Phase patterns between healthy and hemiparetic subjects was evaluated by means of the root mean square of the difference and the cross correlation coefficient. The effects of the group (i.e., healthy vs. hemiparetics), side (i.e., affected vs.unaffected), and speed(e.g., slow vs. fast) were analyzed on all metrics using the Analysis of Variance.
Results:
 

Spatio-temporal parameters of all hemiparetic subjects did not significantly differ from those of healthy subjects nor showed any asymmetry between affected and unaffected limbs. Conversely, both thigh-leg and foot-leg coordination patterns appeared to account for pathology related modifications.
Conclusion:
 

Comparisons between hemiparetic and healthy gait should be carried out when all participants are asked to seek the same suitable dynamic equilibrium led by the same external (i.e., the speed) and internal(i.e., severity of the pathology) conditions. In this respect, biomechanical adaptations reflecting the pathology can be better highlighted by coordinative patterns of coupled segments within each limb than by the spatio-temporal parameters. Accordingly, a deep analysis of the intralimb coordination may be helpful for clinicians while designing therapeutic treatments.
Keywords:
 Hemiparetic gait, Fixed speeds, Spatio-temporal parameters, Intralimb coordination, Stroke
Background
Compensatory strategies adopted by post-stroke patients to increase stability and efficiency of locomotion have been widely described in literature by spatio-temporal parameters, kinematic, and kinetic measures referring to walking both overground [1-3] and on treadmill [4,5]. On the whole, the gait of post-stroke patients is mainly characterized by reduced speed, stride length, and cadence,decreased angular excursions at leg joints, increased energetic cost, and asymmetry in kinematic and kinetic variables [3]. Furthermore, a recent study highlighted that post-stroke patients walk with different patterns between treadmill and overground and, in particular, the treadmill enhances the asymmetry between affected and unaffected limbs, decreases the self-selected speed and the step length,and increases stance and double support percentages [6]. A cerebrovascular accident has been also shown to significantly modify the coordinative relationship of segments
* Correspondence: v.monaco@sssup.it
2
Istituto di BioRobotica, Scuola Superiore Sant
’
Anna, P.za Martiri della Libertà,33, 56127, Pisa, I, ItalyFull list of author information is available at the end of the article
JNER
 JOURNAL OF NEUROENGINEERINGAND REHABILITATION
© 2013 Rinaldi and Monaco; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of theCreative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use,distribution, and reproduction in any medium, provided the original work is properly cited.
Rinaldi and Monaco
 Journal of NeuroEngineering and Rehabilitation
 2013,
 10
:53http://www.jneuroengrehab.com/content/10/1/53

Music Restores Propriospinal Excitation During Stroke Locomotion

Since your doctors and stroke hospital DID NOTHING ON EARLIER MUSIC RESEARCH,  they are going to be fucking incompetent once again and DO NOTHING with this. 

• music (80 posts back to March 2011)

• music therapy (49 posts back to October 2014)

• musical training (13 posts back to June 2014)

The latest here:

Music Restores Propriospinal Excitation During Stroke Locomotion

Iseline Peyre^1,2, Berthe Hanna-Boutros³, Alexandra Lackmy-Vallee¹, Claire Kemlin⁴, Eléonore Bayen⁴, Pascale Pradat-Diehl^1,4 and Véronique Marchand-Pauvert^1*

• ¹Sorbonne Université, Inserm, CNRS, Laboratoire d'Imagerie Biomédicale, LIB, Paris, France
• ²Sorbonne Université, CNRS, Institut de Recherche et de Coordination en Acoustique Musique (IRCAM), UMR Sciences et Technologies de la Musique et du Son (STMS), Paris, France
• ³Physical Therapy Department, Holy Family University, Batroun, Lebanon
• ⁴Sorbonne Université, AP-HP, GRC n°24, Handicap Moteur et Cognitif & Réadaptation (HaMCRe), Paris, France

Music-based therapy for rehabilitation induces neuromodulation at the brain level and improves the functional recovery. In line with this, musical rhythmicity improves post-stroke gait. Moreover, an external distractor also helps stroke patients to improve locomotion. We raised the question whether music with irregular tempo (arrhythmic music), and its possible influence on attention would induce neuromodulation and improve the post-stroke gait. We tested music-induced neuromodulation at the level of a propriospinal reflex, known to be particularly involved in the control of stabilized locomotion; after stroke, the reflex is enhanced on the hemiparetic side. The study was conducted in 12 post-stroke patients and 12 controls. Quadriceps EMG was conditioned by electrical stimulation of the common peroneal nerve, which produces a biphasic facilitation on EMG, reflecting the level of activity of the propriospinal reflex between ankle dorsiflexors and quadriceps (CPQ reflex). The CPQ reflex was tested during treadmill locomotion at the preferred speed of each individual, in 3 conditions randomly alternated: without music vs. 2 arrhythmic music tracks, including a pleasant melody and unpleasant aleatory electronic sounds (AES); biomechanical and physiological parameters were also investigated. The CPQ reflex was significantly larger in patients during walking without sound, compared to controls. During walking with music, irrespective of the theme, there was no more difference between groups. In controls, music had no influence on the size of CPQ reflex. In patients, CPQ reflex was significantly larger during walking without sound than when listening to the melody or AES. No significant differences have been revealed concerning the biomechanical and the physiological parameters in both groups. Arrhythmic music listening modulates the spinal excitability during post-stroke walking, restoring the CPQ reflex activity to normality. The plasticity was not accompanied by any clear improvement of gait parameters, but the patients reported to prefer walking with music than without. The role of music as external focus of attention is discussed. This study has shown that music can modulate propriospinal neural network particularly involved in the gait control during the first training session. It is speculated that repetition may help to consolidate plasticity and would contribute to gait recovery after stroke.

Locomotion and cadence detection using a single trunk-fixed accelerometer: validity for children with cerebral palsy in daily life-like conditions

Our stroke researchers should be able to use this to objectively determine stroke gait problems. Then with that objective data we could map rehab protocols that fix those specific problems. But that won't occur, we don't have two neurons to rub together to create a spark of innovative thought in stroke. 

Locomotion and cadence detection using a single trunk-fixed accelerometer: validity for children with cerebral palsy in daily life-like conditions

• Anisoara Paraschiv-IonescuEmail author,
• Christopher Newman,
• Lena Carcreff,
• Corinna N. Gerber,
• Stephane Armand and
• Kamiar Aminian

Journal of NeuroEngineering and Rehabilitation201916:24

https://doi.org/10.1186/s12984-019-0494-z

©  The Author(s). 2019

• Received: 5 July 2018
• Accepted: 25 January 2019
• Published: 4 February 2019

Abstract

Background

Physical therapy interventions for ambulatory youth with cerebral palsy (CP) often focus on activity-based strategies to promote functional mobility and participation in physical activity. The use of activity monitors validated for this population could help to design effective personalized interventions by providing reliable outcome measures. The objective of this study was to devise a single-sensor based algorithm for locomotion and cadence detection, robust to atypical gait patterns of children with CP in the real-life like monitoring conditions.

Methods

Study included 15 children with CP, classified according to Gross Motor Function Classification System (GMFCS) between levels I and III, and 11 age-matched typically developing (TD). Six IMU devices were fixed on participant’s trunk (chest and low back/L5), thighs, and shanks. IMUs on trunk were independently used for development of algorithm, whereas the ensemble of devices on lower limbs were used as reference system. Data was collected according to a semi-structured protocol, and included typical daily-life activities performed indoor and outdoor.

The algorithm was based on detection of peaks associated to heel-strike events, identified from the norm of trunk acceleration signals, and included several processing stages such as peak enhancement and selection of the steps-related peaks using heuristic decision rules. Cadence was estimated using time- and frequency–domain approaches. Performance metrics were sensitivity, specificity, precision, error, intra-class correlation coefficient, and Bland-Altman analysis.

Results

According to GMFCS, CP children were classified as GMFCS I (n = 7), GMFCS II (n = 3) and GMFCS III (n = 5). Mean values of sensitivity, specificity and precision for locomotion detection ranged between 0.93–0.98, 0.92–0.97 and 0.86–0.98 for TD, CP-GMFCS I and CP-GMFCS II-III groups, respectively.

Mean values of absolute error for cadence estimation (steps/min) were similar for both methods, and ranged between 0.51–0.88, 1.18–1.33 and 1.94–2.3 for TD, CP-GMFCS I and CP-GMFCS II-III groups, respectively. The standard deviation was higher in CP-GMFCS II-III group, the lower performances being explained by the high variability of atypical gait patterns.

Conclusions

The algorithm demonstrated good performance when applied to a wide range of gait patterns, from normal to the pathological gait of highly affected children with CP using walking aids.

The Human Central Pattern Generator for Locomotion: Does It Exist and Contribute to Walking?

Descibing a possible solution but not enough to do any good. More followup needed which will never occur. My takeaway from this is that if they figure how to make this work, people like me that have dead pre-motor cortexes should be able to walk normally again.


http://journals.sagepub.com/doi/abs/10.1177/1073858417699790

Show all authors

Karen Minassian, Ursula S. Hofstoetter, Florin Dzeladini, ...

First Published March 28, 2017 Review Article

Download PDF	Article information

Abstract

The ability of dedicated spinal circuits, referred to as central pattern generators (CPGs), to produce the basic rhythm and neural activation patterns underlying locomotion can be demonstrated under specific experimental conditions in reduced animal preparations. The existence of CPGs in humans is a matter of debate. Equally elusive is the contribution of CPGs to normal bipedal locomotion. To address these points, we focus on human studies that utilized spinal cord stimulation or pharmacological neuromodulation to generate rhythmic activity in individuals with spinal cord injury, and on neuromechanical modeling of human locomotion. In the absence of volitional motor control and step-specific sensory feedback, the human lumbar spinal cord can produce rhythmic muscle activation patterns that closely resemble CPG-induced neural activity of the isolated animal spinal cord. In this sense, CPGs in humans can be defined by the activity they produce. During normal locomotion, CPGs could contribute to the activation patterns during specific phases of the step cycle and simplify supraspinal control of step cycle frequency as a feedforward component to achieve a targeted speed. Determining how the human CPGs operate will be essential to advance the theory of neural control of locomotion and develop new locomotor neurorehabilitation paradigms.

Effects of robotic guidance on the coordination of locomotion

Ask your therapist for guidance.
http://www.jneuroengrehab.com/content/10/1/79/abstract

Abstract (provisional)

Background

Functional integration of motor activity patterns enables the production of coordinated movements, such as walking. The activation of muscles by weightened summation of activation signals has been demonstrated to represent the spatiotemporal components that determine motor behavior during walking. Exoskeleton robotic devices are now often used in the rehabilitation practice to assist physical therapy of individuals with neurological disorders. These devices are used to promote motor recovery by providing guidance force to the patients. The guidance should in principle lead to a muscle coordination similar to physiological human walking. However, the influence of robotic devices on locomotor patterns needs still to be characterized. The aim of this study was to analyze the effect of force guidance and gait speed on the modular organization of walking in a group of eight healthy subjects.

Method

A group of healthy subjects walked on a treadmill with and without robotic aiding at speeds of 1.5, 2.0 and 2.5 Km/h. The guidance force was varied between 20%, 40%, 70% and 100% level of assistance. EMG recordings were obtained from seven leg muscles of the dominant leg and kinematic and kinetic features of the knee and hip joints were extracted.

Results

Four motor modules were sufficient to represent the variety of behavioral goals demanded during robotic guidance, with similar relationships between muscle patterns and biomechanical parameters across subjects, confirming that the low-dimensional and impulsive control of human walking is maintained using robotic force guidance. The conditions of guidance force and speed that maintained correct and incorrect (not natural) modular control were identified.

Conclusion

In neurologically intact subjects robotic-guided walking at various force guidance and speed levels does not alter the basic locomotor control and timing. This allows the design of robotic-aided rehabilitation strategies aimed at the modulation of motor modules, which are altered in stroke.

The complete article is available as a provisional PDF. The fully formatted PDF and HTML versions are in production.

Altered steering strategies for goal-directed locomotion in stroke

Ask your therapist what this means.
http://www.jneuroengrehab.com/content/10/1/80/abstract

Abstract (provisional)

Background

Individuals who have sustained a stroke can manifest altered locomotor steering behaviors when exposed to optic flows expanding from different locations. Whether these alterations persist in the presence of a visible goal and whether they can be explained by the presence of a perceptuo-motor disorder remain unknown. The purpose of this study was to compare stroke participants and healthy participants on their ability to control heading while exposed to changing optic flows and target locations.

Methods

Ten participants with stroke (55.6 +/- 9.3 yrs) and ten healthy controls (57.0 +/- 11.5 yrs) participated in a mouse-driven steering task (perceptuo-motor task) while seated and in a walking steering task. In the seated steering task, participants were instructed to head or 'walk' toward a target in the virtual environment by using a mouse while wearing a helmet-mounted display (HMD). In the walking task, participants performed a similar steering task in the same virtual environment while walking overground at their comfortable speed. For both experiments, the target and/or the focus of expansion (FOE) of the optic flow shifted to the side (+/-20[degree sign]) or remained centered. The main outcome measure was net heading errors (NHE). Secondary outcomes included mediolateral displacement, horizontal head orientation, and onsets of heading and head reorientation.

Results

In the walking steering task, the presence of FOE shifts modulated the extent and timing of mediolateral displacement and head rotation changes, as well as NHE magnitudes. Participants overshot and undershot their net heading, respectively, in response to ipsilateral and contralateral FOE and target shifts. Stroke participants made larger NHEs, especially when the FOE was shifted towards the non-paretic side. In the seated steering task, similar NHEs were observed between stroke and healthy participants.

Conclusions

The findings highlight the fine coordination between rotational and translational steering mechanisms in presence of targets and FOE shifts. The altered performance of stroke participants in walking but not in the seated steering task suggests that an altered perceptuo-motor processing of optic flow is not a main contributing factor and that other stroke-related sensorimotor deficits are involved.

The complete article is available as a provisional PDF. The fully formatted PDF and HTML versions are in production.

Dynamic primitives in the control of locomotion

Sounds like a basic building block that we should start with to recover our motor control again. Ask your therapist how to utilize this.
http://www.frontiersin.org/computational_neuroscience/10.3389/fncom.2013.00071/full?
Some great equations in the article, ask about them. Special html to print that equation.

${\dot{x}}_j(t)={\hat{v}}_j\sigma (t),j=1\dots n$

Humans achieve locomotor dexterity that far exceeds the capability of modern robots, yet this is achieved despite slower actuators, imprecise sensors, and vastly slower communication. We propose that this spectacular performance arises from encoding motor commands in terms of dynamic primitives. We propose three primitives as a foundation for a comprehensive theoretical framework that can embrace a wide range of upper- and lower-limb behaviors. Building on previous work that suggested discrete and rhythmic movements as elementary dynamic behaviors, we define submovements and oscillations: as discrete movements cannot be combined with sufficient flexibility, we argue that suitably-defined submovements are primitives.

As the term “rhythmic” may be ambiguous, we define oscillations as the corresponding class of primitives. We further propose mechanical impedances as a third class of dynamic primitives, necessary for interaction with the physical environment. Combination of these three classes of primitive requires care. One approach is through a generalized equivalent network: a virtual trajectory composed of simultaneous and/or sequential submovements and/or oscillations that interacts with mechanical impedances to produce observable forces and motions. Reliable experimental identification of these dynamic primitives presents challenges: identification of mechanical impedances is exquisitely sensitive to assumptions about their dynamic structure; identification of submovements and oscillations is sensitive to their assumed form and to details of the algorithm used to extract them. Some methods to address these challenges are presented. Some implications of this theoretical framework for locomotor rehabilitation are considered.

Introduction

In a recent publication, we asserted a pressing need for a fundamental mathematical theory to help organize and structure the prodigious volume of knowledge about sensorimotor control (Hogan and Sternad, 2012). We contend that such a theory has come within reach, though we anticipate that its development will require a process of continuous and incremental revision. While it is common practice to develop mathematical models for narrowly-specified sensorimotor tasks, to establish a reliable theoretical foundation it is necessary to take a broader perspective and consider the widest feasible range of behaviors—even if for no other reason than to uncover and confront facts that might prove embarrassing to a narrowly-formulated theory. Previously we outlined a theoretical framework for upper-extremity motor control that could encompass those quintessentially human behaviors, object manipulation and the use of tools. The goal of this essay is to extend this framework to lower-extremity motor control. To illustrate the potential value of such a theory we consider some of its possible implications for locomotor rehabilitation.

Of course, we acknowledge that an integrated theory of upper- and lower-extremity motor control is ambitious, but it ought to be possible—after all, there is only one central nervous system (CNS). Moreover, many commonplace actions require integrated control and coordination of upper and lower extremities, indeed of the entire body. For example, drilling a horizontal hole in a vertical wall using a hand-held drill is commonly performed in a standing position. Therefore, the force exerted by the hand on the drill and wall necessitates tangential force on the ground at the feet. In fact, almost all of the body's degrees of freedom must be coordinated—essentially everything between the hands and feet. The horizontal force results in an overturning moment that must be offset by displacing the center of gravity from the center of pressure below the feet, and a sufficiently strong hand force is typically accomplished by moving the center of gravity far beyond the base of support—i.e., by leaning hard into the push or pull (Dempster, 1958; Rancourt and Hogan, 2001). 

That is a common cause of falls if the horizontal force exceeds the frictional force between feet and ground and the feet slip (Grieve, 1983). Moreover, with feet together in this leaning posture, an unstable dynamic zero is introduced such that the hand force cannot decrease without transiently increasing, and vice-versa (Rancourt and Hogan, 2001). With feet far apart, that dynamic zero can be eliminated. The essential point is that the configuration of the feet dictates the dynamics of force exertion by the hands.

Even aside from the need to integrate upper- and lower-extremity motor control, the spectacular agility of human locomotion demands explanation. Even walking, that most mundane of behaviors, is a subtle and complex dynamic process. Despite intensive and ongoing research, the dynamics of human walking have yet to be reproduced by robots, even though they have actuators faster than muscle by factors of tens to thousands, and communication faster than neurons by a factor of a million or more (Kandel et al., 2000; Hogan and Sternad, 2012). But locomotor behavior is far more versatile than walking. For example, soccer, arguably the world's most popular sport, not only requires agile high-speed maneuvering to avoid equally agile opponents, but controlling the ball requires dexterity with the legs and feet comparable to that of the hands and fingers. In comparison, robot soccer—though fun, highly motivating, and a superb enticement to study science and engineering—is a pale shadow of the “beautiful game.”

Much more at link.

Robot locomotion

Great discussion on what it takes for locomotion and dynamic balance employed by people and animals. I loved the 4 legged robot  following the human around. If they can build this, whats so difficult about 2 legged assisted locomotion for us.

 http://www.somasimple.com/forums/showthread.php?s=330af766a5fceb0d7d4226e028f74289&t=14354