scholarly journals Balance strategy in hoverboard control

2021 ◽  
Author(s):  
Mohammad Shushtari ◽  
Atsushi Takagi ◽  
Judy Lee ◽  
Etienne Burdet ◽  
Arash Arami
Keyword(s):  
Muscle Activation ◽  
Control Strategies ◽  
Dynamic Balance ◽  
Time Warping ◽  
Activation Patterns ◽  
Ankle Strategy ◽  
Co Activation ◽  
How People Learn ◽  
Dynamic Time ◽  
And Control

Abstract This work investigates how people learn to perform lower limb control in a novel task with a hoverboard which requires maintaining dynamic balance. An experiment was designed to investigate the learning of balance and control strategies: i.e. hip versus ankle strategy. Motor learning was indicated by a decrease in total muscle activation and time to complete a trial. The results further show that participants with no prior experience of riding a hoverboard learn an ankle strategy to maintain their balance and control the hoverboard. This is supported by significantly stronger phase synchrony and lower dynamic time warping distance between the hoverboard plate orientation, that controls hoverboard motion, and the ankle angle when compared to the hip angle. A decrease of 14.2% in the co-activation of the muscles acting on the ankle joint also confirms the adoption of the ankle strategy. The adopted ankle strategy is robust to the foot orientation despite salient changes in muscle group activation patterns.

Development of a soft cable-driven hand exoskeleton for assisted rehabilitation training

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dawen Xu ◽  
Qingcong Wu ◽  
Yanghui Zhu
Keyword(s):  
Muscle Activation ◽  
Control Strategies ◽  
Motor Dysfunction ◽  
Force Transmission ◽  
Content Type ◽  
Rehabilitation Training ◽  
Local Structures ◽  
Hand Exoskeleton ◽  
And Control

Purpose Hand motor dysfunction has seriously reduced people’s quality of life. The purpose of this paper is to solve this problem; different soft exoskeleton robots have been developed because of their good application prospects in assistance. In this paper, a new soft hand exoskeleton is designed to help people conduct rehabilitation training. Design/methodology/approach The proposed soft exoskeleton is an under-actuated cable-driven mechanism, which optimizes the force transmission path and many local structures. Specifically, the path of force transmission is optimized and cables are wound around cam-shaped spools to prevent cables lose during fingers movement. Besides, a pre-tightening system is presented to adjust the preload force of the cable-tube. Moreover, a passive brake mechanism is proposed to prevent the cables from falling off the spools when the remote side is relaxed. Findings Finally, three control strategies are proposed to assist in rehabilitation training. Results show that the average correlation coefficient of trajectory tracking is 90.99% and this exoskeleton could provide steady clamping force up to 35 N, which could meet the demands of activities in daily living. Surface electromyography (sEMG)-based intention recognition method is presented to complete assistance and experiments are conducted to prove the effectiveness of the assisted grasping method by monitoring muscle activation, finger angle and interactive force. Research limitations/implications However, the system should be further optimized in terms of hardware and control to reduce delays. In addition, more clinical trials should be conducted to evaluate the effect of the proposed rehabilitation strategies. Social implications May improve the ability of hemiplegic patients to live independently. Originality/value A novel under-actuated soft hand exoskeleton structure is proposed, and an sEMG-based auxiliary grasping control strategy is presented to help hemiplegic patients conduct rehabilitation training.

scholarly journals From maturity to old age: tasks of daily life require a different muscle use in horses

2014 ◽  
Vol 10 (2) ◽  
pp. 75-88 ◽  
Author(s):  
R.R. Zsoldos ◽  
B. Krüger ◽  
T.F. Licka
Keyword(s):  
Life Expectancy ◽  
Muscle Activity ◽  
Dynamic Time Warping ◽  
Muscle Activation ◽  
Daily Life ◽  
Age Groups ◽  
Time Warping ◽  
Neck Extension ◽  
Neck Position ◽  
Dynamic Time

In vertebrates ageing is characterised by reduced viscoelasticity of the ligamentous and tendineous structures and fibre changes in muscle. Also, some vertebral joint degeneration develops with ageing. The aim of this study was to apply dynamic time warping to compare the temporal characteristics of the surface electromyography (sEMG) data and to illustrate the differences in the pattern of muscle use during tasks of daily life in old and mature horses. In vivo kinematics (24 skin markers) and sEMG measurements of neck extensors and flexors were taken in five mature horses (aged 10±2 years, half of mean life expectancy) and five old horses (aged 25±5 years, older than the mean life expectancy). All horses had the same level of activity in the 12 months prior to the measurement. Tasks measured were neck flexion and neck extension as well as neutral neck position. Muscle activation, minimum and maximum muscle activation were collected. Quartiles of muscle activity based on the maximum observed activity of each muscle were calculated to document the relative increase of activity level during the task. Kinematics as well as overall muscle activity patterns were similar across horses and age groups. However, in the neutral position old horses showed increased extensor activity compared to mature horses, indicating that old equine muscle requires more activity to counteract gravity. Dynamic time warping specified optimal temporal alignments of time series, and different temporal performances were identified. The age groups differed during the flexion task, while neck extension and neutral neck position were more similar. The results of this study show that even in the second half of life and in the absence of muscle disuse the muscular strategy employed by horses continues to be adapted.

scholarly journals A Statistical Approach for the Assessment of Muscle Activation Patterns during Gait in Parkinson’s Disease

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1641
Author(s):  
Giulia Pacini Panebianco ◽  
Davide Ferrazzoli ◽  
Giuseppe Frazzitta ◽  
Margherita Fonsato ◽  
Maria Cristina Bisi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Tibialis Anterior ◽  
Muscle Activation ◽  
Statistical Approach ◽  
Healthy Adults ◽  
Activation Patterns ◽  
Gastrocnemius Medialis ◽  
Muscle Activation Patterns ◽  
Co Activation

Recently, the statistical analysis of muscle activation patterns highlighted that not only one, but several activation patterns can be identified in the gait of healthy adults, with different occurrence. Although its potential, the application of this approach in pathological populations is still limited and specific implementation issues need to be addressed. This study aims at applying a statistical approach to analyze muscle activation patterns of gait in Parkinson’s Disease, integrating gait symmetry and co-activation. Surface electromyographic signal of tibialis anterior and gastrocnemius medialis were recorded during a 6-min walking test in 20 patients. Symmetry between right and left stride time series was verified, different activation patterns identified, and their occurrence (number and timing) quantified, as well as the co-activation of antagonist muscles. Gastrocnemius medialis presented five activation patterns (mean occurrence ranging from 2% to 43%) showing, with respect to healthy adults, the presence of a first shorted and delayed activation (between flat foot contact and push off, and in the final swing) and highlighting a new second region of anticipated activation (during early/mid swing). Tibialis anterior presented five activation patterns (mean occurrence ranging from 3% to 40%) highlighting absent or delayed activity at the beginning of the gait cycle, and generally shorter and anticipated activations during the swing phase with respect to healthy adults. Three regions of co-contraction were identified: from heel strike to mid-stance, from the pre- to initial swing, and during late swing. This study provided a novel insight in the analysis of muscle activation patterns in Parkinson’s Disease patients with respect to the literature, where unique, at times conflicting, average patterns were reported. The proposed integrated methodology is meant to be generalized for the analysis of muscle activation patterns in pathologic subjects.

Differences in trapezius muscle activation patterns in office workers with and without chronic neck-shoulder pain, as quantified through exposure variation analysis

2018 ◽  
Vol 62 (1) ◽  
pp. 962-966
Author(s):  
Denean Kelson ◽  
Divya Srinivasan ◽  
Svend Erik Mathiassen
Keyword(s):  
Chronic Pain ◽  
Shoulder Pain ◽  
Muscle Activation ◽  
Trapezius Muscle ◽  
Variation Analysis ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Upper Trapezius ◽  
Exposure Variation Analysis ◽  
And Control

The purpose of this study was to quantify upper-trapezius muscle activation patterns using exposure variation analysis (EVA) in healthy computer workers and those with chronic neck-shoulder pain. Eight healthy and five chronic pain participants were asked to complete three computer-based tasks (TYPE, CLICK, and FORM) in two pacing conditions (self-paced and control-paced). EVA was used to quantify variation using five amplitude classes and five duration classes. Performance in each task was also quantified. Healthy workers and those with chronic pain did not differ in performance, and they both exhibited similarly low levels of muscle activation amplitude. Pain participants, however, were found to spend less time in lower duration classes across tasks and conditions. These results indicate that individuals with chronic neck-shoulder pain utilize movement strategies involving sustained durations of continuous muscle activation. This may be suggestive of decreased temporal variation in muscle activation patterns in those with chronic pain.

An EMG-Driven Forward Dynamics Model to Simulate Stance Phase of Gait

2009 ◽  
Author(s):  
Qi Shao ◽  
Kurt Manal ◽  
Thomas S. Buchanan
Keyword(s):  
Muscle Activation ◽  
Stance Phase ◽  
Control Strategies ◽  
Neuromuscular Control ◽  
Human Movement ◽  
Joint Torque ◽  
Forward Dynamics ◽  
Activation Patterns ◽  
Joint Torques ◽  
Muscle Activation Patterns

Simulations based on forward dynamics have been used to identify the biomechanical mechanisms how human movement is generated. They used either net joint torques [1] or muscle forces [2, 3, 4] as actuators to drive forward simulation. However, very few models used EMG-based patterns to define muscle excitations [4] or were actually driven by EMGs. Muscle activation patterns vary from subject to subject and from movement to movement, and the activations depend on the control task, sometimes quite different even for the same joint angle and joint torque [5]. Using EMG as input can account for subjects’ different muscle activation patterns and help revealing the neuromuscular control strategies.

scholarly journals Between Limb Muscle Co-activation Patterns in the Paretic Arm During Non-paretic Arm Tasks in Hemiparetic Cerebral Palsy

2021 ◽  
Vol 15 ◽  
Author(s):  
Nayo M. Hill ◽  
Theresa Sukal-Moulton ◽  
Julius P. A. Dewald
Keyword(s):  
Cerebral Palsy ◽  
Upper Extremity ◽  
Muscle Activation ◽  
Fine Motor ◽  
Shoulder Abduction ◽  
Descending Pathways ◽  
Activation Patterns ◽  
Effort Level ◽  
Co Activation ◽  
Muscle Activations

Tasks of daily life require the independent use of the arms and hands. Individuals with hemiparetic cerebral palsy (HCP) often experience difficulty with fine motor tasks demonstrating mirrored movements between the arms. In this study, bilateral muscle activations were quantified during single arm isometric maximum efforts and submaximal reaching tasks. The magnitude and direction of mirrored activation was examined in 14 individuals with HCP and 9 age-matched controls. Participants generated maximum voluntary torques (MVTs) in five different directions and completed ballistic reaches while producing up to 80% of shoulder abduction MVT. Electromyography (EMG) signals were recorded from six upper extremity muscles bilaterally. Participants with HCP demonstrated more mirrored activation when volitionally contracting the non-paretic (NP) arm than the paretic arm (F = 83.543, p < 0.001) in isometric efforts. Increased EMG activation during reach acceleration resulted in a larger increase in rest arm co-activation when reaching with the NP arm compared to the paretic arm in the HCP group (t = 8.425, p < 0.001). Mirrored activation is more pronounced when driving the NP arm and scales with effort level. This directionality of mirroring is indicative of the use of ipsilaterally terminating projections of the corticospinal tract (CST) originating in the non-lesioned hemisphere. Peripheral measures of muscle activation provide insight into the descending pathways available for control of the upper extremity after early unilateral brain injury.

Estimation of Corrective Changes in Muscle Activation Patterns for Stroke Patients During FES Intervention

2007 ◽  
Author(s):  
Qi Shao ◽  
Daniel N. Bassett ◽  
Kurt Manal ◽  
Thomas S. Buchanan
Keyword(s):  
Electrical Stimulation ◽  
Muscle Activation ◽  
Control Strategies ◽  
Biomechanical Model ◽  
Stroke Patients ◽  
Activation Patterns ◽  
Know How ◽  
Muscle Activation Patterns ◽  
Person Following ◽  
Human Movements

Functional electrical stimulation (FES) has been used in the rehabilitation of stroke patients. It is important to know how to stimulate the muscles when using FES. Many control methods have been used to derive the required electrical stimulation patterns. However, these models were not developed based on biomechanical model of human neuromuscular system, thus can not account for sophisticated neurological control strategies during human movements. Based on our developed electromyography (EMG) driven model, we have created a biomechanical model to estimate the corrective increases in muscle activation patterns needed for a person following stroke to walk with an improved normal gait.

scholarly journals Influence of Age on Neuromuscular Control during a Dynamic Weight-Bearing Task

2009 ◽  
Vol 17 (3) ◽  
pp. 327-343 ◽  
Author(s):  
Sangeetha Madhavan ◽  
Sarah Burkart ◽  
Gail Baggett ◽  
Katie Nelson ◽  
Trina Teckenburg ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Control Strategies ◽  
Weight Bearing ◽  
Neuromuscular Control ◽  
The Elderly ◽  
Joint Injury ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Knee Movement ◽  
Long Latency

Neuromuscular control strategies might change with age and predispose the elderly to knee-joint injury. The purposes of this study were to determine whether long latency responses (LLRs), muscle-activation patterns, and movement accuracy differ between the young and elderly during a novel single-limb-squat (SLS) task. Ten young and 10 elderly participants performed a series of resistive SLSs (~0–30°) while matching a computer-generated sinusoidal target. The SLS device provided a 16% body-weight resistance to knee movement. Both young and elderly showed significant overshoot error when the knee was perturbed (p< .05). Accuracy of the tracking task was similar between the young and elderly (p= .34), but the elderly required more muscle activity than the younger participants (p< .05). The elderly group had larger LLRs than the younger group (p< .05). These results support the hypothesis that neuromuscular control of the knee changes with age and might contribute to injury.

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