Identifying the Dynamics of Leg Muscle Activation During Human Gait Using Neural Oscillator and Fuzzy Compensator

Background: The goal of this study is to design a model in order to predict the muscle activation pattern because the muscle activation patterns contain valuable information about the muscle dynamics and movement patterns. Therefore, the goal of the presentation of this neural model is to identify the desired muscle activation patterns by Hopf chaotic oscillator during walking. Since the knee muscles activation has a significant effect on the movement pattern during walking, the main concentration of this study is to identify the knee muscles activation dynamics using a modeling technique. Methods: The electromyography (EMG) recording obtained from 5 healthy subjects that electrodes positioned on the tibialis-anterior (TA) and rectus femoris muscles on every 2 feet. In the proposed model, along with the chaotic oscillator, a fuzzy compensator was designed to face the unmolded dynamics. In fact, on the condition, the observed difference between the desired and actual activation patterns violate some specific quantitative ranges, the fuzzy compensator based on predefined rules modify the activity pattern produced by the Hopf oscillator. Results: Some quantitative measures used to evaluate the results. According to the achieved results, the proposed model could generate the trajectories, dynamics of which are similar to the muscle activation dynamics of the studied muscles. In this model, the generated activity pattern by the proposed model cannot follow the desired activity of the TA muscle as well as rectus femoris muscle. Conclusion: The similarity between the generated activity pattern by the model and the activation dynamics of Rectus- Femoris muscle was more in comparison with the similarity observed between activation pattern of Tibialis- Anterior and the pattern generated by the model. In other words, based on the recorded human data, the activation pattern of the Rectus- Femoris is more similar to a rhythmic pattern.

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Spatial muscle activation patterns during different leg exercise protocols in physically active adults using muscle functional MRI: a systematic review

Journal of Applied Physiology ◽

10.1152/japplphysiol.00290.2020 ◽

2020 ◽

Vol 129 (4) ◽

pp. 934-946

Author(s):

Katherine Dooley ◽

Suzanne J. Snodgrass ◽

Peter Stanwell ◽

Samantha Birse ◽

Adrian Schultz ◽

...

Keyword(s):

Muscle Activation ◽

Assessment Tool ◽

Meta Analysis ◽

Lumbar Vertebra ◽

Rectus Femoris ◽

Physically Active ◽

Activation Patterns ◽

Muscle Activation Patterns ◽

Research Questions ◽

Active Adults

An emerging method to measure muscle activation patterns is muscle functional magnetic resonance imaging (mfMRI), where preexercise and postexercise muscle metabolism differences indicate spatial muscle activation patterns. We evaluated studies employing mfMRI to determine activation patterns of lumbar or lower limb muscles following exercise in physically active adults. Electronic systematic searches were conducted until March 2020. All studies employing ≥1.5 Tesla MRI scanners to compare spatial muscle activation patterns at the level of or inferior to the first lumbar vertebra in healthy, active adults. Two authors independently assessed study eligibility before appraising methodological quality using a National Institutes of Health assessment tool. Because of heterogeneity, findings were synthesized without meta-analysis. Of the 1,946 studies identified, seven qualified for inclusion and pertained to hamstring ( n = 5), quadriceps ( n = 1) or extrinsic foot ( n = 1) muscles. All included studies controlled for internal validity, with one employing assessor blinding. MRI physics and differing research questions explain study methodology heterogeneity. Significant mfMRI findings were: following Nordic exercise, hamstrings with previous trauma (strain or surgical autograft harvest) demonstrated reduced activation compared with unharmed contralateral muscles, and asymptomatic individuals preferentially activated semitendinosus; greater biceps femoris long head to semitendinosus ratios reported following 45° hip extension over Nordic exercise; greater rectus femoris activation occurred in “flywheel” over barbell squats. mfMRI parameters differ on the basis of individual research questions. Individual muscles show greater activation following specific exercises, suggesting exercise specificity may be important for rehabilitation, although evidence is limited to single cohort studies comparing interlimb differences preexercise versus postexercise.

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Comparative Muscle Activation Patterns of Healthy Control Limbs and Contralateral Limbs in ACL Reconstruction

ASME 2012 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2012-80334 ◽

2012 ◽

Author(s):

Chelsea Marsh ◽

Scott Tashman

Keyword(s):

Acl Reconstruction ◽

Muscle Activation ◽

Vastus Lateralis ◽

Rectus Femoris ◽

Activation Patterns ◽

Muscle Activation Patterns ◽

Healthy Control ◽

Reconstructed Knee

ACL reconstruction (ACLr) has been found to restore the functionality and mobility of those afflicted with ACL tears. In the process of this restoration, previous work has shown alterations in the activity of the musculature surrounding the reconstructed knee [1]. Specifically, at 5 months post-op, the gastrocnemius, vastus lateralis, and rectus femoris demonstrate significantly different activation patterns. These differences raise the question if the reconstructed leg is the only limb affected by ACLr.

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Bilateral Limb Phase Relationship and Its Potential to Alter Muscle Activity Phasing During Locomotion

Journal of Neurophysiology ◽

10.1152/jn.00211.2009 ◽

2009 ◽

Vol 102 (5) ◽

pp. 2856-2865 ◽

Cited By ~ 9

Author(s):

Laila Alibiglou ◽

Citlali López-Ortiz ◽

Charles B. Walter ◽

David A. Brown

Keyword(s):

Muscle Activity ◽

Muscle Activation ◽

Angular Position ◽

Phase Relationship ◽

Rectus Femoris ◽

Activation Patterns ◽

Muscle Activation Patterns ◽

Relative Contribution ◽

Coordination Patterns ◽

Muscle Phasing

It is well established that the sensorimotor state of one limb can influence another limb and therefore bilateral somatosensory inputs make an important contribution to interlimb coordination patterns. However, the relative contribution of interlimb pathways for modifying muscle activation patterns in terms of phasing is less clear. Here we studied adaptation of muscle activity phasing to the relative angular positions of limbs using a split-crank ergometer, where the cranks could be decoupled to allow different spatial angular position relationships. Twenty neurologically healthy individuals performed the specified pedaling tasks at different relative angular positions while surface electromyographic (EMG) signals were recorded bilaterally from eight lower extremity muscles. During each experiment, the relative angular crank positions were altered by increasing or decreasing their difference by randomly ordered increments of 30° over the complete cycle [0° (in phase pedaling); 30, 60, 90, 120, 150, and 180° (standard pedaling); and 210, 240, 270, 300, and 330° out of phase pedaling]. We found that manipulating the relative angular positions of limbs in a pedaling task caused muscle activity phasing changes that were either delayed or advanced, dependent on the relative spatial position of the two cranks and this relationship is well-explained by a sine curve. Further, we observed that the magnitude of phasing changes in biarticular muscles (like rectus femoris) was significantly greater than those of uniarticular muscles (like vastus medialis). These results are important because they provide new evidence that muscle phasing can be systematically influenced by interlimb pathways.

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The Effect of External Weight Distribution on Muscle Activation Pattern during Obstacle Negotiation for Male Participants

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/1071181319631241 ◽

2019 ◽

Vol 63 (1) ◽

pp. 37-41

Author(s):

Guofu Yi ◽

Xinting Wang ◽

Junxia Zhang ◽

Shuai Hao ◽

Boyi Hu

Keyword(s):

Lower Extremity ◽

Load Distribution ◽

Muscle Activation ◽

Age Groups ◽

External Loading ◽

Activation Pattern ◽

Activation Patterns ◽

Muscle Activation Pattern ◽

Muscle Activation Patterns ◽

Lower Extremity Muscle

Effects of different age groups and different external loading distribution on lower extremity muscle activation during obstacle crossing tasks were tested in this study. Four young participants and five healthy senior participants performed different walking tasks at their own speed carrying multiple different weights while their lower extremity muscle activation patterns were recorded and compared. Older adults showed significantly increased muscle activation patterns in obstacle negotiation. Furthermore, participants showed altered lower extremity muscle activation patterns with different load distribution.

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Muscle Activation in World-Champion, World-Class, and National Breaststroke Swimmers

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2015-0703 ◽

2017 ◽

Vol 12 (4) ◽

pp. 538-547 ◽

Cited By ~ 5

Author(s):

Bjørn Harald Olstad ◽

Christoph Zinner ◽

João Rocha Vaz ◽

Jan M.H. Cabri ◽

Per-Ludvik Kjendlie

Keyword(s):

Tibialis Anterior ◽

Muscle Activation ◽

Rectus Femoris ◽

Biceps Femoris ◽

Triceps Brachii ◽

Activation Patterns ◽

Muscle Activation Patterns ◽

World Class ◽

World Champion ◽

Maximal Effort

Purpose:To investigate the muscle-activation patterns and coactivation with the support of kinematics in some of the world’s best breaststrokers and identify performance discriminants related to national elites at maximal effort.Methods:Surface electromyography was collected in 8 muscles from 4 world-class (including 2 world champions) and 4 national elite breaststroke swimmers during a 25-m breaststroke at maximal effort.Results:World-class spent less time during the leg recovery (P = .043), began this phase with a smaller knee angle (154.6° vs 161.8°), and had a higher median velocity of 0.18 m/s during the leg glide than national elites. Compared with national elites, world-class swimmers showed a difference in the muscle-activation patterns for all 8 muscles. In the leg-propulsion phase, there was less triceps brachii activation (1 swimmer 6% vs median 23.0% [8.8]). In the leg-glide phase, there was activation in rectus femoris and gastrocnemius during the beginning of this phase (all world-class vs only 1 national elite) and a longer activation in pectoralis major (world champions 71% [0.5] vs 50.0 [4.3]) (propulsive phase of the arms). In the leg-recovery phase, there was more activation in biceps femoris (50.0% [15.0] vs 20.0% [14.0]) and a later and quicker activation in tibialis anterior (40.0% [7.8] vs 52.0% [6.0]). In the stroke cycle, there was no coactivation in tibialis anterior and gastrocnemius for world champions.Conclusion:These components are important performance discriminants. They can be used to improve muscle-activation patterns and kinematics through the different breaststroke phases. Furthermore, they can be used as focus points for teaching breaststroke to beginners.

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Muscle Activation Patterns Correlate With Race Walking Economy in Elite Race Walkers: A Waveform Analysis

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2018-0851 ◽

2019 ◽

Vol 14 (9) ◽

pp. 1250-1255

Author(s):

Josu Gomez-Ezeiza ◽

Jordan Santos-Concejero ◽

Jon Torres-Unda ◽

Brian Hanley ◽

Nicholas Tam

Keyword(s):

Muscle Activation ◽

Gluteus Maximus ◽

Rectus Femoris ◽

Biceps Femoris ◽

Medial Gastrocnemius ◽

Initial Contact ◽

Activation Patterns ◽

Muscle Activation Patterns ◽

Race Walking ◽

Walking Economy

Purpose: To analyze the association between muscle activation patterns on oxygen cost of transport in elite race walkers over the entire gait waveform. Methods: A total of 21 Olympic race walkers performed overground walking trials at 14 km·h−1 where muscle activity of the gluteus maximus, adductor magnus, rectus femoris, biceps femoris, medial gastrocnemius, and tibialis anterior were recorded. Race walking economy was determined by performing an incremental treadmill test ending at 14 km·h−1. Results: This study found that more-economical race walkers exhibit greater gluteus maximus (P = .022, r = .716), biceps femoris (P = .011, r = .801), and medial gastrocnemius (P = .041, r = .662) activation prior to initial contact and weight acceptance. In addition, during the propulsive and the early swing phase, race walkers with higher activation of the rectus femoris (P = .021, r = .798) exhibited better race walking economy. Conclusions: This study suggests that the neuromuscular system is optimally coordinated through varying muscle activation to reduce the metabolic demand of race walking. These findings highlight the importance of proximal posterior muscle activation during initial contact and hip-flexor activation during early swing phase, which are associated with efficient energy transfer. Practically, race walking coaches may find this information useful in the development of specific training strategies on technique.

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The cost of being stable: Trade-offs between effort and stability across a landscape of redundant motor solutions

10.1101/477083 ◽

2018 ◽

Author(s):

M. Hongchul Sohn ◽

Lena H. Ting

Keyword(s):

Muscle Activity ◽

Muscle Activation ◽

Activation Pattern ◽

Activation Patterns ◽

Trade Off ◽

Muscle Activation Pattern ◽

Muscle Activation Patterns ◽

Limb Dynamics ◽

Trade Offs ◽

Muscular Effort

AbstractCurrent musculoskeletal modeling approaches cannot account for variability in muscle activation patterns seen across individuals, who may differ in motor experience, motor training, or neurological health. While musculoskeletal simulations typically select muscle activation patterns that minimize muscular effort, and generate unstable limb dynamics, a few studies have shown that maximum-effort solutions can improve limb stability. Although humans and animals likely adopt solutions between these two extremes, we lack principled methods to explore how effort and stability shape how muscle activation patterns differ across individuals. Here we characterized trade-offs between muscular effort and limb stability in selecting muscle activation patterns for an isometric force generation task in a musculoskeletal model of the cat hindlimb. We define effort as the sum of squared activation across all muscles, and limb stability by the maximum real part of the eigenvalues of the linearized musculoskeletal system dynamics, with more negative values being more stable. Surprisingly, stability increased rapidly with only small increases in effort from the minimum-effort solution, suggesting that very small amounts of muscle coactivation are beneficial for postural stability. Further, effort beyond 40% of the maximum possible effort did not confer further increases in stability. We also found multiple muscle activation patterns with equivalent effort and stability, which could underlie variability observed across individuals with similar motor ability. Trade-off between muscle effort and limb stability could underlie diversity in muscle activation patterns observed across individuals, disease, learning, and rehabilitation.Author summaryCurrent computational musculoskeletal models select muscle activation patterns that minimize the amount of muscle activity used to generate a movement, creating unstable limb dynamics. However, experimentally, muscle activation patterns with various level of co-activation are observed for performing the same task both within and across individuals that likely help to stabilize the limb. Here we show that a trade-off between muscular effort and limb stability across the wide range of possible muscle activation patterns for a motor task could explain the diversity of muscle activation patterns seen across individuals, disease, learning and rehabilitation. Increased muscle activity is necessary to stabilize the limb, but could also limit the ability to learn new muscle activation pattern, potentially providing a mechanism to explain individual-specific muscle coordination patterns in health and disease. Finally, we provide a straightforward method for improving the physiological relevance of muscle activation pattern and musculoskeletal stability in simulations.

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Is the Occurrence of the Sticking Region in Maximum Smith Machine Squats the Result of Diminishing Potentiation and Co-Contraction of the Prime Movers among Recreationally Resistance Trained Males?

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18031366 ◽

2021 ◽

Vol 18 (3) ◽

pp. 1366

Author(s):

Roland van den Tillaar ◽

Eirik Lindset Kristiansen ◽

Stian Larsen

Keyword(s):

Muscle Activity ◽

Muscle Activation ◽

Gluteus Maximus ◽

Knee Extensors ◽

Force Output ◽

Activation Patterns ◽

Muscle Activation Patterns ◽

Prime Movers ◽

Almost All ◽

Height Data

This study compared the kinetics, barbell, and joint kinematics and muscle activation patterns between a one-repetition maximum (1-RM) Smith machine squat and isometric squats performed at 10 different heights from the lowest barbell height. The aim was to investigate if force output is lowest in the sticking region, indicating that this is a poor biomechanical region. Twelve resistance trained males (age: 22 ± 5 years, mass: 83.5 ± 39 kg, height: 1.81 ± 0.20 m) were tested. A repeated two-way analysis of variance showed that Force output decreased in the sticking region for the 1-RM trial, while for the isometric trials, force output was lowest between 0–15 cm from the lowest barbell height, data that support the sticking region is a poor biomechanical region. Almost all muscles showed higher activity at 1-RM compared with isometric attempts (p < 0.05). The quadriceps activity decreased, and the gluteus maximus and shank muscle activity increased with increasing height (p ≤ 0.024). Moreover, the vastus muscles decreased only for the 1-RM trial while remaining stable at the same positions in the isometric trials (p = 0.04), indicating that potentiation occurs. Our findings suggest that a co-contraction between the hip and knee extensors, together with potentiation from the vastus muscles during ascent, creates a poor biomechanical region for force output, and thereby the sticking region among recreationally resistance trained males during 1-RM Smith machine squats.

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Electromyographic activation patterns during swallowing in older adults

Scientific Reports ◽

10.1038/s41598-021-84972-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jin Young Ko ◽

Hayoung Kim ◽

Joonyoung Jang ◽

Jun Chang Lee ◽

Ju Seok Ryu

Keyword(s):

Older Adults ◽

Viscous Fluid ◽

Muscle Activation ◽

Fatty Infiltration ◽

Liquid Volume ◽

Type I ◽

Type Ii ◽

Activation Patterns ◽

Muscle Activation Patterns ◽

Age Related

AbstractAge-related weakness due to atrophy and fatty infiltration in oropharyngeal muscles may be related to dysphagia in older adults. However, little is known about changes in the oropharyngeal muscle activation pattern in older adults. This was a prospective and experimental study. Forty healthy participants (20 older [> 60 years] and 20 young [< 60 years] adults) were enrolled. Six channel surface electrodes were placed over the bilateral suprahyoid (SH), bilateral retrohyoid (RH), thyrohyoid (TH), and sternothyroid (StH) muscles. Electromyography signals were then recorded twice for each patient during swallowing of 2 cc of water, 5 cc of water, and 5 cc of a highly viscous fluid. Latency, duration, and peak amplitude were measured. The activation patterns were the same, in the order of SH, TH, and StH, in both groups. The muscle activation patterns were classified as type I and II; the type I pattern was characterized by a monophasic shape, and the type II comprised a pre-reflex phase and a main phase. The oropharyngeal muscles and SH muscles were found to develop a pre-reflex phase specifically with increasing volume and viscosity of the swallowed fluid. Type I showed a different response to the highly viscous fluid in the older group compared to that in the younger group. However, type II showed concordant changes in the groups. Therefore, healthy older people were found to compensate for swallowing with a pre-reflex phase of muscle activation in response to increased liquid volume and viscosity, to adjust for age-related muscle weakness.

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