Muscle Activation Research Articles

An open-source toolbox for enhancing the assessment of muscle activation patterns during cyclical movements

Objective.The accurate temporal analysis of muscle activations is of great importance in several research areas spanning from the assessment of altered muscle activation patterns in orthopaedic and neurological patients to the monitoring of their motor rehabilitation. Several studies have highlighted the challenge of understanding and interpreting muscle activation patterns due to the high cycle-by-cycle variability of the sEMG data. This makes it difficult to interpret results and to use sEMG signals in clinical practice. To overcome this limitation, this study aims at presenting a toolbox to help scientists easily characterize and assess muscle activation patterns during cyclical movements.Approach.CIMAP(Clustering for the Identification of Muscle Activation Patterns) is an open-source Python toolbox based on agglomerative hierarchical clustering that aims at characterizing muscle activation patterns during cyclical movements by grouping movement cycles showing similar muscle activity.Main results.From muscle activation intervals to the graphical representation of the agglomerative hierarchical clustering dendrograms, the proposed toolbox offers a complete analysis framework for enabling the assessment of muscle activation patterns. The toolbox can be flexibly modified to comply with the necessities of the scientist.CIMAPis addressed to scientists of any programming skill level working in different research areas such as biomedical engineering, robotics, sports, clinics, biomechanics, and neuroscience. CIMAP is freely available on GitHub (https://github.com/Biolab-PoliTO/CIMAP).Significance.CIMAPtoolbox offers scientists a standardized method for analyzing muscle activation patterns during cyclical movements.

Altering prosthetic alignment does not affect hip and low back joint loading during sit-to-stand in people with a transtibial amputation

People with a transtibial amputation (TTA) have greater prevalence of low back and hip joint pain compared to the general population. Altered movement, loading patterns, and neuromuscular activation during daily tasks like sit-to-stand likely contribute to these high rates of pain. In addition, muscle activation, ground reaction forces, and trunk range of motion can be affected by prosthetic alignment during sit-to-stand. However, it is unclear how prosthetic alignment affects joint contact forces during this task. The purpose of this study was to investigate the effect of prosthetic alignment on hip and low-back joint loading in people with TTA during sit-to-stand. Kinematics, ground reaction forces, and muscle activity data were collected from 10 people with TTA and 10 age- and sex- matched individuals without limb loss during five self-paced sit-to-stand trials. Participants with TTA completed the sit-to-stand task with their prescribed alignment and six altered alignment conditions (±10 mm anterior/posterior, medial/lateral, and ± 20 mm short/tall). A musculoskeletal model was used to calculate hip and L4-L5 joint loading. There were no differences in hip or L4-L5 joint loading between alignments. Participants with TTA had a greater peak hip joint contact force on the intact side hip compared to the amputated side hip across all alignments. Participants with TTA had greater L4-L5 joint contact force compared to those without amputation. While prosthetic alignment did not affect joint loading during sit-to-stand, future work on additional dynamic tasks is needed to better understand the potential role of prosthetic alignment on joint loading.

Differences Between The Bilateral And Unilateral Battle Rope Exercises In Joint Forces And Muscle Activation

Differences Between The Bilateral And Unilateral Battle Rope Exercises In Joint Forces And Muscle Activation

Effectiveness Of An 8-week Progressive Resistance Training Protocol On Muscle Activation And Recovery Time During Slipping In Older Adults

Effectiveness Of An 8-week Progressive Resistance Training Protocol On Muscle Activation And Recovery Time During Slipping In Older Adults

Effect Of Supraspinal Input On Muscle Activation During Assisted Leg Cycling After Complete Spinal Cord Injury

Effect Of Supraspinal Input On Muscle Activation During Assisted Leg Cycling After Complete Spinal Cord Injury

The effect of trunk exercises with hip strategy training to maximize independence level and balance for patient with stroke: Randomized controlled study.

Balance while seated and the capacity to conduct selective trunk movements are significant predictors of functional outcomes following stroke. Patients with inappropriate muscle activation and inadequate movement control in the trunk muscles cause mobility and daily function difficulties. Stroke patients have weak leg muscles and decreased balance, resulting in compensatory changes. Functional postural strategy training is necessary to restore balance in these patients. Few studies have examined the effect of physical therapy trunk exercises with hip strategy training on improving balance and increasing independence after stroke. This study aimed to explore the effect of selective trunk exercises (STE) with hip strategy training in improving balance in patients with stroke as well as independence levels. A multicenter inpatient stroke treatment randomized pre- and post-test control trial. Forty-six stroke survivors were randomly allocated to experimental or control groups (n=23 each). The experimental group received hip strategy training and trunk exercises. All groups received Neuro-Developmental Treatment (NDT)-based physical therapy four times a week for 6weeks. Trunk impairment scale, Berg Balance Scale (BBS), and functional independence measure (FIM) measured static and dynamic seated balance, functional balance, and trunk movement coordination pre- and post-therapy. The experimental group's post-therapeutic measures were substantially higher than the control group. The experimental group's TIS score, and subscale improved more than the control group. The experimental group considerably increased the BBS score. The experimental group also showed greater FIM gains. This study demonstrated that adding STE in conjunction with hip strategy training to patients after has a positive impact on trunk control while maintaining static and dynamic sitting balance, functional balance, and independence levels which are effective in stroke rehabilitation.

The role of extradiaphragmatic muscles’ ultrasound on the diagnosis and follow-up of diaphragmatic dysfunction associated with cervical septic arthritis: A case report and literature review

Cervical septic arthritis can lead to complications such as epidural abscess, which may result in respiratory failure. We present a case of a 78-year-old male with cervical septic arthritis complicated by epidural abscess, leading to severe diaphragm dysfunction. Ultrasound evaluation revealed dysfunction of the left hemidiaphragm and compensatory activation of accessory respiratory muscles. Treatment included antibiotic therapy and corticosteroids, alongside respiratory support. After 21 days, improvements were observed in diaphragmatic function and respiratory muscle activation. Our findings highlight the importance of assessing both diaphragm and accessory respiratory muscles in cases of cervical septic arthritis with respiratory complications.

Intra-session Reliability Of Strength And Evoked Measures During Isometric Muscle Actions In Men

Intra-session Reliability Of Strength And Evoked Measures During Isometric Muscle Actions In Men

Muscle Activation Rate Variations During Pull-ups: Post-training Assessment Using An Innovative Assisting Device

Muscle Activation Rate Variations During Pull-ups: Post-training Assessment Using An Innovative Assisting Device

Differences In Lower Extremity Muscle Activation Are Characteristic Between Curves And Straight Paths In Older Adults

Differences In Lower Extremity Muscle Activation Are Characteristic Between Curves And Straight Paths In Older Adults

Trunk And Lower Extremity Muscle Activation During Yoga

Trunk And Lower Extremity Muscle Activation During Yoga

Knee joint pathology and efferent pathway dysfunction: Mapping muscle inhibition from motor cortex to muscle force

BackgroundDysfunction in efferent pathways after knee pathology is tied to long-term impairments in quadriceps and hamstrings muscle performance, daily function, and health-related quality of life. Understanding the underlying etiology is crucial for effective treatment and prevention of poor outcomes, such as post-traumatic osteoarthritis or joint replacement. ObjectivesTo synthesize recent evidence of efferent pathway dysfunction (i.e., motor cortex, motor units) among individuals with knee pathology. DesignCommentary. MethodWe summarize the current literature investigating the motor cortex, corticospinal tract, and motoneuron pool in individuals with three common knee pathologies: anterior cruciate ligament (ACL) injury, anterior knee pain (AKP), and knee osteoarthritis (OA). To offer a complete perspective, we draw from studies applying a range of neuroimaging and neurophysiologic techniques. ResultsAdaptations within the motor cortices, corticospinal tract, and motoneuron pool are present in those with knee pathology and underline impairments in quadriceps and hamstrings muscle function. Each pathology has evidence of altered motor system excitability and reduced volitional muscle activation and force-generating capacity, but few impairments were common across ACL injury, AKP, and OA studies. These findings underscore the central role of the motor cortex and motor unit behavior in the long-term outcomes of individuals with knee pathology. ConclusionsAdaptations in the efferent pathways underlie persistent muscle dysfunction across three common knee pathologies. This review provides an overview of these changes and summarizes key findings from neurophysiology and neuroimaging studies, offering direction for future research and clinical application in the rehabilitation of joint injuries.

Potentiation of cortico-spinal output via targeted electrical stimulation of the motor thalamus

Cerebral white matter lesions prevent cortico-spinal descending inputs from effectively activating spinal motoneurons, leading to loss of motor control. However, in most cases, the damage to cortico-spinal axons is incomplete offering a potential target for therapies aimed at improving volitional muscle activation. Here we hypothesize that, by engaging direct excitatory connections to cortico-spinal motoneurons, stimulation of the motor thalamus could facilitate activation of surviving cortico-spinal fibers thereby immediately potentiating motor output. To test this hypothesis, we identify optimal thalamic targets and stimulation parameters that enhance upper-limb motor-evoked potentials and grip forces in anesthetized monkeys. This potentiation persists after white matter lesions. We replicate these results in humans during intra-operative testing. We then design a stimulation protocol that immediately improves strength and force control in a patient with a chronic white matter lesion. Our results show that electrical stimulation targeting surviving neural pathways can improve motor control after white matter lesions.

IDL: 338195 Targeted Multifidus Muscle Activation Reduces Fibrosis of the Multifidus Muscle Following Intervertebral Disc Injury

IDL: 338195 Targeted Multifidus Muscle Activation Reduces Fibrosis of the Multifidus Muscle Following Intervertebral Disc Injury

Topology, dynamics, and control of a muscle-architected soft arm

Muscular hydrostats, such as octopus arms or elephant trunks, lack bones entirely, endowing them with exceptional dexterity and reconfigurability. Key to their unmatched ability to control nearly infinite degrees of freedom is the architecture into which muscle fibers are weaved. Their arrangement is, effectively, the instantiation of a sophisticated mechanical program that mediates, and likely facilitates, the control and realization of complex, dynamic morphological reconfigurations. Here, by combining medical imaging, biomechanical data, live behavioral experiments, and numerical simulations, an octopus-inspired arm made of [Formula: see text]200 continuous muscle groups is synthesized, exposing "mechanically intelligent" design and control principles broadly pertinent to dynamics and robotics. Such principles are mathematically understood in terms of storage, transport, and conversion of topological quantities, effected into complex 3D motions via simple muscle activation templates. These are in turn composed into higher-level control strategies that, compounded by the arm's compliance, are demonstrated across challenging manipulation tasks, revealing surprising simplicity and robustness.

Assessing The Influence Of Work Of Breathing On Sex-differences In Inspiratory Muscle Activation During Exercise

Assessing The Influence Of Work Of Breathing On Sex-differences In Inspiratory Muscle Activation During Exercise

Influence of the surrounding environment on the response of seated midsize male volunteers subjected to lateral sled accelerations

Predicting vehicle occupants’ posture during evasive manoeuvres is crucial for assessing their safety in the event of a collision. Volunteer experiments have been performed in the past under lateral accelerations, both within a vehicle cabin and on a seat mounted on a sled. However, discrepancies in the volunteer responses between both setups have been identified. This study hypothesizes that the response of the volunteers differs as a consequence of the proximity to the frame in the vehicle cabin, in comparison to the absence of such a structure on the sled.The present study conducted a novel sled experiment, on which five volunteers with anthropometry comparable to the 50th percentile male were subjected to 0.3 g lateral accelerations, with three different surrounding environments. In twelve pulses, an additional lateral structure was placed to the right or left side of the seated volunteers. The volunteers were asked to either brace or relax their muscles.The results show significant differences between the configurations with and without the structure placed on the right side. This effect was observed for both the lateral excursion of the upper body and the corresponding rotation when the volunteers were relaxed (p < 0.01). The average maximum lateral head rotation decreased from 27° to 14° with the structure on the right. No significant difference in head rotation was found for the braced muscle configuration.This study supports the hypothesis that the proximity to a surrounding environment influences human responses during dynamic loading. Nevertheless, there was no significant difference in maximum muscle activation between the configurations, but a faster reaction of the sternocleidomastoid muscle with the presence of the structure.

Surface Electromyography: A Pilot Study in Canine Spinal Muscles

In veterinary practice, rehabilitation modalities are often used to help in the recovery of animals affected by InterVertebral Disc Disease (IVDD), a condition frequently observed in chondrodystrophic dog breeds and can lead to Spinal Cord Injury (SCI), resulting in pain, motor impairments and neurological deficits, but there is a lack of objective assessment tools for patient evolution. In this work, an innovative approach using surface ElectroMyoGraphy (sEMG) is proposed to be applied in the field of veterinary medicine rehabilitation. The observed results are thought to be a direct result of nerve compression, leading to unusual patterns of muscle activation; this phenomenon can be attributed to muscle denervation, where the loss of Motor Units (MU) is the primary cause. This is thought to be responsible for the decrease in recorded sEMG amplitude and the increase in frequency observed in the pathological group.•This study involved rigorous animal preparation and signal acquisition protocols, involving multiple exercises and sub-movements, which were subsequently analysed.•RMSA is most used metric to analyse amplitude in sEMG signals, as it results in a more representative measurement of the signal variability than the Mean amplitude or the Standard Deviation.

Alternating Muscle Activation Patterns Across The Deltoid Muscles During Sustained Fatiguing Contractions

Alternating Muscle Activation Patterns Across The Deltoid Muscles During Sustained Fatiguing Contractions

People with hip osteoarthritis have poor muscle activation and altered motor cortex excitability: a case-control study

People with hip osteoarthritis have poor muscle activation and altered motor cortex excitability: a case-control study