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European Journal of Physical and... Aug 2018The Modified Ashworth Scale is the most widely clinical scale used to measure the increase of muscle tone. Reliability is not an immutable property of a scale and can... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
The Modified Ashworth Scale is the most widely clinical scale used to measure the increase of muscle tone. Reliability is not an immutable property of a scale and can vary as a function of the variability and composition of the sample to which it is administered. The best method to examine how the reliability of a test scores varies is by conducting a systematic review and meta-analysis of the reliability coefficients obtained in different applications of the test with the data at hand. The objectives of this systematic revision are: what is the mean inter- and intra-rater reliability of the Modified Ashworth Scale's scores in upper and lower extremities? Which study characteristics affect the reliability of the scores in this scale?
EVIDENCE ACQUISITION
The PubMed, Embase and CINAHL databases were searched from 1987 to February 2015. Two reviewers independently selected empirical studies published in English or in Spanish that applied the Modified Ashworth Scale and reported any reliability coefficient with the data at hand in children, adolescents or adults with spasticity.
EVIDENCE SYNTHESIS
Thirty-three studies reported any reliability estimate of Modified Ashworth Scale scores (N.=1065 participants). For lower extremities and inter-rater agreement, the mean intraclass correlation was ICC+=0.686 (95% CI: 0.563 and 0.780) and for kappa coefficients, κ+=0.360 (95% CI: 0.241 and 0.468); for intra-rater agreement: ICC+=0.644 (95% CI: 0.543 and 0.726) and κ+=0.488 (95% CI: 0.370 and 0.591). For upper extremities and inter-rater agreement: ICC+=0.781 (95% CI: 0.679 and 0.853) and κ+=0.625 (95% CI: 0.350 and 0.801); for intra-rater agreement: ICC+=0.748 (95% CI: 0.671 and 0.809) and κ+=0.593 (95% CI: 0.467 and 0.696). The type of design, the study focus, and the number of raters presented statistically significant relationships with ICC both for lower and upper extremities.
CONCLUSIONS
Inter- and intra-rater agreement for Modified Ashworth Scale scores was satisfactory. Modified Ashworth Scale' scores exhibited better reliability when measuring upper extremities than lower. Several characteristics of the studies were statistically associated to inter-rater reliability of the scores for lower and upper extremities.
Topics: Disability Evaluation; Evidence-Based Medicine; Female; Humans; Male; Muscle Spasticity; Muscle Tonus; Observer Variation; Physical and Rehabilitation Medicine; Severity of Illness Index
PubMed: 28901119
DOI: 10.23736/S1973-9087.17.04796-7 -
Journal of Sports Science & Medicine Mar 2019Dynamic stretching (DS) is often performed during warm-up to help avoid hamstring muscle injuries, increase joint flexibility, and optimize performance. We examined the...
Dynamic stretching (DS) is often performed during warm-up to help avoid hamstring muscle injuries, increase joint flexibility, and optimize performance. We examined the effects of DS of the hamstring muscles on passive knee extension range of motion (ROM), passive torque (PT) at the onset of pain (as a measure of stretch tolerance), and passive stiffness of the muscle-tendon unit over an extended period after stretching. Twenty-four healthy subjects participated, with 12 each in the experimental and control groups. Stretching was performed, and measurements were recorded using an isokinetic dynamometer pre-intervention, and at 0, 15, 30, 45, 60, 75, and 90 min post-intervention. DS consisted of ten 30-s sets of 15 repetitions of extension and relaxation of the hamstrings. ROM increased significantly (range, 7%-10%) immediately after DS, and the increase was sustained over 90 min. PT at the onset of pain also increased immediately by 10% but returned to baseline by 30 min. Passive stiffness decreased significantly (range, 7.9%-16.7%) immediately after DS, and the decrease was sustained over 90 min. Post-DS values were normalized to pre-DS values for the respective outcomes in both groups. ROM was significantly higher (range, 7.4%-10%) and passive stiffness was significantly lower (range, 5.4%-14.9%) in the experimental group relative to the control group at all time points. Normalized PT values at the onset of pain were significantly higher in the experimental group at 0-15 min than in the controls, but the differences were smaller at 30-45 min and not significant thereafter. We conclude that DS increases ROM and decreases passive stiffness in a sustained manner, and increases PT at the onset of pain for a shorter period. Overall, our results indicate that when performed prior to exercise, DS is beneficial for the hamstring muscles in terms of increasing flexibility and reducing stiffness.
Topics: Female; Hamstring Muscles; Humans; Knee; Male; Muscle Stretching Exercises; Muscle Tonus; Myalgia; Range of Motion, Articular; Torque; Young Adult
PubMed: 30787647
DOI: No ID Found -
Journal of Biomechanics May 2023The classical view of muscles as independent motors has been challenged over the past decades. An alternative view has emerged in which muscles are not isolated but... (Review)
Review
The classical view of muscles as independent motors has been challenged over the past decades. An alternative view has emerged in which muscles are not isolated but embedded in a three-dimensional connective tissue network that links them to adjacent muscles and other non-muscular structures in the body. Animal studies showing that the forces measured at the distal and proximal ends of a muscle are not equal have provided undisputable evidence that these connective tissue linkages are strong enough to serve as an extra pathway for muscular force transmission. In this historical review, we first introduce the terminology and anatomy related to these pathways of muscle force transmission and provide a definition for the term epimuscular force transmission. We then focus on important experimental evidence indicating mechanical interactions between synergistic muscles that may affect force transmission and/or influence the muscles' force generating capacity. We illustrate that there may exist different expressions of the highly relevant force-length properties depending on whether the force is measured at the proximal or distal tendon and depending on the dynamics of surrounding structures. Changes in length, activation level or disruption of the connective tissue of neighboring muscles, can affect how muscles interact and produce force on the skeleton. While most direct evidence is from animal experiments, studies on humans also suggest functional implications of the connective tissues surrounding muscles. These implications may explain how distant segments, which are not part of the same joint system, affect force generation at a given joint, and, in clinical conditions, explain observations from tendon transfer surgeries, where a muscle transferred to act as an antagonist continues to produce agonistic moments.
Topics: Humans; Muscle, Skeletal; Animals; Connective Tissue; Muscle Tonus; Muscle Strength
PubMed: 37120913
DOI: 10.1016/j.jbiomech.2023.111575 -
American Journal of Physiology. Lung... Oct 2019
Topics: Animals; Bronchiectasis; Mice; Muscle Tonus; Respiratory System
PubMed: 31508977
DOI: 10.1152/ajplung.00363.2019 -
Journal of Speech, Language, and... May 2022Despite the high prevalence of primary muscle tension dysphonia (MTD-1), its underlying mechanisms and their interrelationships have yet to be fully identified. The... (Review)
Review
PURPOSE
Despite the high prevalence of primary muscle tension dysphonia (MTD-1), its underlying mechanisms and their interrelationships have yet to be fully identified. The objectives of this integrative review were (a) to describe and classify the suggested underlying mechanisms for MTD-1, (b) to appraise the empirical evidence supporting each of the proposed mechanisms, and (c) to summarize the information in an integrative model.
METHOD
PubMed, Scopus, and CINAHL were searched for all publications pertaining to muscle tension dysphonia. Papers were retained if they included theoretical or empirical data pertaining to underlying mechanisms of MTD-1. A total of 921 papers initially qualified for screening, of which 100 remained for consideration in this review. Underlying mechanisms of MTD-1 were extracted using a consensus approach.
RESULTS
Seven broad categories of putative mechanisms involved in MTD-1 were identified: psychosocial, autonomic, sensorimotor, respiratory, postural, inflammatory, and neuromuscular. These categories were further divided into 19 subcategories detailed in the body of this review article. Based on the reviewed evidence, our proposed integrative model presents MTD-1 as an idiosyncratic motor adaptation to physiological perturbation or perceived threat. Under this model, physiologically or psychologically aversive stimuli can instigate a series of motor adaptations at multiple levels of the nervous system, ultimately disturbing muscle activation patterns and their biomechanical outcomes. Importantly, these adaptations appear to have the potential to become chronic even after threatening stimuli are withdrawn.
CONCLUSIONS
The proposed model highlights the importance of personalized rehabilitation in MTD-1 treatment. Limitations of the literature are discussed to provide guidance for future research aimed at improving our understanding of MTD-1.
SUPPLEMENTAL MATERIAL
https://doi.org/10.23641/asha.19586065.
Topics: Dysphonia; Hoarseness; Humans; Muscle Tonus
PubMed: 35446683
DOI: 10.1044/2022_JSLHR-21-00575 -
Journal of Musculoskeletal & Neuronal... 2009The ability of a muscle to shorten and produce force is crucial for locomotion, posture, balance and respiration. During a contraction, myosin heads on the myosin... (Review)
Review
The ability of a muscle to shorten and produce force is crucial for locomotion, posture, balance and respiration. During a contraction, myosin heads on the myosin filament propel the actin filament via ATP hydrolysis, resulting in shortening of the muscle and/or force generation. The maximal shortening velocity of a muscle fibre is largely determined by the myosin ATPase activity, while maximal force is primarily determined by the cross-sectional area. Since most muscles are pennate rather than parallel-fibred and work at different lever ratios, muscle architecture and joint-tendon anatomy has to be taken into account to obtain the force and velocity characteristics of a muscle. Additionally, the recruitment of agonistic and antagonistic muscles will contribute to the torque generated during a contraction. Finally, tendon compliance may impact on the rate of force rise and force generated if it is such that the muscle contraction proceeds in the ascending limb of the length-tension relation. Even when magnetic resonance imaging and ultrasound, combined with EMG and/or electrical stimulation, have been applied to relate changes in muscle contractile properties to alterations in muscle size and architecture during ageing and resistance training, a disproportionate change in muscle strength and size remains to be explained.
Topics: Adenosine Triphosphate; Aging; Humans; Muscle Contraction; Muscle Strength; Muscle Tonus; Muscle, Skeletal; Organ Size; Physical Fitness; Resistance Training
PubMed: 19724146
DOI: No ID Found -
Sensors (Basel, Switzerland) Aug 2023"Muscle tone" is a clinically important and widely used term and palpation is a crucial skill for its diagnosis. However, the term is defined rather vaguely, and... (Review)
Review
"Muscle tone" is a clinically important and widely used term and palpation is a crucial skill for its diagnosis. However, the term is defined rather vaguely, and palpation is not measurable objectively. Therefore, several methods have been developed to measure muscle tone objectively, in terms of biomechanical properties of the muscle. This article aims to summarize these approaches. Through database searches, we identified those studies related to objective muscle tone measurement in vivo, in situ. Based on them, we described existing methods and devices and compared their reliability. Furthermore, we presented an extensive list of the use of these methods in different fields of research. Although it is believed by some authors that palpation cannot be replaced by a mechanical device, several methods have already proved their utility in muscle biomechanical property diagnosis. There appear to be two issues preventing wider usage of these objective methods in clinical practice. Firstly, a high variability of their reliability, and secondly, a lack of valid mathematical models that would provide the observed mechanical characteristics with a clear physical significance and allow the results to be compared with each other.
Topics: Reproducibility of Results; Muscle Tonus; Databases, Factual; Muscles; Palpation
PubMed: 37631726
DOI: 10.3390/s23167189 -
American Journal of Physiology.... Jul 2021Aging can lead to rectoanal incontinence due to internal anal sphincter (IAS) dysfunction, which is characterized by a decrease in IAS tone and contractility and an...
Aging can lead to rectoanal incontinence due to internal anal sphincter (IAS) dysfunction, which is characterized by a decrease in IAS tone and contractility and an increase in nonadrenergic noncholinergic (NANC) relaxation. We aimed to determine whether brain-derived neurotropic factor (BDNF) rescues this aging-associated IAS dysfunction (AAID). To do so, we studied the effects of BDNF on the basal and G protein-coupled receptors (GPCR)-stimulated IAS smooth muscle tone and on NANC relaxation in Fischer 344 rats representing different age groups [26-mo-old (aging) vs. 6-mo-old (young)], before and after tyrosine kinase receptor B (TrkB) antagonist K252a. We also used isolated smooth muscle cells (SMCs) to determine the effects of BDNF before and after different agonists. For some studies, we monitored NO release using smooth muscle perfusates. BDNF reversed AAID by rescuing the basal IAS tone and agonists [thromboxane A analog (U46619) and angiotensin II (ANG II)]-induced contractility, and NANC relaxation. These rescue effects of BDNF were selective as K252a attenuated the changes in the IAS without modifying the effects of Kdepolarization. Because of the direct association between the basal and GPCR-stimulated IAS tone and RhoA/ROCK activation, we speculate that this pathway in the rescue effects of BDNF. Conversely, our data suggest that aging-associated increased NANC relaxation is reversed by decreased release of NO and decrease in the sensitivity of the released inhibitory neurotransmitter. In summary, BDNF rescue of AAID involves RhoA/ROCK and inhibitory neurotransmission. These data have direct implications for the role of BDNF in the pathophysiology and therapeutic targeting of aging-associated rectoanal motility disorders. These studies demonstrate that brain-derived neurotropic factor (BDNF) rescues the aging-associated internal anal sphincter (IAS) dysfunction, characterized by a decrease in IAS tone, and increase in non-adrenergic noncholinergic relaxation. We determined the effects of BDNF on the basal and GPCR (TXA and ANG II)-stimulated IAS tone, and on NANC relaxation, before and after TrkB inhibitor K252a. BDNF may have an important role in the pathophysiology and therapeutic targeting of certain rectoanal motility disorders.
Topics: Aging; Animals; Brain; Brain-Derived Neurotrophic Factor; Male; Muscle Contraction; Muscle Relaxation; Muscle Tonus; Muscle, Smooth; Myocytes, Smooth Muscle; Rats; Rats, Inbred F344; Signal Transduction; rho-Associated Kinases
PubMed: 34075793
DOI: 10.1152/ajpgi.00090.2021 -
Hypertension (Dallas, Tex. : 1979) Jan 2000Ion channels in the plasma membrane of vascular muscle cells that form the walls of resistance arteries and arterioles play a central role in the regulation of vascular... (Review)
Review
Ion channels in the plasma membrane of vascular muscle cells that form the walls of resistance arteries and arterioles play a central role in the regulation of vascular tone. Current evidence indicates that vascular smooth muscle cells express at least 4 different types of K(+) channels, 1 to 2 types of voltage-gated Ca(2+) channels, >/=2 types of Cl(-) channels, store-operated Ca(+) (SOC) channels, and stretch-activated cation (SAC) channels in their plasma membranes, all of which may be involved in the regulation of vascular tone. Calcium influx through voltage-gated Ca(2+), SOC, and SAC channels provides a major source of activator Ca(2+) used by resistance arteries and arterioles. In addition, K(+) and Cl(-) channels and the Ca(2+) channels mentioned previously all are involved in the determination of the membrane potential of these cells. Membrane potential is a key variable that not only regulates Ca(+2) influx through voltage-gated Ca(2+) channels, but also influences release of Ca(2+) from internal stores and Ca(2+)- sensitivity of the contractile apparatus. By controlling Ca(2+) delivery and membrane potential, ion channels are involved in all aspects of the generation and regulation of vascular tone.
Topics: Animals; Calcium Channels; Humans; Muscle Tonus; Muscle, Smooth, Vascular; Potassium Channels; Vascular Resistance; Vasoconstriction
PubMed: 10642294
DOI: 10.1161/01.hyp.35.1.173 -
Journal of Neuroengineering and... Aug 2012Movement disorders after stroke are still captured by clinical gaze and translated to ordinal scores of low resolution. There is a clear need for objective... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Movement disorders after stroke are still captured by clinical gaze and translated to ordinal scores of low resolution. There is a clear need for objective quantification, with outcome measures related to pathophysiological background. Neural and non-neural contributors to joint behavior should be separated using different measurement conditions (tasks) and standardized input signals (force, position and velocity).
METHODS
We reviewed recent literature for the application of biomechanical and/or elektromyographical (EMG) outcome measures under various measurement conditions in clinical research.
RESULTS
Since 2005, 36 articles described the use of biomechanical and/or EMG outcome measures to quantify post-stroke movement disorder. Nineteen of the articles strived to separate neural and non-neural components. Only 6 of the articles measured biomechanical and EMG outcome measures simultaneously, while applying active and passive tasks and multiple velocities.
CONCLUSION
The distinction between neural and non-neural components to separately assess paresis, stiffness and muscle overactivity is not commonplace yet, while a large gap is to be bridged to attain reproducible and comparable results. Pathophysiologically clear concepts, substantiated with a comprehensive and concise measuring protocol will help professionals to identify and treat limiting factors in movement capabilities of post-stroke patients.
Topics: Adult; Biomechanical Phenomena; Electromyography; Female; Fixation, Ocular; Humans; Joints; Male; Movement Disorders; Muscle Tonus; Muscle, Skeletal; Paresis; Range of Motion, Articular; Stroke; Treatment Outcome; Viscosity
PubMed: 22925463
DOI: 10.1186/1743-0003-9-61