PRACTICAL CONSIDERATIONS FOR STANDARDIZED RECORDING OF MUSCLE MECHANICAL PROPERTIES USING A MYOMETRIC DEVICE: RECORDING SITE, MUSCLE LENGTH, STATE OF CONTRACTION AND PRIOR ACTIVITY

Purpose: This study aimed to systematically examine the influence of various muscle and experimental conditions on Myoton recordings. Methods: A cross-sectional, observational design was used to examine muscle conditions and experimental factors (different recording sites, muscle length, level of contraction and prior physical activity) that may influence reproducibility of Myoton recordings for biceps brachii (BB) and rectus femoris (RF). Fifty-three healthy adults (26 young, 27 older) aged 18–90 years were studied. Muscle stiffness, tone and elasticity were measured using the MyotonPRO device. Results: Statistically significant differences in Myoton parameters were found for aspects of all four muscle and experimental conditions compared with the control condition ([Formula: see text]). However, clinically relevant differences in tone, stiffness and elasticity were only found for contracted compared to resting muscle, with changes being greater than the minimal detectable change. Elasticity was not affected by prior activity. Conclusions: The conditions studied significantly altered Myoton parameters of BB and RF in healthy adults, but only changes in parameters during muscle contraction were clinically relevant. These findings provide evidence to support the need to consider muscle condition and experimental factors for improving the robustness of test protocols for assessing muscle mechanical properties using the MyotonPRO device.

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Changes in muscle ultrasound for the diagnosis of intensive care unit acquired weakness in critically ill patients

Scientific Reports ◽

10.1038/s41598-021-97680-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Weiqing Zhang ◽

Jun Wu ◽

Qiuying Gu ◽

Yanting Gu ◽

Yujin Zhao ◽

...

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Diagnostic Accuracy ◽

Biceps Brachii ◽

Rectus Femoris ◽

Apache Ii ◽

Cross Sectional ◽

Icu Admission ◽

The Right ◽

Muscle Ultrasound

AbstractTo test diagnostic accuracy of changes in thickness (TH) and cross-sectional area (CSA) of muscle ultrasound for diagnosis of intensive care unit acquired weakness (ICU-AW). Fully conscious patients were subjected to muscle ultrasonography including measuring the changes in TH and CSA of biceps brachii (BB) muscle, vastus intermedius (VI) muscle, and rectus femoris (RF) muscles over time. 37 patients underwent muscle ultrasonography on admission day, day 4, day 7, and day 10 after ICU admission, Among them, 24 were found to have ICW-AW. Changes in muscle TH and CSA of RF muscle on the right side showed remarkably higher ROC-AUC and the range was from 0.734 to 0.888. Changes in the TH of VI muscle had fair ROC-AUC values which were 0.785 on the left side and 0.779 on the right side on the 10th day after ICU admission. Additionally, Sequential Organ Failure Assessment (SOFA), Acute Physiology, and Chronic Health Evaluation II (APACHE II) scores also showed good discriminative power on the day of admission (ROC-AUC 0.886 and 0.767, respectively). Ultrasonography of changes in muscles, especially in the TH of VI muscle on both sides and CSA of RF muscle on the right side, presented good diagnostic accuracy. However, SOFA and APACHE II scores are better options for early ICU-AW prediction due to their simplicity and time efficiency.

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Impact of acute ascites on the action of the canine abdominal muscles

Journal of Applied Physiology ◽

10.1152/japplphysiol.01336.2007 ◽

2008 ◽

Vol 104 (6) ◽

pp. 1568-1573 ◽

Cited By ~ 4

Author(s):

Dimitri Leduc ◽

André De Troyer

Keyword(s):

Muscle Length ◽

Abdominal Muscle ◽

Transversus Abdominis ◽

Oblique Muscle ◽

Abdominal Muscles ◽

Cross Sectional ◽

Control Value ◽

Airway Opening ◽

Internal Oblique ◽

Resting Muscle

Although ascites causes abdominal expansion, its effects on abdominal muscle function are uncertain. In the present study, progressively increasing ascites was induced in supine anesthetized dogs, and the changes in abdominal (ΔPab) and airway opening (ΔPao) pressure obtained during stimulation of the internal oblique and transversus abdominis muscles were measured; the changes in internal oblique muscle length were also measured. As ascites increased from 0 to 100 ml/kg body wt, Pab and muscle length during relaxation increased. ΔPab also showed a threefold increase ( P < 0.001). However, ΔPao decreased ( P < 0.001). When ascites increased further to 200 ml/kg, resting muscle length continued to increase and muscle shortening during stimulation became very small so that active muscle length was 155% of the resting muscle length in the control condition. Concomitantly, ΔPab returned to the control value, and ΔPao continued to decrease. Similar results were obtained with the animals in the head-up posture, although the decrease in ΔPao appeared only when ascites was greater than 125 ml/kg. It is concluded that 1) ascites adversely affects the expiratory action of the abdominal muscles on the lung; 2) this effect results primarily from the increase in diaphragm elastance; and 3) when ascites is severe, the abdomen cross-sectional area is also increased and the abdominal muscles are excessively lengthened so that their active pressure-generating ability itself is reduced.

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Bleaching Effects on Color, Chemical, and Mechanical Properties of White Spot Lesions

Operative Dentistry ◽

10.2341/15-015-l ◽

2016 ◽

Vol 41 (3) ◽

pp. 318-326 ◽

Cited By ~ 3

Author(s):

Y Kim ◽

HH Son ◽

K Yi ◽

JS Ahn ◽

J Chang

Keyword(s):

Mechanical Properties ◽

Hardness Test ◽

Knoop Hardness ◽

White Spot ◽

Control Group ◽

White Spot Lesions ◽

Lesion Area ◽

Experimental Conditions ◽

Cross Sectional ◽

The Cross

SUMMARY Objective: The purpose of the study was to evaluate the effect of bleaching on teeth with white spot lesions. Methods and Materials: Carious lesions with standardized whiteness were produced on the buccal and lingual surfaces of human premolars by pH cycling. Specimens were subjected to four experimental conditions (n=20/group) as follows: group 1, control; group 2, caries formation followed by remineralization using fluoride-containing casein phosphopeptide–amorphous calcium phosphate (CPP-ACP; Tooth Mousse Plus, GC, Tokyo, Japan); group 3, caries formation followed by bleaching using 10% carbamide peroxide; and group 4, caries formation followed by both bleaching and remineralization. The CIE L*a*b* color values were measured with a spectroradiometer, the mineral content was measured with electron probe microanalysis (EPMA) on the cross-sectional surface of each specimen, and the Knoop hardness test was carried out along the EPMA scan line. Two-way analysis of variance was performed with Tukey post hoc comparison. Results: The change in the CIE color values was not significantly different between the caries-formed (ΔE*=7.03) and the bleached enamel (ΔE*=7.60). Bleaching of the carious enamel extended the whiteness (ΔE*=3.38) without additional mineral loss (p<0.05). The remineralization treatment significantly increased the calcium (Ca), phosphate (P), and fluoride content of the subsurface lesion area (p<0.05). The cross-sectional microhardness values correlated well with the Ca and P content (R>0.80). Conclusions: Bleaching reduced the color disparities between sound and carious enamel without deteriorating the chemical and mechanical properties. The application of CPP-ACP paste enhanced mineral deposition in the subsurface lesion area of carious enamel.

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Bronchial smooth muscle mechanics of a canine model of allergic airway hyperresponsiveness

Journal of Applied Physiology ◽

10.1152/jappl.1992.72.1.39 ◽

1992 ◽

Vol 72 (1) ◽

pp. 39-45 ◽

Cited By ~ 45

Author(s):

H. Jiang ◽

K. Rao ◽

A. J. Halayko ◽

W. Kepron ◽

N. L. Stephens

Keyword(s):

Mechanical Properties ◽

Smooth Muscle ◽

Muscle Mechanics ◽

Bronchial Hyperresponsiveness ◽

Muscle Length ◽

Canine Model ◽

Control Group ◽

Shortening Velocity ◽

Bronchial Smooth Muscle ◽

Cross Sectional

Although we have reported that tracheal smooth muscle from sensitized dogs shows altered mechanical properties, we did not know, because of technical difficulties with the preparation, whether similar changes occur in the properties of sensitized central bronchial smooth muscle (BSM), the site at which the acute asthmatic response is believed to develop. We have now succeeded in developing a cartilage-free BSM preparation that retains optimal mechanical properties. Such strips were obtained from mongrel dogs that had been sensitized to ragweed pollen. Controls were littermates injected with adjuvant alone. Length-tension relationships were obtained for both control and sensitized BSM strips (CBSM and SBSM, respectively). The maximal active stresses were the same (P greater than 0.05) when normalized to muscle fraction in total tissue cross-sectional area [6.2 +/- 0.6 x 10(4) and 5.9 +/- 0.6 x 10(4) (SE) for SBSM and CBSM, respectively]. This suggests that optimal tension is an insensitive indicator of bronchial hyperresponsiveness and that isotonic studies might be more revealing. The maximal shortening velocity (Vo) for SBSM at 2 s [0.35 +/- 0.017 (SE) lo/s, where lo signifies optimal muscle length], in the course of a 10-s contraction, was significantly greater (P less than 0.05) than Vo measured for CBSM (0.27 +/- 0.015 lo/s). However, Vo did not differ at the 8-s point of contraction. The sensitized group demonstrated a statistically significantly greater maximal shortening capacity (0.67 +/- 0.04 lo) than the control group (0.51 +/- 0.04 lo). At 2 s of contraction, 80% of maximal SBSM shortening had been completed and was significantly greater than for CBSM.(ABSTRACT TRUNCATED AT 250 WORDS)

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Effects of BDM, [Ca2+]o, and temperature on the dynamic stiffness of quiescent cardiac trabeculae from rat

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00906.2004 ◽

2005 ◽

Vol 288 (4) ◽

pp. H1662-H1667 ◽

Cited By ~ 7

Author(s):

R. S. Kirton ◽

A. J. Taberner ◽

P. M. F. Nielsen ◽

A. A. Young ◽

D. S. Loiselle

Keyword(s):

Mechanical Properties ◽

Cardiac Tissue ◽

Dynamic Stiffness ◽

Low Frequency ◽

Muscle Length ◽

Small Degree ◽

Experimental Conditions ◽

Cross Bridge ◽

Intracellular Ca ◽

Increasing Temperature

Studies of the passive mechanical properties of cardiac tissue have traditionally been conducted at subphysiological temperatures and various concentrations of extracellular Ca2+ ([Ca2+]o). More recently, the negative inotropic agent 2,3-butanedione monoxime (BDM) has been used. However, there remains a lack of data regarding the influence of temperature, Ca2+, and BDM on the passive mechanical properties of cardiac tissue. We have used the dynamic stiffness technique, a sensitive measurement of cross-bridge activity, in which minute (∼0.2% of muscle length) sinusoidal perturbations are applied at various frequencies (0.2–100 Hz) to quiescent, viable right ventricular rat trabeculae at two temperatures (20°C and 26°C) and at two [Ca2+]o (0.5 and 1.25 mM) in the presence and absence of BDM (20 mM). The stiffness spectra (amplitude and phase) were sensitive to temperature and [Ca2+]o in the absence of BDM but insensitive in the presence of BDM. From the index of cross-bridge cycling (the ratio of high- to low-frequency stiffness amplitude), we infer that BDM inhibits a small degree of spontaneous sarcomere activity, thereby allowing the true passive properties of trabeculae to be determined. In the absence of BDM, the extent of spontaneous sarcomere activity decreases with increasing temperature. We caution that the measured mechanical properties of passive cardiac tissue are critically dependent on the experimental conditions under which they are measured. Experiments must be performed at sufficiently high temperatures (>25°C) to ensure a low resting concentration of intracellular Ca2+ or in the presence of an inhibitor of cross-bridge cycling.

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Relative and Absolute Interrater Reliabilities of a Hand-Held Myotonometer to Quantify Mechanical Muscle Properties in Patients with Acute Stroke in an Inpatient Ward

BioMed Research International ◽

10.1155/2017/4294028 ◽

2017 ◽

Vol 2017 ◽

pp. 1-12 ◽

Cited By ~ 12

Author(s):

Wai Leung Ambrose Lo ◽

Jiang Li Zhao ◽

Le Li ◽

Yu Rong Mao ◽

Dong Feng Huang

Keyword(s):

Mechanical Properties ◽

Acute Stroke ◽

Biceps Brachii ◽

Intraclass Correlation ◽

Rectus Femoris ◽

Muscle Properties ◽

Inpatient Ward ◽

Stroke Population ◽

First Occurrence ◽

Absolute Reliability

Introduction. The reliability of using MyotonPRO to quantify muscles mechanical properties in a ward setting for the acute stroke population remains unknown. Aims. To investigate the within-session relative and absolute interrater reliability of MyotonPRO. Methods. Mechanical properties of biceps brachii, brachioradialis, rectus femoris, and tibialis anterior were recorded at bedside. Participants were within 1 month of the first occurrence of stroke. Relative reliability was assessed by intraclass correlation coefficient (ICC). Absolute reliability was assessed by standard error of measurement (SEM), SEM%, smallest real difference (SRD), SRD%, and the Bland-Altman 95% limits of agreement. Results. ICCs of all studied muscles ranged between 0.63 and 0.97. The SEM of all muscles ranged within 0.30–0.88 Hz for tone, 0.07–0.19 for decrement, 6.42–20.20 N/m for stiffness, and 0.04–0.07 for creep. The SRD of all muscles ranged within 0.70–2.05 Hz for tone, 0.16–0.45 for decrement, 14.98–47.15 N/m for stiffness, and 0.09–0.17 for creep. Conclusions. MyotonPRO demonstrated acceptable relative and absolute reliability in a ward setting for patients with acute stroke. However, results must be interpreted with caution, due to the varying level of consistency between different muscles, as well as between different parameters within a muscle.

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Sonoelastography to Assess Muscular Stiffness Among Older Adults and its Use for the Diagnosis of Sarcopenia: A Systematic Review

Ultraschall in der Medizin - European Journal of Ultrasound ◽

10.1055/a-1293-8057 ◽

2020 ◽

Author(s):

Ewa Magdalena Janczyk ◽

Noémie Champigny ◽

Emeline Michel ◽

Charles Raffaelli ◽

Cédric Annweiler ◽

...

Keyword(s):

Systematic Review ◽

Older Adults ◽

Older Patients ◽

Shear Wave Elastography ◽

Rectus Femoris ◽

Muscle Stiffness ◽

Cross Sectional ◽

Significant Difference ◽

Independent Review ◽

Cross Sectional Design

AbstractChanges in muscle stiffness have been reported with sarcopenia. Sonoelastography is an accessible and non-radiating imaging technique allowing quantification of elastic properties of tissue. We performed a systematic review of the literature to investigate whether sonoelastography can be a reliable method to assess sarcopenia in older patients. We searched Medline, Google Scholar, Scopus, SpringerLink and Science direct from January 1, 1990 to April 1, 2020. Three independent review authors assessed trial eligibility, extracted the data, and assessed risk of bias. We intended to learn which types of elastography have been tested, if such measures are repeatable, and if they have been compared to the currently accepted diagnostic method. Ten studies met the inclusion criteria. Most followed a cross-sectional design with young and older adult subgroups. The gastrocnemius, rectus femoris, and vastus intermedius appeared most frequently. Nine of the included studies used shear wave elastography and one-strain elastography. The passive elastic constant was significantly greater in sarcopenic versus healthy subjects after passive stretching (124.98 ± 60.82 vs. 46.35 ± 15.85, P = 0.004). However, even in non-sarcopenic patients, the age of the patient was responsible for about 45.5 % of the variance in SWV. Among ten included articles, four reported higher stiffness in the muscles of older adults, two reported lower stiffness, and four found no significant difference. Due to the substantial heterogenicity of actual data, we could not make any conclusions about the potential usefulness of elastography to assess sarcopenia. Further studies are needed, including a larger sample of older patients and using a standardized and reproducible protocol.

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Differences in scapular upward rotation, pectoralis minor and levator scapulae muscle length between the symptomatic, the contralateral asymptomatic shoulder and control subjects: a cross-sectional study in a Spanish primary care setting

BMJ Open ◽

10.1136/bmjopen-2018-023020 ◽

2019 ◽

Vol 9 (6) ◽

pp. e023020 ◽

Cited By ~ 1

Author(s):

Santiago Navarro-Ledesma ◽

Manuel Fernandez-Sanchez ◽

Filip Struyf ◽

Javier Martinez-Calderon ◽

Jose Miguel Morales-Asencio ◽

...

Keyword(s):

Primary Care ◽

Muscle Length ◽

Pain Syndrome ◽

Cross Sectional Study ◽

Minimal Detectable Change ◽

Cross Sectional ◽

Pectoralis Minor ◽

Levator Scapulae ◽

Shoulder Elevation ◽

Levator Scapulae Muscle

ObjectiveTo determine the potential differences in both scapular positioning and scapular movement between the symptomatic and asymptomatic contralateral shoulder, in patients with unilateral subacromial pain syndrome (SAPS), and when compared with participants free of shoulder pain.SettingThree different primary care centres.ParticipantsA sample of 73 patients with SAPS in their dominant arm was recruited, with a final sample size of 54 participants.Primary outcome measuresThe scapular upward rotation (SUR), the pectoralis minor and the levator scapulae muscles length tests were carried out.ResultsWhen symptomatic shoulders and controls were compared, an increased SUR at all positions (45°, 90° and 135°) was obtained in symptomatic shoulders (2/3,98/8,96°, respectively). These differences in SUR surpassed the minimal detectable change (MDC95) (0,91/1,55/2,83° at 45/90/135° of shoulder elevation). No differences were found in SUR between symptomatic and contralateral shoulders. No differences were found in either pectoralis minor or levator scapulae muscle length in all groups.ConclusionsSUR was greater in patients with chronic SAPS compared with controls at different angles of shoulder elevation.

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Perturbation measurements of papillary muscle elasticity

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1981.241.2.h155 ◽

1981 ◽

Vol 241 (2) ◽

pp. H155-H173 ◽

Cited By ~ 2

Author(s):

A. J. Brady ◽

S. T. Tan ◽

N. V. Ricchiuti

Keyword(s):

Mechanical Properties ◽

Papillary Muscle ◽

Muscle Length ◽

Step Length ◽

Muscle Stiffness ◽

Force Measurements ◽

Lumped Model ◽

Isometric Twitch ◽

Whole Muscle ◽

Total Muscle

Small step-length perturbations (less than 0.5% Lmax) have been applied to rabbit papillary muscle for the purpose of measuring muscle stiffness at rest and during isometric twitch-force development. These stiffness-force measurements were fitted to four mechanical analogs to evaluate whether any of the models adequately predict the mechanical properties of papillary muscle. Stiffness-force relations have been measured at varied initial muscle lengths so that a broad range of applicability of an analog could be evaluated. This study shows that none of the four experimentally definable analogs predicts the stiffness-force responses of the muscle over a physiological range of initial muscle lengths. A two-segment nonhomogeneous analog has the same stiffness-force characteristics as a six-parameter lumped model but cannot be differentiated from the lumped model without a measurement of segmental variations. It is concluded that the passive elastic elements of papillary muscle cannot be controlled only by the manipulation of total muscle length so as to deduce cross-bridge mechanical properties from whole-muscle measurements.

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Ultrasound assessment of sarcopenia in patients with rheumatoid arthritis

Modern Rheumatology ◽

10.1093/mr/roab049 ◽

2021 ◽

Author(s):

Takeshi Yoshida ◽

Yoshitaka Kumon ◽

Naoko Takamatsu ◽

Taiki Nozaki ◽

Masataka Inoue ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Biceps Brachii ◽

Vastus Lateralis ◽

Subcutaneous Fat ◽

Rectus Femoris ◽

Receiver Operating Curve ◽

Cross Sectional ◽

Discriminative Performance ◽

Receiver Operating Curve Analysis ◽

Ultrasound Assessment

ABSTRACT Objectives To evaluate the efficacy of ultrasound (US) as a diagnostic tool for sarcopenia in patients with rheumatoid arthritis (RA). Methods Female RA patients aged >50 years and matched controls were cross-sectionally assessed. Sarcopenia was diagnosed based on the 2019-updated Asian Working Group for Sarcopenia definition. The cross-sectional area (CSA) and echo intensity (EI) of the biceps brachii, rectus femoris, and EI of the vastus lateralis were examined bilaterally. Correction for subcutaneous fat and calculation of the recorrected EI (rcEI) were performed. We performed logistic regression using both muscle rcEI and CSA with receiver operating curve analysis to evaluate the discriminative performance per muscle group. Results Seventy-eight consecutive RA patients and 15 age-and sex-matched controls were assessed. Sarcopenia was diagnosed in 34 RA patients (43.6%). The rcEI of examined muscles were significantly higher, whereas CSA were significantly lower in sarcopenic RA patients than in non-sarcopenic patients and matched controls. The combined discriminative performance of rcEI and CSA was superior to those of rcEI or CSA alone. Conclusions This study suggests the use of US for the diagnosis of sarcopenia in RA patients. The diagnostic performance increases when both echogenicity and CSA are considered together rather than individually.

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