Gastrocnemius Muscle Thickness Research Articles

Comparison of Muscle Regeneration Effects at Different Melittin Concentrations in Rabbit Atrophied Muscle.

This research aimed to explore the healing impacts of Melittin treatment on gastrocnemius muscle wasting caused by immobilization with a cast in rabbits. Twenty-four rabbits were randomly allocated to four groups. The procedures included different injections: 0.2 mL of normal saline to Group 1 (G1-NS); 4 μg/kg of Melittin to Group 2 (G2-4 μg/kg Melittin); 20 μg/kg of Melittin to Group 3 (G3-20 μg/kg Melittin); and 100 μg/kg of Melittin to Group 4 (G4-100 μg/kg Melittin). Ultrasound was used to guide the injections into the rabbits' atrophied calf muscles following two weeks of immobilization via casting. Clinical measurements, including the length of the calf, the compound muscle action potential (CMAP) of the tibial nerve, and the gastrocnemius muscle thickness, were assessed. Additionally, cross-sectional slices of gastrocnemius muscle fibers were examined, and immunohistochemistry and Western blot analyses were performed following two weeks of therapy. The mean regenerative changes, as indicated by clinical parameters, in Group 4 were significantly more pronounced than in the other groups (p < 0.05). Furthermore, the cross-sectional area of the gastrocnemius muscle fibers and immunohistochemical indicators in Group 4 exceeded those in the remaining groups (p < 0.05). Western blot analysis also showed a more significant presence of anti-inflammatory and angiogenic cytokines in Group 4 compared to the others (p < 0.05). Melittin therapy at a higher dosage can more efficiently activate regeneration in atrophied gastrocnemius muscle compared to lower doses of Melittin or normal saline.

The Relationship of Gastrocnemius-Soleus Muscle Architecture with Balance and Functional Strength in Acute Stroke Patients

Balance and functional impairment could occur due to the weakness of the gastrocsoleus muscles in acute stroke patients. This study was planned to determine the muscle architecture and its relationship to balance and functional strength functional ability in patients with acute stroke. A cross-sectional analysis of 22 stroke patients (68.59 ± 8.16) was performed in this study. Gastrocnemius muscle thickness and cross-sectional area were significantly greater on the non-paretic than on the paretic sides (p = 0.004, p = 0.005, respectively). Partial correlation analysis showed that soleus muscle thickness and cross-sectional area was significantly correlated with Berg Balance Scale, Single Leg Stance Test, Five Times Sit to Stand Test and Tandem test results in the paretic side (r = 0.49–0.77, p < 0.05). The gastrocnemius muscle thickness of the non-paretic side had a significant relationship with balance (r = 0.45–0.65, p < 0.05). The muscle thickness and cross-sectional area of the soleus muscle on the paretic sides was significantly related with the functional strength and balance after stroke. It may be beneficial to develop clinical assessment and intervention programs focusing on distal plantar flexor muscle groups in order to improve the functional status and balance.

Functional Performance and Tendon Morphology After Operative or Nonoperative Treatment of Achilles Tendon Ruptures.

While controversy remains as to the relative benefit of operative (OM) versus non-operative management (NOM) of Achilles tendon (AT) ruptures (ATR), few studies have examined the effect on high impact maneuvers such as jumping and hopping. The purpose of this study was to determine if functional performance including strength, jumping, and hopping outcomes differed between OM and NOM of acute ATR. The secondary objective was to assess the degree of association between AT morphology and performance outcomes. Retrospective cohort with a single prospective evaluation. All patients were treated at an institutional secondary care center. Eligible participants (n=12 OM; 12 NOM) who were treated with OM or NOM of ATR within three weeks of injury were evaluated a minimum 20 months following ATR. AT length, thickness and gastrocnemius muscle thickness were assessed with B-mode ultrasound. Isokinetic plantar flexor strength, hop tests and countermovement and drop jumps were completed. Two-way ANOVAS were completed on all tests with unilateral values, independent t-tests were used for bilateral outcomes, and linear regressions were completed to assess the relationship between normalized AT length and performance. Affected limb AT was elongated and thickened (p\<0.01), gastrocnemius was atrophied (p\< 0.01) and angle-specific plantar flexor torque was reduced at 120°/s when measured at 20° plantar flexion (p = 0.028). Single leg drop vertical jump was higher in OM (p = 0.015) with no difference for hop and jump tests. AT length was related to plantar flexor torque but had no relationship with hopping performance. Hop test performance was maintained despite plantarflexion weakness, gastrocnemius atrophy, and AT elongation. This may be the result of compensatory movement patterns. AT length holds limited explanatory power in plantar flexor strength, although this relationship should be evaluated further. Level III.

Botulinum Toxin Treatment for Calf Contouring Based on the Study of Combined Injection of Gastrocnemius and Soleus.

Botulinum toxin is administered to paralyze the gastrocnemius muscle and reduce its size, thereby improving the calf contour and reducing the leg circumference of the calf. In pursuit of better efficacy, we designed a new injection protocol that targeted both the gastrocnemius and soleus. An algorithm of botulinum toxin injection for calf contouring was proposed based on the results of the study and ultrasonographic data. A prospective, self-controlled, double-blind study was conducted. The gastronemius muscle (GM) group (n = 17) included the patients whose gastrocnemius muscles were treated, and the GM + soleus muscle (SM) group (n = 17) included the patients who had both the gastrocnemius and soleus treated. Parameters including the maximum leg circumference and the subcutaneous fat, gastrocnemius muscle, and soleus muscle thicknesses were collected before and after injection. Both GM and GM + SM injection helped improve calf contour. Although the thickness of the gastrocnemius muscle was reduced, reducing the leg circumference, the subcutaneous fat and soleus muscle had compensatory thickening after injection, especially over the long term, which may affect the efficacy. Compared with the GM group, the GM + SM group effectively reduced the tendency of the soleus muscle to thicken. Calf muscle thickness could be roughly estimated by constructing a fitting equation and measuring height, weight, and leg circumference. Two injection methods achieved the effect of improving calf contour and reducing the leg circumference with equivalent patient satisfaction. The GM + SM injection group did not show any obvious extra clinical benefit when compared with the GM injection group.

The Role of Muscle Ultrasonography to Diagnose Malnutrition and Sarcopenia in Maintenance Hemodialysis

Sarcopenia and malnutrition are commonly seen and fundamental indicators of prognosis and are directly associated with increased mortality in maintenance hemodialysis (MHD) patients. We aimed to reveal the frequency of malnutrition and sarcopenia in patients undergoing MHD and investigate the role of muscle ultrasound (US) parameters to predict sarcopenia and malnutrition. A total of 45 patients who have undertaken MHD for more than 6months three times a week were evaluated for the present study. The US measurement was performed on gastrocnemius medialis, rectus femoris (RF), and abdominal muscles, including rectus abdominis, external oblique abdominalis, internal oblique abdominalis, and transversus abdominis. Nutritional status of the participants was assessed by mini-nutritional assessment short-form (MNA-SF). The prevalence of probable and confirmed sarcopenia was 51.1% (n=23) and 35.6% (n=16), respectively. The malnutrition and risk of malnutrition were observed in 31.1% of the whole study population (n=14). All muscle US measurements were lower in the sarcopenic group; however, the difference is meaningful only for RF cross-sectional area (CSA) (P=.046). The malnourished group had substantially lower muscle thickness and CSA, except for the gastrocnemius muscle thickness. The value of RFCSA to predict sarcopenia and malnutrition was observed as 4.61cm2, respectively (P<.05). RFCSA was independently associated with sarcopenia (odds ratio: 0.37; 95% confidence interval: 0.17-0.79; P=.011) and malnutrition (odds ratio: 0.45; 95% confidence interval: 0.23-0.87; P=.017). RFCSA may be a useful and simple predictor for predicting patients undergoing hemodialysis who are at risk of sarcopenia and malnutrition.

Echo Intensity of Gastrocnemius Is Independently Associated with 6-Minute Walking Distance in Male Patients with Peripheral Arterial Disease.

Background and Objectives: This study aimed to examine the differences in the thickness and echo intensity (EI) of the gastrocnemius muscle measured via ultrasonography between healthy adults and patients with peripheral arterial disease (PAD) and to determine the associations of gastrocnemius thickness (GT) and EI within a 6 min walking distance (6MD) in patients with PAD. Materials and Methods: This cross-sectional study targeted 35 male patients with PAD (mean age, 73.7 years; mean body mass index [BMI], 23.5 kg/m2) and age- and gender-matched 73 male healthy adults (mean age, 73.2 years; mean BMI, 23.3 kg/m2). The gastrocnemius thickness (GT) and EI were measured using ultrasound. Both legs of patients with PAD were classified based on higher and lower ankle brachial pressure index (ABI), and the GTs and EIs with higher and lower ABI were compared with those of healthy adults. Multiple regression analysis incorporated 6MD as a dependent variable and each GT and EI with higher and lower ABI, age, and BMI as independent variables. Results: This study showed that GT was considerably greater in healthy adults than in both legs with higher and lower ABI (median values, 13.3 vs. 11.3 vs. 10.7, p < 0.01), whereas EI was lower in healthy adults than in the lower ABI leg (72.0 vs. 80.8 vs. 83.6, p < 0.05). The 6MD was shown to be substantially related to EI in both legs with higher and lower ABIs (p < 0.01) but not in the GT. Conclusions: In patients with PAD, the GT was lower, and EI was higher than in healthy adults. In addition, EIs in both legs with higher and lower ABIs were independently associated with 6MD in male PAD patients. This study showed that the EI measured via ultrasonography could become an important indicator for treatments for patients with PAD.

The value of ultrasound measurement of muscle thickness at different sites and shear wave elastography in Parkinson's disease with sarcopenia: a pilot study.

Patients with Parkinson's disease (PD) and sarcopenia often exhibit resilience, frailty, disability, and depression, highlighting the complex and interrelated nature of these conditions. Despite the presence of clinical manifestations of muscle atrophy in both PD and sarcopenia, accurately discerning the coexistence of sarcopenia in PD patients remains a challenging task with significant implications for treatment strategies and prognostic assessments. This study aims to elucidate the specific ultrasonic diagnostic parameters associated with PD accompanied by sarcopenia through a comparative analysis of muscle ultrasound parameters in patients with PD, thereby presenting a novel approach for rapid identification of this condition. A total of 110 participants were enrolled in this study, including patients with PD and control subjects. Demographic data, clinical characteristics, physical performance tests, appendicular skeletal muscle mass index (ASMI), bioelectrical impedance analysis and muscle ultrasound measurements were collected from all participants. The muscle ultrasound measurements encompassed assessments of muscle thickness, pennation angle and shear wave elastography at various anatomical sites. Parkinson's disease patients exhibited decreased muscle strength and physical performance, and increased shear wave elastography value. In PD patients with sarcopenia, body circumference, including calf circumference, mid-arm circumference, Waist-to-Hip Ratio and body mass index (BMI) were all significantly decreased. Biceps brachii muscle thickness (MT) and gastrocnemius MT decreased in PD patients with sarcopenia and low ASMI. Binary logistic regression analysis revealed that male PD patients, BMI and gastrocnemius MT were predictive factors for ASMI in PD patients. Biceps brachii MT and gastrocnemius MT are important indicators for distinguishing whether PD patients have sarcopenia. Male patients, low BMI and gastrocnemius MT were identified as valid predictors of low ASMI in PD patients. The findings of this study provide important insights into the use of muscle ultrasound in the diagnosis of PD with sarcopenia.

Suitable ultrasound screening method for older adults with disability to identify low muscle mass.

This study aimed to investigate the accuracy and consistency of different ultrasound protocols for the measurement of gastrocnemius muscle (GM) thickness and to identify a suitable ultrasound scheme that can be used to detect the low muscle mass in older with disability. In this cross-sectional study, each participant underwent three different ultrasound protocols for the measurement of the GM thickness, and each measurement was repeated three times. The three measurement schemes were as follows: method A, lying on the examination bed in a prone position with legs stretched and relaxed and feet hanging outside the examination bed; method B, lateral right side lying position with legs separated (left leg flexed and right leg in a relaxed state); and method C, right side lying position with legs together and lower limb muscles in a relaxed state. The low muscle mass was determined by averaging two or three measurements of the GM thickness determined using different sonographic protocols. The study included 489 participants. The difference in the prevalence of low muscle mass identified between two and three replicates of the same measurement protocol ranged from 0 to 1.3%. Considering the three repeated measurements of the method A as the reference, the area under the curve (AUC) in different measurement schemes were 0.977-1 and 0.973-1 in males and females, respectively. Furthermore, male and female Kappa values from low to high were 0.773, 0.801, 0.829, 0.839, and 0.967 and 0.786, 0.794, 0.804, 0.819, and 0.984, respectively. Different ultrasound measurement protocols showed high accuracy and consistency in identifying low muscle mass. Repeating the measurements two or three times was found to be feasible.

A Mixture of Morus alba and Angelica keiskei Leaf Extracts Improves Muscle Atrophy by Activating the PI3K/Akt/mTOR Signaling Pathway and Inhibiting FoxO3a In Vitro and In Vivo.

Muscle atrophy, which is defined as a decrease in muscle mass and strength, is caused by an imbalance between the anabolism and catabolism of muscle proteins. Thus, modulating the homeostasis between muscle protein synthesis and degradation represents an efficient treatment approach for this condition. In the present study, the protective effects against muscle atrophy of ethanol extracts of Morus alba L. (MA) and Angelica keiskei Koidz. (AK) leaves and their mixtures (MIX) were evaluated in vitro and in vivo. Our results showed that MIX increased 5-aminoimidazole-4-carboxamide ribonucleotide-induced C2C12 myotube thinning, and enhanced soleus and gastrocnemius muscle thickness compared to each extract alone in dexamethasone-induced muscle atrophy Sprague Dawley rats. In addition, although MA and AK substantially improved grip strength and histological changes for dexamethasone-induced muscle atrophy in vivo, the efficacy was superior in the MIX-treated group. Moreover, MIX further increased the expression levels of myogenic factors (MyoD and myogenin) and decreased the expression levels of E3 ubiquitin ligases (atrogin-1 and muscle-specific RING finger protein-1) in vitro and in vivo compared to the MA- and AK-alone treatment groups. Furthermore, MIX increased the levels of phosphorylated phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), and mammalian target of rapamycin (mTOR) that were reduced by dexamethasone, and downregulated the expression of forkhead box O3 (FoxO3a) induced by dexamethasone. These results suggest that MIX has a protective effect against muscle atrophy by enhancing muscle protein anabolism through the activation of the PI3K/Akt/mTOR signaling pathway and attenuating catabolism through the inhibition of FoxO3a.

Polydeoxyribonucleotide and Shock Wave Therapy Sequence Efficacy in Regenerating Immobilized Rabbit Calf Muscles.

This study primarily aimed to investigate the combined effects of polydeoxyribonucleotide (PDRN) and extracorporeal shock wave therapy (ESWT) sequences on the regenerative processes in atrophied animal muscles. Thirty male New Zealand rabbits, aged 12 weeks, were divided into five groups: normal saline (Group 1), PDRN (Group 2), ESWT (Group 3), PDRN injection before ESWT (Group 4), and PDRN injection after ESWT (Group 5). After 2 weeks of cast immobilization, the respective treatments were administered to the atrophied calf muscles. Radial ESWT was performed twice weekly. Calf circumference, tibial nerve compound muscle action potential (CMAP), and gastrocnemius (GCM) muscle thickness after 2 weeks of treatment were evaluated. Histological and immunohistochemical staining, as well as Western blot analysis, were conducted 2 weeks post-treatment. Staining intensity and extent were assessed using semi-quantitative scores. Groups 4 and 5 demonstrated significantly greater calf muscle circumference, GCM muscle thickness, tibial nerve CMAP, and GCM muscle fiber cross-sectional area (type I, type II, and total) than the remaining three groups (p < 0.05), while they did not differ significantly in these parameters. Groups 2 and 3 showed higher values for all the mentioned parameters than Group 1 (p < 0.05). Group 4 had the greatest ratio of vascular endothelial growth factor (VEGF) to platelet endothelial cell adhesion molecule-1 (PECAM-1) in the GCM muscle fibers compared to the other four groups (p < 0.05). Western blot analysis revealed significantly higher expression of angiogenesis cytokines in Groups 4 and 5 than in the other groups (p < 0.05). The combination of ESWT and PDRN injection demonstrated superior regenerative efficacy for atrophied calf muscle tissue in rabbit models compared to these techniques alone or saline. In particular, administering ESWT after PDRN injection yielded the most favorable outcomes in specific parameters.

The relationship of multifidus and gastrocnemius muscle thickness with postural stability in patients with ankylosing spondylitis.

This study aimed to investigate potential changes in the thickness of the multifidus and gastrocnemius muscles and to demonstrate the association of muscle thickness with postural stability in ankylosing spondylitis (AS) patients. The cross-sectional observational study enrolled 32 AS patients (23 males, 9 females; mean age: 39.4±7.2 years; range, 18 to 65 years) diagnosed according to the modified New York criteria and 32 healthy controls (22 males, 10 females; mean age: 36.6±7.5 years; range, 18 to 65 years) between April 2017 and October 2018. Plantar center of pressure (CoP) excursions were recorded using a pressure platform to evaluate postural stability. The thickness of the lumbar multifidus and gastrocnemius muscles was measured using ultrasound. Patients with AS showed reduced muscle thickness at the multifidus (p<0.05) muscle and medial gastrocnemius (p=0.002) and lateral gastrocnemius (p=0.002) muscles compared to controls. Increased CoP excursions were observed only in the anteroposterior direction in the double-leg (standard) stance with the eyes closed (p=0.003) and in both anteroposterior and mediolateral directions in tandem and single-leg stances (all p<0.05). Center of pressure excursions in standard stance with the eyes closed were negatively correlated with all muscle thickness values (all p<0.05). In the single-leg stance, CoP excursions were negatively correlated with muscle thickness of medial gastrocnemius (p=0.008) and lateral G (p=0.016) muscles. Early planning of exercise programs taking muscle loss into account can help improve balance and thereby prevent falls and fractures in AS patients.

Associations between Muscle-Tendon Morphology and Functional Movements Capacity, Flexibility, and Balance in Older Women.

Loss of functional movement capacity in older adults is related to adverse changes in musculotendinous morphology, but this relationship is poorly understood. This study examined the associations between musculotendinous morphology and functional movements, flexibility, and balance ability. Ninety-nine older women (66.6 ± 4.6 years, body mass index 23.5 ± 3.3 kg∙m−2) were recruited from Chonburi Province, Thailand. During one 90-min visit, muscle ultrasound imaging of vastus lateralis, biceps femoris, and medial gastrocnemius muscles, and tendon ultrasonography of the Achilles tendon and patellar tendon were performed. Measures were also obtained for the straight leg raise, passive dorsiflexion, balance, and functional tests (Five Times Sit to Stand (5TSTS), Timed Up and Go (TUG), 10-Meter Fast Walk Test (10-MFWT), and 6-Minute Walk Test (6-MWT)). The results specify that functional movement performance correlates most strongly with medial gastrocnemius muscle thickness (5TSTS (r = −0.26), TUG (r = −0.44), 10-MFWT (r = 0.41), and 6-MWT (r = 0.48) all p < 0.05) and that vastus lateralis muscle thickness and medial gastrocnemius muscle thickness correlate positively with balance ability (r = 0.24, 0.34; p < 0.05) and negatively with fear of falling. It appears that muscle mass, rather than other morphological parameters, such as muscle quality or fascicle length, is the main factor affecting the susceptibility of older women to frailty.

Combination Therapy of Polydeoxyribonucleotide and Microcurrent in Muscle Regeneration on Cast-Induced Muscle Atrophy in Rabbit.

The aim of this study was to evaluate how polydeoxyribonucleotide (PDRN) and microcurrent therapy (MT) functioned synergistically in a cast-immobilized rabbit model with an atrophied calf muscle. At the age of 12 weeks, 32 male New Zealand rabbits were enrolled in four groups. After 2 weeks of cast-immobilization, 4 procedures were performed on atrophied calf muscle [weekly two injections normal saline 0.2 ml injection group 1 (G1-NS), weekly two injections 0.2 ml PDRN injection group 2 (G2-PDRN), MT group 3 (G3-MT), and 0.2 ml PDRN injection with MT group 4 (G4-PDRN+MT)]. For 2 weeks, MT was used for 60 minutes each day. The calf circumference (CC), the thickness of gastrocnemius muscle (TGCM), and the tibial nerve compound muscle action potential (CMAP) were evaluated using ultrasound before and after 2 weeks of treatment. Proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor, and platelet endothelial cell adhesion molecule-1 (PECAM-1) of GCM fibers (type I, type II, and total) were measured. Statistical analyses were performed using ANOVA. The mean atrophic alterations of right CC, CMAP, and TGCM (medial/lateral) were substantially lower in G4-PDRN+MT than in the G1-NS, G2-PDRN, and G3-MT, respectively (p < 0.05). Furthermore, mean CSAs (type I, type II, and total) of medial and lateral GCM muscle fibers in G4-PDRN+MT were significantly higher when compared to other three groups (p < 0.05). In terms of the PCNA-, VEGF-, and PECAM-1-positive cell ratio of medial and lateral GCM muscle fibers, G4-PDRN+MT was considerably higher than G1-NS, G2-PDRN, and G3-MT (p < 0.05). On the atrophied calf muscle of the rabbit model, PDRN injection combined with MT was more effective than PDRN injection alone, MT alone, and normal saline injection separately.

Frailty and sarcopenia among Turkish people aged 40 and above living with HIV.

People living with HIV face a variety of challenges, including accelerated ageing and geriatric syndromes. In this study, we aimed to examine the prevalence of frailty and sarcopenia among Turkish people living with HIV. In total, 100 people living with HIV were recruited in this study. Frailty was determined using Fried's frailty phenotype, and we calculated the Charlson Comorbidity Index, Veterans Aging Cohort Study (VACS) index, fracture risk assessment tool scores, and Mini-Mental State Exam scores. We determined muscle mass using bioelectric impedance analysis, gastrocnemius muscle thickness using ultrasonography, and muscle strength using handgrip strength. The mean±standard deviation age was 50.0±8.3years. In total, 11% of the patients were frail. The risk of comorbidity and mortality, VACS index, and 5-year mortality risk was significantly higher in the frail group, as was sarcopenia. Fat-free muscle mass and handgrip strength were correlated with gastrocnemius muscle thickness. Gastrocnemius muscle thickness suggestive of sarcopenia was defined as 13.05mm. The cognitive impairment rate was 5% and was associated with physical frailty. Frailty is common and associated with higher morbidity and mortality rates among Turkish people living with HIV.

Prediction Model including Gastrocnemius Thickness for the Skeletal Muscle Mass Index in Japanese Older Adults.

Non-invasive and easy alternative methods to indicate skeletal muscle mass index (SMI) have not been established when dual energy X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) cannot be performed. This study aims to construct a prediction model including gastrocnemius thickness using ultrasonography for skeletal muscle mass index (SMI). Total of 193 Japanese aged ≥65 years participated. SMI was measured by BIA, and subcutaneous fat thickness and gastrocnemius thickness in the medial gastrocnemius were measured by using ultrasonography, and age, gender and body mass index (BMI), grip strength, and gait speed were collected. The stepwise multiple regression analysis was conducted, which incorporated SMI as a dependent variable and age, gender, BMI, gastrocnemius thickness, and other factors as independent variables. Gender, BMI, and gastrocnemius thickness were included as significant factors, and the formula: SMI = 1.27 × gender (men: 1, women: 0) + 0.18 × BMI + 0.09 × gastrocnemius thickness (mm) + 1.3 was shown as the prediction model for SMI (R = 0.89, R2 = 0.8, adjusted R2 = 0.8, p < 0.001). The prediction model for SMI had high accuracy and could be a non-invasive and easy alternative method to predict SMI in Japanese older adults.

Neural and muscular alterations of the plantar flexors in middle-aged women.

Considering the large population of middle-aged adults, it is important to understand the age-related change in lower limb muscles and the possible mechanisms before old age (> 65years old). The purpose of this study was to investigate age-related neural and muscular alterations of the plantar flexors in young and middle-aged women. Twenty two middle-aged (54.0±5.8yrs) and 17 young (21.8±1.4yrs) recreationally active women performed rapid maximal voluntary isometric contractions (MVIC) of the plantar flexors. Absolute and normalized rate of torque development (RTD) and electromyography (EMG) were examined. Electrical stimulation was used to examine voluntary activation and contractile properties of the muscle. Ultrasonography was used to examine medial and lateral gastrocnemius muscle thickness and pennation angle. A 6-minute walk and sit to stand task were also performed by all participants. The middle-aged women had significantly lower MVIC torque (141±49 vs. 109±30Nm, P=0.031), absolute RTD (753.0±313.6 vs. 423.0±156.1Nm/s, P=0.001), and normalized peak RTD (554.0±191.0 vs. 388.0±91.9% MVIC/s, P=0.001). Normalized early RTD0-50 and late RTD100-200, voluntary activation, and EMG were similar between groups. Resting twitch data showed that time to peak (124.0±20.4 vs. 143.0±16.7ms, P=0.002) and half relaxation time (73.1±15.2 vs. 107.0±28.2ms, P<0.001) was significantly faster for the young women. Thickness was greater in the lateral gastrocnemius (1.6±0.2 vs. 1.4±0.2cm, P=0.006) for the young women. Pennation angle of both muscles were greater for the young women (15.8±3.9 vs. 13.1±2.7 degrees, P<0.05). Performance of the 6-minute walk was similar between groups, however, the young women performed more repetitions during the sit to stand task (25.6±6.7 vs. 18.3±4.7 reps, P<0.001). Compared to young women, middle-age women were shown to have lower MVIC torque, peak RTD, and functional performance. Muscle architecture and contractile properties are affected by aging.

Progression of Venous Disease is Associated with Biomechanical and Morphological Changes in the Calf Muscle Pump

Background: Chronic venous disease (CVD) is a common progressive disorder. Calf muscle incompetence due to muscle weakness and ankle movement abnormalities is an important factor in CVD, but the biomechanical and morphological characteristics of the calf muscle remain unknown Aim:To evaluate the biomechanical and morphological characteristics of the calf muscle in subjects with CVD and healthy controls. Place and duration of study: Study was conducted at University of Social Welfare and Rehabilitation Sciences, Tehran, Iran, for the duration of six months, from January, 2021 to June, 2021. Materials and methods:In this case-control study, sixty patients with CVD in three equal groups (mild: C1 – C2, moderate: C3 – C4, severe: C5 – C6) and 20 healthy subjects in a control group participated. The shear wave elastography (SWE) and thickness of medial gastrocnemius muscle (GM) were measured using an ultrasonography. Results: The results of analysis of variance (ANOVA) showed significant differences in SWE and thickness values between groups for medial GM (P&lt;0.05). There was a statistically significant decrease in thickness and a significant increase in SWE in patients with CVD. A positive and negative correlation was discovered between disease grades and the medial GM SWE and thickness in patients with CVD, respectively. Conclusion:A change in the SWE and thickness of the calf muscle compared to the control group indicates a biomechanical and morphological change in the calf muscle pump. The SWE and thickness values of the calf muscle may be valuable information in the diagnosis and follow-up of patients with CVD. Keywords: Calf muscle pump; Chronic venous disease; Thickness; Ultrasonography; Stiffness

Ultrasonographic/regional muscle measurements for diagnosing sarcopenia in older adults with and without dementia.

Sarcopenia and dementia are growing concerns among older adults that muscle and brain atrophy may cooccur. We aimed to compare the age-related loss of muscle mass by using ultrasound (US), and skeletal muscle mass index (SMI) by bioelectrical impedance analysis in older adults with and without dementia. A total of 221 older adults aged ≥65 years were included in the study. The diagnosis of sarcopenia was established if low muscle mass according to either SMI or sonographic gastrocnemius (GC) muscle thickness was combined with low grip strength. The diagnosis of dementia was based on the National Institute of Aging and Alzheimer's Association criteria and the major neurocognitive disorder definition in the Diagnostic and Statistical Manual of Mental Disorders-V. Muscle strength was measured by hand dynamometer and physical performance was assessed by 4-meter usual gait speed. There were similar/moderate correlation coefficients between GC muscle thickness and SMI with functional parameters (all p < 0.01). Forty-six patients (20.8%) had dementia, and 21 (45.7%) of them had sarcopenia diagnosed by GC thickness (p < 0.001). Age was older but weight, body mass index, and all sarcopenia-related parameters were lower in dementia patients (all p < 0.01). When clinical variables were taken into binary logistic regression analyses, age [OR = 1.095 (95% CI: 1.028-1.167)], weight [OR = 0.918 (95% CI: 0.887-0.950)], and presence of dementia [OR = 5.109 (95% CI: 2.002-13.033)] were independently associated with sarcopenia diagnosed with GC muscle thickness (all p < 0.05). This study showed that sarcopenia is highly prevalent in older adults with dementia (45.7%) than without dementia (11.4%). Amongst different factors, increased age, having low body weight, and the presence of dementia independently increased the risk of sarcopenia diagnosed by GC muscle thickness (but not diagnosed by SMI) in older adults. Thus, we can evaluate easily and successfully the loss of (regional) muscle mass in dementia patients by using US in outpatient clinics.

Reliability of lower leg muscle thickness measurement along the long axis of the muscle using ultrasound imaging, in a sitting position.

[Purpose] To verify the reliability and validity of lower leg muscle thickness (MT) assessment along the muscle’s long axis using ultrasound imaging (USI) in a sitting position. [Participants and Methods] Twenty healthy adult female participants (aged, 20.3 ± 0.9 years) were included in the study. Intra- and inter-examiner reliability of the proximal, middle, and distal MT of the tibialis anterior (TA) and medial head of the gastrocnemius (GM) were verified using USI in a sitting position. Additionally, the relationship between MT measurement using USI and muscle cross-sectional area (MCSA) measurement using magnetic resonance imaging (MRI), as well as the ankle joint’s maximum muscle strength, were examined. [Results] The reliability of TA and GM MT measurement using USI was high for all regions. The relationship between MCSA measurement using MRI and MT measurement using USI showed a significant correlation in all the regions for both muscles. The relationship between ankle muscle strength and USI of MT was not significantly correlated in any region for both muscles. [Conclusion] Measurement of MT using USI is reliable and valid for MCSA, but must be combined with assessments of other factors for muscle strength.

Acute Ultrasonographic Changes in Lower Extremity Muscle Structure after Motor Complete Spinal Cord Injury.

There is a lack of studies examining ultrasonographic muscle changes in patients with acute spinal cord injury (SCI). We recruited adults with motor complete acute SCI and performed longitudinal ultrasound measurements. The primary outcome measures were rectus femoris and medial gastrocnemius thickness and echo intensity. This study recruited 20 patients, with a mean time to the first ultrasound measurement of 17.2 ± 2.14 days, with the second measurement done 4 weeks after the first measurement. We found that there was a mean decrease in the rectus femoris muscle thickness of 18.7% (P = 0.027), as well as a mean increase in the rectus femoris echo intensity of 13.0 a.u. (P = 0.009), although no significant differences were found for the medial gastrocnemius. This study demonstrates decreased thickness and increased echo intensity in the rectus femoris but not in the medial gastrocnemius in patients with motor complete SCI.