Muscle Thickness Research Articles

Does increasing the resistance-training volume lead to greater gains? The effects of weekly set progressions on muscular adaptations in females

ABSTRACT We investigated the effect of increasing the number of sets per week every fortnight versus performing a constant set volume on muscular adaptations over 12 weeks. Thirty females (RT experience 2.1 ± 1.0 years) were randomly assigned to a constant group (CG, n = 9) that performed 22 sets per week, a two-set progression group (2SG, n = 11), or a four-set progression group (4SG, n = 10). Forty-five degree leg press one-repetition maximum (1RM), vastus lateralis cross-sectional area (VL-CSA), and the sum of proximal, middle and distal lateral thigh muscle thickness (∑MT) were assessed at baseline and after the intervention. We observed that the 4SG and 2SG conditions showed greater improvements in 1RM than the CG (p < 0.001, p = 0.032, respectively), with no differences between 4SG and 2SG (p = 0.118). Regarding VL-CSA, the 4SG group showed greater increases than the CG (p = 0.029) but not than the 2SG (p = 0.263), whereas no differences between the 2SG and CG (p = 0.443) were observed. There were no differences between groups for ∑MT (p = 0.783). While all groups demonstrated improvements in the measured outcomes, our findings suggest that increasing weekly sets may offer additional benefits for 1RM and vastus lateralis cross-sectional area. However, no additional benefits were observed for ∑MT.

Passive dehydration reduces muscle thickness after resistance exercise

ABSTRACT Dehydration-induced increased plasma osmolality (Posmo) alters whole body fluid balance which could alter resistance exercise (RE) induced intramuscular (IM) fluid shift. PURPOSE: The purpose of the current report was to investigate the effect of dehydration on RE-induced change in whole body fluid balance in resistance trained (RT) men. METHODS: Fourteen RT men performed two identical RE sessions, either in a hydrated (EUHY) or dehydrated (DEHY) state induced by a 24 hr fluid restriction. Total body fluid, urine osmolality (Uosmo), urine specific gravity (USG), Posmo, hematocrit (HCT), muscle thickness were measured and plasma volume (%ΔPV) was calculated using HCT. RESULTS: A significant (p < 0.050) condition effect was observed for total body fluid and muscle thickness such that EUHY was 2.6% and 13.0% greater than DEHY, respectively. Significant time × condition effects were observed for Posmo, Uosmo, and USG. At all times, EUHY (collapsing for time: Posmo: 3.9%; Uosmo: 133.5%; USG: 1.6%) was lower than DEHY. A significant time effect was observed for %ΔPV. %ΔPV 5 min after RE was −12.5% lower than PRE. CONCLUSION: Dehydration with RE altered whole body fluid balance indicated by greater fluid retention and efflux of IM fluid could at least partly maintain %ΔPV following DEHY in RT men.

Predicting early diagnosis of intensive care unit-acquired weakness in septic patients using critical ultrasound and biological markers

ObjectiveEarly diagnosis of intensive care unit-acquired weakness (ICUAW) is crucial for improving the outcomes of critically ill patients. Hence, this study was designed to identify predisposing factors for ICUAW and establish a predictive model for the early diagnosis of ICUAW.MethodsThis prospective observational multicenter study included septic patients from the comprehensive ICUs of West China Hospital of Sichuan University and 10 other hospitals between September and November 2023. Inclusion criteria were as follows: age over 18 years; expected ICU stay longer than 3 days; and voluntary informed consent. Patients were classified into ICUAW (MRC score < 48) and non-ICUAW (MRC score ≥ 48) groups based on muscle strength assessments. The analyzed key predictive factors encompassed demographic data, SOFA and APACHE II scores, inflammatory markers (PCT, IL-6, and CRP), and ultrasound measurements of muscle thickness and cross-sectional area. Logistic regression analysis was conducted for variable selection and nomogram model construction.ResultsA total of 116 septic patients were included, comprising 77 males and 39 females (mean age: 56.94 ± 19.90 years). A nomogram model predicting ICUAW probability was developed, which involved vastus intermedius diameter, rectus femoris cross-sectional area, IL-6, and CRP. The AUC of the composite diagnostic ROC curve was 0.966 (95%CI: 0.936 − 0.996), with a sensitivity of 88% and a specificity of 95.8%.ConclusionsConclusively, a nomogram model is constructed for diagnosing ICUAW in septic patients, which is simple and rapid and allows for visual representation, with excellent diagnostic capability.

Comparative magnetic resonance imaging-based study of pelvic floor morphology and function before pregnancy and after primigravida vaginal delivery

BackgroundVaginal childbirth is one of the main risk factors for pelvic floor dysfunction. Magnetic resonance imaging (MRI) can facilitate quantitative evaluation of the morphology and function of the pelvic floor in static and dynamic environments. The objective of this study was to investigate the changes in pelvic floor morphology and function in primigravida women before pregnancy (BP) and after vaginal delivery.MethodsPrimigravida women underwent pelvic floor MRI scans BP, at 3 months postpartum (3mPP), and at 6 months postpartum (6mPP). Various pelvic floor MRI data were measured, including the obturator internus muscle (OIM) area, anterior pelvic area, puborectalis muscle thickness (PRT), levator plate angle (LPA), iliococcygeal angle, bladder–pubococcygeal line (B-PCL), uterus–pubococcygeal line (U-PCL), puborectal hiatus line, muscular pelvic floor relaxation line, levator hiatus area, urethral mobility, bladder neck descent, and cervix descent.ResultsIn the resting state, the OIM area and PRT decreased whereas the anterior pelvic area increased from BP to 3mPP. During the straining maneuver, all parameters except U-PCL and urethral mobility showed statistically significant differences (P < 0.05). The OIM area and PRT increased whereas the anterior pelvic area decreased from 3mPP to 6mPP. During the straining maneuver, B-PCL, bladder neck descent, levator hiatus area, and LPA showed statistically significant differences (P < 0.05). In the resting state, the OIM area and PRT decreased whereas the anterior pelvic area increased from BP to 6mPP. During the straining maneuver, B-PCL, muscular pelvic floor relaxation line, and bladder neck descent showed statistically significant differences (P < 0.05).ConclusionVaginal delivery can cause pelvic floor injury that may gradually recover over time. However, the injury does not fully recover to the pre-pregnancy level within 6mPP.

P0576 Ultrasound assessment of sarcopenia and body composition in patients with inflammatory bowel disease

Abstract Background Sarcopenia is a progressive pathological condition which can present in inflammatory bowel disease (IBD) together with changes in body composition. Aim To provide ultrasound assessment of muscle mass and bioimpedance analysis of body composition in patients with IBD. Methods: Material and Method The study included 102 patients with IBD, 50 (49%) with ulcerative colitis (UC), 52 (51%) with Crohn's disease (CD), 10 persons formed the control group (CG). The average age of patients with IBD was 39,5 [28,5; 50] year, in the CG – 37 [26; 38] years. There were 52 (51%) women in the IBD group and 5 (50%) in CG. Patients underwent an examination with assessment of body mass index (BMI), mid-upper arm circumference (MUAC, cm) and mid-thigh circumference (MTC, cm) of dominant side; bioimpedance analysis of body composition using the ABC-02 “MEDASS” apparatus; ultrasound examination of the muscle thickness (MT) at the following two points of the leading side: ultrasound mid upper arm, ultrasound mid-thigh. Results According to BMI, patients were distributed as follows: normal body weight was observed in 57 (55,9%) patients; deficiency – in 12 (11,8%); overweight 25 (24,5%); obesity – 8 (7,8%). The average MUAC values of the dominant hand in women were 28 [24,9; 31] cm, in the CG were 28 [27; 28,5] cm (p&amp;gt;0.05); in men 29,8 [27; 32] cm, in the CG were 33 [31; 34] cm (p&amp;lt;0.05). The average MTC in women with IBD were 54,25 [48,15; 58,1] cm, in the CG were 61,5 [56; 67] cm (p&amp;lt;0.05); in men 48 [46; 51,4] cm, in the CG were 54 [53; 54] cm (p&amp;lt;0.05). The MT in ultrasound mid upper arm in women with IBD was 19,60 [18,23; 22,84] mm, CG 22.49 [20.41; 22.66] (p&amp;gt;0.05); in men with IBD 26,45 [22,87; 29,24] mm, in the CG 21,54 [21,18; 25,13] mm (p&amp;gt;0.05). The MT in ultrasound mid-thigh in women with IBD was 31,05 [23,21; 37,11] mm, CG 41,30 [35,55; 41,74] mm (p&amp;lt;0.05), in men with IBD 30,90 [25,64; 39,99] mm, in the CG 40,67 [39,10; 41,84] (p&amp;lt;0.05). According to the results of bioimpedance, a deficiency of skeletal muscle mass was detected in 31% patients, in 66% patients skeletal muscle mass was normal, excess muscle mass was detected in 3% patients. The MT in ultrasound mid upper arm correlated with MUAC (r=0,557; p&amp;lt;0.05), with BMI (r=0,448; p&amp;lt;0.05), with skeletal muscle mass according to bioimpedancemetry (r=0,666; p&amp;lt;0.05). The MT in ultrasound mid-thigh correlated with MTC (r=0,505; p&amp;lt;0.05), with BMI (r= 0,376; p&amp;lt;0.05), with skeletal muscle mass according to bioimpedancemetry (r=0,373; p&amp;lt;0.05). Conclusion In patients with IBD MTC was lower than in CG. The muscle thickness in ultrasound mid-thigh in women and men with IBD was less than in CG, which correlated with MTC, BMI, skeletal muscle mass according to bioimpedancemetry.

Transdermal Delivery of Botulinum Neurotoxin A: A Novel Formulation with Therapeutic Potential

Background: Botulinum neurotoxin is widely regarded as a “wonder medicine” due to its therapeutic efficacy in treating a variety of conditions. While it is traditionally classified as a neurotoxin, it is arguably more appropriate to refer to it as a neuromedicine. All FDA-approved formulations of botulinum neurotoxin are currently administered through intramuscular injections, with no other delivery methods widely used. The primary reasons for this include the following: (a) the extremely high potency of the toxin, (b) the potential for diffusion to adjacent muscles, (c) factors related to the site of administration (e.g., muscle thickness), (d) the large size of the molecule, (e) the impermeability of skin to large protein molecules, and (f) safety concerns. Despite these challenges, there is growing interest in the development of an effective transdermal formulation of botulinum neurotoxin. Refining and standardizing the delivery technology for topical or transdermal use remains an important goal for the future. Methods: The aim of this study was to develop a nanoemulsion-based transdermal formulation capable of delivering active botulinum neurotoxin (BoNT) through human skin. The goal was to demonstrate its efficacy in a mouse model, highlighting the therapeutic effects on both neuromuscular activity and hyperhidrosis. We successfully developed a nanoemulsion-based formulation that facilitates the transdermal delivery of BoNT. The formulation was homogeneous, stable, and efficacious. In a mouse model, we evaluated the neurotoxin’s impact on neuromuscular function using the Digital Abduction Score (DAS) for toe-spread and rota-rod assay to assess motor coordination. Results: The results confirmed the successful paralytic effect of the neuotoxin. The formulation significantly reduced sweating in the hyperhidrosis mouse model, indicating the therapeutic potential for this indication. Beyond the neurotoxin’s paralyzing effect, we also observed the recovery of nerve function, showing that the neurotoxin does not cause permanent damage, further underscoring its safety and efficacy. Conclusions: This formulation is the first of its kind to successfully deliver a large biomolecule like BoNT across the skin and produce a therapeutic effect. The ability to deliver large biomolecules transdermally has the potential to serve as a platform technology for treating a variety of conditions, including neuromuscular disorders, skin conditions, and localized pain management.

Neuromuscular Response to High-Velocity, Low-Amplitude Spinal Manipulation—An Overview

The clinical use of spinal manipulation to treat musculoskeletal conditions has nearly tripled in the United States since 1980, and it is currently recommended by most global clinical guidelines as a conservative treatment for musculoskeletal pain, despite a lack of knowledge concerning its mechanisms of action. This overview highlights evidence of direct neuromuscular responses to high-velocity, low-amplitude spinal manipulation (HVLA-SM) as delivered by chiropractic, osteopathic, and physical therapy clinicians, with an intent to foster greater interprofessional dialogue and collaborative research to better address current gaps in mechanistic knowledge of the neuromuscular response to HVLA-SM. Three databases (PubMed, CINAHL Ultimate (EBSCO), EMBASE (Elsevier)) were searched from 2000 to December 2024 with specific search terms related to thrust HVLA-SM and the neuromuscular response. To focus strictly on neuromuscular responses related to HVLA-SM, this literature overview excluded articles using non-HVLA-SM manual therapy techniques (i.e., massage, non-thrust joint mobilization, and/or combined HVLA-SM with other forms of treatment such as exercise or non-thrust joint mobilization) and studies in which patient-centered outcomes (i.e., pain scores) were the primary outcomes of the HVLA-SM interventions. Pediatric studies, animal studies, and studies in languages other than English were also excluded. One-hundred and thirty six articles were identified and included in this overview. Neuromuscular findings related to HVLA-SM in the areas of electromyography (EMG), muscle thickness, muscle strength, reflexes, electroencephalogram (EEG), and evoked potential were often mixed; however, evidence is beginning to accumulate either in favor of or opposed to particular neuromuscular responses to HVLA-SM as larger and more scientifically rigorous studies are being performed. Recurrent limitations of many HVLA-SM-related studies are small sample sizes, leading to a lack of generalizability, and the non-standardization of HVLA-SM delivery, which has prevented researchers from arriving at definitive conclusions regarding neuromuscular responses to HVLA-SM. Discussions of future neuromuscular research needs related to HVLA-SM are included for clinicians and researchers inside and outside of the field of manual therapy, to advance this field.

Blood Flow Restriction Training Following Achilles Tendon Reconstruction: A Case Report

BACKGROUND: This case report aimed to demonstrate positive changes in Achilles tendon (AT) morphology and functional performance of a six-month post-surgical individual following an 8-week bout of blood flow restriction (BFR) training. CASE PRESENTATION: A 26-year-old male athlete who had an AT repair followed by six months of physical therapy presented to the authors with persistent deficits including limited strength, jumping, running, and the ability to play basketball. To enhance recovery, eight weeks of BFR training was performed to improve gastrocnemius/soleus muscle performance. OUTCOME AND FOLLOW-UP: The participant showed improvements in strength (heel rise height), muscle thickness, and limb symmetry during landing following the 8-week BFR training. The participant returned to recreational basketball competition with no complaints. DISCUSSION: This case illustrates the effective use of BFR training in late-stage rehabilitation following AT repair. It also demonstrates how BFR training could facilitate participants’ strength and performance to return to sport.

The adductor pollicis muscle thickness is not associated with physical function, lean mass, and nutritional status in patients on maintenance hemodialysis

BackgroundThe adductor pollicis muscle thickness (APMT) may be associated with the muscle strength in patients on hemodialysis. However, the association of APMT with other physical function assessment tests has not yet been tested. Moreover, because it is considered a good nutritional indicator and not influenced by fluid overload, the APMT may be associated with the muscle mass and nutritional status of these patients. Therefore, the objective was to assess the association of APMT with physical function, muscle mass and nutritional status in patients on hemodialysis.MethodsThe APMT was measured using a skinfold caliper between pollicis finger and index finger. Physical function was evaluated by handgrip strength (HGS), Short Physical Performance Battery (SPPB), the sit-to-stand test, gait speed test, and timed up and go (TUG). Appendicular muscle mass index (AMMI) was estimated using bioelectrical impedance. The nutritional status was evaluated by the Malnutrition Inflammation Score (MIS).ResultsFifty-one patients were included, 60.8% men, mean age 58.4 ± 12.6 years. There were no significant correlations of APMT with physical function, muscle mass and nutritional status. Values of APMT were not different between the groups according to adequate physical function or muscle mass. In the multiple linear regression analysis adjusted for sex, age and diabetes, APMT was not significantly associated with physical function tests, as HGS (β = 0.101; p = 0.778), gait speed (β = −0.014; p = 0.180), SPPB (β = −0.054; p = 0.590), TUG (β = 0.202; p = 0.109), lean mass AMMI (β = 0.058; p = 0.147).ConclusionThere were no associations of APMT with physical function, muscle mass and nutritional status in patients on hemodialysis. We suggest APMT should not be used in physical function and nutritional assessments of these patients.

Evaluation of the core muscles of children and adolescents with nocturnal enuresis using shear wave elastography: a preliminary study

The purpose of this study was to determine any changes in the rectus abdominis and diaphragm muscles, which are core muscles, in children and adolescents with nocturnal enuresis (NE) using the shear wave elastography (SWE). In this case-control study, the rectus abdominis and diaphragm muscles of 40 children and adolescents with NE and 40 healthy controls were evaluated. The rectus abdominis muscle was examined at the right supra- and subumbilical levels, and the diaphragm at the right 9th-10th intercostal space. The thickness of both muscles was measured by gray scale ultrasound and muscle stiffness was measured by SWE. The demographic characteristics of the patients such as sex and age and their anthropometric measurements including height, weight, and BMI were recorded. Compared to the control group, the NE group had significantly lower mean rectus abdominis muscle stiffness values on both the supraumbilical and subumbilical levels (p < 0.05). There was no significant difference in mean rectus abdominis thickness and diaphragm thickness-stiffness values between the groups (p > 0.05). According to the results of the study, it is thought that NE children have problems with core stabilization and that children with NE should be directed to appropriate treatment. However, future studies are needed with larger sample sizes and other factors that are thought to affect muscle architecture.

The Effects of Floor Isometric Trunk Extension Exercise on Muscle Thickness and Activation Vary Between Different Combinations of Duration and Repetition Number.

Intermittent floor trunk extensions are popular exercises in group fitness programs. The aim of this study was to investigate whether fewer repetitions of longer isometric trunk extension efforts compared with more repetitions of shorter isometric contractions have different acute effects on muscle thickness and activation as well as perceived exertion. This study followed a cross-sectional design. Twenty healthy young males performed floor prone trunk extension exercises using 3 different exercise protocols of repetition and duration: 10 × 5seconds (D10 × 5), 2 × 25seconds (D2 × 25), and 5 × 10seconds (D5 × 10). Ultrasound multifidus thickness and rate of perceived exertion on a 10-point scale were measured immediately after each protocol. Electromyographic activation from the erector spinae, multifidus, and gluteus maximum during each protocol was measured using bipolar surface electrodes. The longer duration (D2 × 25) protocol showed a significant greater rate of perceived exertion (6.22 [0.73]) and rest multifidus thickness change (median: 8.04%) compared with the other protocols (P < .05). Within each protocol, root mean square of all muscles increased from trial to trial in the D2 × 25 and D5 × 10 (P < .05), but not during the D10 × 5 protocol (P > .05). The maximum root mean square was achieved in the shorter duration (D10 × 5) protocol compared with the other ones (P < .05). If trunk extension exercises on the floor are used in a training setting, then using exercises with long duration and fewer repetitions may elicit a greater metabolic response.

Structural elucidation and anti-asthmatic effects of semi-crystalline polysaccharides from Lignosus rhinocerotis (Cooke) Ryvarden.

Asthma is a chronic respiratory disease characterized by airway inflammation. Lignosus rhinocerotis (LR), a medicinal mushroom rich in polysaccharide, has been traditionally used to treat various diseases, including asthma. This study aimed to fractionate, characterize and evaluate the anti-asthmatic effects of polysaccharides from LR (LRP). LRP was isolated and characterized using high-performance liquid chromatography (HPLC), x-ray diffraction analysis (XRD), fourier transform infrared spectrometry (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. In an OVA-induced asthma model, BALB/c mice were sensitized, challenged, and intranasally treated with LRP. Experimental findings demonstrated that LRP exhibits a semi-crystalline nature with predicted structure of → 4)-α-D-Glcp-(1 → and → 3)-β-D-Glcp-(1→. LRP significantly reduced eosinophilia, Th2 cytokines, and IgE levels. Histological analysis revealed LRP's ability to decrease epithelial damage and epithelial and smooth muscle thickness in lung. Reductions in inflammatory cell infiltration, mucus production, and transforming growth factor (TGF)-β1 expression were observed, although not statistically significant. Gene expression analysis indicated that LRP significantly downregulated the inducible nitric oxide synthase (iNOS) expression. This study highlights a detailed structural analysis of LRP and its potential as an alternative for the management of asthma. Further research is needed to elucidate the precise mechanisms of action and optimize its therapeutic application.

Effect of Different Reduced Training Frequencies After 12 Weeks of Concurrent Ballistic and Aerobic Training on Muscle Power and Triceps Brachii Muscle Architecture.

Background/Objectives: The aim of the present study was to investigate the effect of two long-term reduced concurrent training frequencies (incorporating power training for the upper and high-intensity interval aerobic training for the lower extremities), in which participants performed one training session every either 7 or 14 days, after 12 weeks of systematic concurrent training on upper extremities' muscle strength, power, and morphology in young females. Methods: After a 12-week concurrent resistance and aerobic training period, participants were assigned into three groups and performed either one training session every 7 days (G7), or once every 14 days (G14), or detraining (GD) for 12 weeks, followed by 12 additional weeks of detraining. Results: Performance and muscle mass increased after the initial 12-week training period. After the reduced training frequency period, bench press 1-RM and aerobic power remained unchanged in G7 and decreased significantly in G14 (-5.9 ± 4.9%; -1.4 ± 4.5%). Muscle power and muscle thickness of the triceps branchii long head decreased significantly in G7 (-9.8 ± 7.7%; -0.9 ± 0.6%; respectively, p < 0.05) and G14 (-10.9 ± 7.6%; -2.8 ± 2.7%, respectively, p < 0.05), without significant differences between groups (p > 0.05). Conclusions: In conclusion, 12 weeks of systematic concurrent resistance (upper extremities) and aerobic training (lower extremities) induced significant improvements in upper extremities muscle power/strength and muscle architecture characteristics. Both reduced training frequencies led to significant reductions in power performance. Thus, performing one training session every 2 weeks for 3 months may preserve 90 to 95% of the muscle power/strength, aerobic power and 72% of muscle mass adaptations achieved with systematic concurrent training. However, greater preservations in the above parameters could be observed if the training frequency is one training session per week.

Age- and sex-adjusted CT-based reference values for temporal muscle thickness, cross-sectional area and radiodensity

Muscle mass has been traditionally assessed by measuring paraspinal muscle areas at the level of the third lumbar vertebra on computed tomography (CT). Neurological or neurosurgical patients seldom undergo CT scans of the lumbar region. Instead, temporal muscle thickness (TMT), cross-sectional area (TMA) and radiodensity measured from head CT scans are readily available measures of muscle mass and quality in these patient cohorts. The purpose of this retrospective study was to establish CT-based reference values for TMT, TMA and radiodensity for each decade of age from 0 to 100 years normalized by age and sex, and to define cut-off values for subjects at risk for sarcopenia as defined by the European Working Group on Sarcopenia in Older People (EWGSOP). Subjects diagnosed with a concussion at the Oulu University Hospital between January 2014 and December 2022 (n = 9254) were identified to obtain a reference population. Subjects with significant pre-existing co-morbidities were excluded. TMT, TMA and radiodensity were measured, measurement reliability was quantified, and sex-adjusted reference values were calculated for each age decade. Quantile regression was used to model age-related changes in muscle morphomics. A total of 500 subjects [250 (50.0%) males] with a mean age of 49.2 ± 27.9 years were evaluated. Inter- and intra-observer reliability was almost perfect for TMT and TMA, and substantial-to-almost perfect for radiodensity. The mean TMT, TMA and radiodensity were 5.2 ± 1.9 mm, 284 ± 159 mm2 and 44.6 ± 17.7HU, respectively. The cut-off values for reduced TMT, TMA and radiodensity for males/females using the European Working Group on Sarcopenia in Older People compliant criteria were ≤ 4.09 mm/≤3.44 mm, ≤ 166 mm2/≤156 mm2, and ≤ 35.5HU/≤35.2HU, respectively. We described a standardized CT-based TMT and TMA measurement protocol practical for clinical use with almost perfect reliability. Using the protocol, we produced quantile regression models for the detection of reduced TMT, TMA and radiodensity at the lowest 5th, 10th, 20th, 30th, 40th and 50th percentiles as well as the EWGSOP compliant criteria cut-off values for reduced muscle mass to facilitate generalizable radiological sarcopenia research.

Quantification of the Anterior-Centripetal Movement of the Ciliary Muscle During Accommodation Using Dynamic OCT Imaging.

Although the lens undoubtedly plays a major role in presbyopia, altered lens function could be in part secondary to age-related changes of the ciliary muscle. Ciliary muscle changes with accommodation have been quantified using optical coherence tomography, but so far these studies have been limited to quantifying changes in ciliary muscle thickness, mostly at static accommodative states. Quantifying ciliary muscle thickness changes does not effectively capture the dynamic anterior-centripetal movement of the ciliary muscle during accommodation. To address this issue, we present a method to quantify the movement of the ciliary muscle during accommodation using trans-scleral optical coherence tomography images obtained dynamically. An image processing framework including distortion correction, geometric transformation, and Procrustes analysis, was used to quantify the anterior-centripetal movement of the ciliary muscle apex and centroid during accommodation. The method was applied in a preliminary study to quantify ciliary muscle displacement and its relation to lens thickness change with accommodation on two young adults and two prepresbyopes. The magnitude and the direction relative to the pupil plane of the apex/centroid displacement in response to a two diopters (2D) stimulus were 0.16/0.20 mm at 11.3°/30.5° and 0.26/0.34 mm at 6.6°/33.2° for the young adults and 0.20/0.20 mm at 29.7°/40.6° and 0.24/0.40 mm at 33.0°/31.7° for the prepresbyopes, respectively. This study demonstrates the feasibility of quantifying dynamic anterior-centripetal movement of the ciliary muscle during accommodation using optical coherence tomography. The method better captures the functional response of the muscle than the quantification of thickness changes. We provide a method that holds potential to better understand the age-related changes of the ciliary muscle on presbyopia.

Sonographic and Anthropometric Measurements for Body Composition and Their Relationship with Functioning in Adolescent Obesity.

Obesity is one of the most common chronic diseases seen in children and adolescents. This study aims to examine the impact of obesity on body composition, assessed by sonographic and anthropometric measurements, and health-related quality of life (HRQoL) in adolescents.Anthropometric measurements, sonographic measurements of subcutaneous fat, quadriceps muscle, Achilles tendon thickness, and HRQoL were performed in children between 12-18 years of age. Comparisons between adolescents with obesity and normal body mass index (BMI) were examined.A total of 300 adolescents with similar physical activity levels, 28.7% with obesity, were enrolled. The thickness of mid-forearm/mid-thigh subcutaneous fat tissue and quadriceps muscle was significantly higher in participants with obesity (p≤0.001). Moderate-to-strong correlation with BMI and waist circumference was observed (r>0.40, p<0.01). Participants with longer duration of obesity had thicker quadriceps muscle irrespective of the severity of obesity or presence of metabolic syndrome. Achilles tendon thickness did not differ between the groups. HRQoL was significantly lower in adolescents with obesity and indicated a negative moderate correlation between physical functioning and subcutaneous fat thickness (r<- 0.50, p<0.01).An important relationship between sonographic and anthropometric measurements, and physical functioning was demonstrated in adolescents. Ultrasound seems to have a role in the evaluation of body composition in obesity beyond what is captured by overall BMI. Significantly increased quadriceps muscle thickness in adolescents with obesity, coupled with its relation to the duration of obesity, implies potential temporal association between excess body weight and adaptation of quadriceps muscle.

Different whole body HIIT protocols do not promote different muscle thickness and functional adaptations among healthy physically active subjects

IntroductionDespite robust evidence on the benefits of high intensity interval training using body weight (WB-HIIT), the effects of different training configurations on morpho-functional adaptations are still unclear. Therefore, the aim of the present study was to assess the effects of two distinct WB-HIIT protocols on morphological and general fitness adaptations in healthy active young individuals.MethodsThirty-four participants (22 males and 12 females) were randomly assigned to one of the following groups: 30 s of all-out effort interspersed with 10 s of passive recovery (G30 × 10, n = 17) or 40 s of an all-out effort interspersed with 20 s of passive recovery (G40 × 20, n = 17). Nine exercises were performed for both protocols, in two weekly sessions, during a 6-week intervention period. Morphological (ultrasound-derived muscle thickness of the vastus lateralis [MTVL]) and general fitness (muscle endurance and maximal oxygen consumption) assessments were performed at pre- and post-intervention moments.ResultsBoth training protocols elicited significant improvements in all dependent variables (p &amp;lt; 0.05), with no significant between-group differences.ConclusionRegardless of the training configuration, both WB-HIIT programs serve as time-efficient strategies to induce changes in muscle thickness of the vastus lateralis and functional adaptations in healthy, physically active young individuals.

Ankle muscle strength and activation are associated with walking patterns in preschool and school-age children.

Walking patterns can differ between children and adults, both kinematically and kinetically. However, the detailed nature of the ankle pattern has not been clarified. We investigated musculature, biomechanics, and muscle activation strategies and their relevance to walking performance in preschool (PS) and school children (SC), with adults (AD) as reference. Twenty-six PS (3-5 yr), 20 SC (6-8 yr), and 17 AD (18-30 yr) participated. Tibialis anterior (TA) and medial gastrocnemius (MG) thicknesses, fascicle lengths, and maximal voluntary dorsi- and plantar flexion isometric torques were measured. Hip, knee, and ankle kinematics, ground reaction forces (GRFs), and TA and MG electromyographic activities were recorded during shod walking at each participant's preferred speed. Walking speed, step length, and cadence were correlated with age in PS. These walking performance measures were also correlated with muscle thickness and fascicle length, showing higher speed in individuals with thicker muscles and longer TA and MG fascicles (conversely, higher cadence with thinner muscles and shorter fascicles). AD demonstrated the largest values for muscle thickness (p<0.001), fascicle length (p<0.001), strength (p<0.001), and walking performance (speed p = 0.004; step length p<0.001; cadence p<0.001), followed by SC then PS. Both PS and SC exhibited higher TA activities than AD during the stance phase, resulting in a higher co-activation index. The GRFs relative to body weight were lower in both horizontal and vertical components in PS compared to SC and AD, while the relative lateral force during stance was greatest in PS followed by SC and then AD. Differences in preferred walking speed and step length were associated with age and muscle size. Children, particularly preschool-aged, employed a co-activation strategy of dorsi- and plantar flexors for stabilization, which resulted in sideways steps even at a preferred walking speed.

Factors Associated With Balance and Fear of Falling in Patients With Benign Paroxysmal Positional Vertigo: A Controlled Cross-Sectional Study.

The aim of this study is to evaluate the factors influencing balance and fear of falling (FOF) in patients with benign paroxysmal positional vertigo (BPPV). A controlled cross-sectional study. Single center study. A total of 31 patients with BPPV and 30 controls were included in this cross-sectional study. The handgrip strength (HGS) was measured using the Jamar hydraulic hand dynamometer. Ultrasound measurements of muscle thickness (MT) of the biceps brachii, medial head of gastrocnemius, and lateral head of gastrocnemius were recorded. MT/body mass index was calculated. FOF was assessed using the Falls Efficacy Scale (FES). The Berg Balance Scale (BBS) was used to assess the participants' balance. The timed up and go test (TUG) was used to evaluate physical function. The video head impulse test (VHIT) was used to evaluate the semicircular canals. The FES scores and TUG duration were higher and the BBS scores were lower in patients with BPPV compared with the control group (p < 0.001). Univariate analysis showed that dominant HGS (B = -1.380, p = 0.012), BMI (B = 2.391, p = 0.011), and female gender (B = 18.369, p = 0.036) were associated factors for the FES in patients with BPPV. Age (B = -0.239, p < 0.001), dominant HGS (B = 0.441, p < 0.001), BMI (B = -0.503, p = 0.032) and R ASC (B = -12.601, p = 0.006) were associated variables for the BBS. Age was an associated factor for the TUG (B = 0.158, p = 0.017). Lower HGS, higher BMI and female gender were associated factors for greater FOF in patients with BPPV. Clinicians should be aware of risk factors and educate patients regarding balance and FOF.

Distinct muscle growth and strength adaptations after preacher and incline biceps curl.

We compared performing preacher and incline biceps curls on changes in elbow flexors muscle size and strength. This was a between-group repeated measures randomized trial. Sixty-three young women performed preacher biceps curl (PC, n = 30) or incline biceps curl (IC, n = 33) for 8 weeks, twice a week. We measured the muscle thickness of elbow flexors at the proximal, middle, and distal sites. We assessed muscle strength using three repetition maximum (3RM) tests in the preacher curl (3RM-PC) and incline curl (3RM-IC). We observed a greater increase in proximal elbow flexors thickness in the IC compared to the PC (meandiff = 0.08 cm [95% confidence interval (95% CI): 0.02, 0.13 cm]). We observed a greater increase in distal elbow flexor thickness in the PC compared to the IC (meandiff = 0.10 cm [95% CI: 0.04, 0.15 cm]). The PC showed a greater increase in 3RM-PC (meandiff = 1.88 kg [95% CI: 1.14, 2.62 kg]). The IC showed a greater in-crease in 3RM-IC (meandiff = 0.86 kg [95% CI: 0.10, 1.62 kg]). Our findings suggest regional dif-ferences in muscle growth induced by the preacher and incline biceps curls. Strength gains appear to follow the principle of specificity.