Rectus Femoris Research Articles

Oxygenation Kinetics of Three Quadriceps Muscles During Squatting Exercise in Trained Men.

This study aimed to monitor the oxygenation and blood supply in three quadriceps muscles [the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF)] during squatting exercise to exhaustion. Eighteen young resistance-trained males performed five sets of 15 back squats in a Smith machine, with two warm-up sets [at 14% and 45% of the 15-repetition maximum (15RM)] and three main sets at 100% of the 15RM. Three near-infrared spectroscopy devices were attached to the VL, VM, and RF to record the muscle oxygen saturation (SmO2) and total hemoglobin (tHb, an index of muscle blood supply). The blood lactate concentration was measured after each set with a portable analyzer. The SmO2 and tHb data were analyzed by repeated-measures two-way ANOVA (muscle × set). Lactate data were analyzed by repeated-measures one-way ANOVA. The statistical significance was set at α = 0.05. The SmO2 dropped during each set (hitting zero in many instances) and was reinstated during recovery. The three main sets caused severe deoxygenation in the VL and VM, as opposed to moderate deoxygenation in the RF. From one set to the next, the initial value and the drop in the SmO2 increased, whereas the final SmO2 value decreased. The tHb increased in the VL, did not change considerably in the VM, and decreased in the RF during each set. The blood lactate concentration increased gradually from one set to the next, reaching about 10 mmol/L. These findings show pronounced differences in the physiological and metabolic responses of three quadriceps muscles to squatting exercise, thus highlighting the importance of studying such responses at multiple sites.

Muscle ultrasound in Spondyloarthritis patients receiving biologic disease-modifying anti-rheumatic drugs early in treatment

Objective: This study evaluated muscle ultrasound in spondyloarthritis (SpA) patients receiving biologic disease-modifying anti-rheumatic drugs (b-DMARDs) early in treatment. Methods: A prospective study was conducted with 110 b-DMARD-naive SpA patients. The baseline and control muscle strength, physical performance tests, ultrasonographic muscle parameters, and disease activity scores of 67 controlled patients were examined. Results: During the follow-up period, there were significant improvements in the thickness of the gastrocnemius medialis (GM) muscle (p<0.001), the length of the GM fascicle (p=0.031), the thickness of the rectus femoris (RF) muscle (p<0.001), the cross-sectional area of the RF (RFCSA) muscle (p<0.001), the thickness of the rectus abdominis (RA) muscle (p<0.001), the thickness of the transverse abdominis (TA) muscle (p=0.004), and the thickness of the external oblique (EO) muscle (p=0.042). Besides, ASDAS-CRP scores were related to GM muscle thickness, RFCSA, and TA muscle thickness percent changes in patients whose disease activity regressed from high to moderate (respectively; p=0.030, p=0.040, p=0.002). Conclusion: Muscle ultrasound examination can show muscle mass improvement in SpA patients during treatment.

Intersession Intra-Rater and Inter-Rater Reliability of Myotonometer for Upper and Lower Extremity Muscles in Children with Spinal Muscular Atrophy.

Background/Objectives: This study aimed to examine intra- and inter-rater reliability of a myotonometer (MyotonPRO) in measuring upper and lower extremity mechanical properties in children with spinal muscular atrophy types I and II. Methods: Biceps brachii, triceps brachii, rectus femoris, and gastrocnemius muscle tone and stiffness in children (n = 21) were measured using the MyotonPRO device. Examiner 1 performed two sets of measurements in 60 min to determine intra-rater reliability. Examiner 2 performed measurements between Examiner 1's sets. Intra-interclass correlation coefficient, minimal detectable change, and standard error of measurement values were calculated to assess intra- and inter-rater reliabilities in this cross-sectional study. Results: The results showed excellent intra- and inter-rater reliability analyses for frequency and stiffness values except for the stiffness value of the gastrocnemius muscle, which presented good reliability (ICC = 0.71). Minimal detectable change values ranged from 0.59 to 1.98 Hz for muscle tone and 16.08 to 124.74 N/m for stiffness (for both intra- and inter-rater reliabilities). Conclusions: Our findings indicate that MyotonPRO is a reliable tool for quantifying upper and lower extremity mechanical properties within one session in children with spinal muscular atrophy types I and II. Mechanical properties of the extremity muscle can be determined using this easily applied tool in future studies.

Multiparametric Approach to the Colorectal Cancer Phenotypes Integrating Morphofunctional Assessment and Computer Tomography.

(1) Background: Accurate body composition assessment in CCR patients is crucial due to the high prevalence of malnutrition, sarcopenia, and cachexia affecting survival. This study evaluates the correlation between body composition assessed by CT imaging as a reference technique, BIVA, nutritional ultrasound, and handgrip strength in CCR patients. (2) Methods: This retrospective study included CCR patients assessed by the Endocrinology and Nutrition Services of Virgen de la Victoria in Malaga and Vall d'Hebron in Barcelona from October 2018 to July 2023. Assessments included anthropometry, BIVA, NU, HGS, and AI-assisted CT analysis at the L3 level for body composition. Pearson's analysis determined the correlation of CT-derived variables with BIVA, NU, and HGS. (3) Results: A total of 267 CCR patients (mean age 68.2 ± 10.9 years, 61.8% men) were studied. Significant gender differences were found in body composition and strength. CT-SMI showed strong correlations with body cell mass (r = 0.65), rectus femoris cross-sectional area (r = 0.56), and handgrip strength (r = 0.55), with a Cronbach's alpha of 0.789. CT-based adipose tissue measurements showed significant correlations with fat mass (r = 0.56), BMI (r = 0.78), A-SAT (r = 0.49), and L-SAT (r = 0.66). Regression analysis indicated a high predictive power for CT-SMI, explaining approximately 80% of its variance (R2 = 0.796). (4) Conclusions: Comprehensive screening of colorectal cancer patients through BIVA, NU, HGS, and CT optimizes the results of the evaluation. These methods complement each other in assessing muscle mass, fat distribution, and nutritional status in CCR. When CT is unavailable or bedside assessment is needed, HGS, BIVA, and NU provide an accurate assessment of body composition.

TRANSPOSIÇÃO LATERAL E DISTAL DA TUBEROSIDADE TIBIAL NO TRATAMENTO DA LUXAÇÃO MEDIAL DE PATELA GRAU II ASSOCIADA À PATELA ALTA EM CÃO – RELATO DE CASO

The objective was to report the diagnosis and treatment of a mixed breed dog, 3 years old, with high patella and grade II medial patellar dislocation in the right pelvic limb. The patient was seen complaining of lameness in the affected limb and, after orthopedic examination, a grade II medial dislocation of the patella was diagnosed, possibly associated with patella alta. Patellar chondropathy and osteoarthrosis were also suggested due to the presence of crepitus in the joint on examination. Radiographs confirmed the diagnosis and enabled surgical planning. Surgery included trochleoplasty, medial desmotomy, lateral imbrication, lateral and distal transposition of the tibial tuberosity and tenotomy of the rectus femoris muscle. Two weeks after the procedure, there was an improvement in patellar stability and locomotion, with slight residual lameness. Upon return after 30 days, no lameness, patellar dislocation and joint pain were observed. One year after the procedure, a virtual reassessment was carried out with videos sent by the tutor, demonstrating the absence of lameness and the patient's good general condition. It is concluded that the recommended surgical treatment was effective in correcting patellar dislocation and patella alta, resulting in an improvement in the patient's quality of life due to the good clinical results presented.

Short-Term Multicomponent Exercise Impact on Muscle Function and Structure in Hospitalized Older at Risk of Acute Sarcopenia.

Hospitalization exacerbates sarcopenia and physical dysfunction in older adults. Whether tailored inpatient exercise prevents acute sarcopenia is unknown. This study aimed to examine the effect of a multicomponent exercise programme on muscle and physical function in hospitalized older adults. We hypothesized that participation in a brief tailored exercise regimen (i.e., 3-5 days) would attenuate muscle function and structure changes compared with usual hospital care alone. This randomized clinical trial with blinded outcome assessment was conducted from May 2018 to April 2021 at Hospital Universitario de Navarra, Spain. Participants were 130 patients aged 75 years and older admitted to an acute care geriatric unit. Patients were randomized to a tailored 3- to 5-day exercise programme (n = 64) or usual hospital care (control, n = 66) consisting of physical therapy if needed. The coprimary endpoints were between-group differences in changes in short physical performance battery (SPPB) score and usual gait velocity from hospital admission to discharge. Secondary endpoints included changes in rectus femoris echo intensity, cross-sectional area, thickness and subcutaneous and intramuscular fat by ultrasound. Among 130 randomized patients (mean [SD] age, 87.7 [4.6] years; 57 [44%] women), the exercise group increased their mean SPPB score by 0.98 points (95% CI, 0.28-1.69 points) and gait velocity by 0.09 m/s (95% CI, 0.03-0.15 m/s) more than controls (both p < 0.01). No between-group differences were observed in any ultrasound muscle outcomes. There were no study-related adverse events. Three to 5 days of tailored multicomponent exercise provided functional benefits but did not alter muscle or fat architecture compared with usual hospital care alone among vulnerable older patients. Brief exercise may help prevent acute sarcopenia during hospitalization. ClinicalTrials.gov identifier: NCT04600453.

Exploring the use of wearable sensors for assessing risk factors during orthopedic surgeries: A protocol for data collection

During orthopedic surgeries, surgeons are generally exposed to prolonged periods of standing, awkward and sustained body postures, and forceful movements, which can increase the likelihood of developing work-related musculoskeletal disorders (WRMSD). Therefore, this study proposes a protocol to measure parameters related to physical risk factors contributing to lower limb WRMSD, during orthopedic surgery procedures. The protocol development was preceded by an initial phase of understanding and specifying the context of use, followed by pre-tests in laboratory environment. It integrates a motion capture system, using inertial measurement units (IMU) to collect posture data from hip, knee, and ankle, and electromyography system (EMG) to measure and record data from muscle activity of biceps femoris, rectus femoris, and gastrocnemius lateralis. Pre-tests provided insights for protocol optimization, estimating a 3-hour data collection session per surgery due to sensor battery limitations, streamlining the process by placing EMG sensors before IMU and refining thigh sensor placement strategies. The protocol presents an opportunity for a real-time and quantitative approach to monitor surgeon's exposure to risk factors contributing to lower limb WRMSD while performing surgical procedures. Two months after pre-tests, the protocol implementation began in a real work context. The study's final outcomes fall outside the paper's scope.

Correlation between the biomechanical characteristics and stability of the 143D movement during the balance phase in competitive Tai Chi.

To explore the biomechanical factors affecting the stability of athletes in the 143D balance phase of competitive Tai Chi. The Vicon 3D motion capture system, Kistler 3D force platform, and Noraxon surface electromyography (sEMG) system were used to measure the joint angle, joint moment, center of gravity, ground reaction force, and sEMG data of athletes. The stability index was then calculated according to the formula. Pearson's or Spearman's correlation tests were used to analyze the associations between the biomechanical factors and stability index. (1) Medial lateral stability index (MLSI): A significant negative correlation was found between the ankle inversion angle of the supporting leg (SL) and MLSI (p < 0.05). (2) Anterior posterior stability index (APSI): Significant negative correlations were observed between the ankle intorsion angle, integrated electromyography (iEMG) of the gastrocnemius, and muscle contribution rates of the tibialis anterior, external oblique, and gastrocnemius of the non-supporting leg (NL) with the APSI (p < 0.05). The ankle dorsiflexion moment, iEMG of the rectus femoris and tibialis anterior, muscle contribution rate of the biceps femoris, and root mean-squared (RMS) amplitude of the gluteus maximus of the SL also showed significant negative correlations with the APSI (p < 0.05). Strong and significant negative correlations were also identified between the hip intorsion angle, iEMG of the tibialis anterior, and RMS amplitude of the rectus femoris of the NL with the APSI (p < 0.01). Further strong and significant negative correlation was also found between the RMS amplitude of the biceps femoris of the SL and APSI (p < 0.01). The knee extorsion angle of the NL was positively correlated with the APSI (p < 0.05). (3) Dynamic postural stability index (DPSI): The knee adduction angle, iEMG of the tibialis anterior, and RMS amplitude of the erector spinae of the NL were significantly positively correlated with the DPSI (p < 0.05). The knee abduction and hip extension moments of the SL were also significantly positively correlated with the DPSI (p < 0.05). The ankle inversion angle of the SL impacts left-right stability, while the NL's hip and ankle intorsion angles, knee extorsion angle, and exertion on the core muscle and SL's main muscles, as well as exertion of specific muscles of the NL affect anterior-posterior stability. The hip extension and knee abduction moments of the SL, knee adduction angle, exertion on the tibialis anterior, and activation of the erector spinae of the NL significantly affect the overall stability of an athlete.

Quadriceps Architectural Adaptations in Team Sports Players: A Meta-analysis.

Resistance training is the most effective strategy to modify muscle architecture, enhancing sport performance and reducing injury risk. The aim of this study was to compare the effects of high loads (HL) versus lower loads (LL), maximal versus submaximal efforts, and high frequency (HF) versus low frequency (LF) on quadriceps architectural adaptations in team sports players. Five databases were searched. Vastus lateralis thickness, fascicle length and pennation angle, and rectus femoris thickness were analyzed as main outcomes. Overall, resistance training significantly improved muscle thickness and pennation angle, but not fascicle length. LL led to greater fascicle length adaptations in the vastus lateralis compared to HL (p=0.01), while no substantial differences were found for other load comparisons. Degree of effort and training frequency did not show meaningful differences (p>0.05). In conclusion, LL lengthen the fascicle to a greater extent than HL, and training with LL twice a week could maximize architectural adaptations, whereas the degree of effort does not appear to be a determinant variable on quadriceps architectural adaptations.

Comparison of muscle activity in school students while carrying backpacks and trolley bags.

Trolley bags have gained popularity among students, but there is limited research comparing them to backpack-style school bags. This study aimed to compare how carrying a backpack versus a trolley bag affects the activity of trunk and lower limb muscles in secondary school students. Electromyographic activity was measured in 25 students (13.4±1.1 years) as they walked on level ground and up/down stairs while carrying both types of bags. The activity of the gastrocnemius, tibialis anterior, semitendinosus, rectus femoris, lumbar erector spinae, and rectus abdominis muscles was assessed on both the dominant and non-dominant sides. The study found significantly reduced muscle activation in most of the targeted muscles when walking on level ground with the trolley bag and when going up/down stairs with the backpack. Lifting a trolley bag depends on the slope of the walking surface and is more efficient on level ground, while carrying a backpack is more efficient when going up and down stairs. Since it is not practical to switch bags when encountering stairs in schools, a bag with a mixed model design incorporating features of both trolley and backpack may be more beneficial and practical for students to use. Students, parents, and teachers should be aware of the injury risks associated with carrying different types of bags.

8068 Beneficial Effects of a Personalized Exercise Program for Patients with Cushing's Disease and Acromegaly After Biochemical Control

Abstract Disclosure: E. Valassi: None. L. Martel-Duguech: None. H. Bascuñana: None. V. Priego-Corredor: None. J. Viñals-Ribé: None. O. González-Viñuela: None. T. Caparrós-Pons: None. S.M. Webb: None. Background: Patients with Cushing’s disease (CD) in remission and controlled acromegaly (ACRO) present with residual metabolic derangements, muscle dysfunction, and poor quality of life (QoL). Although exercise is known to exert positive effects on psychophysical health in several conditions, evidence demonstrating its potential benefits in pituitary diseases is scanty. Main hypothesis: A personalized program of combined (aerobic and resistance training) exercise lasting 12 weeks improves cardiometabolic parameters, body composition, physical performance and QoL in patients with CD in remission and controlled ACRO. Methodology: Ten female patients with CD in remission [mean (±SD) age, 59±4 years, mean (±SD) BMI, 35±2 Kg/m2, median (IQR) duration of remission, 5(4) years] and 10 male patients with controlled ACRO [mean (±SD) age, 53±9 years, mean (±SD) BMI, 27±4 Kg/m2, median (IQR) duration of control, 6(3) years] underwent a 12-week, structured, personalized program of combined aerobic and resistance exercise, under the supervision of professional trainers. We evaluated the following parameters at baseline and within 72 hours after the completion of the exercise program: blood pressure (BP), BMI, waist and neck circumferences; physical performance (gait speed, hand grip strength, 30-Second Chair Stand; Timed “Up and Go”); lumbar and femoral bone mineral density (BMD) and body composition, using dual x-ray absorptiometry (DXA); muscle thickness (cm) at the middle and distal third of rectus femoris (RF) and vastus intermedius (VI) on both sides, using muscle ultrasound scans in the transverse plane (Philips Affiniti 70; The Netherlands); quality of life (QoL), using the questionnaires CushingQoL in CD patients and AcroQoL in ACRO patients. Major results: After completion of the exercise program, CD patients had lower diastolic BP and waist circumference as compared with baseline (p&amp;lt;0.05). Physical performance globally improved (p&amp;lt;0.01 for all function tests). Femoral BMD was higher, percentage of lean mass increased while trunk fat decreased (p&amp;lt;0.01). RF and VI muscle thickness was greater at both the middle and distal third on the right side (p&amp;lt;0.01), and at the distal third on the left as compared with baseline (p&amp;lt;0.05). ACRO patients had a lower systolic BP as compared with baseline. Gait speed and hand grip strength increased while performance on the 30-Second Chair Stand improved (p&amp;lt;0.05). Muscle thickness at the middle third of the right RF was greater as compared with baseline (p&amp;lt;0.05). QoL was unchanged in both CS and ACRO patients at the end of the program. Conclusions: A customized exercise program promotes beneficial cardiometabolic and muscle changes in patients with CD and ACRO and, therefore, should be offered in a specialized pituitary clinic, within an integrated multidisciplinary team approach. Study financed by ISCIII research project number FIS PI21/01223 Presentation: 6/1/2024

Surface Electromyography and Gait Features in Patients after Anterior Cruciate Ligament Reconstruction.

An important reason for the poor recovery of anterior cruciate ligament (ACL) injuries is the poor recovery of muscle function. Therefore, we used surface electromyography (sEMG) and gait analysis to explore the muscle activation patterns and gait characteristics between lower limbs under different exercise states in patients, following anterior cruciate ligament reconstruction (ACLR). Forty-one adults with unilateral ACL injuries in Binzhou Medical University Hospital from October 2022 to June 2023 were allocated to three groups according to the time after ACL reconstruction: group A (≤3 months, 16), group B (3 months-1 year, 13), and group C (>1 year, 12). Patients were tested by sEMG and gait, while straight leg raising (SLR), walking at normal speed, fast walking, and walking up and down the stairs. Two related sample tests were performed for the normalized root mean square (RMS) values and gait parameters. Muscle function changes varied in different training tasks. The RMS value of the involved side was more than the uninvolved side in biceps femoris and semitendinosus of group A (p < 0.010), and for the bilateral rectus femoris (RS), vastus medialis (VM), and vastus lateralis in group B, only the comparison of the RS was significant in group C during fast walking and going up and down the stairs. The ground impact (0.90 [0.63, 1.33] vs. 0.71 [0.43, 1.02], p = 0.035) of the uninvolved side was significantly decreased compared to those of the involved side in patients with ACLR when going down the stairs. Different muscles need to be focused on at different stages of the postoperative period. sEMG and gait analysis can guide the development of a rehabilitation program.

12571 Ultrasonography Is A Potential Cost-effective Tool To Evaluate Muscle Impairment In Patients With Controlled Cushing’S Disease And Acromegaly

Abstract Disclosure: L. Martel-Duguech: None. H. Bascuñana: None. S. Webb: None. E. Valassi: None. Myopathy is a frequent feature in patients with Cushing’s syndrome (CS) and in patients with acromegaly (ACRO) long-term after biochemical control is achieved. Although ultrasonography (US) is an easy and cost-effective tool to evaluate muscle impairment in the clinical setting, its usefulness in patients with “controlled” ACRO end CS patients has not been established The aim of our study was to evaluate muscle structure using US and assess the correlation between US parameters, muscle function and quality of life (QoL). We included 36 female patients with CS [mean (±SD) age, 50±12 years; mean (±SD) BMI, 26.7±3.8] and 36 age- and BMI-matched healthy women. Mean (±SD) duration of remission was 132±87 months. We also included 36 patients with ACRO [20 females and 16 males, mean (±SD) age, 53±9 years, BMI 27±4 Kg/m2 and duration of control 92±58 months], and 36 age, gender and BMI-matched controls. We obtained transverse ultrasound images of the rectus femoris and assessed muscle intensity at both the midpoint (QmitR) and the distal third (QtercR), between the anterior inferior iliac spine and the proximal end of the patella. We scored muscle intensity using the Heckmatt’s rating scale and classified our findings as follows: 1-normal, 2-mildy increased muscle echoes with normal bone reflection, 3-moderately increased muscle echoes with reduced bone, 4-severely increased muscle echoes with absent bone reflection. We found that mean US intensity score was increased in patients with CS (QmitR p&amp;lt;0.001) and in patients with ACRO (QmitR p&amp;lt;0.05; QtercR p&amp;lt;0.001) vs. the controls, suggesting more impaired muscle architecture in the former, likely due to fibrosis/fatty infiltration. We also measured muscle function using the following tests: gait speed velocity (GS), timed up and go (TUG) and 30-second chair stand. QoL was assessed using both generic (SF-36) and disease-specific (CushingQoL and AcroQoL) questionnaires. US parameters, QoL and muscle function were correlated; in CS patients, higher QtercR was associated with slower GS (r=-0.421, p=0.041) and lower scores in social dimensions on CushingQoL ( friends/family , r=-0.510, p=0.013; and work/study, r=-0.523, p=0.010) . In ACRO patients, higher QmedR was associated with slower GS (r=-0.382, p=0.031) and decreased TUG (r=-0.497, p=0.004) and 30-second chair stand (r=-0.444, p=0.011) in all patients. Higher QmedR was also associated with lower score in physical function (ρ=-0.734, p=0.024), vitality (ρ=-0.728, p=0.026), and AcroQoL total score (ρ=-0.725, p=0.027), in male patients only. Conclusion: muscle US architectural parameters are impaired in “controlled” CS and ACRO patients, and are correlated with muscle function and QoL in both groups of patients. US may be a useful technique to identify, in a clinical setting, those CS and ACRO patients showing residual myopathy. This work was supported by PI17/00749 and PI21/01223 and FEDER funds Presentation: 6/3/2024

The effect of squats on muscle activity in standing, kneeling, and half-kneeling positions: A cross-sectional study.

Kneeling and half-kneeling training are common positions used in physical therapy. however, research on lower extremity muscle activity is lacking compared to the ergonomic aspects and trunk muscle activity. The purpose of this study is to investigate the effects on lower extremity muscle activity during squats in kneeling and half-kneeling positions. The study was designed as a cross-sectional study with a single group of healthy adults. Participants were instructed to perform squats while assuming 3 positions (standing, kneeling, and half-kneeling). Surface electromyography data were recorded 3 times from the rectus femoris (RF), gluteus maximus (GMax), gluteus medius (GMed), and biceps femoris (BF) on the participant's dominant side, and the mean values were analyzed. The participants performed squats for 9 seconds, with 4 seconds of the descent phase, 1 second of the maintenance phase, and 4 seconds of the ascent phase. A metronome was used to ensure precise timing. The study included 30 participants (19 males and 11 females). The muscle activities of the RF, GMed, and BF showed statistically significant differences among the 3 positions, being highest in the half-kneeling position (HKP), followed by the standing position (SP) and kneeling position (KP). The muscle activity of the GMax was significantly higher in the HKP than in the SP and KP (P < .05). The co-contraction ratio was significantly higher with KP than with the SP and HKP (P < .05). In the SP and KP, there were statistically significant differences between the ascent and descent phases of the RF, GMax, GMed, and BF (P < .05). In the HKP, there were statistically significant differences between the ascent and descent phases of the RF, GMax, and GMed (P < .05). The results of this study indicate that squats in the HKP (especially during the ascent phase) require the highest muscle activity, whereas squats in the KP (especially during the descent phase) can be performed with the lowest muscle activity. It can be concluded that these findings could serve as selective indicators for squat exercises and in enhancing postural control, muscle strength, and lower extremity stabilization.

Utility of ultrasound in measuring quadriceps muscle thickness in patients receiving maintenance hemodialysis: comprehensive systematic review and meta-analysis.

Muscle wasting, a prevalent issue in hemodialysis patients, is effectively assessed by measuring quadriceps muscle thickness, a crucial health indicator. This meta-analysis integrates findings from various studies on the application of ultrasonography (US) for measuring the thickness of quadriceps muscles in patients undergoing maintenance hemodialysis. We conducted a thorough literature search across PubMed, Scopus, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science up to April 2023. The R software's Meta package was used for mean difference analysis of quadriceps rectus femoris thickness (QRFT) and quadriceps vastus intermedius thickness (QVIT) between hemodialysis patients and healthy controls. All of the patients entered the meta-analysis are Caucasians. Sub-group analyses based on measurement sites and pre- and post-dialysis comparisons were performed. Among 15 studies with 1584 patients, a significant decrease in QRFT and QVIT was observed in hemodialysis patients compared to healthy controls (mean difference = 0.40cm, 95% CI: -0.49 to -0.31 and 0.46cm, respectively). Right and left QRFT were notably thinner in hemodialysis patients (RT: mean difference = 0.39cm; LT: mean difference = 0.42cm). Similarly, right and left QVIT were notably thinner in hemodialysis patients (RT: mean difference = 0.45cm; LT: mean difference = 0.47cm). No significant pre- and post-dialysis QRFT differences were found. Ultrasonography is a reliable, accessible tool for assessing quadriceps muscle thickness in hemodialysis patients, revealing consistent muscle thickness reduction. These findings emphasize the need for routine muscle health monitoring in this population and support ultrasound use for regular assessments.

Use of muscular ultrasound to detect intensive care unit-acquired weakness: a systematic review and Meta-analysis.

This systematic review and meta-analysis aims to detecting performance of muscular ultrasound for intensive care unit (ICU)-acquired weakness (ICUAW). We searched PubMed, Web of Science, Embase, Cochrane library, CNKI, VIP, and Wanfang databases for articles published before July 2024. A random-effects model was utilized to derive the summary estimates of sensitivity, specificity, and diagnostic odds ratio (DOR) with 95% confidence interval (CI). Additionally, the sources of heterogeneity were explored by subgroup analysis and meta-regression. This meta-analysis comprised ten prospective studies involving 561 participants, of whom 241 (42.96%) were diagnosed as ICUAW. Overall, muscular ultrasound exhibited good performance for detecting ICUAW, with the area of SROC curve of 0.85 (95%CI 0.82-0.88), sensitivity of 0.76 (95%CI 0.70-0.81), specificity of 0.80 (95%CI 0.74-0.84), and DOR of 12.43 (95%CI 7.98-19.38). Upon pre-defined subgroup analysis, the rectus femoris exhibited significantly superior discriminatory ability in identifying ICUAW than the non-rectus femoris, with higher SROC (0.88 [95%CI 0.85-0.91] vs. 0.76 [95%CI 0.72-0.79], p < 0.01). Moreover, cross-sectional area was more effective than thickness, with higher specificity (0.86 [95%CI 0.80-0.91] vs. 0.74 [95%CI 0.68-0.79], p = 0.02) and SROC (0.89 [95%CI 0.86-0.92] vs. 0.76 [95%CI 0.72-0.80], p < 0.01). Furthermore, integrated analysis of these two indicators revealed that the cross-sectional area of rectus femoris was statistically superior to the thickness of rectus femoris, with higher sensitivity (0.82 [95%CI 0.74-0.87] vs. 0.75 [95%CI 0.65-0.83], p < 0.05) and AUC (0.91 [95%CI 0.88-0.93] vs. 0.80 [95%CI 0.76-0.83], p < 0.01). Muscular ultrasound could be a reliable tool for ICUAW detection. Compared with alternative indices, the cross-sectional area of the rectus femoris exhibits superior detection efficacy and may be considered as a valuable parameter for clinical application.

Specific Contribution of the Transversus Abdominis for Postural Control Against Perturbation Caused by Kinesthetic Illusion.

Functional independence of the transversus abdominis (TrA) from other trunk muscles for postural control is still unclear. This study aimed to clarify the specific function of the TrA to control standing posture by vibratory stimulation of the triceps surae. Fifteen men participated in this study. Muscle activity of the TrA, internal oblique, lumbar multifidus, gluteus maximus, rectus femoris, biceps femoris, gastrocnemius, and tibialis anterior was measured using fine-wire and surface electrodes. Participants were asked to maintain a quiet standing posture with and without vibration of the triceps surae, which induced a kinesthetic illusion and the concomitant backward sway of the body. The muscle activity of each muscle for 10s was extracted with and without vibration. The muscle activity levels were compared between the conditions by a paired t-test or Wilcoxon signed-rank test. The activity of the TrA and rectus femoris was increased, whereas the internal oblique showed no change as a result of the induced kinesthetic illusion. In addition, the activity of the multifidus and biceps femoris was decreased. The TrA and rectus femoris could contribute to control the backward sway of the body. Furthermore, the TrA may have functional independence from the internal oblique during standing postural control. These results warrant further study in patients with low back pain.

Muscle activity during multi-step descent

BackgroundPrevious step studies have shown mechanical variances across steps in descent; however, muscle activity differences have not been examined across steps in a staircase. The purpose of this study was to quantify differences in muscle activity during step descent between step strategies (step-over-step and step-match) and across steps. MethodsTwenty-five individuals descended a seven-step staircase at self-selected pace (rise: 15.5 cm) in both descent types. Muscle activity was recorded with bipolar electrodes placed on the right tibialis anterior, peroneals, medial gastrocnemius, rectus femoris, and biceps femoris. Two-way Repeated Measures ANOVA tests were conducted for co-activation (ankle: tibialis anterior/medial gastrocnemius; knee: rectus femoris/biceps femoris) and integrated EMG in the lead and trail limbs. ResultsResults showed muscle activity is dependent on the step number for both descent strategies. ConclusionsBetween strategies, lead limb step-match co-activation began the staircase high then decreased for both ankle and knee, while step-over-step activity was the opposite. Trail limb co-activation was more similar beginning high for both joints in step-over-step and the knee in step-match. Across steps, this study supports previous findings of differences between entry and exit steps compared to middle stairs. Additionally, differences were found between mid-staircase steps. These differences in both descent strategies counters previous assumptions of ‘steady-state’ step descent, which may have implications for individuals dealing with lower extremity musculoskeletal issues. Patients may benefit by training on their most encountered staircase length, and researchers must recognize the challenge of generalizing across step studies of varying step number.

Automatic gait evoking in healthy adults through Vojta’s peripheric somatosensory stimulation: a double-blind randomized controlled trial

BackgroundTo study the effects of different interventions on automatic gait processing in contrast with voluntary gait processing in healthy subjects.MethodsA double-blind randomised controlled trial was designed (120 able-body persons between 18 and 65 years old entered and completed the study), with pre-intervention and post-intervention assessments using the 6-Minute Walk Test (6MWT). The participants were randomly distributed into four groups. Prior to intervention, all participants performed voluntary gait on the ground (VoG) in a calibrated circuit following the 6MWT. The presence of automatic gait (AG) was explored post-intervention without a voluntary demand in the same circuit following the 6MWT. Each group received a different intervention for 30 min: Vojta stimulation, MOTOMED® at no less than 60 revolutions/minute, treadmill walking at 3 km/h, and resting in a chair (control). The main assessment, conducted by a blinded rater, was the difference in distance covered (in meters) during the 6MWT between pre- and post-intervention. Surface electromyography (sEMG) average root mean square (RMS) signals in the right tibialis anterior, right soleus, right rectus femoris, and right biceps femoris were also considered outcome measures.ResultsThe Vojta group was the only one that initiated AG after the intervention (476.4 m ± 57.1 in VoG versus 9.0 m ± 8.9 in AG, p < 0.001) with comparable kinematics and EMG parameters during voluntary gait, except for ankle dorsal flexion. Within the Vojta group, high variability in kinematics, sEMG activity, and distance covered was observed.ConclusionsAG isolation is approachable through Vojta at only one session measurable with the 6MWT without any voluntary gait demand. No automatic gait effects were observed post-intervention in the other groups.Trial registrationNCT04689841 (ClinicalTrials.gov).

Comparative Effects of Different Focus Methods on Muscular Activation During Single-Leg-Squat Exercise

Background: Single-leg squats are frequently featured in training and rehabilitation programs. The use of focus during exercise changes the state of concentration during exercise. This causes changes in muscular activity. No study has been found comparing focusing methods’ effectiveness during single-leg squat movement. Aim: This study aims to compare the changes in lower extremity muscular activations in cases of external focus, internal focus, and absence of focus. Methods: The muscular activities (Gluteus Medius, Vastus Lateralis, Vastus Medialis, Rectus Femoris, Biceps Femoris, and Semitendinosus) of the healthy participants included in the study were measured with the surface electromyography (EMG) device. External focus, internal focus and without-focus positions were used. Results: Seventeen recreationally active participants were included in this study. The muscular activities of the participants, which occurred in three different situations, were measured with the surface electromyography (EMG) device. While the quadriceps were more active in the descent phase, the hamstring muscle group was more active in the ascent phase. The external focus provided more muscular activation than the other two focal conditions. Conclusion: According to the results of this study, the use of focus during single-leg squat training and rehabilitation may change the muscular response obtained.