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The development of a knee locker with closed-loop functional electrical stimulation (FES) for hemiplegia in gait training.

PURPOSE: A knee locker with closed-loop functional electrical stimulation (FES) system has been developed to prevent the quadriceps weakness … ed t-test indicated that differences in the electromyography (EMG) of the tibialis anterior and the quadriceps muscles between patient's disabled (affected-side) foot and normal (unaffected-side) foot are not significant (p > 0.05) after 16 weeks of training. CONCLUSIONS: It is concluded that this new knee locker with closed-loop FES system is capable of providing …

Association between muscle strength and echogenicity using greyscale ultrasound software: a diagnostic accuracy study in kidney transplant candidates.

BACKGROUND: Advanced chronic kidney disease disrupts the delicate equilibrium between protein anabolism and catabolism, leading to alteratio … y of echogenicity (index test) assessed with the ImageJ software greyscale as a potential marker of quadriceps muscle weakness (reference test) were calculated. Muscle weakness was considered as maximal voluntary isometric contraction of the quadriceps (Q-MVIC) <40% of body weight. Other variables included body composition parameters derived from multifrequency ele …

Home-Based Functional Electrical Stimulation of Human Permanent Denervated Muscles: A Narrative Review on Diagnostics, Managements, Results and Byproducts Revisited 2020.

Spinal cord injury (SCI) produces muscle wasting that is especially severe after complete and permanent damage of lower motor neurons, as can occur in complete conus and cauda equina syndrome. Even in this worst-case scenario, mass and function of permanently denervated quadriceps muscle can be rescued by surface functional electrical stimulation using a purpose designed home-based rehabilitation strategy. Early diagnostics is a key factor in the long-term success of this management. Function of quadriceps muscle was quantitated by force measurements. Muscle gross cross-sections were evaluated…

An electromyographic analysis of the knee during functional activities. I. The normal profile.

This study describes the fine-wire electromyographic profile of the normal knee. Twenty-two subjects with no prior history of knee injury volunteered for the study. Each subject had fine-wire electromyographic evaluation of 8 muscles (vastus medialis oblique, vastus lateralis, rectus femoris, semimembranosus, biceps femoris, tibialis anterior, gastrocnemius, and soleus muscles) while performing 7 functional activities. The percentage of maximum manual test for each muscle during each phase of the activities was used to determine means and standard deviations for the group. Walking and ramp and

Repeatability of alkaline inorganic phosphate quantification in the skeletal muscle using 31P-magnetic resonance spectroscopy at 3 T.

The detection of a secondary inorganic phosphate (Pi) resonance, a possible marker of mitochondrial content in vivo, using phosphorus magnetic resonance spectroscopy (31P-MRS), poses technical challenges at 3 Tesla (T). Overcoming these challenges is imperative for the integration of this biomarker into clinical research. To evaluate the repeatability and reliability of measuring resting skeletal muscle alkaline Pi (Pialk) using with 31P-MRS at 3 T. After an initial set of experiments on five subjects to optimize the sequence, resting 31P-MRS of the quadriceps muscles were acquired on two visi…

Quadriceps Strength and Functional Performance After Anterior Cruciate Ligament Reconstruction in Professional Soccer players at Time of Return to Sport.

Herrington, L, Ghulam, H, and Comfort, P. Quadriceps strength and functional performance after anterior cruciate ligament reconstruction in professional soccer players, at time of return to sport. J Strength Cond Res 35(3): 769-775, 2021-Poor quadriceps strength has been associated with poor outcome after anterior cruciate ligament (ACL) reconstruction (ACLR). This study aims to assess quadriceps strength, muscle inhibition, and hop test performance in professional soccer players after ACLR. Fifteen professional soccer players (age 22.3 ± 3.1 years, body mass 81.0 ± 11.5 kg, and height 1.75 ±

Differential Muscle Involvement in Mice and Humans Affected by McArdle Disease.

McArdle disease (muscle glycogenosis type V) is caused by myophosphorylase deficiency, which leads to impaired glycogen breakdown. We invest … scle isoform. In the mice, the tibialis anterior (TA) muscles were invariably more damaged than the quadriceps muscles. This may relate to a 7-fold higher level of myophosphorylase in TA compared to quadriceps in wild-type mice and suggests higher glucose turnover in the TA. Thus, despite differences, the mouse model of McArdle disease shares fundamental physiologi …

Effectiveness of static quadriceps stretching in individuals with patellofemoral joint pain.

OBJECTIVE: To determine if a 3-week static stretching program would increase quadriceps muscle flexibility in patellofemoral joint pain syndrome (PJPS) individuals. DESIGN: Pretest/posttest control group design. SETTING: Institutional based clinical rehabilitation setting. PARTICIPANTS: Participants (n = 83) were between the ages of 18 and 45 years of age with no history of surgery or trauma to the hip, knee, or lower leg region. INTERVENTION: Participants were sorted into normal and PJPS groups via orthopaedic assessment of knee pain and function, and their quadriceps flexibility was eval…

The effect of isolating the paretic limb on weight-bearing distribution and EMG activity during squats in hemiplegic and healthy individuals.

BACKGROUND: Neural reorganization for movement therapy after a stroke is thought to be an important mechanism that facilitates motor recover … might help patients with hemiplegia to improve weight-bearing and achieve greater activation of the quadriceps muscle in the paretic limb.

Isokinetic strength testing does not predict hamstring injury in Australian Rules footballers.

OBJECTIVE: To determine the relation of hamstring and quadriceps muscle strength and imbalance to hamstring injury using a prospective observational cohort study METHOD: A total of 102 senior male Australian Rules footballers aged 22.2 (3.6) years were tested at the start of a football season. Maximum voluntary concentric and eccentric torque of the hamstring and quadriceps muscles of both legs was assessed using a Kin-Com isokinetic dynamometer at angular velocities of 60 and 180 degrees/second. Twelve (11.8%) players sustained clinically diagnosed hamstring strains which caused them to miss…

Respiratory responses to sustained isometric muscle contractions in man: the effect of muscle mass.

1. Respiratory responses to sustained isometric contractions of a small mass of muscle (the finger flexors) during handgripping, and of a larger mass of muscle (the quadriceps) during extension of the leg at the knee, have been studied in man. 2. For both masses of muscle the increases of ventilation and of oxygen consumption were greater for contractions at 40% maximum voluntary contraction (MVC) than for contractions at 20% MVC. 3. The increase of ventilation was not related to the mass of muscle involved. 4. At 20% MVC oxygen consumption during contraction of the quadriceps was greater than

Effect of inspiratory muscle fatigue on exercise performance taking into account the fatigue-induced excess respiratory drive.

Inspiratory muscle fatigue (IMF) is suggested to compromise exercise performance, possibly via a respiratory muscle metaboreflex that impairs blood flow to working muscles, thereby accelerating the development of fatigue in these muscles. Cycling with IMF has also been associated with an excess ventilatory response, which could per se impair performance. Therefore, the present study investigated whether prior-induced IMF would affect subsequent cycling performance via increased quadriceps muscle fatigue alone and whether fatigue-induced excess ventilation would contribute to this impairment. F…

The Effect of Minimalist Versus Motion Control Shoes on Patellofemoral Joint Forces in Adolescents With Patellofemoral Pain During Running: A Randomized Crossover Study.

BACKGROUND: High joint forces can contribute to the pathogenesis of patellofemoral pain in adolescents. Minimalist shoes may reduce patellof … e forces by 26.6% (MD, 449.3 N [95% CI, 298.6-560]). The minimalist shoe did not meaningfully alter quadriceps muscle forces compared with the motion-control shoe. CONCLUSION: As hypothesized, running in minimalist shoes reduced peak resultant patellofemoral joint and lateral patellar forces compared with running in motion-control shoes, while gastrocnemius forces …

Full-Body Radiographic Imaging-Based Thigh Muscle Measurement for Sarcopenia: Association with Functional Assessments and Sagittal Alignment in Adult Spinal Deformity Patients.

STUDY DESIGN: Multicenter retrospective cohort study of prospectively collected data. OBJECTIVE: Evaluate the impact of EOS-derived thigh m … patients demonstrate impaired proximal and increased distal compensations. Incorporating thigh and quadriceps muscle thickness measurements into preoperative assessment may improve surgical planning and patient management in ASD. LEVEL OF EVIDENCE: Prognostic Level III.

Effects of Virtual Reality Versus Whole-Body Vibration on Muscle Strength and Balance in Children with Duchenne Muscular Dystrophy: a Randomized Controlled Trial.

ObjectiveTo compare the effects of virtual reality versus whole-body vibration on quadriceps muscle strength and balance in children with Duchenne muscular dystrophy.MethodsIn this assessor-blinded, parallel-group randomized controlled trial (1:1 allocation), 50 ambulatory boys with DMD (aged 6-10 years; AFCSD levels I-II) were recruited from Cairo University's outpatient clinic. Both groups received a structured physical therapy program (warm-up, stretching, isometric contractions) three times weekly for 12 weeks. VR Group (n = 25) additionally performed 10 min of semi-immersive VR (Nintendo …

Clinimetric evaluation of the 1-minute sit-to-stand test as a functional performance measure associated with quadriceps strength in children with spastic hemiplegic cerebral palsy.

PURPOSE: To evaluate the construct validity, test-retest reliability, and clinical applicability of the 1-minute sit-to-stand test (1-MSTST) … adverse events occurred. These findings indicate that the 1-MSTST is significantly associated with quadriceps muscle strength and may reflect functional lower limb performance, rather than serving as a direct measure of isolated muscle strength capacity. CONCLUSION: The 1-MSTST is a valid, reliable, and clinically feasible tool for assessing functional performanc …

Arthroscopic anterior cruciate ligament reconstruction with quadriceps tendon autograft: clinical outcome in 4-7 years.

Surgical reconstruction of the anterior cruciate ligament (ACL) is indicated in the ACL-deficient knee with symptomatic instability and mult … aving a suitable size, making it an acceptable graft choice for ACL reconstruction. There is little quadriceps muscle strength loss after quadriceps harvest. A quadriceps tendon-patellar autograft is an adequate graft choice to ACL reconstruction.

Повышение эффективности гибридных экзоскелетов путем пространственного распределения асинхронной стимуляции и ультразвуковых измерений усталости.

В настоящем документе предлагается новаторский подход - пространственно распределенная асинхронная стимуляция (СДАС), призванная повысить устойчивость к усталости мышц с электрическими стимуляторами для содействия мобильности у лиц с травмой спинного мозга, инсультом и множественным склерозом. Основное внимание в исследовании уделяется модуляции интенсивности стимуляции на многоразовых распределенных электродах с помощью феноменологической модели SDAS в целях повышения производительности мышц. Для разработки оптимальных профилей силы SDAS для слежения за распространением колена используется по

Совпадение в аннотации оригинала
This paper introduces an innovative approach, Spatially distributed asynchronous stimulation (SDAS), designed to enhance the fatigue resista … dy also establishes a strong correlation between Ultrasound (US)-derived strain measurements of the quadriceps muscle and the model's fatigue parameter. The model is extended to predict non-isometric knee extension and integrated with US-derived feedback from the quadriceps muscle to control stepping with the hybrid exoskeleton. The results demonstrate that the opt …

The effects of short-term exercise training on peak-torque are time- and fiber-type dependent.

We examined the susceptibility of fast and slow twitch muscle fibers in the quadriceps muscle to eccentric exercise-induced muscle damage. Nine healthy men (age: 22.5 ± 1.6 years) performed maximal eccentric quadriceps contractions at 120°·s-1 over a 120° of knee joint range of motion for 6 consecutive days. Biopsies were taken from the vastus lateralis muscle before repeated bouts of eccentric exercise on the third and seventh day. Immunohistochemical procedures were used to determine fiber composition and fibronectin activity. Creatine kinase (CK) and lactate dehydrogenase (LDH) were determi…

Late Activation of the Vastus Medialis in Determining the Risk of Anterior Cruciate Ligament Injury in Soccer Players.

CONTEXT: Activation time of the quadriceps is important in determining injury risk in professional soccer players. OBJECTIVE: To compare the activation time of the quadriceps and hamstrings muscles during a movement that puts stress on anterior cruciate ligament (ACL) to assess the risk of ACL injury. DESIGN: Case series. SETTING: University laboratory for movement analysis. PATIENTS OR OTHER PARTICIPANTS: Twenty (10 males and 10 females) professional soccer players. INTERVENTION(S): An inertial sensor and 4 electrodes positioned on the quadriceps and hamstrings muscles were used for the