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1.
Arch Endocrinol Metab ; 68: e230026, 2024 May 06.
Article En | MEDLINE | ID: mdl-38709150

Muscle weakness has been associated to insulin resistance and metabolic syndrome in the general population. However, it is still unclear whether this association is maintained in older adults. This study investigated correlations between low handgrip strength (HGS) and metabolic syndrome, or some of its components, in older adults through a systematic review of the literature. Searches were conducted in the Virtual Health Library Regional Portal, Scopus, Cochrane, Embase, MEDLINE/ PubMed, SciELO, and Web of Science databases for relevant studiesinvestigating muscle weakness (measured by hand dynamometer) and metabolic syndrome or its components in older adult populations, published up to September 2023. From the 2050 references initially identified, 20 studies, comprising a total of 31,264 older adults of both genders, completely met the inclusion/exclusion criteria. Eighteen studies showed that lower HGS was associated with metabolic syndrome or some of its risk factors, such as abdominal obesity, hyperglycemia, insulin resistance, dyslipidemia, or high blood pressure. Two studies found that older men with high blood pressure had increased HGS. Most studies included in this systematic review revealed a significant correlation between reduced HGS and metabolic syndrome or some of its components, especially abdominal obesity and insulin resistance. We conclude that below-average HGS can be associated with metabolic syndrome in older adults.


Hand Strength , Metabolic Syndrome , Humans , Metabolic Syndrome/physiopathology , Hand Strength/physiology , Aged , Male , Female , Muscle Weakness/physiopathology , Risk Factors , Insulin Resistance/physiology
2.
Article En | MEDLINE | ID: mdl-38709603

Neck muscle weakness due to amyotrophic lateral sclerosis (ALS) can result in dropped head syndrome, adversely impacting the quality of life of those affected. Static neck collars are currently prescribed to hold the head in a fixed upright position. However, these braces are uncomfortable and do not allow any voluntary head-neck movements. By contrast, powered neck exoskeletons have the potential to enable head-neck movements. Our group has recently improved the mechanical structure of a state-of-the-art neck exoskeleton through a weighted optimization. To evaluate the effect of the structural changes, we conducted an experiment in which patients with ALS were asked to perform head-neck tracking tasks while using the two versions of the neck exoskeleton. We found that the neck muscle activation was significantly reduced when assisted by the structurally enhanced design compared to no assistance provided. The improved structure also improved kinematics tracking performance, allowing users to better achieve the desired head poses. In comparison, the previous design did not help reduce the muscle effort required to perform these tasks and even slightly worsened the kinematic tracking performance. It was also found that biomechanical benefits gained from using the structurally improved design were consistent across participants with both mild and severe neck weakness. Furthermore, we observed that participants preferred to use the powered neck exoskeletons to voluntarily move their heads and make eye contact during a conversation task rather than remain in a fixed upright position. Each of these findings highlights the importance of the structural design of neck exoskeletons in achieving desired biomechanical benefits and suggests that neck exoskeletons can be a viable method to improve the daily life of patients with ALS.


Amyotrophic Lateral Sclerosis , Exoskeleton Device , Neck Muscles , Humans , Amyotrophic Lateral Sclerosis/physiopathology , Male , Female , Middle Aged , Neck Muscles/physiopathology , Biomechanical Phenomena , Aged , Electromyography , Head Movements , Neck/physiopathology , Equipment Design , Adult , Muscle Weakness/physiopathology
3.
J Alzheimers Dis ; 99(1): 393-402, 2024.
Article En | MEDLINE | ID: mdl-38669541

Background: The joint associations of handgrip strength (HGS) weakness and asymmetry with cognitive decline remain understudied in older adults. Objective: To investigate the associations between HGS weakness, asymmetry, and lower cognitive function in a nationally representative sample of older Americans. Methods: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey 2011-2014. Weakness was defined as HGS <26 kg for men and <16 kg for women. Asymmetry was determined by calculating the ratio of dominant to non-dominant HGS. Participants with an HGS ratio <0.90 or >1.10 were classified as having any HGS asymmetry. Those with an HGS ratio >1.10 exhibited dominant HGS asymmetry, while those with an HGS ratio <0.90 displayed nondominant HGS asymmetry, respectively. Lower cognitive functioning was defined as global cognitive composite scores more than 1 standard deviation below the mean. Covariate-adjusted logistic regression models were used to analyze the associations between HGS asymmetry/weakness and lower cognitive functioning. Results: Compared to individuals with non-weak and symmetric HGS, those with any HGS asymmetry alone and weakness alone had 1.017 (95% confidence interval [CI]: 0.707-1.463) and 1.391 (95% CI: 0.542-3.571) greater odds for cognitive decline, while co-occurrence of both HGS asymmetry and weakness was associated with 3.724 (95% CI: 1.711-8.107) greater odds for lower cognitive function after controlling for confounders. Cnclusions: Individuals exhibiting both diminished and asymmetrical HGS demonstrated an elevated susceptibility to cognitive impairment, thereby implying that the inclusion of HGS asymmetry assessment in conjunction with weakness evaluation may enhance the accuracy of prognosticating cognitive decline.


Cognitive Dysfunction , Hand Strength , Muscle Weakness , Nutrition Surveys , Humans , Male , Female , Hand Strength/physiology , Cross-Sectional Studies , Aged , Muscle Weakness/physiopathology , Muscle Weakness/epidemiology , Cognitive Dysfunction/physiopathology , Cognitive Dysfunction/epidemiology , Cognitive Dysfunction/diagnosis , Aged, 80 and over , United States/epidemiology , Middle Aged , Cognition/physiology
4.
J Neurol Sci ; 460: 123021, 2024 May 15.
Article En | MEDLINE | ID: mdl-38653115

BACKGROUND: Late-onset Pompe disease (LOPD) patients may still need ventilation support at some point of their disease course, despite regular recombinant human alglucosidase alfa treatment. This suggest that other pathophysiological mechanisms than muscle fibre lesion can contribute to the respiratory failure process. We investigate through neurophysiology whether spinal phrenic motor neuron dysfunction could contribute to diaphragm weakness in LOPD patients. MATERIAL AND METHODS: A group of symptomatic LOPD patients were prospectively studied in our centre from January 2022 to April 2023. We collected both demographic and clinical data, as well as neurophysiological parameters. Phrenic nerve conduction studies and needle EMG sampling of the diaphragm were perfomed. RESULTS: Eight treated LOPD patients (3 males, 37.5%) were investigated. Three patients (37.5%) with no respiratory involvement had normal phrenic nerve motor responses [median phrenic compound muscle action potential (CMAP) amplitude of 0.49 mV; 1st-3rd interquartile range (IQR), 0.48-0.65]. Those with respiratory failure (under nocturnal non-invasive ventilation) had abnormal phrenic nerve motor responses (median phrenic CMAP amplitude of 0 mV; 1st-3rd IQR, 0-0.15), and were then investigated with EMG. Diaphragm needle EMG revealed both myopathic and neurogenic changes in 3 (60%) and myopathic potentials in 1 patient. In the last one, no motor unit potentials could be recruited. CONCLUSIONS: Our study provide new insights regarding respiratory mechanisms in LOPD, suggesting a contribution of spinal phrenic motor neuron dysfunction for diaphragm weakness. If confirmed in further studies, our results recommend the need of new drugs crossing the blood-brain barrier.


Diaphragm , Electromyography , Glycogen Storage Disease Type II , Motor Neurons , Muscle Weakness , Phrenic Nerve , Humans , Glycogen Storage Disease Type II/complications , Glycogen Storage Disease Type II/physiopathology , Male , Diaphragm/physiopathology , Female , Middle Aged , Muscle Weakness/etiology , Muscle Weakness/physiopathology , Phrenic Nerve/physiopathology , Motor Neurons/physiology , Motor Neurons/pathology , Adult , Neural Conduction/physiology , Muscle Fibers, Skeletal/pathology , Muscle Fibers, Skeletal/physiology , Aged , Respiratory Insufficiency/etiology , Respiratory Insufficiency/physiopathology , Prospective Studies , Action Potentials/physiology
5.
Article En | MEDLINE | ID: mdl-38652620

Individuals with neurological disorders often exhibit altered manual dexterity and muscle weakness in their upper limbs. These motor impairments with tremor lead to severe difficulties in performing Activities of Daily Living (ADL). There is a critical need for ADL-focused robotic training that improves individual's strength when engaging with dexterous ADL tasks. This research introduces a new approach to training ADLs by employing a novel robotic rehabilitation system, Spherical Parallel INstrument for Daily Living Emulation (SPINDLE), which incorporates Virtual Reality (VR) to simulate ADL tasks. The study results present the feasibility of training individuals with movements similar to ADLs while interacting with the SPINDLE. A new game-based robotic training paradigm is suggested to perform ADL tasks at various intensity levels of resistance as needed. The proposed system can facilitate the training of various ADLs requiring 3-dimensional rotational movements by providing optimal resistance and visual feedback. We envision this system can be utilized as a table-top home device by restoring the impaired motor function of individuals with tremor and muscle weakness, guiding to improved ADL performance and quality of life.


Activities of Daily Living , Robotics , Tremor , Virtual Reality , Humans , Tremor/rehabilitation , Tremor/physiopathology , Male , Female , Middle Aged , Resistance Training/methods , Feedback, Sensory , Adult , Video Games , Feasibility Studies , Muscle Weakness/rehabilitation , Muscle Weakness/physiopathology , Quality of Life
6.
Medwave ; 24(3): e2783, 2024 Apr 30.
Article En | MEDLINE | ID: mdl-38687996

Introduction: Chronic obstructive pulmonary disease is a systemic disease characterized not only by respiratory symptoms but also by physical deconditioning and muscle weakness. One prominent manifestation of this disease is the decline in respiratory muscle strength. Previous studies have linked the genotypes of insulin-like growth factor 1 and 2 (IGF-1 and IGF-2) to muscle weakness in other populations without this disease. However, there is a notable knowledge gap regarding the biological mechanisms underlying respiratory muscle weakness, particularly the role of IGF-1 and IGF-2 genotypes in this pulmonary disease. Therefore, this study aimed to investigate, for the first time, the association between IGF-1 and IGF-2 genotypes with respiratory muscle strength in individuals with chronic obstructive pulmonary disease. In addition, we analyzed the relationship between oxidative stress, chronic inflammation, and vitamin D with respiratory muscle strength. Methods: A cross sectional study with 61 individuals with chronic obstructive pulmonary disease. Polymerase chain reaction of gene polymorphisms IGF-1 (rs35767) and IGF-2 (rs3213221) was analyzed. Other variables, related to oxidative stress, inflammation and Vitamin D were dosed from peripheral blood. Maximal inspiratory and expiratory pressure were measured. Results: The genetic polymorphisms were associated with respiratory muscle strength ( 3.0 and 3.5; = 0.57). Specific genotypes of IGF-1 and IGF-2 presented lower maximal inspiratory and expiratory pressure (<0.05 for all). Oxidative stress, inflammatory biomarkers, and vitamin D were not associated with respiratory muscle strength. Conclusion: The polymorphisms of IGF-1 and IGF-2 displayed stronger correlations with respiratory muscle strength compared to blood biomarkers in patients with chronic obstructive pulmonary disease. Specific genotypes of IGF-1 and IGF-2 were associated with reduced respiratory muscle strength in this population.


Introducción: La enfermedad pulmonar obstructiva crónica es una enfermedad sistémica caracterizada no solo por síntomas respiratorios, sino también por el deterioro físico y la debilidad muscular. Una manifestación destacada de esta enfermedad es el declive en la fuerza de los músculos respiratorios. Estudios previos han vinculado los genotipos de factor de crecimiento insulínico 1 y 2 (IGF-1 e IGF-2) con la debilidad muscular en poblaciones sin esta enfermedad. Sin embargo, existe un vacío de conocimiento con respecto a los mecanismos biológicos subyacentes a la debilidad de los músculos respiratorios, en particular el papel de los genotipos IGF-1 e IGF-2 en esta enfermedad pulmonar. Por lo tanto, este estudio tuvo como objetivo investigar, por primera vez, la asociación de los genotipos IGF-1 e IGF-2 con la fuerza de los músculos respiratorios en individuos con enfermedad pulmonar obstructiva crónica. Además, analizamos la relación entre el estrés oxidativo, la inflamación crónica y la vitamina D con la fuerza de los músculos respiratorios. Métodos: Un estudio transversal con 61 individuos con enfermedad pulmonar obstructiva crónica. Se analizó la reacción en cadena de la polimerasa de los polimorfismos genéticos IGF-1 (rs35767) e IGF-2 (rs3213221). Otras variables relacionadas con el estrés oxidativo, la inflamación y la vitamina D se dosificaron a partir de muestras de sangre periférica. Se midieron las presiones inspiratorias y espiratorias máximas. Resultados: Los polimorfismos genéticos están asociados con la fuerza de los músculos respiratorios (F: 3.0 y 3.5; R2= 0.57). Genotipos específicos de IGF-1 e IGF-2 presentaron bajos valores en las presiones inspiratorias y espiratorias (p<0.05 en todos los casos). El estrés oxidativo, los biomarcadores inflamatorios y la vitamina D no se asociaron con la fuerza de los músculos respiratorios. Conclusión: Los polimorfismos de IGF-1 e IGF-2 mostraron correlaciones más sólidas con la fuerza de los músculos respiratorios en pacientes con enfermedad pulmonar obstructiva crónica en comparación con los biomarcadores sanguíneos. Genotipos específicos de IGF-1 e IGF-2 se asociaron con una disminución de la fuerza de los músculos respiratorios en esta población.


Genotype , Insulin-Like Growth Factor II , Insulin-Like Growth Factor I , Muscle Strength , Oxidative Stress , Pulmonary Disease, Chronic Obstructive , Respiratory Muscles , Humans , Cross-Sectional Studies , Pulmonary Disease, Chronic Obstructive/physiopathology , Pulmonary Disease, Chronic Obstructive/genetics , Muscle Strength/physiology , Male , Insulin-Like Growth Factor I/metabolism , Respiratory Muscles/physiopathology , Insulin-Like Growth Factor II/genetics , Insulin-Like Growth Factor II/metabolism , Aged , Female , Middle Aged , Inflammation/physiopathology , Inflammation/genetics , Vitamin D/blood , Muscle Weakness/physiopathology , Muscle Weakness/genetics
7.
Trop Med Int Health ; 29(5): 405-413, 2024 May.
Article En | MEDLINE | ID: mdl-38503276

OBJECTIVE: Inspiratory muscle strength (IMS) appears to be reduced in subjects with chronic Chagas heart disease (CHD), especially in the presence of heart failure (HF). However, only one study about IMS and inspiratory muscle endurance (IME) in those with CHD without heart failure is available. This study aimed to compare IMS and IME in subjects with CHD in the presence and absence of HF. METHODS: This is a cross-sectional study in which 30 CHD adult patients were divided into CHD-CC group (initial phase of CHD, without HF; n = 15) and CHD-HF group (advanced phase of CHD, with HF; n = 15). We assessed IMS by maximum inspiratory pressure (MIP) and IME by incremental (Pthmax) and constant load (TLim) tests. Reduced IMS and IME were considered by predicted MIP values <70% and Pthmax/MIP <75%, respectively. RESULTS: Inspiratory muscle weakness (IMW) was more frequent in CHD-HF than in CHD-CC (46.7% vs. 13.3%; p = 0.05), and both groups had high frequencies of reduced IME (93.3% CHD-CC vs. 100.0% CHD-HF; p = 0.95). Age-adjusted logistic regression analysis using HF as a dependent variable showed that HF was associated with an increased chance of IMW compared with the CHD-CC group (OR = 7.47; p = 0.03; 95% CI 1.20-46.19). CONCLUSION: This study suggests that, in patients with CHD, HF is associated with IMW, and that reduction of IME is already present in the initial phase, similar to the advanced phase with HF.


Chagas Cardiomyopathy , Respiratory Muscles , Humans , Cross-Sectional Studies , Male , Female , Middle Aged , Respiratory Muscles/physiopathology , Chagas Cardiomyopathy/physiopathology , Adult , Chronic Disease , Heart Failure/physiopathology , Muscle Strength/physiology , Inhalation/physiology , Muscle Weakness/physiopathology , Physical Endurance , Aged
8.
Br J Sports Med ; 58(9): 500-510, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38537939

OBJECTIVE: We aimed to determine hip and lower-leg muscle strength in people after ACL injury compared with an uninjured control group (between people) and the uninjured contralateral limb (between limbs). DESIGN: Systematic review with meta-analysis. DATA SOURCES: MEDLINE, EMBASE, CINAHL, Scopus, Cochrane CENTRAL and SportDiscus to 28 February 2023. ELIGIBILITY CRITERIA: Primary ACL injury with mean age 18-40 years at time of injury. Studies had to measure hip and/or lower-leg muscle strength quantitatively (eg, dynamometer) and report muscle strength for the ACL-injured limb compared with: (i) an uninjured control group and/or (ii) the uninjured contralateral limb. Risk of bias was assessed according to Cochrane Collaboration domains. RESULTS: Twenty-eight studies were included (n=23 measured strength ≤12 months post-ACL reconstruction). Most examined hip abduction (16 studies), hip extension (12 studies) and hip external rotation (7 studies) strength. We found no meaningful difference in muscle strength between people or between limbs for hip abduction, extension, internal rotation, flexion or ankle plantarflexion, dorsiflexion (estimates ranged from -9% to +9% of comparator). The only non-zero differences identified were in hip adduction (24% stronger on ACL limb (95% CI 8% to 42%)) and hip external rotation strength (12% deficit on ACL limb (95% CI 6% to 18%)) compared with uninjured controls at follow-ups >12 months, however both results stemmed from only two studies. Certainty of evidence was very low for all outcomes and comparisons, and drawn primarily from the first year post-ACL reconstruction. CONCLUSION: Our results do not show widespread or substantial muscle weakness of the hip and lower-leg muscles after ACL injury, contrasting deficits of 10%-20% commonly reported for knee extensors and flexors. As it is unclear if deficits in hip and lower-leg muscle strength resolve with appropriate rehabilitation or no postinjury or postoperative weakness occurs, individualised assessment should guide training of hip and lower-leg strength following ACL injury. PROSPERO REGISTRATION NUMBER: CRD42020216793.


Anterior Cruciate Ligament Injuries , Hip , Muscle Strength , Humans , Muscle Strength/physiology , Anterior Cruciate Ligament Injuries/surgery , Anterior Cruciate Ligament Injuries/physiopathology , Leg , Anterior Cruciate Ligament Reconstruction/rehabilitation , Muscle, Skeletal/physiopathology , Muscle, Skeletal/physiology , Muscle Weakness/etiology , Muscle Weakness/physiopathology
9.
Knee ; 47: 171-178, 2024 Mar.
Article En | MEDLINE | ID: mdl-38401341

BACKGROUND: Physical function and knee kinematics recovery after discoid lateral meniscus (DLM) tear surgery are essential for a better prognosis. However, these alterations remain unclear. Therefore, this study aimed to investigate changes in physical function and knee kinematics following saucerization and DLM tear repair. METHODS: We enrolled 16 patients who underwent saucerization and DLM tear repair. Postoperative changes in knee kinematics during gait, and physical function, were evaluated at 3, 6, and 12 months. RESULTS: The peak flexion angle of the operated limb during weight acceptance was significantly higher than that of the contralateral limb at 3 (operated limb: 34.6 ± 8.9°, contralateral limb: 23.7 ± 8.3°; P < 0.01) and 6 months (operated limb: 32.1 ± 9.7°, contralateral limb: 24.6 ± 8.2°; P = 0.03) postoperatively, but not at 12 months (operated limb: 27.1 ± 7.1°, contralateral limb: 23.1 ± 9.5°; P = 0.22) postoperatively. The knee extensor strength of the operated limb was significantly lower than that of the contralateral limb at 3 (operated limb: 1.00 ± 0.59 Nm/kg, contralateral limb: 1.37 ± 0.59 Nm/kg; P = 0.01), 6 (operated limb: 1.22 ± 0.55 Nm/kg, contralateral limb: 1.48 ± 0.60 Nm/kg; P < 0.01), and 12 months (operated limb: 1.39 ± 0.57 Nm/kg, contralateral limb: 1.55 ± 0.64 Nm/kg; P = 0.04) postoperatively. CONCLUSION: Knee extension deficits and extensor weakness persisted at 6 months after saucerization and repair of DLM tears. Postoperative rehabilitation should be focused on knee extension function.


Gait , Range of Motion, Articular , Tibial Meniscus Injuries , Humans , Tibial Meniscus Injuries/surgery , Tibial Meniscus Injuries/physiopathology , Male , Female , Adult , Gait/physiology , Range of Motion, Articular/physiology , Middle Aged , Biomechanical Phenomena , Knee Joint/physiopathology , Knee Joint/surgery , Muscle Weakness/physiopathology , Muscle Weakness/etiology , Recovery of Function , Young Adult , Menisci, Tibial/surgery , Menisci, Tibial/physiopathology
10.
Arch Gerontol Geriatr ; 122: 105385, 2024 Jul.
Article En | MEDLINE | ID: mdl-38417298

BACKGROUND: To evaluate the association between handgrip strength (HGS) weakness and asymmetry with incident hip fracture among older Chinese adults. METHODS: Data was obtained from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study (CHARLS). HGS weakness was defined as maximal HGS 〈 28 kg in men and < 18 kg in women. HGS asymmetry was defined as the HGS ratio < 0.9 or 〉 1.1. Participants were categorized into normal HGS, weakness only, asymmetry only, and both weakness and asymmetry. Given the sex differences in HGS, the association between HGS weakness and asymmetry was analyzed by sex using the multivariable logistic regression models. RESULTS: A total of 4789 participants aged ≥ 60 years old without hip fracture at baseline were included in the final analysis. Over the four-year follow-up, there were 152 (3.17 %) participants having incident hip fractures, of which 69 (2.90 %) were men and 83 (3.45 %) were women. Compared to the normal group, men with both weakness and asymmetry had a significantly higher risk of incident hip fracture in the fully adjusted model (adjusted odds ratio (OR): 2.31, 95 % confidence interval (CI):1.17-4.52). There was no significant association between HGS asymmetry and weakness with hip fracture in women. CONCLUSIONS: Our findings indicated that among the Chinese population, men with both HGS weakness and asymmetry were associated with increased odds of hip fracture, while no significant association was observed in women.


Hand Strength , Hip Fractures , Muscle Weakness , Humans , Male , Female , Hip Fractures/epidemiology , Aged , Hand Strength/physiology , Muscle Weakness/epidemiology , Muscle Weakness/physiopathology , China/epidemiology , Longitudinal Studies , Middle Aged , Incidence , Risk Factors , Sex Factors , Aged, 80 and over , East Asian People
11.
J Sport Health Sci ; 13(3): 419-427, 2024 May.
Article En | MEDLINE | ID: mdl-38219958

BACKGROUND: Pediatric cancer survivors are at increased risk of muscle weakness and low areal bone mineral density (aBMD). However, the prevalence of muscle strength deficits is not well documented, and the associations of muscle strength with aBMD are unknown in this population. Therefore, this study aimed to investigate the prevalence of upper- and lower-body muscle strength deficits and to examine the associations of upper- and lower-body muscle strength with age-, sex, and race-specific aBMD Z-scores at the total body, total hip, femoral neck, and lumbar spine. METHODS: This cross-sectional study included 116 pediatric cancer survivors (12.1 ± 3.3 years old, mean ± SD; 42.2% female). Upper- and lower-body muscle strength were assessed by handgrip and standing long jump test, respectively. Dual­energy X­ray absorptiometry was used to measure aBMD (g/cm2). Associations between muscle strength and aBMD were evaluated in multivariable linear regression models. Logistic regression was used to evaluate the contribution of muscle strength (1-decile lower) to the odds of having low aBMD (Z-score ≤ 1.0). All analyses were adjusted for time from treatment completion, radiotherapy exposure, and body mass index. RESULTS: More than one-half of survivors were within the 2 lowest deciles for upper- (56.9%) and lower- body muscle strength (60.0%) in comparison to age- and sex-specific reference values. Muscle strength deficits were associated with lower aBMD Z-scores at all sites (B = 0.133-0.258, p = 0.001-0.032). Each 1-decile lower in upper-body muscle strength was associated with 30%-95% higher odds of having low aBMD Z-scores at all sites. Each 1-decile lower in lower-body muscle strength was associated with 35%-70% higher odds of having low aBMD Z-scores at total body, total hip, and femoral neck. CONCLUSION: Muscle strength deficits are prevalent in young pediatric cancer survivors, and such deficits are associated with lower aBMD Z-scores at all sites. These results suggest that interventions designed to improve muscle strength in this vulnerable population may have the added benefit of improving aBMD.


Bone Density , Cancer Survivors , Hand Strength , Muscle Strength , Humans , Female , Male , Cross-Sectional Studies , Bone Density/physiology , Child , Adolescent , Muscle Strength/physiology , Hand Strength/physiology , Absorptiometry, Photon , Femur Neck , Muscle Weakness/physiopathology , Muscle Weakness/etiology
12.
PeerJ ; 11: e16261, 2023.
Article En | MEDLINE | ID: mdl-37818333

Purpose: The purpose of this investigation was to compare the quality of neural drive and recruited quadriceps motor units' (MU) action potential amplitude (MUAPAMP) and discharge rate (mean firing rate (MFR)) relative to recruitment threshold (RT) between individuals with anterior cruciate ligament reconstruction (ACLR) and controls. Methods: Fourteen individuals with ACLR and 13 matched controls performed trapezoidal knee extensor contractions at 30%, 50%, 70%, and 100% of their maximal voluntary isometric contraction (MVIC). Decomposition electromyography (dEMG) and torque were recorded concurrently. The Hoffmann reflex (H-reflex) and central activation ratio (CAR) were acquired bilaterally to detail the proportion of MU pool available and volitionally activated. We examined MUAPAMP-RT and MFR-RT relationships with linear regression and extracted the regression line slope, y-intercept, and RT range for each contraction. Linear mixed effect modelling used to analyze the effect of group and limb on regression line slope and RT range. Results: Individuals with ACLR demonstrated lower MVIC torque in the involved limb compared to uninvolved limb. There were no differences in H-reflex or CAR between groups or limbs. The ACLR involved limb demonstrated smaller mass-normalized RT range and slower MU firing rates at high contraction intensities (70% and 100% MVIC) compared to uninvolved and control limbs. The ACLR involved limb also demonstrated larger MU action potentials in the VM compared to the contralateral limb. These differences were largely attenuated with relative RT normalization. Conclusions: These results suggest that persistent strength deficits following ACLR may be attributable to a diminished quadriceps motor neuron pool and inability to upregulate the firing rate of recruited MUs.


Action Potentials , Anterior Cruciate Ligament Injuries , Anterior Cruciate Ligament Reconstruction , Muscle Weakness , Quadriceps Muscle , Recruitment, Neurophysiological , Humans , Anterior Cruciate Ligament Injuries/physiopathology , Anterior Cruciate Ligament Injuries/surgery , Anterior Cruciate Ligament Reconstruction/adverse effects , Anterior Cruciate Ligament Reconstruction/methods , Knee/physiopathology , Knee/surgery , Knee Joint/physiopathology , Knee Joint/surgery , Quadriceps Muscle/physiopathology , Muscle Weakness/etiology , Muscle Weakness/physiopathology
15.
Nat Med ; 28(1): 20-23, 2022 01.
Article En | MEDLINE | ID: mdl-35039657
16.
Eur J Appl Physiol ; 122(2): 357-369, 2022 Feb.
Article En | MEDLINE | ID: mdl-34729636

PURPOSE: Cortical mechanisms may contribute to weakness in participants with previous hamstring strain injury. This study aims to examine intra-cortical inhibition (SICI) and corticospinal excitability in previously injured participants. METHODS: In this cross-sectional study, TMS was used to examine SICI, silent period, silent period: MEP ratios and area under the stimulus response curve in the biceps femoris and medial hamstrings. Comparisons were made between participants with (n = 10) and without (n = 10) previous hamstring strain injury. Motor threshold and isometric knee flexor strength were also compared between participants and the relationship between strength and SICI in control and previously injured participants was examined. RESULTS: Isometric knee flexor strength was lower in previously injured limbs compared with control limbs (mean difference = - 41 Nm (- 26%) [95% CI = - 80 to - 2 Nm], p = 0.04, Cohen's d = - 1.27) and contralateral uninjured limbs (mean difference = - 23 Nm (- 17%), [95% CI = - 40 to - 6 Nm], p = 0.01, Cohen's d = - 0.57). Previously injured limbs exhibited smaller responses to paired pulse stimulation (i.e. greater levels of SICI) in the biceps femoris compared with control limbs (mean difference = - 19%, [95% CI = - 34 to - 5%], p = 0.007, Cohen's d = - 1.33). Isometric knee flexor strength was associated with the level of SICI recorded in the biceps femoris in previously injured participants (coefficient = 23 Nm [95% CI = 7-40 Nm], adjusted R2 = 0.31, p = 0.01). There were no differences in markers of corticospinal excitability between previously injured and control limbs (all p > 0.24, all Cohen's d < 0.40). CONCLUSION: Athletes with previous injury in the biceps femoris exhibit increased SICI in this muscle compared with control participants. Increased SICI is related to lower levels of hamstring strength, and rehabilitation programs targeting the removal of intra-cortical inhibition should be considered.


Athletic Injuries/physiopathology , Athletic Injuries/rehabilitation , Hamstring Muscles/injuries , Muscle Weakness/physiopathology , Neural Inhibition/physiology , Transcranial Magnetic Stimulation , Cross-Sectional Studies , Electromyography , Humans , Male , Young Adult
17.
Respir Physiol Neurobiol ; 295: 103789, 2022 01.
Article En | MEDLINE | ID: mdl-34560292

Critically ill mechanically ventilated (MV) patients develop significant muscle weakness, which has major clinical consequences. There remains uncertainty, however, regarding the severity of leg weakness, the precise relationship between muscle strength and thickness, and the risk factors for weakness in MV patients. We therefore measured both diaphragm (PdiTw) and quadriceps (QuadTw) strength in MV patients using magnetic stimulation and compared strength to muscle thickness. Both PdiTw and QuadTw were profoundly reduced for MV patients, with PdiTw 19 % of normal and QuadTw 6% of normal values. There was a poor correlation between strength and thickness for both muscles, with thickness often remaining in the normal range when strength was severely reduced. Regression analysis revealed reductions in PdiTw correlated with presence of infection (p = 0.006) and age (p = 0.007). QuadTw best correlated with duration of MV (p = 0.036). Limb muscles are profoundly weak in critically ill patients, with a severity that mirrors the level of weakness observed in the diaphragm.


Critical Illness , Diaphragm/physiopathology , Muscle Weakness/diagnosis , Muscle Weakness/physiopathology , Quadriceps Muscle/physiopathology , Respiration, Artificial , Age Factors , Critical Illness/therapy , Humans , Intensive Care Units , Magnetic Fields , Muscle Weakness/etiology , Physical Stimulation , Time Factors
18.
Acta Orthop ; 93: 11-28, 2022 01 03.
Article En | MEDLINE | ID: mdl-34607499

Background and purpose - After initial clubfoot correction through Ponseti treatment, recurrence rates range from 26% to 48%. Even though various factors have been associated with increased recurrence risk, systematic assessments of the prognostic capacity of recurrence risk factors and their clinical relevance are lacking. Therefore we assessed clinically relevant prognostic factors for recurrent idiopathic clubfoot deformity after initial correction through Ponseti treatment. Methods - PubMed, Embase, Cinahl, and Web of Science were systematically searched for studies investigating the association between clinically relevant factors and recurrence rates. Prognostic factors were qualitatively assessed and included in the meta-analysis if ≥ 2 studies investigated the same factor and methods were comparable. Results - 34 articles were included in the qualitative synthesis, of which 22 were also included in the meta-analysis. Meta-analysis revealed that poor evertor muscle activity (OR = 255, 95% CI 30-2,190), brace non-compliance (OR = 10, CI 5-21), no additional stretching (OR = 31, CI 10-101), more casts (OR = 3.5, CI 1.6-7.8), lower education level of parents (OR = 1.8, CI 1.2-2.6), non-marital status of parents (OR = 1.8, CI 1.1-3.0), and higher Dimeglio scores (OR = 1.9, CI 1.2-3.3) were associated with higher recurrence rates. Interpretation - Brace non-compliance and poor evertor muscle activity have been identified as main recurrence risk factors and are therefore important to be closely monitored during clinical follow-up of clubfoot patients. Adding additional stretching during the bracing protocol might be promising in the quest to prevent relapse, but scientific evidence for clear clinical treatment recommendations is still limited.


Clubfoot/therapy , Secondary Prevention/methods , Braces , Casts, Surgical , Combined Modality Therapy , Humans , Muscle Weakness/physiopathology , Patient Compliance , Prognosis , Plastic Surgery Procedures/methods , Recurrence , Risk Factors , Severity of Illness Index
19.
J Burn Care Res ; 43(1): 70-76, 2022 01 05.
Article En | MEDLINE | ID: mdl-34142710

This study aimed to evaluate pulmonary function measurements and respiratory muscle parameters in patients with major burn injury and smoke inhalation. The inclusion criteria included patients who were diagnosed with a smoke inhalation burn or a major burn of more than 20% of total body surface area (TBSA). All subjects underwent a pulmonary function test, respiratory muscle strength test, peak cough flow and fluoroscopic diaphragmatic movement measurement, and 6-minute walk test before starting pulmonary rehabilitation. Evaluations were conducted on the 88th day after the injury, the average time of admission to the Department of the Rehabilitation Medicine for burn rehabilitation after the completion of the acute treatment. The average degree of burns of the total 67 patients was 34.6% TBSA. All parameters in the patient group were significantly lower than the healthy controls, and a mild restrictive pattern of impairment with a reduction in diffusing capacity and more reduced expiratory muscle, than inspiratory muscle strength were observed. Peak cough flow, respiratory muscle strength, and forced vital capacity in the patient group with inhalation burn were significantly lower than in those without inhalation burn. The conditions of the majority of patients with major burn and inhalation injury were consistent with restrictive impairment and significant reduction in diffusion capacity. The patients had expiratory muscle weakness, decreased diaphragmatic movement, and exercise capacity impairment.


Burns/physiopathology , Smoke Inhalation Injury/physiopathology , Adult , Burns/rehabilitation , Case-Control Studies , Cough/physiopathology , Diaphragm/physiopathology , Female , Humans , Male , Middle Aged , Muscle Weakness/physiopathology , Prospective Studies , Respiratory Function Tests , Respiratory Muscles/physiopathology , Smoke Inhalation Injury/rehabilitation , Walk Test
20.
Phys Ther ; 102(1)2022 01 01.
Article En | MEDLINE | ID: mdl-34751784

OBJECTIVE: Chronic low back pain (CLBP) is a disabling and costly condition for older adults that is difficult to properly classify and treat. In a cohort study, a subgroup of older adults with CLBP who had elevated hip pain and hip muscle weakness was identified; this subgroup differentiated itself by being at higher risk for future mobility decline. The primary purpose of this clinical trial is to evaluate whether a hip-focused low back pain (LBP) treatment provides better disability and physical performance outcomes for this at-risk group compared with a spine-focused LBP treatment. METHODS: This study is a multisite, single-blinded, randomized controlled, parallel arm, Phase II trial conducted across 3 clinical research sites. A total of 180 people aged between 60 and 85 years with CLBP and hip pain are being recruited. Participants undergo a comprehensive baseline assessment and are randomized into 1 of 2 intervention arms: hip-focused or spine-focused. They are treated twice weekly by a licensed physical therapist for 8 weeks and undergo follow-up assessments at 8 weeks and 6 months after randomization. Primary outcome measures include the Quebec Low Back Disability Scale and the 10-Meter Walk Test, which are measures of self-report and performance-based physical function, respectively. IMPACT: This multicenter, randomized clinical trial will determine whether a hip-focused or spine-focused physical therapist intervention results in improved disability and physical performance for a subgroup of older adults with CLBP and hip pain who are at increased risk of mobility decline. This trial will help further the development of effective interventions for this subgroup of older adults with CLBP.


Arthralgia/therapy , Exercise Therapy/methods , Hip Joint/physiopathology , Low Back Pain/therapy , Muscle Weakness/therapy , Musculoskeletal Manipulations/methods , Aged , Aged, 80 and over , Arthralgia/physiopathology , Chronic Pain , Disability Evaluation , Humans , Low Back Pain/physiopathology , Middle Aged , Muscle Weakness/physiopathology , Single-Blind Method , Walk Test
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