RESUMEN
BACKGROUND & AIMS: Sarcopenia and myosteatosis are common in patients with cirrhosis. This study aimed to determine the prevalence of these muscle changes, their interrelations and their prognostic impact over a 12-month period. METHODS: We conducted a prospective multicentre study involving 433 patients. Sarcopenia and myosteatosis were evaluated using computed tomography scans. The 1-year cumulative incidence of relevant events was assessed by competing risk analysis. We used a Fine-Gray model adjusted for known prognostic factors to evaluate the impact of sarcopenia and myosteatosis on mortality, hospitalization, and liver decompensation. RESULTS: At enrolment, 166 patients presented with isolated myosteatosis, 36 with isolated sarcopenia, 135 with combined sarcopenia and myosteatosis and 96 patients showed no muscle changes. The 1-year cumulative incidence of death in patients with either sarcopenia and myosteatosis (13.8%) or isolated myosteatosis (13.4%) was over twice that of patients without muscle changes (5.2%) or with isolated sarcopenia (5.6%). The adjusted sub-hazard ratio for death in patients with muscle changes was 1.36 (95% CI 0.99-1.86, p = 0.058). The cumulative incidence of hospitalization was significantly higher in patients with combined sarcopenia and myosteatosis than in patients without muscle changes (adjusted sub-hazard ratio 1.18, 95% CI 1.04-1.35). The cumulative incidence of liver decompensation was greater in patients with combined sarcopenia and myosteatosis (p = 0.018) and those with isolated sarcopenia (p = 0.046) than in patients without muscle changes. Lastly, we found a strong correlation of function tests and frailty scores with the presence of muscle changes. CONCLUSIONS: Myosteatosis, whether alone or combined with sarcopenia, is highly prevalent in patients with cirrhosis and is associated with significantly worse outcomes. The prognostic role of sarcopenia should always be evaluated in relation to the presence of myosteatosis. IMPACT AND IMPLICATIONS: This study investigates the prognostic role of muscle changes in patients with cirrhosis. The novelty of this study is its multicentre, prospective nature and the fact that it distinguishes between the impact of individual muscle changes and their combination on prognosis in cirrhosis. This study highlights the prognostic role of myosteatosis, especially when combined with sarcopenia. On the other hand, the relevance of sarcopenia could be mitigated when considered together with myosteatosis. The implication from these findings is that sarcopenia should never be evaluated individually and that myosteatosis may play a dominant role in the prognosis of patients with cirrhosis.
RESUMEN
BACKGROUND: Historical exclusion of females in research has been, in part, due to the perceived influence of natural menstrual (NAT) and oral contraceptive pill (OCP) cycles on vascular outcomes. NAT and OCP cycle phases may influence brachial artery (BA) endothelial function, however, findings are mixed. Minimal research has examined arterial stiffness, smooth muscle and lower limb endothelial function. The purpose of this study was to investigate the influence of NAT and OCP cycles on cardiovascular outcomes and cellular regulation. METHODS: Forty-nine premenopausal females (n=17 NAT, n=17 2nd generation OCP, n=15 3rd generation OCP) participated in two randomized order visits in the low (LH: early follicular/placebo) and high (HH: mid-luteal/active) hormone cycle phases. BA and femoral artery (SFA) endothelial function [flow-mediated dilation (FMD) test], smooth muscle function (nitroglycerine-mediated dilation test) and carotid and peripheral (pulse wave velocity) arterial stiffness were assessed. Cultured female human endothelial cells were exposed to participant serum for 24h to examine endothelial nitric oxide synthase (eNOS) and estrogen receptor alpha (ERα) protein content. RESULTS: BA FMD was elevated in the HH versus LH phase, regardless of group (HH:7.7±3.5%, LH:7.0±3.3%, p=0.02); however, allometric scaling for baseline diameter resulted in no phase effect (HH:7.6±2.6%, LH:7.1±2.6%, p=0.052, d=0.35). SFA FMD, BA and SFA smooth muscle function, arterial stiffness, and eNOS and ERα protein content were unaffected. CONCLUSIONS: NAT and OCP phases examined have minimal influence on vascular outcomes and ERα-eNOS pathway, apart from a small effect on BA endothelial function partially explained by differences in baseline artery diameter.
RESUMEN
BACKGROUND: An increasing number of women are choosing mastectomy and subpectoral implant (SI) breast reconstruction over breast-conserving therapy (BCT). It is unclear to what extent these procedures differ in their effect on the pectoralis major (PM). The purpose of this study was to assess the impact of choosing BCT or SI breast reconstruction on PM function. METHODS: Ultrasound shear wave elastography images were acquired from the PM fiber regions and surface electromyography obtained activity from six shoulder muscles, while 14 BCT participants, 14 SI participants, and 14 age-matched controls remained at rest or generated submaximal shoulder torques. RESULTS: BCT and SI participants were significantly weaker in shoulder adduction, while BCT participants were also weaker in internal and external rotation (all p ≤ 0.003). PM function was altered following either BCT or SI. In all treatment groups, the clavicular fiber region contributed primarily to flexion, and the sternocostal primarily contributed to adduction. However, healthy participants utilized the clavicular region more during adduction and the sternocostal region more during flexion when compared to BCT or SI participants (all p ≤ 0.049). The still intact clavicular region increased its contributions to flexion torques in SI participants compared to controls (p = 0.016). Finally, BCT and SI participants compensated for changes in PM function using synergistic shoulder musculature. CONCLUSION: Both BCT and SI breast reconstruction result in significant long-term upper extremity strength deficits. Our results suggest changes to the underlying function of the PM and the adoption of unique but inadequate neuromuscular compensation strategies drive these deficits.
RESUMEN
INTRODUCTION: Regular assessment of motor impairments is crucial in people with haemophilic arthropathy (PwHA). This study aimed to determine if there are differences in 30-seconds sit-to-stand (30-STS) power and maximal voluntary isometric contraction (MVIC) of the knee extensors between PwHA and healthy control group (CG). The secondary aims were to investigate the correlation between 30-STS power and MVIC of knee extensors with clinical characteristics and to assess their effectiveness in identifying motor impairment in PwHA. METHODS: A cross-sectional study was conducted by collecting data from PwHA (n = 17) and a sedentary CG (n = 15). MVIC (torque) and 30-STS power were normalised to body mass. Correlation analysis and simple linear regression adjusted for age were used to assess the association between tests and clinical variables. Using z-scores derived from the mean and standard deviation of the CG, we compared the MVIC and the 30-STS power in PwHA. RESULTS: PwHA showed lower MVIC and 30-STS power compared to CG (p < .001; large effect size d > .8). Lower 30-STS power was associated with greater joint impairment and greater fear of movement, whereas MVIC showed no association with clinical variables. 30-STS power showed a lower z-score compared to MVIC (p < .001). In addition, 30-STS power detected 47% of PwHA with motor impairment compared to 0% for MVIC (p = .002). CONCLUSIONS: Our results suggest that 30-STS power may be more effective than knee extensors MVIC in detecting motor impairment in PwHA. Consequently, lower limb skeletal muscle power, rather than maximum knee extensor strength, appears to be more affected in PwHA.
Asunto(s)
Hemofilia A , Contracción Isométrica , Fuerza Muscular , Humanos , Masculino , Contracción Isométrica/fisiología , Adulto , Hemofilia A/complicaciones , Hemofilia A/fisiopatología , Estudios Transversales , Fuerza Muscular/fisiología , Femenino , Adulto Joven , Persona de Mediana Edad , Articulación de la Rodilla/fisiopatología , Rodilla/fisiopatología , Artropatías/fisiopatología , Artropatías/diagnóstico , Artropatías/etiología , Hemartrosis/etiología , Hemartrosis/fisiopatología , Hemartrosis/diagnósticoRESUMEN
Force-length relationships derived from isometric activations may not directly apply to muscle force production during dynamic contractions. As such, different muscle starting lengths between isometric and dynamic conditions could be required to achieve maximal force and power. Therefore, this study examined the effects of starting length [±5-10% of length corresponding to maximal twitch force (L0)] on work loop (WL) power output (PO), across a range of cycle frequencies, of the soleus (SOL) and extensor digitorum longus muscle (EDL; N=8-10) isolated from â¼8 week old C57 mice. Furthermore, passive work was examined at a fixed cycle frequency to determine the association of passive work and active net work. Starting length affected maximal WL PO of the SOL and EDL across evaluated cycle frequencies (P<0.030, ηp2>0.494). For the SOL, PO produced at -5% L0 was greater than that at most starting lengths (P<0.015, Cohen's d>0.6), except -10% L0 (P=0.135, d<0.4). However, PO produced at -10% L0 versus L0 did not differ (P=0.138, d=0.35-0.49), indicating -5% L0 is optimal for maximal SOL WL PO. For the EDL, WL PO produced at -10% L0 was lower than that at most starting lengths (P<0.032, d>1.08), except versus -5% L0 (P=0.124, d<0.97). PO produced at other starting lengths did not differ (P>0.163, d<1.04). For the SOL, higher passive work was associated with reduced PO (Spearman's r=0.709, P<0.001), but no relationship was observed between passive work and PO of the EDL (Pearson's r=0.191, r2=0.04, P=0.184). This study suggests that starting length should be optimised for both static and dynamic contractions and confirms that the force-length curve during dynamic contractions is muscle specific.
Asunto(s)
Ratones Endogámicos C57BL , Contracción Muscular , Músculo Esquelético , Animales , Músculo Esquelético/fisiología , Ratones/fisiología , Contracción Muscular/fisiología , Masculino , Fenómenos Biomecánicos , Contracción Isométrica/fisiologíaRESUMEN
The isometric force-length (F-L) and isotonic force-velocity (F-V) relationships characterize the contractile properties of skeletal muscle under controlled conditions, yet it remains unclear how these properties relate to in vivo muscle function. Here, we map the in situ F-L and F-V characteristics of guinea fowl (Numida meleagris) lateral gastrocnemius (LG) to the in vivo operating range during walking and running. We test the hypothesis that muscle fascicles operate on the F-L plateau, near the optimal length for force (L0) and near velocities that maximize power output (Vopt) during walking and running. We found that in vivo LG velocities are consistent with optimizing power during work production, and economy of force at higher loads. However, LG does not operate near L0 at higher loads. LG length was near L0 at the time of electromyography (EMG) onset but shortened rapidly such that force development during stance occurred on the ascending limb of the F-L curve, around 0.8L0. Shortening across L0 in late swing might optimize potential for rapid force development near the swing-stance transition, providing resistance to unexpected perturbations that require rapid force development. We also found evidence of in vivo passive force rise in late swing, without EMG activity, at lengths where in situ passive force is zero, suggesting that dynamic viscoelastic effects contribute to in vivo force development. Comparison of in vivo operating ranges with F-L and F-V properties suggests the need for new approaches to characterize muscle properties in controlled conditions that more closely resemble in vivo dynamics.
Asunto(s)
Galliformes , Músculo Esquelético , Animales , Galliformes/fisiología , Músculo Esquelético/fisiología , Fenómenos Biomecánicos , Carrera/fisiología , Electromiografía , Caminata/fisiología , Contracción Muscular/fisiología , Contracción Isométrica/fisiologíaRESUMEN
OBJECTIVE: To assess the effectiveness of pre- and postoperative supervised pelvic floor muscle training (PFMT) on the recovery of continence and pelvic floor muscle (PFM) function after robot-assisted laparoscopic radical prostatectomy (RARP). PATIENTS AND METHODS: We carried out a single-blind randomised controlled trial involving 54 male patients scheduled to undergo RARP. The intervention group started supervised PFMT 2 months before RARP and continued for 12 months after surgery with a physiotherapist. The control group was given verbal instructions, a brochure about PFMT, and lifestyle advice. The primary outcome was 24-h pad weight (g) at 3 months after RARP. The secondary outcomes were continence status (assessed by pad use), PFM function, and the Expanded Prostate Cancer Index Composite (EPIC) score. RESULTS: Patients who participated in supervised PFMT showed significantly improved postoperative urinary incontinence (UI) compared with the control group (5.0 [0.0-908.0] g vs 21.0 [0.0-750.0] g; effect size: 0.34, P = 0.022) at 3 months after RARP based on 24-h pad weight. A significant improvement was seen in the intervention compared with the control group (65.2% continence [no pad use] vs 31.6% continence, respectively) at 12 months after surgery (effect size: 0.34, P = 0.030). Peak pressure during a maximum voluntary contraction was higher in the intervention group immediately after catheter removal and at 6 months, and a longer duration of sustained contraction was found in the intervention group compared with the control group. We were unable to demonstrate a difference between groups in EPIC scores. CONCLUSION: Supervised PFMT can improve postoperative UI and PFM function after RARP. Further studies are needed to confirm whether intra-anal pressure reflects PFM function and affects continence status in UI in men who have undergone RARP.
RESUMEN
AIM: The study aimed to determine whether pelvic floor muscle (PFM) function before surgery may correlate with the success of surgical interventions for treating stress urinary incontinence (SUI). Our hypothesis was that addressing identified variables in preoperative rehabilitation could potentially improve surgical outcomes. METHODS: This prospective observational study was conducted at a single center and enrolled women qualified to mid-urethral tape insertion for SUI between 2020 and 2022. Digital palpation and manometry (Peritron™ 9300 V) were used to evaluate PFM function. The following parameters were acquired: vaginal resting pressure, vaginal pressure during maximal voluntary contraction (MVC), the area under the curve during a 10-second MVC, moreover the ability to perform correct PFM contraction, reflexive PFM contraction during cough and relaxation were assessed. All measurements were performed before the surgical treatment and during follow-up assessments at 1, 3, and 6 months postoperatively. The primary endpoint of the study was defined as objective cure, characterized by a negative cough stress test (CST), along with a subjective assessment based on the Urogenital Distress Inventory-6 (UDI-6) and Incontinence Impact Questionnaire-7 (IIQ-7). RESULTS: The study involved 57 eligible female participants, all of whom completed the 6-month follow-up. Objective cure was observed in 75.44% of cases, while subjective cure was reported in 33%. There was no association between PFM parameters and surgical outcomes. CONCLUSION: The success of surgical treatment of SUI 6 months postsurgery is not related to preoperative pelvic floor muscle function.
Asunto(s)
Diafragma Pélvico , Incontinencia Urinaria de Esfuerzo , Humanos , Femenino , Incontinencia Urinaria de Esfuerzo/cirugía , Incontinencia Urinaria de Esfuerzo/fisiopatología , Diafragma Pélvico/fisiopatología , Diafragma Pélvico/cirugía , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento , Adulto , Anciano , Contracción Muscular , Manometría , Cabestrillo SuburetralRESUMEN
BACKGROUND: Emerging evidence suggests health-promoting properties of increased protein intake. There is increased interest in plant protein but a dearth of information in relation to its impact on muscle function. The objective of the present work was to examine the impact of intake of different types of proteins on muscle functional parameters including handgrip strength, biomarkers of metabolic health, sleep quality and quality of life in a group of older adults. METHODS: Healthy men and women aged 50 years and older entered a double-blinded, randomised, controlled nutritional intervention study with three parallel arms: high plant protein, high dairy protein and low protein. Participants consumed once daily a ready-to-mix shake (containing 20 g of protein in high protein groups) for 12 weeks. Changes in handgrip and leg strength, body composition, metabolic health, quality of life and sleep quality were analysed by linear mixed models in an intention-to-treat approach. RESULTS: Eligible participants (n = 171) were randomly assigned to the groups (plant: n = 60, dairy: n = 56, low protein: n = 55) and 141 completed the study. Handgrip strength increased after the intervention (Ptime = 0.038), with no significant difference between the groups. There was no significant difference between groups for any other health outcomes. CONCLUSIONS: In a population of older adults, increasing protein intake by 20 g daily for 12 weeks (whether plant-based or dairy-based) did not result in significant differences in muscle function, body composition, metabolic health, sleep quality or quality of life, compared with the low protein group.
Asunto(s)
Composición Corporal , Fuerza de la Mano , Calidad de Vida , Sueño , Humanos , Masculino , Femenino , Método Doble Ciego , Anciano , Persona de Mediana Edad , Sueño/fisiología , Proteínas de Vegetales Comestibles/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Músculo Esquelético/fisiología , Factores de Tiempo , Factores de Edad , Dieta Rica en Proteínas , Estado NutricionalRESUMEN
Individuals born preterm present lower exercise capacity. Along with the cardiopulmonary responses and activity level, muscle strength is a key determinant of exercise capacity. This systematic review aimed to summarize the current knowledge on the impact of preterm birth on skeletal muscle mass and function across the lifespan. The databases PubMed, MEDLINE, EBM, Embase, CINAHL Plus, Global Index Medicus, and Google Scholar were searched using keywords and MeSH terms related to skeletal muscle, preterm birth, and low birth weight. Two independent reviewers undertook study selection, data extraction, and quality appraisal using Covidence review management. Data were pooled to estimate the prematurity effect on muscle mass and function using the R software. From 4378 studies retrieved, 132 were full-text reviewed and 25 met the inclusion/exclusion criteria. Five studies presented a low risk of bias, and 5 had a higher risk of bias due to a lack of adjustment for confounding factors and presenting incomplete outcomes. Meta-analyses of pooled data from homogenous studies indicated a significant reduction in muscle thickness and jump test (muscle power) in individuals born preterm versus full-term with standardized mean difference and confidence interval of - 0.58 (0.27, 0.89) and - 0.45 (0.21, 0.69), respectively. Conclusion: Overall, this systematic review summarizing the existing literature on the impact of preterm birth on skeletal muscle indicates emerging evidence that individuals born preterm, display alteration in the development of their skeletal muscle mass and function. This work also highlights a clear knowledge gap in understanding the effect of preterm birth on skeletal muscle development. What is Known: ⢠Preterm birth, which occurs at a critical time of skeletal muscle development and maturation, impairs the development of different organs and tissues leading to a higher risk of comorbidities such as cardiovascular diseases. ⢠Preterm birth is associated with reduced exercise capacity. What is New: ⢠Individuals born preterm display alterations in muscle mass and function compared to individuals born at term from infancy to adulthood. ⢠There is a need to develop preventive or curative interventions to improve skeletal muscle health in preterm-born individuals.
Asunto(s)
Fuerza Muscular , Músculo Esquelético , Nacimiento Prematuro , Humanos , Músculo Esquelético/fisiología , Músculo Esquelético/fisiopatología , Recién Nacido , Fuerza Muscular/fisiología , Recien Nacido Prematuro/crecimiento & desarrolloRESUMEN
BACKGROUND AND AIMS: The predictive value of phase angle for sarcopenia diagnosis has been discussed for years. The present investigation was conducted to determine the association between phase angle and sarcopenia in patients with COPD. METHODS: In this case-control study, 222 smoker men were divided into healthy and COPD groups. COPD was diagnosed by a pulmonologist through spirometry. Anthropometric indices, phase angle, muscle function, sarcopenia, and dietary intake were assessed. RESULTS: A significant inverse association was observed between phase angle and sarcopenia after adjustment for age and energy intake (OR: 0.31, 95% CI 0.18-0.52) and after adjustment for BMI (OR: 0.31, 95% CI 0.18-0.52). A significant decrease was detected in anthropometric indices and indicators of sarcopenia and muscle function in COPD cases compared to the healthy controls. CONCLUSIONS: Although further studies are suggested, phase angle might be considered an indicator of sarcopenia and muscle function in COPD patients.
Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica , Sarcopenia , Masculino , Humanos , Estudios de Casos y Controles , Antropometría , Músculos , Enfermedad Pulmonar Obstructiva Crónica/complicacionesRESUMEN
PURPOSE: While muscle mass and skeletal muscle fibers phenotype have been shown atypical in constitutional thinness (CT), force production capacities and its architectural determinants have never been explored. The present study compared muscle functionality and architecture between participants with CT and their normal-weight (NW) counterparts. METHODS: Anthropometry, body composition (Dual-X-ray Absorptiometry), physical activity/sedentary behavior (ActiGraph wGT3X-BT), ultrasound recording of the Vastus Lateralis (2D-ultrasound system), and functional capacities at maximal isometric and isokinetic voluntary contractions (MVCISO and MVCCON) during knee extension (isokinetic dynamometer chair Biodex) have been measured in 18 women with CT (body mass index < 17.5 kg/m2) and 17 NW women. RESULTS: A lower fat-free mass (ES: -1.94, 95%CI: -2.76 to -1.11, p < 0.001), a higher sedentary time, and a trend for a lower time spent at low-intensity physical activity, were observed in CT vs NW participants. While absolute MVCISO, MVCCON, rate of torque development (RTD), and torque work were all markedly lower in CT, these differences disappeared when normalized to body or muscle mass. Muscle thickness and fascicle length were found lower in CT (ES: -1.29, 95%CI: -2.03 to -0.52, p < 0.001; and ES: -0.87, 95%CI: -1.58 to -0.15, p = 0.02, respectively), while pennation angle was found similar. CONCLUSION: Despite lower absolute strength capacities observed in CT, present findings support the hypothesis of physiological adaptations to the low body and muscle mass than to some intrinsic contractile impairments. These results call for further studies exploring hypertrophy-targeted strategies in the management of CT.
RESUMEN
PURPOSE: This study aimed to assess the reliability of lower limb muscle function (knee extensor/flexor peak torque, rate of torque development (RTD), impulse, and countermovement jump (CMJ) performance) and sprint performance (acceleration capacity). METHODS: CMJ performance was evaluated on a force plate. MVIC, RTD and impulse variables were investigated using a portable isometric dynamometer and sprint performance was assessed with dual-beam photocells in elite female athletes. RESULTS: CMJ test variables maximal vertical jump height, peak and mean power, concentric work, and body center of mass displacement demonstrated good-to-excellent test-retest correlations between Test 1 and Test 2 (ICC ≥ 0.70, CWw-s = 3.4-11.0%). Peak MVIC torque for the knee extensors and flexors demonstrated excellent test-retest correlations (both ICC = 0.84) along with CVw-s values of 6.8 and 6.0%, respectively. Late-phase (0-100 ms, 0-200 ms) RTD for the knee flexors demonstrated excellent test-retest correlations (ICC = 0.89-0.91, CVw-s = 4.8-8.5%). Sprint times at 10- and 20-m demonstrated excellent test-retest reproducibility (ICC = 0.83 and ICC = 0.90, respectively) with CVw-s values of 1.9 and 1.5%. For 5-m sprint times, test-retest reproducibility was good (ICC = 0.71) with CVw-s of 2.8%. Sprint testing performed while dribbling a handball improved (p < 0.05) from test to retest at 5-, 10- and 20-m. CONCLUSION: In conclusion, the force plate, the mobile isometric dynamometer, and dual-beam photocells provide reproducible tools for field-based testing of countermovement jump performance, knee extensor and flexor strength and sprint performance.
RESUMEN
OBJECTIVE: To assess the association of residual diuresis with sarcopenia in patients with Chronic Kidney Disease (CKD) on hemodialysis. METHODS: Through a cross-sectional study, patients on hemodialysis were subjected to a Dual Energy Radiologic Absorption (DEXA) exam to record muscle mass. Based on the volume of urine collected in 24 hours, patients were classified as anuric (diuresis ≤ 100 mL/day) or non-anuric (diuresis > 100 mL/day). Functional performance was evaluated by Short Physical Performance Battery (SPPB) and muscle strength by handgrip strength and 5-repetition sit-to-stand test. The association between the absence of residual urine and the presence of sarcopenia, low SPPB, and low muscle strength was analyzed using a binary logistic regression model. RESULTS: Ninety-two patients, with a mean age of 54.4 years (95% CI 51.3 - 57.4) and with a mean diuresis volume of 476.3 mL/day (95% CI 320.4 - 632.2) were evaluated (48 anuric and 44 non-anuric). Anuric patients had a 2.77 (95% CI 1.14 - 6.73) times greater probability of sarcopenia and had a 3.55 (1.14 - 11.0) times greater probability of low SPPB, regardless of gender, age, and time on dialysis. Gender was the other associated variable for the presence of sarcopenia, with males having a 3.30 (95% CI 1.34 - 8.13) times higher risk. There were no associations with muscle strength. CONCLUSION: The absence of residual diuresis in patients on hemodialysis is associated with a higher risk of sarcopenia and low functional performance.
RESUMEN
PURPOSE: The capacity to explosively contract quadriceps within the critical timeframe associated with anterior cruciate ligament (ACL) injury, quantified by the rate of torque development, is potentially essential for safe landing mechanics. This study aimed to investigate the influence of explosive quadriceps strength on ACL-related sagittal-plane landing mechanics in females with and without ACL reconstruction (ACLR). METHODS: Quadriceps explosive strength and landing mechanics were assessed in 19 ACLR and 19 control females during isometric contractions and double- and single-leg jump landings. A stepwise multiple linear regression model determined the variance in each of the landing biomechanics variables for the ACLR limb and nondominant limb of controls that could be explained by the group, rate of torque development and/or their interaction. If peak kinetic variables could be predicted by the rate of torque development or interaction, additional analyses were conducted, accounting for knee flexion as a covariate in the regression model. RESULTS: During single-leg landings, ACLR females exhibited greater knee flexion at initial contact than controls (p = 0.04). Greater quadriceps rate of torque development predicted higher peak posterior ground reaction force and anterior tibial shear force in both groups (p = 0.04). However, after controlling for knee flexion angle at those peak forces, quadriceps rate of torque development was not predictive. In double-leg landings, greater explosive quadriceps strength was associated with quicker attainment of peak knee extension moment and posterior ground reaction force in the ACLR limb (p = 0.03). CONCLUSION: Regardless of ACL injury status, females with greater explosive quadriceps strength adopted safer single-leg landings through increased knee flexion, potentially mitigating ACL loading despite encountering higher peak forces. During double-leg landings, a greater explosive quadriceps strength of the ACLR limb is associated with faster achievement of peak force upon landing. Incorporating explosive quadriceps strengthening into post-ACLR rehabilitation and injury prevention programmes may enhance landing mechanics for reducing primary and subsequent ACL injury risks. LEVEL OF EVIDENCE: Level II.
Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Fuerza Muscular , Músculo Cuádriceps , Torque , Humanos , Femenino , Músculo Cuádriceps/fisiología , Fenómenos Biomecánicos , Adulto Joven , Fuerza Muscular/fisiología , Lesiones del Ligamento Cruzado Anterior/cirugía , Lesiones del Ligamento Cruzado Anterior/fisiopatología , Adulto , Contracción Isométrica/fisiología , Estudios de Casos y Controles , Articulación de la Rodilla/fisiopatología , Articulación de la Rodilla/fisiologíaRESUMEN
PURPOSE: Previous evidence indicated that the tibiofemoral bone configuration might elevate the risk of an anterior cruciate ligament (ACL) injury. Furthermore, a low hamstring-to-quadriceps muscle ratio predisposes especially females to unfavourable knee kinematics. The primary objective of the present study was to investigate sex-specific associations between tibiofemoral bone geometry and isokinetic knee flexion torque in patients with primary ACL injury followed by ACL reconstruction. METHODS: N = 100 patients (72 = male, 28 = female, age = 31.3 ± 10.2, body mass index = 25.3 ± 3.6) with primary ACL rupture with isokinetic knee flexion torque assessments before and 6 months after ACL reconstruction surgery were analysed. Magnetic resonance imaging scans were analysed for medial posterior tibial slope (MPTS) and lateral posterior tibial slope, notch width index (NWI) and lateral femoral condyle index (LFCI). Additionally, isokinetic knee flexion torque (60°/s) and hamstring-quadriceps ratios were evaluated. Subsequently, functional parameters were correlated with imaging data for gender subgroups. RESULTS: The findings showed that presurgical isokinetic knee flexion torque was not associated with any marker of femoral or tibial bone geometry. Further, while significant differences were observed between female (0.883 ± 0.31 Nm/kg) and male (1.18 ± 0.35 Nm/kg) patients regarding preoperative normalized knee flexion torque (p < 0.001), no significant sex differences were found for percentage increases in normalized knee flexion torque from presurgery to postsurgery. Generally, female patients demonstrated significantly higher MPTS magnitudes (p < 0.05) and lower LFCI values (p < 0.05) compared to men. CONCLUSION: The present results demonstrated no association between tibial or femoral bone geometry and muscle strength of the hamstrings in patients with ACL reconstruction, indicating an important mismatch of muscular compensation to deviations in bone geometry. There were no sex-specific differences in tibiofemoral bone parameters. LEVEL OF EVIDENCE: Level III.
RESUMEN
BACKGROUND: Rotator cuff tears are a common musculoskeletal condition which can lead to functional limitations and impairments in quality of life. The purpose of the present study was to investigate the effects of arthroscopic repair surgery on isokinetic muscle function before and 6-months after surgery. Additionally, the mediating effects of tear type, tear size and tendon retraction were examined. METHODS: Data from n = 67 patients (56 ± 9 years) with full-thickness rotator cuff tears were analyzed. Before and 6-months after surgery, isokinetic muscle function in external/internal rotation and abduction/adduction movements was assessed. Further, tear size, tear type (Collin classification) and tendon retraction (Patte classification) were analyzed using magnetic resonance imaging. RESULTS: After statistical analysis, a significant increase in limb symmetry index of external (P < .001), internal rotation (P < .01), abduction (P < .001), and adduction (P < .001) were observed from preto postsurgery. The results revealed that tear size and tendon tear type significantly mediated the functional outcome, with no significant effect of tendon retraction. CONCLUSION: The present findings point toward the notion that the functional outcome following rotator cuff repair was significantly dependent on tear type and tear size but not tendon retraction. Patients with larger sized tears presented pronounced deficits following 6-months indicating that rehabilitation times need to be adjusted accordingly.
RESUMEN
INTRODUCTION: The levator veli palatini (LVP) muscle has two segments with distinct roles in velopharyngeal function. Previous research suggests longer extravelar segments with shorter intravelar segments may lead to a more advantageous mechanism for velopharyngeal closure. The purpose of this study was to examine whether the distribution of the LVP intravelar and extravelar segments differs between children with cleft palate with and without VPI and controls. METHODS: The study included 97 children: 37 with cleft palate +/- lip with VPI, 37 controls, and 19 with cleft palate with normal resonance. Measures included mean LVP length, mean extravelar LVP length, and intravelar LVP length. RESULTS: Overall mean LVP length was similar (P = .267) between controls and children with cleft palate (with and without VPI). However, there was a significant difference (P < .001) between group for both intravelar and extravelar LVP lengths: the intravelar segment was significantly longer in those with VPI compared to controls and children with cleft palate and normal resonance; and the extravelar segment was significantly shorter in those with VPI compared to controls and children with cleft palate and normal resonance. CONCLUSIONS: Results from this study demonstrate a significant difference between the distribution of the functional segments of the LVP among children with VPI, with a more disadvantageous distribution of the muscle segments among those with VPI.
RESUMEN
Exercise intolerance and dyspnea are the major symptoms of patients with chronic heart failure (CHF) and are associated with a poor quality of life. In addition to impaired central hemodynamics, symptoms may be attributed to changes in peripheral skeletal muscles. This study aimed to evaluate the effects of aerobic interval training (AIT) combined with inspiratory muscle training (IMT) on cardiac and skeletal muscle function and on functional capacity and dyspnea in patients with CHF and inspiratory muscle weakness.Left ventricle ejection fraction was improved significantly after AIT and AIT & IMT with a high percentage of amelioration (17%, P < 0.042) in the combined group compared to the control group. Therefore, we showed a significant improvement in maximal voluntary isometric force, isometric endurance time, root mean square, and frequency median in both strength and endurance manipulations in the aerobic and combined group; however, the improvement was superior in the combined group compared to the control group. Significant amelioration was proved in functional capacity and dyspnea after all types of training but was performed at 18% higher in 6 minutes' walk test and 43% lower in dyspnea for the combined group compared to the control group.Combining AIT to IMT had optimized exercise training benefits in reversing the cardiac remodeling process and improving skeletal muscle function, functional capacity, and dyspnea in patients with CHF.
Asunto(s)
Ejercicios Respiratorios , Insuficiencia Cardíaca , Humanos , Electromiografía , Calidad de Vida , Músculos Respiratorios/fisiología , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/terapia , Enfermedad Crónica , Disnea/etiología , Tolerancia al Ejercicio/fisiologíaRESUMEN
Psychological well-being is essential for the maintenance of good metabolic health. Modern management of most chronic metabolic disorders rightly focusses on improving the health-related quality of life of persons living with disease. In this brief communication we describe the bidirectional association between muscle function and mood (psychological health), explore the various pathways that link these aspects of health, and underscore their clinical implications. This paper emphasizes the importance of maintaining good mental health through exercise and vice a versa.