123 research outputs found
Using Xbox kinect motion capture technology to improve clinical rehabilitation outcomes for balance and cardiovascular health in an individual with chronic TBI
Background Motion capture virtual reality-based rehabilitation has become more common. However, therapists face challenges to the implementation of virtual reality (VR) in clinical settings. Use of motion capture technology such as the Xbox Kinect may provide a useful rehabilitation tool for the treatment of postural instability and cardiovascular deconditioning in individuals with chronic severe traumatic brain injury (TBI). The primary purpose of this study was to evaluate the effects of a Kinect-based VR intervention using commercially available motion capture games on balance outcomes for an individual with chronic TBI. The secondary purpose was to assess the feasibility of this intervention for eliciting cardiovascular adaptations. Methods A single system experimental design (n = 1) was utilized, which included baseline, intervention, and retention phases. Repeated measures were used to evaluate the effects of an 8-week supervised exercise intervention using two Xbox One Kinect games. Balance was characterized using the dynamic gait index (DGI), functional reach test (FRT), and Limits of Stability (LOS) test on the NeuroCom Balance Master. The LOS assesses end-point excursion (EPE), maximal excursion (MXE), and directional control (DCL) during weight-shifting tasks. Cardiovascular and activity measures were characterized by heart rate at the end of exercise (HRe), total gameplay time (TAT), and time spent in a therapeutic heart rate (TTR) during the Kinect intervention. Chi-square and ANOVA testing were used to analyze the data. Results Dynamic balance, characterized by the DGI, increased during the intervention phase χ 2 (1, N = 12) = 12, p = .001. Static balance, characterized by the FRT showed no significant changes. The EPE increased during the intervention phase in the backward direction χ 2 (1, N = 12) = 5.6, p = .02, and notable improvements of DCL were demonstrated in all directions. HRe (F (2,174) = 29.65, p = \u3c .001) and time in a TTR (F (2, 12) = 4.19, p = .04) decreased over the course of the intervention phase. Conclusions Use of a supervised Kinect-based program that incorporated commercial games improved dynamic balance for an individual post severe TBI. Additionally, moderate cardiovascular activity was achieved through motion capture gaming. Further studies appear warranted to determine the potential therapeutic utility of commercial VR games in this patient population. Trial registration Clinicaltrial.gov ID - NCT0288928
Quantitative ultrasound: Measurement considerations for the assessment of muscular dystrophy and sarcopenia
Diagnostic musculoskeletal ultrasound has potential clinical utility in characterizing pathological muscle tissue. Sonography has been long proposed as method of assessing muscle damage due to neuromuscular diseases such as muscular dystrophy, and more recently, changes in body and tissue composition associated with muscle wasting disorders such as sarcopenia. The use of quantitative ultrasound as an adjunct diagnostic procedure has different technical challenges than the traditional use of ultrasound in clinical medicine. Operator-dependent technique and variation are critical considerations when obtaining measures of echointensity (i.e., tissue composition estimates) and tissue dimensions (i.e., muscle thickness) – key elements of the ultrasound assessment of muscular dystrophy and sarcopenia. The use of calibration phantoms and force-feedback augmented ultrasound may be viable methods of providing operator training and augmenting real-time ultrasound measurement consistency. The standardization of specific assessment techniques, and the development of a means to foster measurement reliability in clinical environments, may increase the utilization of this non-invasive, low-risk, and inexpensive imaging modality in the management of muscle disorders
Rate of Force Development Is Related to Maximal Force and Sit-to-Stand Performance in Men With Stages 3b and 4 Chronic Kidney Disease
Introduction: The primary aims of the present study were to assess the relationships of early (0–50 ms) and late (100–200 ms) knee extensor rate of force development (RFD) with maximal voluntary force (MVF) and sit-to-stand (STS) performance in participants with chronic kidney disease (CKD) not requiring dialysis.Methods: Thirteen men with CKD (eGFR = 35.17 ±.5 ml/min per 1.73 m2, age = 70.56 ±.4 years) and 12 non-CKD men (REF) (eGFR = 80.31 ± 4.8 ml/min per 1.73 m2, age = 70.22 ±.9 years) performed maximal voluntary isometric contractions to determine MVF and RFD of the knee extensors. RFD was measured at time intervals 0–50 ms (RFD0−50) and 100–200 ms (RFD100−200). STS was measured as the time to complete five repetitions. Measures of rectus femoris grayscale (RF GSL) and muscle thickness (RF MT) were obtained via ultrasonography in the CKD group only. Standardized mean differences (SMD) were used to examine differences between groups. Bivariate relationships were assessed by Pearson's product moment correlation.Results: Knee extensor MVF adjusted for body weight (CKD=17.14 ±.1 N·kg0.67, REF=21.55 ±.3 N·kg0.67, SMD = 0.79) and STS time (CKD = 15.93 ±.4 s, REF = 12.23 ±.7 s, SMD = 1.03) were lower in the CKD group than the REF group. Absolute RFD100−200 was significantly directly related to adjusted MVF in CKD (r = 0.56, p = 0.049) and REF (r = 0.70, p = 0.012), respectively. STS time was significantly inversely related to absolute (r = −0.75, p = 0.008) and relative RFD0−50 (r = −0.65, p = 0.030) in CKD but not REF (r = 0.08, p = 0.797; r = 0.004, p = 0.991). Significant inverse relationships between RF GSL adjusted for adipose tissue thickness and absolute RFD100−200 (r =−0.59, p = 0.042) in CKD were observed.Conclusion: The results of the current study highlight the declines in strength and physical function that occur in older men with CKD stages 3b and 4 not requiring dialysis. Moreover, early RFD was associated with STS time in CKD while late RFD was associated MVF in both CKD and REF.Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT03160326 and NCT02277236
Temporal Changes in Cortical and Hippocampal Expression of Genes Important for Brain Glucose Metabolism Following Controlled Cortical Impact Injury in Mice
Traumatic brain injury (TBI) causes transient increases and subsequent decreases in brain glucose utilization. The underlying molecular pathways are orchestrated processes and poorly understood. In the current study, we determined temporal changes in cortical and hippocampal expression of genes important for brain glucose/lactate metabolism and the effect of a known neuroprotective drug telmisartan on the expression of these genes after experimental TBI. Adult male C57BL/6J mice (n = 6/group) underwent sham or unilateral controlled cortical impact (CCI) injury. Their ipsilateral and contralateral cortex and hippocampus were collected 6 h, 1, 3, 7, 14, 21, and 28 days after injury. Expressions of several genes important for brain glucose utilization were determined by qRT-PCR. In results, (1) mRNA levels of three key enzymes in glucose metabolism [hexo kinase (HK) 1, pyruvate kinase, and pyruvate dehydrogenase (PDH)] were all increased 6 h after injury in the contralateral cortex, followed by decreases at subsequent times in the ipsilateral cortex and hippocampus; (2) capillary glucose transporter Glut-1 mRNA increased, while neuronal glucose transporter Glut-3 mRNA decreased, at various times in the ipsilateral cortex and hippocampus; (3) astrocyte lactate transporter MCT-1 mRNA increased, whereas neuronal lactate transporter MCT-2 mRNA decreased in the ipsilateral cortex and hippocampus; (4) HK2 (an isoform of hexokinase) expression increased at all time points in the ipsilateral cortex and hippocampus. GPR81 (lactate receptor) mRNA increased at various time points in the ipsilateral cortex and hippocampus. These temporal alterations in gene expression corresponded closely to the patterns of impaired brain glucose utilization reported in both TBI patients and experimental TBI rodents. The observed changes in hippocampal gene expression were delayed and prolonged, when compared with those in the cortex. The patterns of alterations were specific to different brain regions and exhibited different recovery periods following TBI. Oral administration of telmisartan (1 mg/kg, for 7 days, n = 10 per group) ameliorated cortical or hippocampal mRNA for Glut-1/3, MCT-1/2 and PDH in CCI mice. These data provide molecular evidence for dynamic alteration of multiple critical factors in brain glucose metabolism post-TBI and can inform further research for treating brain metabolic disorders post-TBI
Use of the Adult Myopathy Assessment Tool as a predictor of functional abilities in people with multiple sclerosis
Background: People with multiple sclerosis (PwMS) are at greater risk for decreased muscle performance which may lead to decreased functional abilities. The Kurtzke Expanded Disability Status Scale (EDSS) is commonly used as a disability status rating scale in PwMS. Nevertheless, the EDSS is largely comprised of neurological tests and may not best reflect functional performance. A functional battery such as The Adult Myopathy Assessment Tool (AMAT) may better reflect functional performance. The AMAT was designed to assess both functional strength and endurance in clinical settings. However, the AMAT has not been validated for the assessment of PwMS.
Objective: The purpose of the study was to determine the comparative association of the AMAT and EDSS with measures of strength, fatigability, and functional performance. Methods: Twenty-nine people (mean age 48.6 ±11.2), with a history of MS (EDSS \u3c 7.0) were recruited. Participants completed functional testing (5 times sit to stand and gait speed) and an assessment of disability and functional status using the EDSS and AMAT, respectively. Muscle performance was assessed via a 60 s maximal volitional isometric contraction (MVIC) of the knee extensors using an isokinetic dynamometer, and expressed as fatigability (exhaustion time to 60% of MVIC), peak torque, and peak torque scaled to body weight.
Results:The participants exhibited moderate levels of disability (EDSS, 3.6 ±1.4) and function (AMAT total score, 36.1 ±7.6; AMAT function subscale, 18.2 ±3.3). Peak force was 70.1 kg ±22.0 kg, exhaustion time was 38.4 s ±17.4 s, gait speed was 1.3 m/s ±0.3 m/s, and five time sit to stand was 11.4 s ±4.1 s. The AMAT function subscale was associated with scaled peak torque (r=0.426, p=.021), gait speed (r=0.825, p=0.00), and 5 time sit to stand (r=-0.632, p
Conclusions: The AMAT was more strongly associated with scaled peak torque and functional measures in comparison to the EDSS. This may reflect the observation that relative strength is a better predictor of functional abilities than unadjusted strength measures. Whereas, the stronger association of the EDSS with fatigability may be explained by the pyramidal systems measures within the tool and the well-known association of MS-related fatigue with disability. Based on the results of the study, we suggest clinicians administer the AMAT in addition to the EDSS, to gain insight into functional impairments and assist with formulating a comprehensive plan of care
Diagnostic ultrasound estimates of muscle mass and muscle quality discriminate between women with and without sarcopenia
Introduction: Age-related changes in muscle mass and muscle tissue composition contribute to diminished strength in older adults. The objectives of this study are to examine if an assessment method using mobile diagnostic ultrasound augments well-known determinants of lean body mass (LBM) to aid sarcopenia staging, and if a sonographic measure of muscle quality is associated with muscle performance.Methods: Twenty community-dwelling female subjects participated in the study (age = 43.4 ±20.9 years; BMI: 23.8, interquartile range: 8.5). Dual energy X-ray absorptiometry (DXA) and diagnostic ultrasound morphometry were used to estimate LBM. Muscle tissue quality was estimated via the echogenicity using grayscale histogram analysis. Peak force was measured with grip dynamometry and scaled for body size. Bivariate and multiple regression analyses were used to determine the association of the predictor variables with appendicular lean mass (aLM/ht2), and examine the relationship between scaled peak force values and muscle echogenicity. The sarcopenia LBM cut point value of 6.75 kg/m2 determined participant assignment into the Normal LBM and Low LBM subgroups.Results: The selected LBM predictor variables were body mass index (BMI), ultrasound morphometry, and age. Although BMI exhibited a significant positive relationship with aLM/ht2 (adj. R2 = .61, p \u3c .001), the strength of association improved with the addition of ultrasound morphometry and age as predictor variables (adj. R2 = .85, p \u3c .001). Scaled peak force was associated with age and echogenicity (adj. R2 = .53, p \u3c .001), but not LBM. The Low LBM subgroup of women (n = 10) had higher scaled peak force, lower BMI, and lower echogenicity values in comparison to the Normal LBM subgroup (n = 10; p \u3c .05).Conclusions: Diagnostic ultrasound morphometry values are associated with LBM, and improve the BMI predictive model for aLM/ht2 in women. In addition, ultrasound proxy measures of muscle quality are more strongly associated with strength than muscle mass within the study sample
Diagnostic ultrasound estimates of muscle mass and muscle quality discriminate between women with and without sarcopenia
Introduction: Age-related changes in muscle mass and muscle tissue composition contribute to diminished strength in older adults. The objectives of this study are to examine if an assessment method using mobile diagnostic ultrasound augments well-known determinants of lean body mass (LBM) to aid sarcopenia staging, and if a sonographic measure of muscle quality is associated with muscle performance.Methods: Twenty community-dwelling female subjects participated in the study (age = 43.4 ±20.9 years; BMI: 23.8, interquartile range: 8.5). Dual energy X-ray absorptiometry (DXA) and diagnostic ultrasound morphometry were used to estimate LBM. Muscle tissue quality was estimated via the echogenicity using grayscale histogram analysis. Peak force was measured with grip dynamometry and scaled for body size. Bivariate and multiple regression analyses were used to determine the association of the predictor variables with appendicular lean mass (aLM/ht2), and examine the relationship between scaled peak force values and muscle echogenicity. The sarcopenia LBM cut point value of 6.75 kg/m2 determined participant assignment into the Normal LBM and Low LBM subgroups.Results: The selected LBM predictor variables were body mass index (BMI), ultrasound morphometry, and age. Although BMI exhibited a significant positive relationship with aLM/ht2 (adj. R2 = .61, p \u3c .001), the strength of association improved with the addition of ultrasound morphometry and age as predictor variables (adj. R2 = .85, p \u3c .001). Scaled peak force was associated with age and echogenicity (adj. R2 = .53, p \u3c .001), but not LBM. The Low LBM subgroup of women (n = 10) had higher scaled peak force, lower BMI, and lower echogenicity values in comparison to the Normal LBM subgroup (n = 10; p \u3c .05).Conclusions: Diagnostic ultrasound morphometry values are associated with LBM, and improve the BMI predictive model for aLM/ht2 in women. In addition, ultrasound proxy measures of muscle quality are more strongly associated with strength than muscle mass within the study sample
Interrater reliability of quantitative ultrasound using force feedback among examiners with varied levels of experience
Background. Quantitative ultrasound measures are influenced by multiple external factors including examiner scanning force. Force feedback may foster the acquisition of reliable morphometry measures under a variety of scanning conditions. The purpose of this study was to determine the reliability of force-feedback image acquisition and morphometry over a range of examiner-generated forces using a muscle tissuemimicking ultrasound phantom.
Methods. Sixty material thickness measures were acquired from a muscle tissue mimicking phantom using B-mode ultrasound scanning by six examiners with varied experience levels (i.e., experienced, intermediate, and novice). Estimates of interrater reliability and measurement error with force feedback scanning were determined for the examiners. In addition, criterion-based reliability was determined using material deformation values across a range of examiner scanning forces (1–10 Newtons) via automated and manually acquired image capture methods using force feedback.
Results. All examiners demonstrated acceptable interrater reliability (intraclass correlation coefficient, ICC = .98, p \u3c .001) for material thickness measures obtained using force feedback. Individual examiners exhibited acceptable reliability with the criterion-based reference measures (ICC \u3e .90, p \u3c .001), independent of their level of experience. The measurement error among all examiners was 1.5%–2.9% across all applied stress conditions.
Conclusion. Manual image capture with force feedback may aid the reliability of morphometry measures across a range of examiner scanning forces, and allow for consistent performance among examiners with differing levels of experience
Diurnal secretion of growth hormone, cortisol, and dehydroepiandrosterone in pre- and perimenopausal women with active rheumatoid arthritis: a pilot case-control study
Rheumatoid arthritis (RA) is associated with neuroendocrine and immunologic dysfunction leading to rheumatoid cachexia. Although excess proinflammatory cytokines can decrease somatotropic axis activity, little is known about the effects of RA on growth hormone/insulin-like growth factor-1 (GH/IGF-I) axis function. We tested the hypothesis that patients with active RA exhibit decreased GH/IGF-I axis activity. To do so, we conducted a pilot case-control study at a clinical research center in 7 pre- and perimenopausal women with active RA and 10 age- and body mass index-matched healthy women. Participants underwent blood sampling every 20 minutes for 24 hours (8 a.m. to 8 a.m.), and sera were assayed for GH, cortisol, and dehydroepiandrosterone (DHEA). Sera obtained after overnight fasting were assayed for IGF-I, IGF-binding protein (IGFBP)-1, IGFBP-3, C-reactive protein (CRP), interleukin-6 (IL-6), glucose, insulin, and lipids. Body composition and bone mineral density were evaluated by DEXA (dual emission x-ray absorptiometry) scans. In patients with RA, mean disease duration was 7.6 ± 6.8 years, and erythrocyte sedimentation rate, CRP, and IL-6 were elevated. GH half-life was shorter than in control subjects (p = 0.0037), with no other significant group differences in GH deconvolution parameters or approximate entropy scores. IGF-I (p = 0.05) and IGFBP-3 (p = 0.058) were lower, whereas IGFBP-1 tended to be higher (p = 0.066), in patients with RA, with nonsignificantly increased 24-hour total GH production rates. There were no significant group differences in cortisol or DHEA secretion. Lean body mass was lower in patients with RA (p = 0.019), particularly in the legs (p = 0.01). Women with active RA exhibit a trend toward GH insensitivity and relatively diminished diurnal cortisol and DHEA secretion for their state of inflammation. Whether these changes contribute to rheumatoid cachexia remains to be determined
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