88 research outputs found

    Muscle-Tendon Unit Function During Continuous And Maximal Hopping

    Get PDF
    The purpose of the current study was to determine the amount of power contributed by the triceps surae muscle complex and Achilles tendon individually during low-force, continuous hopping in comparison to a maximal hop to determine the amount of power restored to the system by the tendon via stored strain energy. Five male subjects were fitted with an ultrasound probe on the triceps surae muscle complex of their right leg for muscle fascicle imaging. Three-dimensional motion analysis was performed by using the VICON motion analysis system. Participants were placed on a customized sled at a ten-degree angle with all work isolated to the right ankle joint and asked to complete a maximal counter-movement hop followed by submaximal continuous hopping where data were collected after five minutes. The muscle-tendon unit (MTU) and tendon were both found to have significantly different negative and net power (p<0.05) between hops where net power was found to be significantly lower during the continuous hop. The results suggest that subjects used active muscle contractility during both the continuous and maximal hops however, energy restoration was not from stored elastic energy of the tendon as hypothesized and was restored by the muscles during the continuous hop

    Coping, Pain Severity, Interference, and Disability: The Potential Mediating and Moderating Roles of Race and Education

    Get PDF
    Researchers have demonstrated that certain types of pain coping are correlated with less pain severity and disability and that there are differences between Caucasians and African-American pain patients in their use of specific coping strategies. However, the extent to which racial group differences exist in the associations between pain coping strategies and pain severity, interference, and disability is unclear. Furthermore, the role of education in these associations is uncertain. We recruited a diverse community sample of individuals with chronic pain and their spouses to examine this issue (N =105). Participants completed the Coping Strategies Questionnaire, Multidimensional Pain Inventory, and Sickness Impact Profile. Results showed that African-American participants reported significantly more pain severity, interference, and disability and reported using diverting attention and prayer and hoping pain-coping strategies significantly more often than Caucasian participants; however, only the racial group difference in prayer and hoping remained when controlling for education. We also examined whether race and education interacted with coping strategies in relating to pain and disability. Significant three-way interactions were found for physical and psychosocial disability, suggesting that educational level should be included in analyses exploring racial group differences. The results suggest the need for pain treatments that take into account the educational and cultural context of pain

    Effect of IMU location on estimation of vertical ground reaction force during jumping

    Get PDF
    Introduction: Several investigations have examined utilizing inertial measurement units (IMU) to estimate ground reaction force (GRF) during exercise. The purpose of this investigation was to determine the effect of inertial measurement units location on the estimation of ground reaction force during vertical jumping.Methods: Eight male subjects completed a series of ten countermovement jumps on a force plate (FP). The subjects had an inertial measurement units attached to the sacrum, back and chest. Ground reaction force was estimated from data from the individual inertial measurement units and by using a two-segment model and combined sensor approach.Results: The peak ground reaction force values for the sacrum, back, chest and combined inertial measurement units were 1,792 ± 278 N, 1,850 ± 341 N, 2,054 ± 346 N and 1,812 ± 323 N, respectively. The sacral inertial measurement units achieved the smallest differences for ground reaction force estimates providing a root mean square error (RMSE) between 88 N and 360 N. The inertial measurement units on the sacrum also showed significant correlations in peak ground reaction force (p < 0.001) and average ground reaction force (p < 0.001) using the Bland-Altman 95% Limits of Agreement (LOA) when in comparison to the force plate.Discussion: Based on assessment of bias, Limits of Agreement, and RMSE, the inertial measurement units located on the sacrum appears to be the best placement to estimate both peak and average ground reaction force during jumping

    Microvascular changes in renal allografts associated with FK506 (Tacrolimus) therapy

    Get PDF
    FK506 (Tacrolimus) recently has been shown to be an effective immunosuppressant after renal transplantation. It is associated with less hypertension, hypercholesterolemia and steroid use compared with cyclosporine. We report 10 patients on FK506 who showed fibrin thrombi within the glomerular capillaries and/or arterioles at renal allograft biopsy. These biopsies were generally performed to assess increasing serum creatinine levels; laboratory evidence of hemolytic uremic syndrome was present in one instance. Plasma or whole blood FK506 levels were elevated in eight of 10 cases. Reduction of immunosuppression led to clinical improvement or biopsy- proven resolution of thrombi in all cases. These observations suggest that FK506 may occasionally produce microvascular changes in the renal allograft. The estimated incidence of this occurrence (1%) is comparable with that reported with cyclosporine (3%)

    Individuals with chronic low back pain have greater difficulty in engaging in positive lifestyle behaviours than those without back pain: An assessment of health literacy

    Get PDF
    Background: Despite the large volume of research dedicated to understanding chronic low back pain (CLBP), patient outcomes remain modest while healthcare costs continue to rise, creating a major public health burden. Health literacy - the ability to seek, understand and utilise health information - has been identified as an important factor in the course of other chronic conditions and may be important in the aetiology of CLBP. Many of the currently available health literacy measurement tools are limited since they measure narrow aspects of health literacy. The Health Literacy Measurement Scale (HeLMS) was developed recently to measure broader elements of health literacy. The aim of this study was to measure broad elements of health literacy among individuals with CLBP and without LBP using the HeLMS.Methods: Thirty-six community-dwelling adults with CLBP and 44 with no history of LBP responded to the HeLMS. Individuals were recruited as part of a larger community-based spinal health study in Western Australia. Scores for the eight domains of the HeLMS as well as individual item responses were compared between the groups.Results: HeLMS scores were similar between individuals with and without CLBP for seven of the eight health literacy domains (p &gt; 0.05). However, compared to individuals with no history of LBP, those with CLBP had a significantly lower score in the domain &lsquo;Patient attitudes towards their health&rsquo; (mean difference [95% CI]: 0.46 [0.11- 0.82]) and significantly lower scores for each of the individual items within this domain (p &lt; 0.05). Moderate effect sizes ranged from d = 0.47-0.65.Conclusions: Although no differences were identified in HeLMS scores between the groups for seven of the health literacy domains, adults with CLBP reported greater difficulty in engaging in general positive health behaviours. This aspect of health literacy suggests that self-management support initiatives may benefit individuals with CLBP.<br /

    Persistent Deficits in Heart Rate Response Habituation Following Neonatal Binge Ethanol Exposure

    Get PDF
    Background: We have previously shown that the rate of habituation of the heart rate orienting response to a novel odor in rats is negatively affected by neonatal ethanol exposure. Thus far, however, only young rats (16 days of age) have been tested. Given the persistence of attention and memory problems evident in humans exposed to ethanol in utero, the purpose of this experiment was to examine the longer-term consequences of ethanol exposure on response habituation. Methods: Ethanol (5.25 g/kg/d) was administered intragastrically to male and female Sprague-Dawley rats on postnatal days (PD) 4 to 9, and controls were given sham intubations. Animals were tested for heart rate orienting and response habituation to a novel olfactory stimulus (amyl acetate) on PD 16, 23, or 30. Results: Animals tested on PD 16 or 23 showed normal heart rate deceleration to the novel odor, a measure of the orienting response. However, ethanol-treated subjects showed impaired response habituation compared with sham controls. While controls exhibited complete habituation within 4 to 5 trials, ethanol-treated animals continued to respond throughout the testing session, with little decrement in heart rate response magnitude across 10 stimulus presentations. A different pattern of responding was observed in animals tested during adolescence (PD 30). Control animals failed to show the typical heart rate decrease indicative of orienting, and instead showed a tendency toward tachycardia. In contrast, ethanol-treated animals tested on PD 30 showed orienting bradycardia that persisted for several trials. Conclusions: These data suggest that there are relatively long-term consequences of neonatal ethanol exposure on nonassociative memory. This impairment in habituation may be relevant to the distractibility and poor focused attention that is pervasive among humans diagnosed with fetal alcohol spectrum disorders

    Patient engagement in designing, conducting, and disseminating clinical pain research : IMMPACT recommended considerations

    Get PDF
    The consensus recommendations are based on the views of IMMPACT meeting participants and do not necessarily represent the views of the organizations with which the authors are affiliated. The following individuals made important contributions to the IMMPACT meeting but were not able to participate in the preparation of this article: David Atkins, MD (Department of Veterans Affairs), Rebecca Baker, PhD (National Institutes of Health), Allan Basbaum, PhD (University of California San Francisco), Robyn Bent, RN, MS (Food and Drug Administration), Nathalie Bere, MPH (European Medicines Agency), Alysha Croker, PhD (Health Canada), Stephen Bruehl, PhD (Vanderbilt University), Michael Cobas Meyer, MD, MBS (Eli Lilly), Scott Evans, PhD (George Washington University), Gail Graham (University of Maryland), Jennifer Haythornthwaite, PhD (Johns Hopkins University), Sharon Hertz, MD (Hertz and Fields Consulting), Jonathan Jackson, PhD (Harvard Medical School), Mark Jensen, PhD (University of Washington), Francis Keefe, PhD (Duke University), Karim Khan, MD, PhD, MBA (Canadian Institutes of Health Research), Lynn Laidlaw (University of Aberdeen), Steven Lane (Patient-Centered Outcomes Research Institute), Karen Morales, BS (University of Maryland), David Leventhal, MBA (Pfizer), Jeremy Taylor, OBE (National Institute for Health Research), and Lena Sun, MD (Columbia University). The manuscript has not been submitted, presented, or published elsewhere. Parts of the manuscript have been presented in a topical workshop at IASP World Congress on Pain in Toronto, in 2022.Peer reviewedPublisher PD

    Spontaneous Prediction Error Generation in Schizophrenia

    Get PDF
    Goal-directed human behavior is enabled by hierarchically-organized neural systems that process executive commands associated with higher brain areas in response to sensory and motor signals from lower brain areas. Psychiatric diseases and psychotic conditions are postulated to involve disturbances in these hierarchical network interactions, but the mechanism for how aberrant disease signals are generated in networks, and a systems-level framework linking disease signals to specific psychiatric symptoms remains undetermined. In this study, we show that neural networks containing schizophrenia-like deficits can spontaneously generate uncompensated error signals with properties that explain psychiatric disease symptoms, including fictive perception, altered sense of self, and unpredictable behavior. To distinguish dysfunction at the behavioral versus network level, we monitored the interactive behavior of a humanoid robot driven by the network. Mild perturbations in network connectivity resulted in the spontaneous appearance of uncompensated prediction errors and altered interactions within the network without external changes in behavior, correlating to the fictive sensations and agency experienced by episodic disease patients. In contrast, more severe deficits resulted in unstable network dynamics resulting in overt changes in behavior similar to those observed in chronic disease patients. These findings demonstrate that prediction error disequilibrium may represent an intrinsic property of schizophrenic brain networks reporting the severity and variability of disease symptoms. Moreover, these results support a systems-level model for psychiatric disease that features the spontaneous generation of maladaptive signals in hierarchical neural networks
    corecore