188 research outputs found

    Lunar and mars gravity induce similar changes in spinal motor control as microgravity

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    Introduction: Once more, plans are underway to send humans to the Moon or possibly even to Mars. It is therefore, important to know potential physiological effects of a prolonged stay in space and to minimize possible health risks to astronauts. It has been shown that spinal motor control strategies change during microgravity induced by parabolic flight. The way in which spinal motor control strategies change during partial microgravity, such as that encountered on the Moon and on Mars, is not known. Methods: Spinal motor control measurements were performed during Earth, lunar, Mars, and micro-gravity conditions and two hypergravity conditions of a parabola. Three proxy measures of spinal motor control were recorded: spinal stiffness of lumbar L3 vertebra using the impulse response, muscle activity of lumbar flexors and extensors using surface electromyography, and lumbar curvature using two curvature distance sensors placed at the upper and lower lumbar spine. The participants were six females and six males, with a mean age of 33 years (standard deviation: 7 years). Results: Gravity condition had a statistically significant (Friedmann tests) effect spinal stiffness (p < 0.001); on EMG measures (multifidus (p = 0.047), transversus abdominis (p < 0.001), and psoas (p < 0.001) muscles) and on upper lumbar curvature sensor (p < 0.001). No effect was found on the erector spinae muscle (p = 0.063) or lower curvature sensor (p = 0.170). Post hoc tests revealed a significant increase in stiffness under micro-, lunar-, and Martian gravity conditions (all p's < 0.034). Spinal stiffness decreased under both hypergravity conditions (all p's ≤ 0.012) and decreased during the second hypergravity compared to the first hypergravity condition (p = 0.012). Discussion: Micro-, lunar-, and Martian gravity conditions resulted in similar increases in spinal stiffness, a decrease in transversus abdominis muscle activity, with no change in psoas muscle activity and thus modulation of spinal motor stabilization strategy compared to those observed under Earth's gravity. These findings suggest that the spine is highly sensitive to gravity transitions but that Lunar and Martian gravity are below that required for normal modulation of spinal motor stabilization strategy and thus may be associated with LBP and/or IVD risk without the definition of countermeasures

    Mediolateral Damping of an Overhead Body Weight Support System Assists Stability During Treadmill Walking

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    Background Body weight support systems with three or more degrees of freedom (3-DoF) are permissive and safe environments that provide unloading and allow unrestricted movement in any direction. This enables training of walking and balance control at an early stage in rehabilitation. Transparent systems generate a support force vector that is near vertical at all positions in the workspace to only minimally interfere with natural movement patterns. Patients with impaired balance, however, may benefit from additional mediolateral support that can be adjusted according to their capacity. An elegant solution for providing balance support might be by rendering viscous damping along the mediolateral axis via the software controller. Before use with patients, we evaluated if control-rendered mediolateral damping evokes the desired stability enhancement in able-bodied individuals. Methods A transparent, cable-driven robotic body weight support system (FLOAT) was used to provide transparent body weight support with and without mediolateral damping to 21 able-bodied volunteers while walking at preferred gait velocity on a treadmill. Stability metrics reflecting resistance to small and large perturbations were derived from walking kinematics and compared between conditions and to free walking. Results Compared to free walking, the application of body weight support per-se resulted in gait alterations typically associated with body weight support, namely increased step length and swing phase. Frontal plane dynamic stability, measured by kinematic variability and nonlinear dynamics of the center of mass, was increased under body weight support, indicating reduced balance requirements in both damped and undamped support conditions. Adding damping to the body weight support resulted in a greater increase of frontal plane stability. Conclusion Adding mediolateral damping to 3-DoF body weight support systems is an effective method of increasing frontal plane stability during walking in able-bodied participants. Building on these results, adjustable mediolateral damping could enable therapists to select combinations of unloading and stability specifically for each patient and to adapt this in a task specific manner. This could extend the impact of transparent 3-DoF body weight support systems, enabling training of gait and active balance from an early time point onwards in the rehabilitation process for a wide range of mobility activities of daily life

    Intramuscular coherence during challenging walking in incomplete spinal cord injury: Reduced high-frequency coherence reflects impaired supra-spinal control

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    Individuals regaining reliable day-to-day walking function after incomplete spinal cord injury (iSCI) report persisting unsteadiness when confronted with walking challenges. However, quantifiable measures of walking capacity lack the sensitivity to reveal underlying impairments of supra-spinal locomotor control. This study investigates the relationship between intramuscular coherence and corticospinal dynamic balance control during a visually guided Target walking treadmill task. In thirteen individuals with iSCI and 24 controls, intramuscular coherence and cumulant densities were estimated from pairs of Tibialis anterior surface EMG recordings during normal treadmill walking and a Target walking task. The approximate center of mass was calculated from pelvis markers. Spearman rank correlations were performed to evaluate the relationship between intramuscular coherence, clinical parameters, and center of mass parameters. In controls, we found that the Target walking task results in increased high-frequency (21-44 Hz) intramuscular coherence, which negatively related to changes in the center of mass movement, whereas this modulation was largely reduced in individuals with iSCI. The impaired modulation of high-frequency intramuscular coherence during the Target walking task correlated with neurophysiological and functional readouts, such as motor-evoked potential amplitude and outdoor mobility score, as well as center of mass trajectory length. The Target walking effect, the difference between Target and Normal walking intramuscular coherence, was significantly higher in controls than in individuals with iSCI [F(1.0,35.0) = 13.042, p < 0.001]. Intramuscular coherence obtained during challenging walking in individuals with iSCI may provide information on corticospinal gait control. The relationships between biomechanics, clinical scores, and neurophysiology suggest that intramuscular coherence assessed during challenging tasks may be meaningful for understanding impaired supra-spinal control in individuals with iSCI

    Incommensurable worldviews? Is public use of complementary and alternative medicines incompatible with support for science and conventional medicine?

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    Proponents of controversial Complementary and Alternative Medicines, such as homeopathy, argue that these treatments can be used with great effect in addition to, and sometimes instead of, ?conventional? medicine. In doing so, they accept the idea that the scientific approach to the evaluation of treatment does not undermine use of and support for some of the more controversial CAM treatments. For those adhering to the scientific canon, however, such efficacy claims lack the requisite evidential basis from randomised controlled trials. It is not clear, however, whether such opposition characterises the views of the general public. In this paper we use data from the 2009 Wellcome Monitor survey to investigate public use of and beliefs about the efficacy of a prominent and controversial CAM within the United Kingdom, homeopathy. We proceed by using Latent Class Analysis to assess whether it is possible to identify a sub-group of the population who are at ease in combining support for science and conventional medicine with use of CAM treatments, and belief in the efficacy of homeopathy. Our results suggest that over 40% of the British public maintain positive evaluations of both homeopathy and conventional medicine simultaneously. Explanatory analyses reveal that simultaneous support for a controversial CAM treatment and conventional medicine is, in part, explained by a lack of scientific knowledge as well as concerns about the regulation of medical research

    Mind your step : Target walking task reveals gait disturbance in individuals with incomplete spinal cord injury

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    BACKGROUND: Walking over obstacles requires precise foot placement while maintaining balance control of the center of mass (CoM) and the flexibility to adapt the gait patterns. Most individuals with incomplete spinal cord injury (iSCI) are capable of overground walking on level ground; however, gait stability and adaptation may be compromised. CoM control was investigated during a challenging target walking (TW) task in individuals with iSCI compared to healthy controls. The hypothesis was that individuals with iSCI, when challenged with TW, show a lack of gait pattern adaptability which is reflected by an impaired adaptation of CoM movement compared to healthy controls. METHODS: A single-center controlled diagnostic clinical trial with thirteen participants with iSCI (0.3-24 years post injury; one subacute and twelve chronic) and twelve healthy controls was conducted where foot and pelvis kinematics were acquired during two conditions: normal treadmill walking (NW) and visually guided target walking (TW) with handrail support, during which participants stepped onto projected virtual targets synchronized with the moving treadmill surface. Approximated CoM was calculated from pelvis markers and used to calculate CoM trajectory length and mean CoM Euclidean distance TW-NW (primary outcome). Nonparametric statistics, including spearman rank correlations, were performed to evaluate the relationship between clinical parameter, outdoor mobility score, performance, and CoM parameters (secondary outcome). RESULTS: Healthy controls adapted to TW by decreasing anterior-posterior and vertical CoM trajectory length (p < 0.001), whereas participants with iSCI reduced CoM trajectory length only in the vertical direction (p = 0.002). Mean CoM Euclidean distance TW-NW correlated with participants' neurological level of injury (R = 0.76, p = 0.002) and CoM trajectory length (during TW) correlated with outdoor mobility score (R = - 0.64, p = 0.026). CONCLUSIONS: This study demonstrated that reduction of CoM movement is a common strategy to cope with TW challenge in controls, but it is impaired in individuals with iSCI. In the iSCI group, the ability to cope with gait challenges worsened the more rostral the level of injury. Thus, the TW task could be used as a gait challenge paradigm in ambulatory iSCI individuals. Trial registration Registry number/ ClinicalTrials.gov Identifier: NCT03343132, date of registration 2017/11/17

    Young migrants’ narratives of collective identifications and belonging

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    The article sheds light on the intricate relationship between migration, ‘identity’ and belonging by focusing on young migrants in the context of Greek society. Based upon a qualitative study of youth identities, the key objective is to examine their collective identifications, formed through the dialectic of self-identification and categorization. The analysis of young migrants’ narratives unpacks how their sense of belonging and emotional attachments to their countries of origin and settlement are mediated by processes of racialization and ‘othering’

    Managing and monitoring equality and diversity in UK sport: An evaluation of the sporting equals Racial Equality Standard and its impact on organizational change

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    Despite greater attention to racial equality in sport in recent years, the progress of national sports organizations toward creating equality of outcomes has been limited in the United Kingdom. The collaboration of the national sports agencies, equity organizations and national sports organizations (including national governing bodies of sport) has focused on Equality Standards. The authors revisit an earlier impact study of the Racial Equality Standard in sport and supplement it with another round of interview material to assess changing strategies to manage diversity in British sport. In particular, it tracks the impact on organizational commitment to diversity through the period of the establishment of the Racial Equality Standard and its replacement by an Equality Standard that deals with other diversity issues alongside race and ethnicity. As a result, the authors question whether the new, generic Equality Standard is capable of addressing racial diversity and promoting equality of outcomes. © 2006 Sage Publications

    Acupuncture, chiropractic and osteopathy use in Australia: a national population survey

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    Background There have been no published national studies on the use in Australia of the manipulative therapies, acupuncture, chiropractic or osteopathy, or on matters including the purposes for which these therapies are used, treatment outcomes and the socio-demographic characteristics of users. Methods This study on the three manipulative therapies was a component of a broader investigation on the use of complementary and alternative therapies. For this we conducted a cross-sectional, population survey on a representative sample of 1,067 adults from the six states and two territories of Australia in 2005 by computer-assisted telephone interviews. The sample was recruited by random digit dialling. Results Over a 12-month period, approximately one in four adult Australians used either acupuncture (9.2%), chiropractic (16.1%) or osteopathy (4.6%) at least once. It is estimated that, adult Australians made 32.3 million visits to acupuncturists, chiropractors and osteopaths, incurring personal expenditure estimated to be A$1.58 billion in total. The most common conditions treated were back pain and related problems and over 90% of the users of each therapy considered their treatment to be very or somewhat helpful. Adverse events are reported. Nearly one fifth of users were referred to manipulative therapy practitioners by medical practitioners. Conclusion There is substantial use of manipulative therapies by adult Australians, especially for back-related problems. Treatments incur considerable personal expenditure. In general, patient experience is positive. Referral by medical practitioners is a major determinant of use of these manipulative therapies

    Constructing the assertive teacher

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    This paper describes an in-service MA course for teachers which focuses directly on their own developing professional practice in school. It is shown how after capturing, in their personal writing, incidents arising within their work, teachers on the course re-describe these incidents with an emphasis on asserting the actions they might take in respect of them
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