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  • Evolutionary Basis of Human Running and Its Impact on Neural Function

    http://journal.frontiersin.org/artic...016.00059/full

    Running is not unique to humans, but it is seemingly a basic human capacity. This article addresses the evolutionary origins of humans running long distances, the basic physical capability of running, and the neurogenesis of aerobic fitness. This article more specifically speaks to the conditions that set the stage for the act of running, and then looks at brain expression, and longer-term consequences of running within a context of specific morphological features and diverse information molecules that participate in our capacity for running and sport. While causal factors are not known, we do know that physiological factors are involved in running and underlie neural function. Multiple themes about running are discussed in this article, including neurogenesis, neural plasticity, and memory enhancement. Aerobic exercise increases anterior hippocampus size. This expansion is linked to the improvement of memory, which reflects the improvement of learning as a function of running activity in animal studies. Higher fitness is associated with greater expansion, not only of the hippocampus, but of several other brain regions.


    "The Robust Running Ape: Unravelling the deep underpinnings of coordinated human running proficiency"

    http://journal.frontiersin.org/artic...00892/abstract

    In comparison to other mammals, humans are not especially strong, swift or supple. Nevertheless, despite these apparent physical limitations, we are among Natures most superbly well-adapted endurance runners. Paradoxically, however, notwithstanding this evolutionary-bestowed proficiency, running-related injuries, and Overuse syndromes in particular, are widely pervasive. The term ‘coordination’ is similarly ubiquitous within contemporary coaching, conditioning and rehabilitation cultures. Various theoretical models of coordination exist within the academic literature. However the specific neural and biological underpinnings of ‘running coordination’, and the nature of their integration, remain poorly elaborated.
    Conventionally running is considered a mundane, readily mastered coordination skill. This illusion of coordinative simplicity, however, is founded upon a platform of immense neural and biological complexities. This extensive complexity presents extreme organizational difficulties yet, simultaneously, provides a multiplicity of viable pathways through which the computational and mechanical burden of running can be proficiently dispersed amongst expanded networks of conditioned neural and peripheral tissue collaborators. Learning to adequately harness this available complexity, however, is a painstakingly slowly emerging, practice-driven process, greatly facilitated by innate evolutionary organizing principles serving to constrain otherwise overwhelming complexity to manageable proportions.
    As we accumulate running experiences persistent plastic remodeling customizes networked neural connectivity and biological tissue properties to best fit our unique neural and architectural idiosyncrasies, and personal histories: thus neural and peripheral tissue plasticity embeds coordination habits. When, however, coordinative processes are compromised —under the integrated influence of fatigue and/or accumulative cycles of injury, overuse, misuse and disuse— this spectrum of available ‘choice’ dysfunctionally contracts, and our capacity to safely disperse the mechanical ‘stress’ of running progressively diminishes. Now the running work burden falls increasingly on reduced populations of collaborating components. Accordingly our capacity to effectively manage, dissipate and accommodate running-imposed stress diminishes, and vulnerability to Overuse syndromes escalates.
    Awareness of the deep underpinnings of running coordination enhances conceptual clarity, thereby informing training and rehabilitation insights designed to offset the legacy of excessive or progressively accumulating exposure to running-imposed mechanical stress.
    Keywords: Running, Rehabilitation, coordination, overuse, variability, plasticity

    Update 15/05/2017
    Last edited by Jo Bowyer; 16-05-2017, 01:07 AM.
    Jo Bowyer
    Chartered Physiotherapist Registered Osteopath.
    "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

    Comment


    • Hi Jo!

      When Owen Anderson spoke at a clinic I sponsored back in '98, (his first ever multi day presentation), his theme was "Running is Neural Thing."

      Comment


      • Effect of Preactivation on Torque Enhancement by the Stretch-Shortening Cycle in Knee Extensors

        http://journals.plos.org/plosone/art...l.pone.0159058

        Abstract

        The stretch-shortening cycle is one of the most interesting topics in the field of sport sciences, because the performance of human movement is enhanced by the stretch-shortening cycle (eccentric contraction). The purpose of the present study was to examine whether the influence of preactivation on the torque enhancement by stretch-shortening cycle in knee extensors. Twelve men participated in this study. The following three conditions were conducted for knee extensors: (1) concentric contraction without preactivation (CON), (2) concentric contraction with eccentric preactivation (ECC), and (3) concentric contraction with isometric preactivation (ISO). Muscle contractions were evoked by electrical stimulation to discard the influence of neural activity. The range of motion of the knee joint was set from 80 to 140 degrees (full extension = 180 degrees). Angular velocities of the concentric and eccentric contractions were set at 180 and 90 degrees/s, respectively. In the concentric contraction phase, joint torques were recorded at 85, 95, and 105 degrees, and they were compared among the three conditions. In the early phase (85 degrees) of concentric contraction, the joint torque was larger in the ECC and ISO conditions than in the CON condition. However, these clear differences disappeared in the later phase (105 degrees) of concentric contraction. The results showed that joint torque was clearly different among the three conditions in the early phase whereas this difference disappeared in the later phase. Thus, preactivation, which is prominent in the early phase of contractions, plays an important role in torque enhancement by the stretch-shortening cycle in knee extensors.
        The role of the nervous system was modified here by the use of electrical stimulation. A nice study using 12 subjects which may serve to remind some of us that biomechanics and meat n' bones are of interest to many of us who work with movement.
        Jo Bowyer
        Chartered Physiotherapist Registered Osteopath.
        "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

        Comment


        • Cerebellar physiology – links between microcircuitry properties and sensorimotor functions

          http://onlinelibrary.wiley.com/doi/1...cceptedarticle

          Abstract

          The cerebellar neuronal circuitry is here summarized as a gigantic associative memory, consisting of multiple functional subunits working in parallel, by which useful contingencies between diverse types of information can be stored. The sources of information are the multiple mossy fiber systems that inform the cerebellum about original motor commands/motor plans and sensorimotor information at different levels of abstraction. The output of each functional subunit of the cerebellum is refining the ongoing movement command by linking learnt appropriate sensorimotor functions for the particular context or state. Because of its size, the memory element can house the appropriate associations, translatable to synaptic weights, relevant for all contexts or states that the individual can be expected to experience during a lifetime. It follows that a key component necessary to further improve our understanding of cerebellar function is a precise knowledge of the types and formats of information that reaches the cerebellum via the vast variety of mossy fiber pathways, a subject area that has long been neglected. In parallel, a large part of the cerebellar circuitry is proposed to be devoted to regulating the activity balance in the circuitry. The set points of the balances are internal to the cerebellar neuronal circuitry but influence the excitability of the extracerebellar motor structures so that the drive on individual muscles, for example, is not exaggerated or fall below operative excitation level. The review explores the consistency of this novel interpretational framework with multiple diverse observations at the synaptic and microcircuitry level within the cerebellum.
          This article is protected by copyright. All rights reserved

          via @SimonGandevia

          I would love to read this in full and would be most grateful if anyone is able to post it in SoS
          Jo Bowyer
          Chartered Physiotherapist Registered Osteopath.
          "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

          Comment


          • Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients: randomised controlled trial with two year follow-up

            http://www.bmj.com/content/354/bmj.i3740

            Abstract
            Objective To determine if exercise therapy is superior to arthroscopic partial meniscectomy for knee function in middle aged patients with degenerative meniscal tears.

            Design Randomised controlled superiority trial.

            Setting Orthopaedic departments at two public hospitals and two physiotherapy clinics in Norway.

            Participants 140 adults, mean age 49.5 years (range 35.7-59.9), with degenerative medial meniscal tear verified by magnetic resonance imaging. 96% had no definitive radiographic evidence of osteoarthritis.

            Interventions 12 week supervised exercise therapy alone or arthroscopic partial meniscectomy alone.

            Main outcome measures Intention to treat analysis of between group difference in change in knee injury and osteoarthritis outcome score (KOOS4), defined a priori as the mean score for four of five KOOS subscale scores (pain, other symptoms, function in sport and recreation, and knee related quality of life) from baseline to two year follow-up and change in thigh muscle strength from baseline to three months.

            Results No clinically relevant difference was found between the two groups in change in KOOS4 at two years (0.9 points, 95% confidence interval −4.3 to 6.1; P=0.72). At three months, muscle strength had improved in the exercise group (P≤0.004). No serious adverse events occurred in either group during the two year follow-up. 19% of the participants allocated to exercise therapy crossed over to surgery during the two year follow-up, with no additional benefit.

            Conclusion The observed difference in treatment effect was minute after two years of follow-up, and the trial’s inferential uncertainty was sufficiently small to exclude clinically relevant differences. Exercise therapy showed positive effects over surgery in improving thigh muscle strength, at least in the short term. Our results should encourage clinicians and middle aged patients with degenerative meniscal tear and no definitive radiographic evidence of osteoarthritis to consider supervised exercise therapy as a treatment option.
            Jo Bowyer
            Chartered Physiotherapist Registered Osteopath.
            "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

            Comment


            • How the brain improves motor control. Error signals in motor cortices drive adaptation in reaching

              https://www.sciencedaily.com/release...0721143506.htm

              Adaptation in reaching -- gradual improvement of motor control in response to a perturbation -- is a central issue in motor neuroscience.However, even the cortical origin of errors that drive adaptation has remained elusive. In a new paper published in Neuron, Inoue, Uchimura and Kitazawa have shown that error signals encoded by motor cortical neurons drive adaptation in reaching.
              Jo Bowyer
              Chartered Physiotherapist Registered Osteopath.
              "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

              Comment


              • Transmission of Predictable Sensory Signals to the Cerebellum via Climbing Fiber Pathways Is Gated during Exploratory Behavior

                http://www.jneurosci.org/content/36/30/7841.full

                Introduction

                The inferior olive climbing fiber (olivocerebellar) projection is essential for normal cerebellar operation, but the information conveyed by these afferents remains a subject of intense debate. Olive cells and the complex spikes they generate in Purkinje cells are highly sensitive to stimulation of their peripheral receptive field when an animal is at rest but do not respond reliably during active movement (Gellman et al., 1985; Andersson and Armstrong, 1987). Such findings have led to the notion that transmission in spino-olivocerebellar pathways (SOCPs) is “gated,” thereby limiting the times when sensory signals from the periphery can be forwarded to the cerebellum by this route (Gellman et al., 1985; Kim et al., 1987; Wang et al., 1987; Horn et al., 1996; Apps, 1999). This in turn imposes constraints on the signaling capabilities of climbing fibers and therefore provides important clues to their function.

                For example, transmission in SOCPs relaying signals to the “forelimb-receiving” parts of the cerebellar C1 and C3 zones in lobule V of the cat cerebellum is increased during the swing phase of the ipsilateral forelimb step cycle and reduced during stance (Lidierth and Apps, 1990; Apps et al., 1995; Apps and Lee, 1999; Pardoe et al., 2004). The swing phase is the time during locomotion when the limbs are most likely to encounter obstacles to progression, whereas the stance phase is when self-generated (reafferent) sensory signals are likely to occur as a result of load bearing. Therefore, the gating in SOCPs that target the C1 and C3 cerebellar cortical zones may serve to gate out the predictable (internally generated) sensory consequences of a movement, while permitting transmission of unpredictable (externally generated) sensory signals that can be used to update an internal model (Wolpert and Miall, 1996).

                If this is the case, then the pattern of gating in SOCPs should be modifiable if a sensory stimulus becomes predictable. Some evidence to support this possibility has been obtained during motor learning (Sears and Steinmetz, 1991; Hesslow and Ivarsson, 1996; Apps and Lee, 2002). However, these previous studies involved classical conditioning of an eyeblink or forelimb-withdrawal reflex (associative learning of a simple motor response), and it remains unknown whether the gating is modifiable during voluntary movement. Hence, the current experiments developed a behavioral model in rats that takes advantage of their exploratory activity of rearing. Rearing involves a rat using its hindlimbs to stand upright to scan the environment. During rearing, a rat is vulnerable to predator attack, so it is important that the animal is able to respond at this time to any unexpected peripheral sensory events, including external stimuli to the hindlimbs.

                Previous studies of gating of transmission in SOCPs during movement have focused on forelimb pathways (Apps, 1999). Given that hindlimb paths have a different pattern of organization in terms of number and location of central sites of synaptic relay and differ in their functional responsibilities, it is an open question whether they are also subject to modulation during movement and, if so, what the pattern of gating might be. We first investigated the pattern of gating of transmission in hindlimb SOCPs in relation to rearing behavior and then determined whether a peripheral stimulus, when delivered repeatedly at the same time during rearing, can modify the pattern. When the peripheral stimulus was delivered unpredictably to the hindlimb, the largest reductions in transmission relative to rest occurred during rearing up and rearing down, which coincide with active movement (when self-generated afference is likely to occur), whereas transmission was similar to rest during the upright phase of rearing. When the hindlimb stimulation was delivered only during the upright phase of rearing, so its occurrence became predictable over time, there was a progressive reduction in pathway transmission. Therefore, the findings demonstrate that gating of hindlimb SOCPs occurs during exploratory behavior in rats, can be modified by experience, and is related to the level of predictability of the sensory signal.
                from the discussion section
                Longer-term modification of cerebellar input and possible functional significance

                The present results indicate that pathway transmission can be modified after stimulation delivered during the same phase of rearing behavior over the course of many days. Such findings are consistent with previous studies that used classical conditioning of eye or forelimb reflexes to show transmission in olivo-cerebellar paths can be altered by associative learning (Hesslow and Ivarsson, 1996; Apps and Lee, 2002; Rasmussen et al., 2008). The present results extend these observations by demonstrating that the pattern of modulation can be dynamically altered during natural exploratory behavior.

                The prevailing view is that climbing fibers relay error signals to the cerebellar cortex whenever there is a mismatch between intended and achieved movement to drive long-term changes in Purkinje cell synaptic efficacy underlying motor learning (Yeo and Hesslow, 1998). The notion of error signaling is also incorporated into forward models of motor control (Wolpert et al., 1995). An internal representation of a movement (located within the cerebellum) integrates sensory and motor signals to generate predictions about the outcome of a movement, and sensory error-related climbing fiber signals are thought to be used to update the model (Wolpert and Miall, 1996; Kitazawa et al., 1998).

                The pattern of gating during rearing might then reflect the changing usefulness of climbing fiber signals to update the internal model (cf. Pardoe et al., 2004). Pathway transmission is normally reduced during phases 1 and 3 of rearing when self-generated afferent signals occur, which are predictable (non-error signals) and therefore presumably of limited value for updating the model. In contrast, the same pathways are more open for transmission during the upright phase (phase 2) when the rat needs to be vigilant to predatory attack. However, when the stimulus is delivered repeatedly during phase 2, over many trials, the modulation adapts to gate out a signal that has become expected. The results are therefore consistent with the hypothesis that the gating of transmission in SOCPs serves to prevent predictable sensory signals being forwarded to the cerebellum via the climbing fiber system.



                Learned response sequences in cerebellar Purkinje cells

                http://www.pnas.org/content/early/20...621132114.full

                Significance

                Learning is thought to rely on the strengthening or weakening of synapses. However, we have previously shown that a neuron can also learn when to time its response so that the timing reflects the interval between two stimuli, without any temporal information in the input signal. Here, we report that a neuron can even learn a sequence of at least two, and probably more, accurately timed responses. A single cell is in a sense “programmable,” and can encode a temporal response pattern. This means that the nature of what a cell can learn is very different from the traditional view, and that the information storage capacity may be far greater.
                Abstract
                Associative learning in the cerebellum has previously focused on single movements. In eyeblink conditioning, for instance, a subject learns to blink at the right time in response to a conditional stimulus (CS), such as a tone that is repeatedly followed by an unconditional corneal stimulus (US). During conditioning, the CS and US are transmitted by mossy/parallel fibers and climbing fibers to cerebellar Purkinje cells that acquire a precisely timed pause response that drives the overt blink response. The timing of this conditional Purkinje cell response is determined by the CS–US interval and is independent of temporal patterns in the input signal. In addition to single movements, the cerebellum is also believed to be important for learning complex motor programs that require multiple precisely timed muscle contractions, such as, for example, playing the piano. In the present work, we studied Purkinje cells in decerebrate ferrets that were conditioned using electrical stimulation of mossy fiber and climbing fiber afferents as CS and US, while alternating between short and long interstimulus intervals. We found that Purkinje cells can learn double pause responses, separated by an intermediate excitation, where each pause corresponds to one interstimulus interval. The results show that individual cells can not only learn to time a single response but that they also learn an accurately timed sequential response pattern.
                cerebellum Purkinje cells learning timing classical conditioning

                Update 29/05/2017




                A Molecule for Proper Neural Wiring in the Cerebellum


                http://neurosciencenews.com/cerebell...l-wiring-7199/

                A molecule produced by insulating glial cells facilitates the functional wiring of brain cells involved in motor coordination.
                Update 28/07/2017
                Last edited by Jo Bowyer; 28-07-2017, 11:33 PM.
                Jo Bowyer
                Chartered Physiotherapist Registered Osteopath.
                "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                Comment


                • Characteristics of Haptic Peripersonal Spatial Representation of Object Relations

                  http://journals.plos.org/plosone/art...l.pone.0160095

                  Introduction

                  The high ability to coordinate the hand with vision allows us to reach and grasp a coffee cup, catch a baseball with our hands, and defend ourselves from approaching harm through the use of our hands. Such coordination of the hand and vision are conducted so naturally that we do not consciously distinguish between visual and haptic spatial representations. However, there are numerous studies which show that spatial perception with vision and spatial perception with the hand (haptics) yield a different spatial representation. This can be observed from certain actions of daily life; for instance you may fail to accurately grasp a cup of coffee while keeping eye contact with a friend during a conversation. In such a situation the position of the coffee cup in visual coordinates must be recalculated into haptic coordinates, which seems to make the task a whole lot harder. In fact, bimodal neurons have been found which code visual stimuli in relation to the body and not in relation to the retina ([1,2]; on macaque monkeys; [3]; on humans), which again shows the importance of the hand being in sight for coordination of vision and haptics. However, there are situations where the hand cannot be attended to with sight (e.g. driving) and therefore understanding of the characteristics of haptic spatial representations are needed. The present study aims to investigate the formation of spatial representation of the surroundings (peripersonal space) through the use of haptics, in order to further understand the role of haptics in forming peripersonal spatial representations.

                  When considering the formation of haptic spatial representations, one must consider two spatial frames of reference: the egocentric reference frame and the allocentric reference frame. In the egocentric reference frame an object’s location is defined in relation to the observer’s body, whereas in the allocentric reference frame the object’s location is defined independent of the observer’s body [4]. In both reference frames an object’s location may be defined in terms of orientation and distance; the object’s orientation and distance from the observer for the egocentric reference frame, and the object’s orientation and distance from another object for the allocentric reference frame.

                  Through the parallelity task, deviations have been shown in the haptic perception of orientation. In the parallelity task participants are required to align two bars (one fixed reference bar and one freely moving test bar) to the felt parallel while being blindfolded. The parallelity task has revealed two characteristics of haptic spatial perception: the haptic oblique effect (see [5] for review) and the systematic deviations in the perception of parallelity [6–11]. Perception of horizontal or vertical orientation in Euclidean coordinates outperform oblique orientations (haptic oblique effect). The haptic oblique effect is observed not only on the horizontal plane but also on the mid-sagittal plane and the frontal planes [12]. Such superiority in perception of horizontal and vertical orientations as compared to oblique orientations suggest that haptic perception of space use Euclidean coordinate system to code orientations. However, along with the observation of the haptic oblique effect, systematic deviations which seem to reflect the use of a non-veridical egocentric reference frame are also observed from the parallelity task. When test bars are located to the right of a reference bar, clockwise rotations are perceived as parallel; anti-clockwise rotations are perceived as parallel when test bars are located to the left. The egocenter in the perception of orientation is shown to lie on the hand, as the posture of the hand rotates in a clockwise manner when perceiving bar orientations to the right [13,14]. To further support this view, no rotational deviations are observed when participants make two bars mirror symmetric using two hands as the posture of the left and right hands show mirror relations [6,15]. Investigations on three-dimensional haptic parallelity perception have also shown that the hand-centered egocentric reference frame best describe the systematic deviations [14]. These systematic deviations caused by the posture of the hand are not only observed on the horizontal plane but also on both the mid-sagittal and the frontoparallel planes [16,17]. It has also been found that accuracy in aligning bars to the subjective vertical is higher as compared to when aligning the rod to the gravitational vertical [18]. There is also a reference frame defined with coordinates in relation to the body as posture affects the perception in the vertical direction [19,20]. The posture of the hand (or use of the egocentric reference frame) highly affected the perception of orientation, resulting in systematic deviations, showing that haptic perception of spatial perception is not veridical.

                  Haptic perception of distance has been investigated by measuring performance in the perception of arm position. People tend to overestimate visually perceived reachable space [21] and proprioception is used to perceive the location of the arm in space [22], showing greater deviations when arm postures are at extreme postures such as full flexion or full contraction [23]. Localization of arm location is more precise in the radial direction with respect to the shoulder than in the azimuthal direction [24], as hand location is coded in a reference frame with the shoulder in use as the egocenter [25]. Perception of arm position become prone to errors when the arm is positioned more than 20cm from the body midline [26].

                  Scene recognition deals with perception of both orientation and distance, therefore it is an effective way to investigate haptic perception of object-to-object relations. Haptics is capable of perceiving and recognizing object-to-object relations as accurately as vision [27,28]. However, when the modality changes between learning and recognition, error rates increase showing that there is a cost when converting perceived space through vision or haptics to the other modality [27–29].

                  Previous researches on orientation and object location have highlighted the limitations in the haptic domain. The magnitude of the effects is in some cases very large, yet under everyday situations we are not aware of such deviations. This is because in most cases, spatial information concerning object in peripersonal space are perceived through interaction between vision and haptics. Altered visual feedback of arm position shifts perceived reachable space in the direction of the altered feedback and such changes in perceived reachable space were achieved in only a few trials [21]. Investigations into the perception of orientation have also shown that a weighted average of the egocentric and allocentric reference frames are used [8,30] and non-informative vision and delay between learning and reproduction decreases the magnitude of the deviation as both are known to promote heavier weightings to the allocentric reference frame [10,11,31]. Integration of data from visual only and haptic only trials can predict a participant’s performance in visual-haptic trials using a Bayesian model [32]. Taken together, it is evident that simultaneous acquisition of spatial information through haptics and vision is crucial for Euclidean spatial representation to be formed. However, under situations where visual information concerning hand location is not acquired (e.g., while driving a car), the characteristics caused by haptic original limitations are not calibrated and therefore deviations between spatial representations formed from haptics and vision remain.

                  The current study aims to investigate the characteristics of haptic spatial representation of several objects located in space. Perceiving the location of the hand and perceiving the locational relations of objects are similar yet very different. In both, a single object may be expressed in terms of a single spatial coordinate in relation to the body. However, when perceiving the relation of several object locations, one object's location may be expressed relative to other object’s locations (object-to-object relation), therefore objects may be expressed in different spatial coordinates depending on where the object is coded in relation to. This type of perception of object-to-object relation is allocentric in nature. Such allocentric coding of object location is crucial for trajectory planning of the arm as it is not always the case that the arm moves from the center of the body to the target object. Accurate planning of arm trajectories from one object to another require the use of one objects orientation in relation to another object as well as the distance between the two objects. From the results of previous research on orientation, it may be hypothesized that there is a deformation in the perception of object-to-object relations. However, since investigations concerning object-to-object relations have only been investigated through scene recognition, details concerning how object-to-object relations are deformed are not yet clear. Therefore, we conducted a task where participants were required to reproduce a learned object-to-object relation and examined whether any systematic deformations (or deviations) were observed (experiment 1). We confirmed the use of a different egocenter by introducing factors which affect movement of the arm (e.g. gravity) and observed its effects on the perception of object-to-object relations (experiment 2). Finally, any deviation of reproduced object positions should reflect the effects of the egocentric reference frame in haptic perception of space, therefore experimental manipulations which shift weightings to the allocentric reference frame should decrease the amount of deviation observed (experiment 3).


                  Study in mice identifies neurons that sense touch and motion, a combo needed to actively perceive the external world.


                  http://neurosciencenews.com/motion-touch-neurons-6463/

                  Much like humans use their hands to explore the world through touch, mice use their whiskers, explains O’Connor. Consequently, as the animals began running on the treadmill, they moved their whiskers back and forth in a motion that researchers call “exploratory whisking.”
                  Using a high-speed camera focused on the animals’ whiskers, the researchers took nearly 55,000,000 frames of video while the mice ran and whisked. They then used computer-learning algorithms to separate the movements into three different categories: when the rodents weren’t whisking or in contact with the pole; when they were whisking with no contact; or when they were whisking against the pole.
                  The results show that the Merkel afferents produced action potentials — the electrical spikes that neurons use to communicate with each other and the brain — when their associated whiskers contacted the pole. That finding wasn’t particularly surprising, O’Connor says, because of these neurons’ well-established role in touch.

                  However, he says, the Merkel afferents also responded robustly when they were moving in the air without touching the pole. By delving into the specific electrical signals, the researchers discovered that the action potentials precisely related to a whisker’s position in space. These findings suggest that Merkel afferents play a dual role in touch and proprioception, and in the sensory-motor integration necessary for active touch, O’Connor says.
                  Although these findings are particular to mouse whiskers, he cautions, he and his colleagues believe that Merkel afferents in humans could serve a similar function, because many anatomical and physiological properties of Merkel afferents appear similar across a range of species, including mice and humans.
                  Update 20/04/2017
                  Last edited by Jo Bowyer; 21-04-2017, 12:54 AM.
                  Jo Bowyer
                  Chartered Physiotherapist Registered Osteopath.
                  "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                  Comment


                  • Scaling up physical activity interventions worldwide: stepping up to larger and smarter approaches to get people moving

                    http://www.thelancet.com/pdfs/journa...16)30728-0.pdf

                    Summary
                    The global pandemic of physical inactivity requires a multisectoral, multidisciplinary public-health response. Scaling up interventions that are capable of increasing levels of physical activity in populations across the varying cultural, geographic, social, and economic contexts worldwide is challenging, but feasible. In this paper, we review the factors that could help to achieve this. We use a mixed-methods approach to comprehensively examine these factors, drawing on the best available evidence from both evidence-to-practice and practice-to-evidence methods. Policies to support active living across society are needed, particularly outside the health-care sector, as demonstrated by some of the successful examples of scale up identified in this paper. Researchers, research funders, and practitioners and policymakers in culture, education, health, leisure, planning, and transport, and civil society as a whole, all have a role. We should embrace the challenge of taking action to a higher level, aligning physical activity and health objectives with broader social, environmental, and sustainable development goals.
                    Via @SimonGandevia

                    As long as it's not Pokemon Go #fishinmybed

                    https://www.somasimple.com/forums/sh...&postcount=592
                    Jo Bowyer
                    Chartered Physiotherapist Registered Osteopath.
                    "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                    Comment


                    • Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women

                      http://www.thelancet.com/pdfs/journa...16)30370-1.pdf

                      Summary
                      Background
                      High amounts of sedentary behaviour have been associated with increased risks of several chronic conditions and mortality. However, it is unclear whether physical activity attenuates or even eliminates the detrimental effects of prolonged sitting. We examined the associations of sedentary behaviour and physical activity with all-cause mortality.

                      Methods
                      We did a systematic review, searching six databases (PubMed, PsycINFO, Embase, Web of Science, Sport Discus, and Scopus) from database inception until October, 2015, for prospective cohort studies that had individual level exposure and outcome data, provided data on both daily sitting or TV-viewing time and physical activity, and reported effect estimates for all-cause mortality, cardiovascular disease mortality, or breast, colon, and colorectal cancer mortality. We included data from 16 studies, of which 14 were identified through a systematic review and two were additional unpublished studies where pertinent data were available. All study data were analysed according to a harmonised protocol, which categorised reported daily sitting time and TV-viewing time into four standardised groups each, and physical activity into quartiles (in metabolic equivalent of task [MET]-hours per week). We then combined data across all studies to analyse the association of daily sitting time and physical activity with all-cause mortality, and estimated summary hazard ratios using Cox regression. We repeated these analyses using TV-viewing time instead of daily sitting time.

                      Findings
                      Of the 16 studies included in the meta-analysis, 13 studies provided data on sitting time and all-cause mortality. These studies included 1 005 791 individuals who were followed up for 2–18·1 years, during which 84 609 (8·4%) died. Compared with the referent group (ie, those sitting <4 h/day and in the most active quartile [>35·5 MET-h per week]), mortality rates during follow-up were 12–59% higher in the two lowest quartiles of physical activity (from HR=1·12, 95% CI 1·08–1·16, for the second lowest quartile of physical activity [<16 MET-h per week] and sitting <4 h/day; to HR=1·59, 1·52–1·66, for the lowest quartile of physical activity [<2·5 MET-h per week] and sitting >8 h/day). Daily sitting time was not associated with increased all-cause mortality in those in the most active quartile of physical activity. Compared with the referent (<4 h of sitting per day and highest quartile of physical activity [>35·5 MET-h per week]), there was no increased risk of mortality during follow-up in those who sat for more than 8 h/day but who also reported >35·5 MET-h per week of activity (HR=1·04; 95% CI 0·99–1·10). By contrast, those who sat the least (<4 h/day) and were in the lowest activity quartile (<2·5 MET-h per week) had a significantly increased risk of dying during follow-up (HR=1·27, 95% CI 1·22–1·31). Six studies had data on TV-viewing time (N=465 450; 43 740 deaths). Watching TV for 3 h or more per day was associated with increased mortality regardless of physical activity, except in the most active quartile, where mortality was significantly increased only in people who watched TV for 5 h/day or more (HR=1·16, 1·05–1·28).

                      Interpretation
                      High levels of moderate intensity physical activity (ie, about 60–75 min per day) seem to eliminate the increased risk of death associated with high sitting time. However, this high activity level attenuates, but does not eliminate the increased risk associated with high TV-viewing time. These results provide further evidence on the benefits of physical activity, particularly in societies where increasing numbers of people have to sit for long hours for work and may also inform future public health recommendations.
                      via @SimonGandevia



                      Physical activity and sedentary behaviour in daily life: A comparative analysis of the Global Physical Activity Questionnaire (GPAQ) and the SenseWear armband

                      http://journals.plos.org/plosone/art...l.pone.0177765

                      Abstract

                      Reduction of sedentary time and an increase in physical activity offer potential to improve public health. However, quantifying physical activity behaviour under real world conditions is a major challenge and no standard of good practice is available. Our aim was to compare the results of physical activity and sedentary behaviour obtained with a self-reported instrument (Global Physical Activity Questionnaire (GPAQ)) and a wearable sensor (SenseWear) in a repeated measures study design. Healthy adults (41 in Antwerp, 41 in Barcelona and 40 in London) wore the SenseWear armband for seven consecutive days and completed the GPAQ on the final day. This was repeated three times. We used the Wilcoxon signed rank sum test, Spearman correlation coefficients, mixed effects regression models and Bland-Altman plots to study agreement between both methods. Mixed models were used to assess the effect of personal characteristics on the absolute and relative difference between estimates obtained with the GPAQ and SenseWear. Moderate to vigorous energy expenditure and duration derived from the GPAQ were significantly lower (p<0.05) compared to the SenseWear, yet these variables showed significant correlations ranging from 0.45 to 0.64. Estimates of vigorous-intensity physical activity in particular showed high similarity (r>0.59). Results for sedentary behaviour did not differ, yet were poorly correlated (r<0.25). The differences between all variables were reproducible across repeated measurements. In addition, we observed a relationship between these differences and BMI, body fat and physical activity domain. Due to the lack of a standardized protocol, results from different studies measuring physical activity and sedentary behaviour are difficult to compare. Therefore, we suggested an easy-to-implement approach for future studies adding the GPAQ to the wearable of choice as a basis for comparisons.
                      Update 17/05/2017



                      The surprising science of fidgeting

                      https://theconversation.com/the-surp...idgeting-77525

                      Fidgeting could be a form of general, unconscious self-regulation mechanism that varies depending on what is required – regulating attention, weight or stress. Indeed, it seems that being bored may actually cause us to become unconsciously stressed. Physiological signs of stress are documented to rise significantly during periods of sustained attention (like when watching a lecture). So we may fidget to relieve that stress – rather than to reset our attention levels.

                      Fidgeting may (at least in part) be controlled by the brain’s hypothalamus, which is known to regulate many bodily processes. Indeed, when you inject orexins (a small protein) into part of the hypothalamus in rodents, you see an increase in spontaneous bodily activity. Orexins and the hypothalamus are both linked to arousal, appetite, wakefulness and other regulation processes.
                      Update 24/05/2017
                      Last edited by Jo Bowyer; 24-05-2017, 09:16 PM.
                      Jo Bowyer
                      Chartered Physiotherapist Registered Osteopath.
                      "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                      Comment


                      • MOTOR CONTROL IN MUSCULOSKELETAL PHYSIOTHERAPY: A CONCEPT ANALYSIS Matt Low

                        https://mattlowpt.wordpress.com/2016...cept-analysis/

                        A few people have contacted me with regards to my recent poster presentation that I gave at IFOMPT 2016 in Glasgow. Below is the content of the poster, please feel free to ask questions or post comments in the comment section or via Twitter @MattLowPT.
                        Last edited by Jo Bowyer; 01-08-2016, 10:27 AM.
                        Jo Bowyer
                        Chartered Physiotherapist Registered Osteopath.
                        "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                        Comment


                        • Thanks for this link Jo. Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women.

                          I'm looking forward to reading the full text article. I will be surprised if high levels of moderate activity eliminate the increased risk of death with high sitting times!
                          Christine

                          Comment


                          • There has been a lot in the press, flagging up the amount of sitting around some athletes do when they are not engaged in a training session.

                            Many of those I was involved with used to play golf or go fishing in their down time and they seemed happier and less prone to illness and injury. Most tended to hang out with fellow athletes as they didn't want to get coerced into going drinking or eating junk food, they saved that for celebrations post competition. Many of the girls enjoyed karaoke, dancing, shopping and unshopping......pre internet days you had to take the stuff back to the supplier physically.

                            There was of course overlap, some of the boys were sharp dressers and good dancers, and a few of the girls were fishers.
                            Last edited by Jo Bowyer; 03-08-2016, 10:26 AM.
                            Jo Bowyer
                            Chartered Physiotherapist Registered Osteopath.
                            "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                            Comment


                            • Decreased Activation of Subcortical Brain Areas in the Motor Fatigue State: An fMRI Study

                              http://journal.frontiersin.org/artic...016.01154/full

                              One aspect of motor fatigue is the exercise-induced reduction of neural activity to voluntarily drive the muscle or muscle group. Functional magnetic resonance imaging provides access to investigate the neural activation on the whole brain level and studies observed changes of activation intensity after exercise-induced motor fatigue in the sensorimotor cortex. However, in human, little evidence exists to demonstrate the role of subcortical brain regions in motor fatigue, which is contradict to abundant researches in rodent indicating that during simple movement, the activity of the basal ganglia is modulated by the state of motor fatigue. Thus, in present study, we explored the effect of motor fatigue on subcortical areas in human. A series of fMRI data were collected from 11 healthy subjects while they were executing simple motor tasks in two conditions: before and under the motor fatigue state. The results showed that in both conditions, movements evoked activation volumes in the sensorimotor areas, SMA, cerebellum, thalamus, and basal ganglia. Of primary importance are the results that the intensity and size of activation volumes in the subcortical areas (i.e., thalamus and basal ganglia areas) are significantly decreased during the motor fatigue state, implying that motor fatigue disturbs the motor control processing in a way that both sensorimotor areas and subcortical brain areas are less active. Further study is needed to clarify how subcortical areas contribute to the overall decreased activity of CNS during motor fatigue state.
                              Jo Bowyer
                              Chartered Physiotherapist Registered Osteopath.
                              "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                              Comment


                              • Should proprioceptive training be a priority in the management of chronic pain?

                                http://www.bodyinmind.org/propriocep...ody+in+Mind%29

                                Avid readers of BodyinMind.org know all too well that chronic pain can be associated with perceived distortions of the painful limb, be it in size, shape or posture [1-4]. In some cases, those with chronic pain report that they have limited awareness of the location of their painful body part [4, 5]. What they report may be a disturbance to the sense of limb position, which is a component of proprioception (or sensations derived from the body it self, such as the sense of movement and force). Efforts to potentially restore proprioceptive feedback through training have been incorporated into some chronic pain rehabilitative programs [6]. However, in the case of position sense, it is unclear how chronic pain would influence the perceived position or posture of a painful limb [7].

                                Let’s look at the potential mechanisms. Chronic pain is associated with many changes in brain structure and function [8]. Speculatively, the changes in the brain might underpin alterations in the way proprioceptive information is processed. Alternatively, ongoing tissue damage at the site of the pain, which may involve the receptors in the muscle that provide proprioceptive information could alter proprioceptive processing.

                                The receptors in our muscles that respond to stretch, known as muscle spindles, are primarily responsible for signalling the sense of limb position and movement [9]. Muscle spindles increase their resting discharge in proportion to the stretch imposed on them, and this is how the brain detects that a muscle has become longer. Hence, assessing position sense is a non-invasive measure that reflects muscle spindle function and can be used in chronic pain. In these tests, the participant is blindfolded and asked to either match the position of one arm with the other, or indicate the location of the arm using a pointer. For clarification, the arm being pointed to is designated the reference arm and the arm (or pointer) moved to match the reference arm’s location is called the indicator.

                                Manipulating spindle activity can lead to predictable errors or directional biases when we match our arms in a position sense task [for a review, see 10]. For example, we can generate relatively accurate alignment of the arms when elbow antagonist muscles from both arms have similar nett spindle activity [11, 12]; whereas large errors, in the order of 10° or more, can be produced by inducing different (i.e. high vs low) spindle activity between the arms [11]. This manipulation, called muscle conditioning, is done by performing a voluntary contraction or stretch of the muscle before taking a position sense measurement.

                                In our recent study [13], we investigated position sense at the forearm after muscle conditioning in 30 age- and sex-matched individuals with chronic pain primarily in one arm (upper-limb) or leg (lower-limb), and 15 people without pain. Surprisingly, matching errors were similar no matter whether the painful arm was the reference (being matched to) or the indicator arm (positioned to match the reference arm). Moreover, across different muscle conditioning techniques, i.e. presumably under a high vs low spindle activity between the arms, all participants made large matching errors. Importantly, there were no group differences found amongst those with upper- or lower-limb pain, or those without pain, in any condition. This suggests that the proprioceptive signals from the painful arm are “listened” to just as clearly and accurately as the non-painful arm during a position matching task.

                                We also wanted to know if chronic pain impaired the ability to indicate where the arm was in space. That is, we wanted to know what happens when position sense was determined using information from only one limb. In this task the reference arm was hidden behind a screen and participants were instructed to indicate the perceived position of their painful and non-painful arms, in separate trials, using a pointer. The results were similar across all three groups, as well as between painful and non-painful arms, reinforcing the idea that muscle spindles appear to function normally and that localising a limb in space appears to be unaffected.

                                Future investigations are required in order to elucidate the mechanisms involved in the bodily distortions associated with chronic pain. However, in the case of position sense, our findings seem to suggest that peripheral proprioceptive information remains intact. Hence, proprioceptive training of position sense may not be required in the management of chronic pain.
                                I do train proprioception, as it is an integral part of movement. I do this within the context of transitions and transfers, activities of daily living and work and sport related activity.
                                Last edited by Jo Bowyer; 10-08-2016, 08:06 PM.
                                Jo Bowyer
                                Chartered Physiotherapist Registered Osteopath.
                                "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

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