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  • Separating Predicted and Perceived Sensory Consequences of Motor Learning

    http://journals.plos.org/plosone/art...l.pone.0163556

    Abstract

    During motor adaptation the discrepancy between predicted and actually perceived sensory feedback is thought to be minimized, but it can be difficult to measure predictions of the sensory consequences of actions. Studies attempting to do so have found that self-directed, unseen hand position is mislocalized in the direction of altered visual feedback. However, our lab has shown that motor adaptation also leads to changes in perceptual estimates of hand position, even when the target hand is passively displaced. We attribute these changes to a recalibration of hand proprioception, since in the absence of a volitional movement, efferent or predictive signals are likely not involved. The goal here is to quantify the extent to which changes in hand localization reflect a change in the predicted sensory (visual) consequences or a change in the perceived (proprioceptive) consequences. We did this by comparing changes in localization produced when the hand movement was self-generated (‘active localization’) versus robot-generated (‘passive localization’) to the same locations following visuomotor adaptation to a rotated cursor. In this passive version, there should be no predicted consequences of these robot-generated hand movements. We found that although changes in localization were somewhat larger in active localization, the passive localization task also elicited substantial changes. Our results suggest that the change in hand localization following visuomotor adaptation may not be based entirely on updating predicted sensory consequences, but may largely reflect changes in our proprioceptive state estimate.



    Calibrating skin maps: How are body metrics represented?

    https://motorimpairment.neura.edu.au...ing-skin-maps/

    To accurately move there is a need for proprioception, the sense of where our limbs are in space. Although we know much about how proprioceptive signals arise in the periphery, less is known about how these signals are integrated so that they can be understood in the spatial co-ordinates of the body. The neural activity which reflects this co-ordinate system is often termed a body representation (or map). These representations must update as the body changes with age. How do these representations adjust to the metric properties of the body?
    Update 18/05/2017
    Last edited by Jo Bowyer; 18-05-2017, 09:26 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


    • How consistent are lordosis, range of movement and lumbo-pelvic rhythm in people with and without back pain?

      http://bmcmusculoskeletdisord.biomed...891-016-1250-1

      Abstract

      Background
      Comparing movements/postures in people with and without lower back pain (LBP) may assist identifying LBP-specific dysfunction and its relationship to pain or activity limitation. This study compared the consistency in lumbo-pelvic posture and movement (range and pattern) in people with and without chronic LBP (>12 week’s duration).

      Methods
      Wireless, wearable, inertial measurement units measured lumbar lordosis angle, range of movement (ROM) and lumbo-pelvic rhythm in adults (n = 63). Measurements were taken on three separate occasions: two tests on the same day with different raters and a third (intra-rater) test one to two weeks later. Participants performed five repetitions of tested postures or movements. Test data were captured automatically. Minimal detectable change scores (MDC90) provided estimates of between-test consistency.

      Results
      There was no significant difference between participants with and without LBP for lordosis angle. There were significant differences for pelvic flexion ROM (LBP 60.8°, NoLBP 54.8°, F(1,63) = 4.31, p = 0.04), lumbar right lateral flexion ROM (LBP 22.2°, NoLBP 24.6° F(1,63) = 4.48, p = .04), trunk right lateral flexion ROM (LBP 28.4°, NoLBP 31.7°, F(1,63) = 5.9, p = .02) and lumbar contribution to lumbo-pelvic rhythm in the LBP group (LBP 45.8 %, F(1,63) = 4.20, NoLBP 51.3 % p = .044). MDC90 estimates for intra and inter-rater comparisons were 10°–15° for lumbar lordosis, and 5°–15° for most ROM. For lumbo-pelvic rhythm, we found 8–15 % variation in lumbar contribution to flexion and lateral flexion and 36–56 % variation in extension. Good to excellent agreement (reliability) was seen between raters (mean r = .88, ICC (2,2)).

      Conclusion
      Comparisons of ROM between people with and without LBP showed few differences between groups, with reduced relative lumbar contribution to trunk flexion. There was no difference between groups for lordosis. Wide, within-group differences were seen for both groups for ROM and lordosis. Due to variability between test occasions, changes would need to exceed 10°–15° for lumbar lordosis, 5°–15° for ROM components, and 8–15 % of lumbar contribution to lumbo-pelvic rhythm, to have 90 % confidence that movements had actually changed. Lordosis, range of movement and lumbo-pelvic rhythm typically demonstrate variability between same-day and different-day tests. This variability needs to be considered when interpreting posture and movement changes.
      Keywords

      Low back pain Movement disorders Posture ROM Lordosis Lumbo-pelvic rhythm Reliability





      Characterisation of the correlation between standing lordosis and degenerative joint disease in the lower lumbar spine in women and men: a radiographic study


      https://bmcmusculoskeletdisord.biome...891-017-1696-9

      Abstract

      [ Background


      Degenerative joint disease (DJD) in the lumbar spine is a common condition that is associated with chronic low back pain. Excessive loading of lumbar joints is a risk factor for DJD. Changes in lumbar lordosis significantly redistribute the forces of weight-bearing on the facet joints and the intervertebral discs. However, the relationship between lumbar lordosis and DJD has not been characterized in men and women. Methods


      We characterised the correlation between standing lumbar lordosis and DJD in standing radiographic images from 301 adult female and male chiropractic patients. DJD was rated using the Kellgren-Lawrence scale, and lordosis was measured using the Cobb angle. Linear and curvilinear correlations were investigated while controlling for age and sex. Results


      We found a highly significant curvilinear correlation between lordosis and DJD of the lower lumbar spine in both sexes, but especially in women, irrespective of the effects of age. We found the effect size of lordosis on lower lumbar DJD to be between 17.4 and 18.1% in women and 12.9% in older men. In addition, lordosis of 65 (95% CI 55.3–77.7) and 68 (98% CI 58.7–73.3) degrees were associated with minimal DJD in the lower lumbar spine of women and men respectively, and were therefore considered ‘optimal’. This optimal lordotic angle was 73 (95% CI 58.8–87.2) degrees in older men. Conclusions


      Both hypo- and hyper-lordosis correlate with DJD in the lumbar spine, particularly in women and in older men. These findings may well be of relevance to spinal pain management and spinal rehabilitation.
      Keywords

      Lordosis Lumbar region Osteoarthritis

      Update 02/08/2017




      The effects of bending speed on the lumbo-pelvic kinematics and movement pattern during forward bending in people with and without low back pain

      https://bmcmusculoskeletdisord.biome...891-017-1515-3

      Abstract

      Background
      Impaired lumbo-pelvic movement in people with low back pain during bending task has been reported previously. However, the regional mobility and the pattern of the lumbo-pelvic movement were found to vary across studies. The inconsistency of the findings may partly be related to variations in the speed at which the task was executed. This study examined the effects of bending speeds on the kinematics and the coordination lumbo-pelvic movement during forward bending, and to compare the performance of individuals with and without low back pain.

      Methods
      The angular displacement, velocity and acceleration of the lumbo-pelvic movement during the repeated forward bending executed at five selected speeds were acquired using the three dimensional motion tracking system in seventeen males with low back pain and eighteen males who were asymptomatic. The regional kinematics and the degree of coordination of the lumbo-pelvic movement during bending was compared and analysed between two groups.

      Results
      Significantly compromised performance in velocity and acceleration of the lumbar spine and hip joint during bending task at various speed levels was shown in back pain group (p < 0.01). Both groups displayed a high degree of coordination of the lumbo-pelvic displacement during forward bending executed across the five levels of speed examined. Significant between-group difference was revealed in the coordination of the lumbo-pelvic velocity and acceleration (p < 0.01). Asymptomatic group moved with a progressively higher degree of lumbo-pelvic coordination for velocity and acceleration while the back pain group adopted a uniform lumbo-pelvic pattern across all the speed levels examined.

      Conclusions
      The present findings show that bending speed imposes different levels of demand on the kinematics and pattern of the lumbo-pelvic movement. The ability to regulate the lumbo-pelvic movement pattern during the bending task that executed at various speed levels was shown only in pain-free individuals but not in those with low back pain. Individuals with low back pain moved with a stereotyped strategy at their lumbar spine and hip joints. This specific aberrant lumbo-pelvic movement pattern may have a crucial role in the maintenance of the chronicity in back pain.
      Keywords

      Low back pain Lumbo-pelvic movement Kinematics Coordination Forward bending

      Update 18/04/2017




      Differences in kinematics of the lumbar spine and lower extremities between people with and without low back pain during the down phase of a pick up task, an observational study

      http://www.sciencedirect.com/science...68781216300224

      Highlights

      Group difference in lumbar spine flexion depends on upper vs. lower region.

      LBP subjects flex the lumbar spine more in early ranges of movement than controls.

      LBP subjects display more frontal plane knee movement than controls.

      There were no significant differences in kinematics among movement-based subgroups.

      Abstract
      Background

      Limited research exists on lumbar spine and lower extremity movement during functional tasks in people with and without low back pain (LBP).

      Objective

      To determine differences in lumbar spine and lower extremity kinematics in people with and without LBP during the down phase of a pick up task.

      Design

      Cross-sectional, observational study.

      Method

      35 people (14 M, 21 F, 26.9 ± 10.9 years, 24.8 ± 3.2 kg/m2); 18 with and 17 without LBP were matched based on age, gender and BMI. Kinematics of the lumbar spine and lower extremities were measured using 3D motion capture, while subjects picked up an object off the floor. People with LBP were examined and assigned to movement-based LBP subgroups. Repeated measures ANOVA tests were conducted to determine the effect of group and region on lumbar spine and lower extremity kinematics. A secondary analysis was conducted to examine the effect of LBP subgroup on lumbar spine kinematics.

      Results

      Compared to controls, subjects with LBP displayed greater upper and less lower lumbar flexion (P < 0.05), and more lumbar flexion during the first 25% of the pick up task (P < 0.01). There were no group differences in frontal or axial plane lumbar spine kinematics. Subjects with LBP displayed more frontal plane movement at the knee than control subjects (P < 0.01). There were no significant effects of movement-based LBP subgroup on kinematics (P > 0.05).

      Conclusions

      When evaluating movement during a functional task, the clinician should consider regional differences in the lumbar spine, pattern of movement, and lower extremity movement.
      Keywords
      Low back pain; Lower extremity; Kinematics; Functional

      Update 31/05/2017




      The immediate effects of exercise using the Functional Re-adaptive Exercise Device on lumbopelvic kinematics in people with and without low back pain

      http://www.sciencedirect.com/science...68781216308293

      Abstract
      Background

      Dysfunction of the lumbar multifidus (LM) and transversus abdominis (TrA) muscles is associated with low back pain (LBP). The Functional Re-adaptive Exercise Device (FRED) has shown potential as a non-specific LBP intervention by automatically recruiting LM and TrA. Loss or lordosis and altered lumbopelvic positioning has also been linked to LBP and is often trained within LM and TrA interventions. The effect that FRED exercise has on lumbopelvic positioning and lumbar lordosis is unknown.

      Objectives

      To assess the effect of FRED exercise on lumbopelvic kinematics and alignment to establish whether FRED exercise promotes a favourable lumbopelvic posture for training LM and TrA.

      Design

      Within and between-group comparison study.

      Method

      One hundred and thirty participants, 74 experiencing LBP, had lumbopelvic kinematic data measured during over-ground walking and FRED exercise. Magnitude-based inferences were used to compare walking with FRED exercise within participants and between the asymptomatic and LBP groups, to establish the effects of FRED exercise on lumbopelvic kinematics, compared to walking, in each group.

      Results

      FRED exercise promotes an immediate change in anterior pelvic tilt by 8.7° compared to walking in the no-LBP and LBP groups. Sagittal-plane spinal extension increased during FRED exercise at all spinal levels by 0.9° in the no-LBP group, and by 1.2° in the LBP group.

      Conclusions

      FRED exercise promotes a lumbopelvic position more conducive to LM and TrA training than walking in both asymptomatic people and those with LBP.
      Keywords
      Motor control; Lordosis; Lumbopelvic kinematics; Functional Re-adaptive Exercise Device

      Update 21/06/2017
      Last edited by Jo Bowyer; 02-08-2017, 12:52 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


      • Localization of impaired kinesthetic processing post-stroke

        http://journal.frontiersin.org/artic...00505/abstract

        Kinesthesia is our sense of limb motion, and allows us to gauge the speed, direction, and amplitude of our movements. Over half of stroke survivors have significant impairments in kinesthesia, which leads to greatly reduced recovery and function in everyday activities. Despite the high reported incidence of kinesthetic deficits after stroke, very little is known about how damage beyond just primary somatosensory areas affects kinesthesia. Stroke provides an ideal model to examine structure-function relationships specific to kinesthetic processing, by comparing lesion location with behavioral impairment. To examine this relationship, we performed voxel-based lesion-symptom mapping and statistical region of interest analyses on a large sample of sub-acute stroke subjects (N=142) and compared kinesthetic performance with stroke lesion location. Subjects with first unilateral, ischemic stroke underwent neuroimaging and a comprehensive robotic kinesthetic assessment (~9 days post-stroke). The robotic exoskeleton measured subjects’ ability to perform a kinesthetic mirror-matching task of the upper limbs without vision. The robot moved the stroke-affected arm and subjects’ mirror-matched the movement with the unaffected arm. We found that lesions both within and outside primary somatosensory cortex were associated with significant kinesthetic impairments. Further, sub-components of kinesthesia were associated with different lesion locations. Impairments in speed perception were primarily associated with lesions to the right post-central and supramarginal gyri whereas impairments in amplitude of movement perception were primarily associated with lesions in the right pre-central gyrus, anterior insula, and superior temporal gyrus. Impairments in perception of movement direction were associated with lesions to bilateral post-central and supramarginal gyri, right superior temporal gyrus and parietal operculum. All measures of impairment shared a common association with damage to the right supramarginal gyrus. These results suggest that processing of kinesthetic information occurs beyond traditional sensorimotor areas. Additionally, this dissociation between kinesthetic sub-components may indicate specialized processing in these brain areas that form a larger distributed network.
        Jo Bowyer
        Chartered Physiotherapist Registered Osteopath.
        "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

        Comment


        • Human and avian running on uneven ground: a model-based comparison

          http://rsif.royalsocietypublishing.o...3/122/20160529

          Abstract

          Birds and humans are successful bipedal runners, who have individually evolved bipedalism, but the extent of the similarities and differences of their bipedal locomotion is unknown. In turn, the anatomical differences of their locomotor systems complicate direct comparisons. However, a simplifying mechanical model, such as the conservative spring–mass model, can be used to describe both avian and human running and thus, provides a way to compare the locomotor strategies that birds and humans use when running on level and uneven ground. Although humans run with significantly steeper leg angles at touchdown and stiffer legs when compared with cursorial ground birds, swing-leg adaptations (leg angle and leg length kinematics) used by birds and humans while running appear similar across all types of uneven ground. Nevertheless, owing to morphological restrictions, the crouched avian leg has a greater range of leg angle and leg length adaptations when coping with drops and downward steps than the straight human leg. On the other hand, the straight human leg seems to use leg stiffness adaptation when coping with obstacles and upward steps unlike the crouched avian leg posture.
          Jo Bowyer
          Chartered Physiotherapist Registered Osteopath.
          "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

          Comment


          • One-to-one or strength in numbers – is there a best way to deliver exercise based physiotherapy?

            http://www.bodyinmind.org/exercise-b...ody+in+Mind%29

            Our research group has recently published a systematic review and meta-analysis [7] in the British Journal of Sports Medicine comparing the effectiveness of group and one-to-one physiotherapy interventions including exercise for MSK conditions. The reason we undertook this review was that despite one-to-one appearing to be the most popular mode of delivering physiotherapy including exercise, there is evidence that groups may be as effective (e.g. here) [8].
            Exercise vs. physical therapy
            https://www.somasimple.com/forums/sh...ysiotherapy%3F
            Jo Bowyer
            Chartered Physiotherapist Registered Osteopath.
            "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

            Comment


            • Spatiotemporal Distribution of Location and Object Effects in Primary Motor Cortex Neurons during Reach-to-Grasp

              http://www.jneurosci.org/content/36/....abstract?etoc

              Abstract

              Reaching and grasping typically are considered to be spatially separate processes that proceed concurrently in the arm and the hand, respectively. The proximal representation in the primary motor cortex (M1) controls the arm for reaching, while the distal representation controls the hand for grasping. Many studies of M1 activity therefore have focused either on reaching to various locations without grasping different objects, or else on grasping different objects all at the same location. Here, we recorded M1 neurons in the anterior bank and lip of the central sulcus as monkeys performed more naturalistic movements, reaching toward, grasping, and manipulating four different objects in up to eight different locations. We quantified the extent to which variation in firing rates depended on location, on object, and on their interaction—all as a function of time. Activity proceeded largely in two sequential phases: the first related predominantly to the location to which the upper extremity reached, and the second related to the object about to be grasped. Both phases involved activity distributed widely throughout the sampled territory, spanning both the proximal and the distal upper extremity representation in caudal M1. Our findings indicate that naturalistic reaching and grasping, rather than being spatially segregated processes that proceed concurrently, each are spatially distributed processes controlled by caudal M1 in large part sequentially. Rather than neuromuscular processes separated in space but not time, reaching and grasping are separated more in time than in space.

              SIGNIFICANCE STATEMENT Reaching and grasping typically are viewed as processes that proceed concurrently in the arm and hand, respectively. The arm region in the primary motor cortex (M1) is assumed to control reaching, while the hand region controls grasping. During naturalistic reach–grasp–manipulate movements, we found, however, that neuron activity proceeds largely in two sequential phases, each spanning both arm and hand representations in M1. The first phase is related predominantly to the reach location, and the second is related to the object about to be grasped. Our findings indicate that reaching and grasping are successive aspects of a single movement. Initially the arm and the hand both are projected toward the object's location, and later both are shaped to grasp and manipulate.
              arm grasping hand manipulation reaching



              Posterior parietal cortex contains a command apparatus for hand movements
              http://www.pnas.org/content/early/20...608132114.full

              Significance

              The primate hand has evolved into a specialized sensorimotor device that can grasp, explore, and manipulate objects with extraordinary skill. The frontal lobe is generally thought to be the exclusive source of descending commands to the spinal cord to control hand movements. Here, we identify a region within the parietal lobe that could also contribute commands to control hand movements directly at spinal levels. Intracortical stimulation in a lateral region in area 5 of posterior parietal cortex reliably evokes hand movements. Corticospinal neurons in this region make disynaptic connections with hand motoneurons. These observations suggest that a region within lateral area 5 contains a unique command apparatus that could assist in generating dexterous finger movements required during haptic behavior.
              Update
              04/04/2017
              Last edited by Jo Bowyer; 04-04-2017, 01:32 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


              • Stimulation of PPC Affects the Mapping between Motion and Force Signals for Stiffness Perception But Not Motion Control

                [YT][/YT]http://www.jneurosci.org/content/36/41/10545.full

                Introduction

                Our hands are fascinating organs that we use to sense and interact with our environment. Early studies of sensory processing advanced our understanding of the type of information available to the sensorimotor system during and after generating movements (Adams, 1987; Swinnen, 1996). Information such as position (Gandevia et al., 1992) and force (Jones, 2000; Mileusnic and Loeb, 2009) travels back to the brain and is combined with an efference copy of motor commands to adjust movements online and to provide us with a sense of the environment (Kawato, 1999). For some actions, we clearly rely on one of these signals more than the other. For example, we rely on position feedback when reaching for a pen, but on force feedback when putting pressure on the nib to write. However, in a number of other cases, such as when estimating an object's stiffness, the sensorimotor system integrates online information about position and force signals. How these two sensory signals are weighted to control actions and form a perception of object stiffness is still debated.

                http://ht.ly/Fne53058DS6

                1k9cZ8QNuxU#t=11

                One way to disambiguate the contribution of position and force information to stiffness perception is to change the relationship between them by means of programmable robotic devices. For example, in a perceptual task of stiffness discrimination between pairs of linear elastic force fields, it is possible to introduce a time delay between position and force. Previous studies (Nisky et al., 2008, 2010) have shown that, if force information is delayed during movements probing an elastic force field, then subjects will underestimate stiffness. The less those probing movements break contact with the elastic force field, the more they will underestimate stiffness. To explain this, it has been suggested that a position control strategy is used for coordinating probing movements. In this case, the sensorimotor system obtains an estimate of stiffness by controlling a change in position while measuring the resulting force field and calculating a regression between the two to obtain a stiffness estimate. However, without an effort to probe the underlying neural mechanisms, this mechanistic explanation was necessarily speculative.

                There is already evidence that a position controller exists in the brain. The posterior parietal cortex (PPC) has been shown to be associated with such a controller for reaching movements in free space (Chib et al., 2009; Davare et al., 2012). However, there is no evidence of the PPC integrating force and position information, as in the case of forming perception of stiffness or other forms of impedance. We hypothesize that the PPC is used to generate a regression-based stiffness estimator. Therefore, we expect that inducing a “virtual lesion” of PPC by applying continuous theta-burst stimulation (cTBS) (Huang et al., 2005) should alter stiffness judgment. We postulate two possible outcomes after PPC stimulation: (1) if the stimulation affects the position and force signals that serve as input of the estimator, then our regression model predicts a bias in perception without a change in discrimination sensitivity, and (2) if stimulation affects the output of the estimator, then a change in discrimination sensitivity is expected without a bias. Our results support the former hypothesis.
                Perception of "stiffness" during funtional movement is particularly difficult to rehab. I have plum trees and blackberry bushes I would want to get back to post stroke. Currently my palpatory pareidolia tells me that I can feel and interact with variable degrees of tissue stiffness in those I touch during working hours.

                http://ht.ly/Fne53058DS6

                [YT]1k9cZ8QNuxU#t=11[/YT]
                Last edited by Jo Bowyer; 18-10-2016, 04:58 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


                • Sensorimotor-Conceptual Integration in Free Walking Enhances Divergent Thinking for Young and Older Adults

                  http://journal.frontiersin.org/artic...016.01580/full

                  Prior research has shown that free walking can enhance creative thinking. Nevertheless, it remains unclear whether bidirectional body-mind links are essential for the positive effect of free walking on creative thinking. Moreover, it is unknown whether the positive effect can be generalized to older adults. In Experiment 1, we replicated previous findings with two additional groups of young participants. Participants in the rectangular-walking condition walked along a rectangular path while generating unusual uses for chopsticks. Participants in the free-walking group walked freely as they wished, and participants in the free-generation condition generated unconstrained free paths while the participants in the random-experienced condition walked those paths. Only the free-walking group showed better performance in fluency, flexibility, and originality. In Experiment 2, two groups of older adults were randomly assigned to the free-walking and rectangular-walking conditions. The free-walking group showed better performance than the rectangular-walking group. Moreover, older adults in the free-walking group outperformed young adults in the rectangular-walking group in originality and performed comparably in fluency and flexibility. Bidirectional links between proprioceptive-motor kinematics and metaphorical abstract concepts can enhance divergent thinking for both young and older adults.
                  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 Is Medicine Initiative: Physical Activity as a Vital Sign and Prescription in Adult Rehabilitation Practice

                    http://www.sciencedirect.com/science...03999316303434

                    Abstract
                    To support rehabilitation health care professionals' efforts to increase physical activity levels among their outpatient rehabilitation and postdischarge patients, we review the Exercise is Medicine (EIM) initiative. The EIM initiative was launched in 2007 jointly by the American College of Sports Medicine and American Medical Association. Three principles underlie the EIM initiative. First, physical activity should be monitored as a vital sign; second, physical activity is an effective medical modality and should be prescribed; and third, success of their vision requires top down and bottom up efforts by 3 key stakeholder groups: health care providers, exercise professionals, and the community. The target weekly physical activity level is 150 minutes of moderate-to-vigorous physical activity, as established by the Centers for Disease Control and Prevention and World Health Organization. Persons falling below the weekly target physical activity level should be prescribed physical activity and/or referred to an exercise professional for implementation support. Selection of an exercise professional for referral is based on the patient's risk stratification and need to participate in clinically supervised physical activity.
                    Keywords
                    Brain injuries; Exercise; Multiple sclerosis; Public health; Rehabilitation; Spinal cord injuries; Stroke

                    via @SimonGandevia





                    Resistance Training May Slow Multiple Sclerosis Progression

                    http://neurosciencenews.com/ms-resis...training-7220/

                    In the past, multiple sclerosis patients were advised not to exercise for fear of exacerbating the illness. However, it is now known that physical training can relieve many of the symptoms, including the excessive fatigue and mobility impairments that are often seen. New research now shows that resistance training may protect the nervous system and thus slow the progression of the disease.
                    The study shows that resistance training has a number of positive effects on the brain, which go beyond what can be achieved through effective disease specific medication.

                    “Over the past six years, we have been pursuing the idea that physical training has effects on more than just the symptoms, and this study provides the first indications that physical exercise may protect the nervous system against the disease,” says one of the researchers behind the study, Associate Professor Ulrik Dalgas from the Department of Public Health at Aarhus University.

                    “For the past 15 years, we have known that physical exercise does not harm people with multiple sclerosis, but instead often has a positive impact on, for example, their ability to walk, their levels of fatigue, their muscle strength and their aerobic capacity, which has otherwise often deteriorated. But the fact that physical training also seems to have a protective effect on the brain in people with multiple sclerosis is new and important knowledge,” says Ulrik Dalgas.

                    In the study, the researchers followed 35 people with multiple sclerosis for six months. Half of the group engaged in resistance training twice a week, while the other half continued to live their lives normally without systematic training.

                    Prior to and following the six-month period, the test subjects had their brains MR-scanned, and the researchers could see that there was a tendency for the brain to shrink less in those patients who undertook resistance training.

                    “Among persons with multiple sclerosis, the brain shrinks markedly faster than normal. Drugs can counter this development, but we saw a tendency that training further minimises brain shrinkage in patients already receiving medication. In addition, we saw that several smaller brain areas actually started to grow in response to training,” says Ulrik Dalgas.

                    The researchers behind the study are still unable to explain why training has a positive effect on the brain in people with multiple sclerosis. A bigger and more in-depth on-going study will help to clarify this, and may also lead to improved treatment options, says Ulrik Dalgas. However, he stresses that the aim is not to replace medication with physical training.
                    Update 01/08/2017
                    Last edited by Jo Bowyer; 01-08-2017, 10:49 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


                    • Postural Control Can Be Well Maintained by Healthy, Young Adults in Difficult Visual Task, Even in Sway-Referenced Dynamic Conditions

                      http://journals.plos.org/plosone/art...l.pone.0164400

                      Abstract

                      Purpose

                      To challenge the validity of existing cognitive models of postural control, we recorded eye movements and postural sway during two visual tasks (a control free-viewing task and a difficult searching task), and two postural tasks (one static task in which the platform was maintained stable and a dynamic task in which the platform moved in a sway-referenced manner.) We expected these models to be insufficient to predict the results in postural control both in static–as already shown in the literature reports–and in dynamic platform conditions.

                      Methods

                      Twelve healthy, young adults (17.3 to 34.1 years old) participated in this study. Postural performances were evaluated using the Multitest platform (Framiral®) and ocular recording was performed with Mobile T2 (e(ye)BRAIN®). In the free-viewing task, the participants had to look at an image, without any specific instruction. In the searching task, the participants had to look at an image and also to locate the position of an object in the scene.

                      Results

                      Postural sway was only significantly higher in the dynamic free-viewing condition than in the three other conditions with no significant difference between these three other conditions. Visual task performance was slightly higher in dynamic than in static conditions.

                      Discussion

                      As expected, our results did not confirm the main assumption of the current cognitive models of postural control–i.e. that the limited attentional resources of the brain should explain changes in postural control in our conditions. Indeed, 1) the participants did not sway significantly more in the sway-referenced dynamic searching condition than in any other condition; 2) the participants swayed significantly less in both static and dynamic searching conditions than in the dynamic free-viewing condition. We suggest that a new cognitive model illustrating the adaptive, functional role of the brain to control upright stance is necessary for future studies.
                      Jo Bowyer
                      Chartered Physiotherapist Registered Osteopath.
                      "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                      Comment


                      • Biomechanical Constraints Underlying Motor Primitives Derived from the Musculoskeletal Anatomy of the Human Arm

                        http://journals.plos.org/plosone/art...l.pone.0164050

                        Abstract

                        Neural control of movement can only be realized though the interaction between the mechanical properties of the limb and the environment. Thus, a fundamental question is whether anatomy has evolved to simplify neural control by shaping these interactions in a beneficial way. This inductive data-driven study analyzed the patterns of muscle actions across multiple joints using the musculoskeletal model of the human upper limb. This model was used to calculate muscle lengths across the full range of motion of the arm and examined the correlations between these values between all pairs of muscles. Musculoskeletal coupling was quantified using hierarchical clustering analysis. Muscle lengths between multiple pairs of muscles across multiple postures were highly correlated. These correlations broadly formed two proximal and distal groups, where proximal muscles of the arm were correlated with each other and distal muscles of the arm and hand were correlated with each other, but not between groups. Using hierarchical clustering, between 11 and 14 reliable muscle groups were identified. This shows that musculoskeletal anatomy does indeed shape the mechanical interactions by grouping muscles into functional clusters that generally match the functional repertoire of the human arm. Together, these results support the idea that the structure of the musculoskeletal system is tuned to solve movement complexity problem by reducing the dimensionality of available solutions.
                        Jo Bowyer
                        Chartered Physiotherapist Registered Osteopath.
                        "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                        Comment


                        • Are There Abnormalities in Peripheral and Central Components of Somatosensory Evoked Potentials in Non-Specific Chronic Low Back Pain?

                          http://journal.frontiersin.org/artic...016.00521/full

                          Introduction
                          Back pain has become one of the biggest problems of public health in the Western countries. Low back pain has a lifetime prevalence of 84%. The prevalence of chronic low back pain (CLBP) is 23%, and 12% of the population in the Western countries is disabled by low back pain (Airaksinen et al., 2006). A specific structural pathology cannot be identified in about 85% of patients (Deyo and Weinstein, 2001); therefore, this pain syndrome is commonly classified as non-specific CLBP. Previous studies have demonstrated several changes of the sensorimotor system in CLBP patients. Among others, CLBP patients show impairments of muscle relaxation (Paquet et al., 1994), postural control (Radebold et al., 2000), proprioception (Brumagne et al., 2004), respond with pain to nociceptive stimuli of low intensity (Puta et al., 2012, 2013), and show cortical reorganization of representation areas of the back compared to healthy controls (HC; Flor et al., 1997). Data also indicate that CLBP subjects show significant changes of body image and a decrease of tactile acuity in the body area affected by pain (Moseley, 2008).

                          With respect to motor control, several studies demonstrated altered activation of trunk muscles (for review see van Dieën et al., 2003). While some studies indicated delayed activation of deep abdominal muscles (e.g., Hodges and Richardson, 1996), others found changes in superficial trunk muscle activation during external perturbations in low back pain (Magnusson et al., 1996; Wilder et al., 1996; Radebold et al., 2000; Stokes et al., 2000; van Dieën et al., 2003). Furthermore, trunk muscles demonstrated delayed reflex responses after external perturbations (Reeves et al., 2005; Liebetrau et al., 2013; Navalgund et al., 2013). Consistent with these findings, we showed longer reflex response latencies (~15 ms delay; range from 6 ms to 21 ms) of CLBP patients’ trunk muscles to unpredictable external upper limb perturbations during upright standing (Liebetrau et al., 2013). Our model-based approach indicated that such reflex delays of superficial abdominal muscles might impair spinal stability (Liebetrau et al., 2013). These experimental and model-based results contribute to the on-going discussion (Reeves et al., 2009; Wulf et al., 2012) about the clinical relevance and the possible underlying mechanism of the longer reflex latencies in non-specific CLBP.

                          The time delayed reflex responses in CLBP might be due to several processes: altered thresholds of somatosensory activation, lowered conduction velocity of somatosensory nerves, changes of excitability or inhibition of spinal cord structures, changes of supraspinal spinal cord excitability, lowered conduction velocity of motor nerves, altered thresholds of muscle activation, or a combination of these factors. Some studies demonstrated changes at the peripheral level in chronic non-specific and pseudoradicular back pain. Freynhagen et al. (2008) found subclinical sensory impairments at the affected foot dorsum as indexed by increased mechanical and vibratory detection thresholds using quantitative sensory testing (QST) in patients with pseudoradicular back pain. Moreover, a hypersensitivity to pressure pain and a hyposensitivity to vibration were found at the affected region in female back pain patients at the threshold level (Blumenstiel et al., 2011). Furthermore, we found “pinprick allodynia” (Puta et al., 2012) to punctate low-intensity stimuli, and somatosensory abnormalities for painful and innocuous stimuli in female non-specific CLBP patients (Puta et al., 2013). Importantly, these somatosensory abnormalities were detected both at the affected body site (dorsum of the lower back) and at a site distinct from the region of pain, the dominant hand. Both abnormalities might contribute to the increased reflex latencies described above. In addition, reduced conduction velocities might lead to a time delay in the reflex responses. Moreover, a descriptive study in patients with specific low back pain (lumbar spinal stenosis) identified some patients with altered somatosensory evoked potentials (SEPs) and motor evoked potentials (Leinonen et al., 2002). For example, latency of the N40 component was prolonged in one of 26 patients and a lack of responses was observed in two other patients. In addition, smaller magnitude of the N40 component was observed in 61% of patients with lumbar spinal stenosis. Nevertheless, it remains unclear whether early somatosensory processing in CLBP patients is altered.

                          Therefore, the present study aims to investigate latencies of the N9 SEP component following electrical stimulation of the median nerve in CLBP patients and HC as primary outcome. In addition, latencies and amplitudes of the N20 SEP component, sensory thresholds, motor thresholds and nerve conduction velocity for stimulation of the median nerve were assessed. Median nerve was used because altered reflexes responses were found for trunk muscles to perturbations initiated via the hand (Leinonen et al., 2001, 2007), and somatosensory abnormalities at threshold level were identified at the hand (Puta et al., 2012, 2013) in CLBP.
                          Jo Bowyer
                          Chartered Physiotherapist Registered Osteopath.
                          "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                          Comment


                          • The Organization and Control of Intra-Limb Anticipatory Postural Adjustments and Their Role in Movement Performance

                            http://journal.frontiersin.org/artic...016.00525/full

                            Anticipatory Postural Adjustments (APAs) are commonly described as unconscious muscular activities aimed to counterbalance the perturbation caused by the primary movement, so as to ensure the whole-body balance, as well as contributing to initiate the displacement of the body center of mass when starting gait or whole-body reaching movements. These activities usually create one or more fixation chains which spread over several muscles of different limbs, and may be thus called inter-limb APAs. However, it has been reported that APAs also precede voluntary movements involving tiny masses, like a flexion/extension of the wrist or even a brisk flexion of the index-finger. In particular, such movements are preceded by an intra-limb APA chain, that involves muscles acting on the proximal joints. Considering the small mass of the moving segments, it is unlikely that the ensuing perturbation could threaten the whole-body balance, so that it is interesting to enquire the physiological role of intra-limb APAs and their organization and control compared to inter-limb APAs. This review is focused on intra-limb APAs and highlights a strict correspondence in their behavior and temporal/spatial organization with respect to inter-limb APAs. Hence it is suggested that both are manifestations of the same phenomenon. Particular emphasis is given to intra-limb APAs preceding index-finger flexion, because their relatively simple biomechanics and the fact that muscular actions were limited to a single arm allowed peculiar investigations, leading to important conclusions. Indeed, such paradigm provided evidence that by granting a proper fixation of those body segments proximal to the moving one APAs are involved in refining movement precision, and also that APAs and prime mover activation are driven by a shared motor command.


                            Effects of Changing Body Weight Distribution on Mediolateral Stability Control during Gait Initiation

                            http://journal.frontiersin.org/artic...017.00127/full

                            During gait initiation, anticipatory postural adjustments (APA) precede the execution of the first step. It is generally acknowledged that these APA contribute to forward progression but also serve to stabilize the whole body in the mediolateral direction during step execution. Although previous studies have shown that changes in the distribution of body weight between both legs influence motor performance during gait initiation, it is not known whether and how such changes affect a person’s postural stability during this task. The aim of this study was to investigate the effects of changing initial body weight distribution between legs on mediolateral postural stability during gait initiation. Changes in body weight distribution were induced under experimental conditions by modifying the frontal plane distribution of an external load located at the participants’ waists. Fifteen healthy adults performed a gait initiation series at a similar speed under three conditions: with the overload evenly distributed over both legs; with the overload strictly distributed over the swing-limb side; and with the overload strictly distributed over the stance-leg side. Our results showed that the mediolateral location of center-of-mass (CoM) during the initial upright posture differed between the experimental conditions, indicating modifications in the initial distribution of body weight between the legs according to the load distribution. While the parameters related to the forward progression remained unchanged, the alterations in body weight distribution elicited adaptive changes in the amplitude of APA in the mediolateral direction (i.e., maximal mediolateral shift of the center of pressure (CoP)), without variation in their duration. Specifically, it was observed that the amplitude of APA was modulated in such a way that mediolateral dynamic stability at swing foot-contact, quantified by the margin of stability (i.e., the distance between the base of support boundary and the extrapolated CoM position), did not vary between the conditions. These findings suggest that APA seem to be scaled as a function of the initial body weight distribution between both legs so as to maintain optimal conditions of stability during gait initiation.
                            Update 14/04/2017




                            Influence of slope steepness, foot position and turn phase on plantar pressure distribution during giant slalom alpine ski racing

                            http://journals.plos.org/plosone/art...l.pone.0176975

                            Abstract

                            The purpose of this study was to investigate the evolution of ground reaction force during alpine skiing turns. Specifically, this study investigated how turn phases and slope steepness affected the whole foot normal GRF pattern while performing giant slalom turns in a race-like setting. Moreover, the outside foot was divided into different plantar regions to see whether those parameters affected the plantar pressure distribution. Eleven skiers performed one giant slalom course at race intensity. Runs were recorded synchronously using a video camera in the frontal plane and pressure insoles under both feet’s plantar surface. Turns were divided according to kinematic criteria into four consecutive phases: initiation, steering1, steering2 and completion; both steering phases being separated by the gate passage. Component of the averaged Ground Reaction Force normal to the ski’s surface(, /BW), and Pressure Time Integral relative to the entire foot surface (relPTI, %) parameters were calculated for each turn phases based on plantar pressure data. Results indicated that under the total foot surface differed significantly depending on the slope (higher in steep sections vs. flat sections), and the turn phase (higher during steering2 vs. three other phases), although such modifications were observable only on the outside foot. Moreover, under the outside foot was significantly greater than under the inside foot.RelPTI under different foot regions of the outside foot revealed a global shift from forefoot loading during initiation phase, toward heel loading during steering2 phase, but this was dependent on the slope studied. These results suggest a differentiated role played by each foot in alpine skiing turns: the outside foot has an active role in the turning process, while the inside foot may only play a role in stability.
                            Update 05/05/2017
                            Last edited by Jo Bowyer; 05-05-2017, 12:46 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


                            • One in the Dance: Musical Correlates of Group Synchrony in a Real-World Club Environment

                              http://journals.plos.org/plosone/art...l.pone.0164783

                              Abstract

                              Previous research on interpersonal synchrony has mainly investigated small groups in isolated laboratory settings, which may not fully reflect the complex and dynamic interactions of real-life social situations. The present study expands on this by examining group synchrony across a large number of individuals in a naturalistic environment. Smartphone acceleration measures were recorded from participants during a music set in a dance club and assessed to identify how group movement synchrony covaried with various features of the music. In an evaluation of different preprocessing and analysis methods, giving more weight to front-back movement provided the most sensitive and reliable measure of group synchrony. During the club music set, group synchrony of torso movement was most strongly associated with pulsations that approximate walking rhythm (100–150 beats per minute). Songs with higher real-world play counts were also correlated with greater group synchrony. Group synchrony thus appears to be constrained by familiarity of the movement (walking action and rhythm) and of the music (song popularity). These findings from a real-world, large-scale social and musical setting can guide the development of methods for capturing and examining collective experiences in the laboratory and for effectively linking them to synchrony across people in daily life.
                              Jo Bowyer
                              Chartered Physiotherapist Registered Osteopath.
                              "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                              Comment


                              • Do rocker-sole shoes influence postural stability in chronic low back pain? A randomised trial

                                http://bmjopensem.bmj.com/content/2/1/e000170

                                Abstract
                                Background People with chronic low back pain (CLBP) demonstrate greater postural instability compared with asymptomatic individuals. Rocker-sole shoes are inherently unstable and may serve as an effective balance training device. This study hypothesised that wearing rocker-sole shoes would result in long-term improvement in barefoot postural stability in people with CLBP.

                                Methods 20 participants with CLBP were randomised to wear rocker-sole or flat-sole shoes for a minimum of 2 hours each day. Participants were assessed barefoot and shod, over three 40 s trials, under 4 posture challenging standing conditions. The primary outcome was postural stability assessed by root mean squared error of centre of pressure (CoP) displacement (CoPRMSE AP) and mean CoP velocity (CoPVELAP), both in the anteroposterior direction, using force plates. Participants' were assessed without knowledge of group allocation at baseline, 6 weeks and 6 months (main outcome point). Analyses were by intention-to-treat.

                                Results At 6 months, data from 11 of 13 (84.6%) of the rocker-sole and 5 of 7 (71.4%) of the flat-sole group were available for analysis. At baseline, there was a mean increase in CoPRMSE AP (6.41 (2.97) mm, p<0.01) and CoPVELAP (4.10 (2.97) mm, p<0.01) in the rocker-sole group when shod compared with barefoot; there was no difference in the flat-sole group. There were no within-group or between-group differences in change in CoP parameters at any time point compared with baseline (1) for any barefoot standing condition (2) when assessed shod eyes-open on firm ground.

                                Conclusions Although wearing rocker-sole shoes results in greater postural instability than flat-sole shoes, long-term use of rocker-sole shoes did not appear to influence postural stability in people with CLBP.
                                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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