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  • Sensorimotor Coarticulation in the Execution and Recognition of Intentional Actions

    http://journal.frontiersin.org/artic...017.00237/full

    Humans excel at recognizing (or inferring) another's distal intentions, and recent experiments suggest that this may be possible using only subtle kinematic cues elicited during early phases of movement. Still, the cognitive and computational mechanisms underlying the recognition of intentional (sequential) actions are incompletely known and it is unclear whether kinematic cues alone are sufficient for this task, or if it instead requires additional mechanisms (e.g., prior information) that may be more difficult to fully characterize in empirical studies. Here we present a computationally-guided analysis of the execution and recognition of intentional actions that is rooted in theories of motor control and the coarticulation of sequential actions. In our simulations, when a performer agent coarticulates two successive actions in an action sequence (e.g., “reach-to-grasp” a bottle and “grasp-to-pour”), he automatically produces kinematic cues that an observer agent can reliably use to recognize the performer's intention early on, during the execution of the first part of the sequence. This analysis lends computational-level support for the idea that kinematic cues may be sufficiently informative for early intention recognition. Furthermore, it suggests that the social benefits of coarticulation may be a byproduct of a fundamental imperative to optimize sequential actions. Finally, we discuss possible ways a performer agent may combine automatic (coarticulation) and strategic (signaling) ways to facilitate, or hinder, an observer's action recognition processes.
    Jo Bowyer
    Chartered Physiotherapist Registered Osteopath.
    "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

    Comment


    • Physical performance analysis: A new approach to assessing free-living physical activity in musculoskeletal pain and mobility-limited populations

      http://journals.plos.org/plosone/art...l.pone.0172804

      Abstract

      Background

      Accurate measurement of physical performance in individuals with musculoskeletal pain is essential. Accelerometry is a powerful tool for this purpose, yet the current methods designed to evaluate energy expenditure are not optimized for this population. The goal of this study is to empirically derive a method of accelerometry analysis specifically for musculoskeletal pain populations.

      Methods

      We extracted data from 6,796 participants in the 2003–4 National Health and Nutrition Examination Survey (NHANES) including: 7-day accelerometry, health and pain questionnaires, and anthropomorphics. Custom macros were used for data processing, complex survey regression analyses, model selection, and statistical adjustment. After controlling for a multitude of variables that influence physical activity, we investigated whether distinct accelerometry profiles accompany pain in different locations of the body; and we identified the intensity intervals that best characterized these profiles.

      Results

      Unique accelerometry profiles were observed for pain in different body regions, logically clustering together based on proximity. Based on this, the following novel intervals (counts/minute) were identified and defined: Performance Sedentary (PSE) = 1–100, Performance Light 1 (PL1) = 101–350, Performance Light 2 (PL2) = 351–800, Performance Light 3 (PL3) = 801–2500, and Performance Moderate/Vigorous (PMV) = 2501–30000. The refinement of accelerometry signals into these new intervals, including 3 distinct ranges that fit inside the established light activity range, best captures alterations in real-life physical performance as a result of regional pain.

      Discussion and conclusions

      These new accelerometry intervals provide a model for objective measurement of real-life physical performance in people with pain and musculoskeletal disorders, with many potential uses. They may be used to better evaluate the relationship between pain and daily physical function, monitor musculoskeletal disease progression, gauge disease severity, inform exercise prescription, and quantify the functional impact of treatments. Based on these findings, we recommend that future studies of pain and musculoskeletal disorders analyze accelerometry output based on these new “physical performance” intervals.
      Jo Bowyer
      Chartered Physiotherapist Registered Osteopath.
      "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

      Comment


      • Assessing upper-extremity motion: An innovative method to quantify functional capacity in patients with chronic obstructive pulmonary disease

        http://journals.plos.org/plosone/art...l.pone.0172766

        Abstract

        Background

        Assessment of functional capacity is important in directing chronic obstructive pulmonary disease (COPD) care (e.g., rehabilitation and discharge readiness), and in predicting outcomes (e.g., exacerbation, hospitalization, and mortality). The 6-minute walk distance (6MWD) test for functional capacity assessment, may be time-consuming and burdensome.

        Objective

        The purpose of the current study was to evaluate an upper-extremity function (UEF) test for assessing functional capacity in older adults with COPD.

        Methods

        In this cross-sectional study, 49 older adults (≥55 years) with diagnosed COPD were recruited, and pulmonary function measures and 6MWD were obtained. Participants wore wireless sensors on forearm and upper-arm and performed rapid elbow flexion for 20 seconds (the UEF test). Slowness was assessed by measuring elbow speed, and acceleration and weakness (muscle strength) were assessed by measuring power of movement and elbow moment.

        Results

        Speed, power, and moment UEF parameters were independently associated with 6MWD, when controlling for age, gender, and body mass index (BMI) (r = 0.78, p < .001). Elbow moment showed significant Pearson correlations with all pulmonary function measures and maximal inspiratory/expiratory pressure measures (r = 0.35–0.69, p<0.02).

        Conclusions

        Results show promise of a quick upper-extremity measure of functional capacity in patients with COPD, and as an outcome measure in clinical COPD trials.
        Jo Bowyer
        Chartered Physiotherapist Registered Osteopath.
        "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

        Comment


        • Comparison of wrist-worn Fitbit Flex and waist-worn ActiGraph for measuring steps in free-living adults

          http://journals.plos.org/plosone/art...l.pone.0172535

          Abstract

          Introduction

          Accelerometers are commonly used to assess physical activity. Consumer activity trackers have become increasingly popular today, such as the Fitbit. This study aimed to compare the average number of steps per day using the wrist-worn Fitbit Flex and waist-worn ActiGraph (wGT3X-BT) in free-living conditions.

          Methods

          104 adult participants (n = 35 males; n = 69 females) were asked to wear a Fitbit Flex and an ActiGraph concurrently for 7 days. Daily step counts were used to classify inactive (<10,000 steps) and active (≥10,000 steps) days, which is one of the commonly used physical activity guidelines to maintain health. Proportion of agreement between physical activity categorizations from ActiGraph and Fitbit Flex was assessed. Statistical analyses included Spearman’s rho, intraclass correlation (ICC), median absolute percentage error (MAPE), Kappa statistics, and Bland-Altman plots. Analyses were performed among all participants, by each step-defined daily physical activity category and gender.

          Results

          The median average steps/day recorded by Fitbit Flex and ActiGraph were 10193 and 8812, respectively. Strong positive correlations and agreement were found for all participants, both genders, as well as daily physical activity categories (Spearman's rho: 0.76–0.91; ICC: 0.73–0.87). The MAPE was: 15.5% (95% confidence interval [CI]: 5.8–28.1%) for overall steps, 16.9% (6.8–30.3%) vs. 15.1% (4.5–27.3%) in males and females, and 20.4% (8.7–35.9%) vs. 9.6% (1.0–18.4%) during inactive days and active days. Bland-Altman plot indicated a median overestimation of 1300 steps/day by the Fitbit Flex in all participants. Fitbit Flex and ActiGraph respectively classified 51.5% and 37.5% of the days as active (Kappa: 0.66).

          Conclusions

          There were high correlations and agreement in steps between Fitbit Flex and ActiGraph. However, findings suggested discrepancies in steps between devices. This imposed a challenge that needs to be considered when using Fibit Flex in research and health promotion programs.
          Jo Bowyer
          Chartered Physiotherapist Registered Osteopath.
          "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

          Comment


          • Complementary mechanisms for upright balance during walking

            http://journals.plos.org/plosone/art...l.pone.0172215

            Abstract

            Lateral balance is a critical factor in keeping the human body upright during walking. Two important mechanisms for balance control are the stepping strategy, in which the foot placement is changed in the direction of a sensed fall to modulate how the gravitational force acts on the body, and the lateral ankle strategy, in which the body mass is actively accelerated by an ankle torque. Currently, there is minimal evidence about how these two strategies complement one another to achieve upright balance during locomotion. We use Galvanic vestibular stimulation (GVS) to induce the sensation of a fall at heel-off during gait initiation. We found that young healthy adults respond to the illusory fall using both the lateral ankle strategy and the stepping strategy. The stance foot center of pressure (CoP) is shifted in the direction of the perceived fall by ≈2.5 mm, starting ≈247 ms after stimulus onset. The foot placement of the following step is shifted by ≈15 mm in the same direction. The temporal delay between these two mechanisms suggests that they independently contribute to upright balance during locomotion, potentially in a serially coordinated manner. Modeling results indicate that without the lateral ankle strategy, a much larger step width is required to maintain upright balance, suggesting that the small but early CoP shift induced by the lateral ankle strategy is critical for upright stability during locomotion. The relative importance of each mechanism and how neurological disorders may affect their implementation remain an open question.
            Jo Bowyer
            Chartered Physiotherapist Registered Osteopath.
            "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

            Comment


            • Curved Walking Rehabilitation with a Rotating Treadmill in Patients with Parkinson’s Disease: A Proof of Concept

              http://journal.frontiersin.org/artic...017.00053/full

              Training subjects to step-in-place eyes open on a rotating platform while maintaining a fixed body orientation in space [podokinetic stimulation (PKS)] produces a posteffect consisting in inadvertent turning around while stepping-in-place eyes closed [podokinetic after-rotation (PKAR)]. Since the rationale for rehabilitation of curved walking in Parkinson’s disease is not fully known, we tested the hypothesis that repeated PKS favors the production of curved walking in these patients, who are uneasy with turning, even when straight walking is little affected. Fifteen patients participated in 10 training sessions distributed in 3 weeks. Both counterclockwise and clockwise PKS were randomly administered in each session. PKS velocity and duration were gradually increased over sessions. The velocity and duration of the following PKAR were assessed. All patients showed PKAR, which increased progressively in peak velocity and duration. In addition, before and at the end of the treatment, all patients walked overground along linear and circular trajectories. Post-training, the velocity of walking bouts increased, more so for the circular than the linear trajectory. Cadence was not affected. This study has shown that parkinsonian patients learn to produce turning while stepping when faced with appropriate training and that this capacity translates into improved overground curved walking.
              Fabulous stuff! I have a few younger patients with this diagnosis and there is significant fear factor when any rotational component is introduced into gait related activity.
              Jo Bowyer
              Chartered Physiotherapist Registered Osteopath.
              "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

              Comment


              • Validity and reliability of a new tool to evaluate handwriting difficulties in Parkinson’s disease

                http://journals.plos.org/plosone/art...l.pone.0173157

                Abstract

                Background

                Handwriting in Parkinson’s disease (PD) features specific abnormalities which are difficult to assess in clinical practice since no specific tool for evaluation of spontaneous movement is currently available.

                Objective

                This study aims to validate the ‘Systematic Screening of Handwriting Difficulties’ (SOS-test) in patients with PD.

                Methods

                Handwriting performance of 87 patients and 26 healthy age-matched controls was examined using the SOS-test. Sixty-seven patients were tested a second time within a period of one month. Participants were asked to copy as much as possible of a text within 5 minutes with the instruction to write as neatly and quickly as in daily life. Writing speed (letters in 5 minutes), size (mm) and quality of handwriting were compared. Correlation analysis was performed between SOS outcomes and other fine motor skill measurements and disease characteristics. Intrarater, interrater and test-retest reliability were assessed using the intraclass correlation coefficient (ICC) and Spearman correlation coefficient.

                Results

                Patients with PD had a smaller (p = 0.043) and slower (p<0.001) handwriting and showed worse writing quality (p = 0.031) compared to controls. The outcomes of the SOS-test significantly correlated with fine motor skill performance and disease duration and severity. Furthermore, the test showed excellent intrarater, interrater and test-retest reliability (ICC > 0.769 for both groups).

                Conclusion

                The SOS-test is a short and effective tool to detect handwriting problems in PD with excellent reliability. It can therefore be recommended as a clinical instrument for standardized screening of handwriting deficits in PD.
                Jo Bowyer
                Chartered Physiotherapist Registered Osteopath.
                "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                Comment


                • Proper movements in Muslim prayer ritual can reduce lower back pain

                  https://www.sciencedaily.com/release...0306154230.htm

                  Five times a day, roughly 1.6 billion Muslims worldwide, bow, kneel, and place their foreheads to the ground in the direction of the holy city of Mecca, Saudi Arabia, as part of the Islamic prayer ritual, the Salat. According to research, the complex physical movements of the ritual can reduce lower back pain if performed regularly and properly.
                  It's a delicate subject, younger patients become concerned if they feel that they are unable to perform the movement element of the prayer as they feel they should. Most of my patients are able to show me where they have difficulty on the floor of the treatment room and this can usually be worked around. If they remain worried, the Imam is a source of reassurance, they will have met and dealt with similar situations.
                  Jo Bowyer
                  Chartered Physiotherapist Registered Osteopath.
                  "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                  Comment


                  • Structural and Functional Cortical Connectivity Mediating Cross Education of Motor Function

                    http://www.jneurosci.org/content/37/10/2555?etoc=

                    Abstract

                    Cross-education (CE) is the process whereby training with one limb leads to subsequent improvement in performance by the opposite untrained limb. We used multimodal neuroimaging in humans to investigate the mediating neural mechanisms by relating quantitative estimates of functional and structural cortical connectivity to individual levels of interlimb transfer. Resting-state (rs)-fMRI and diffusion weighted imaging (DWI) scans were undertaken before unilateral ballistic wrist flexion training. The rs-fMRI sequence was repeated immediately afterward. The increase in performance of the untrained limb was 83.6% of that observed for the trained limb and significantly greater than that of a control group who undertook no training. Functional connectivity in the resting motor network between right and left supplementary motor areas (SMA) was elevated after training. These changes were not, however, correlated with individual levels of transfer. Analysis of the DWI data using constrained spherical deconvolution-based tractography indicated that fractional anisotropy and apparent fiber density in tracts connecting bilateral SMA were negatively correlated with and predictive of transfer. The findings suggest that interhemispheric interactions between bilateral SMA play an instrumental role in CE and that the structural integrity of the connecting white matter pathways influences the level of transfer.

                    SIGNIFICANCE STATEMENT Strength or skill training with one limb also brings about improvements in the performance of the opposite, untrained limb. This phenomenon, termed cross-education (CE), has obvious potential for the rehabilitation of functional capacity that has been lost through brain insult or musculoskeletal injury. The neural mechanisms that give rise to CE are, however, poorly understood. We used a combination of neuroimaging methods to investigate the pathways in the human brain that mediate CE. We determined that the supplementary motor area (SMA) plays an important role in the interlimb transfer of performance gains and demonstrate that the quality of the white matter fibers connecting right and left SMA predicts the benefit that an individual derives from CE.
                    interlimb motor learning transfer
                    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 Learning Enhances Use-Dependent Plasticity

                      http://www.jneurosci.org/content/37/10/2673?etoc=

                      Abstract

                      Motor behaviors are shaped not only by current sensory signals but also by the history of recent experiences. For instance, repeated movements toward a particular target bias the subsequent movements toward that target direction. This process, called use-dependent plasticity (UDP), is considered a basic and goal-independent way of forming motor memories. Most studies consider movement history as the critical component that leads to UDP (Classen et al., 1998; Verstynen and Sabes, 2011). However, the effects of learning (i.e., improved performance) on UDP during movement repetition have not been investigated. Here, we used transcranial magnetic stimulation in two experiments to assess plasticity changes occurring in the primary motor cortex after individuals repeated reinforced and nonreinforced actions. The first experiment assessed whether learning a skill task modulates UDP. We found that a group that successfully learned the skill task showed greater UDP than a group that did not accumulate learning, but made comparable repeated actions. The second experiment aimed to understand the role of reinforcement learning in UDP while controlling for reward magnitude and action kinematics. We found that providing subjects with a binary reward without visual feedback of the cursor led to increased UDP effects. Subjects in the group that received comparable reward not associated with their actions maintained the previously induced UDP. Our findings illustrate how reinforcing consistent actions strengthens use-dependent memories and provide insight into operant mechanisms that modulate plastic changes in the motor cortex.

                      SIGNIFICANCE STATEMENT Performing consistent motor actions induces use-dependent plastic changes in the motor cortex. This plasticity reflects one of the basic forms of human motor learning. Past studies assumed that this form of learning is exclusively affected by repetition of actions. However, here we showed that success-based reinforcement signals could affect the human use-dependent plasticity (UDP) process. Our results indicate that learning augments and interacts with UDP. This effect is important to the understanding of the interplay between the different forms of motor learning and suggests that reinforcement is not only important to learning new behaviors, but can shape our subsequent behavior via its interaction with UDP.
                      Jo Bowyer
                      Chartered Physiotherapist Registered Osteopath.
                      "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                      Comment


                      • Perceptions of physical activity and walking in an early stage after stroke or acquired brain injury

                        http://journals.plos.org/plosone/art...l.pone.0173463

                        Abstract

                        Background

                        Physical activity has been established as being highly beneficial for health after stroke. There are considerable global efforts to find rehabilitation programs that encourage increased physical activity for persons with stroke. However, many persons with stroke or acquired brain injury do not reach recommended levels of physical activity and increased knowledge about why is needed. We aimed to explore views and experiences of physical activity and walking among persons with stroke or acquired brain injury.

                        Method

                        A qualitative study was conducted, among persons with stroke (n = 8) or acquired brain injury (n = 2) from a rehabilitation unit at Sahlgrenska University Hospital in Sweden. Semi-structured in-depth interviews were held about perceptions and experiences of walking and physical activity in general. Data were analyzed using qualitative content analysis, with categories that were determined inductively.

                        Results

                        Physical activity in general and walking ability more specifically were considered very important by the participants. However, physical activity was, regardless of exercising habits pre-injury, associated with different kinds of negative feelings and experiences. Commonly reported internal barriers in the current study were; fatigue, fear of falling or getting hurt in traffic, lack of motivation and depression. Reported external barriers were mostly related to walking, for example; bad weather, uneven ground, lack of company or noisy or too busy surroundings.

                        Conclusion

                        Persons with stroke or acquired brain injury found it difficult to engage in and sustain an eligible level of physical activity. Understanding individual concerns about motivators and barriers surrounding physical activity may facilitate the work of forming tailor-made rehabilitation for these groups, so that the levels of physical activity and walking can increase.
                        It's worth reading the excerpts from the patient interviews.
                        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 parameters for gait analysis: a systematic review of healthy human gait


                          http://www.hoajonline.com/phystherrehabil/2055-2386/4/6


                          Abstract


                          Background: Modern gait analysis offers a broad variety of biomechanical parameters through which to quantify gait. However, no consensus has yet been established with regards to which biomechanical parameters are most relevant to evaluate during gait analysis in the healthy population.

                          Purpose: The purpose of the current systematic review was to determine the most relevant biomechanical parameters for gait analysis in the healthy adult population.

                          Methods: PubMed, EMBASE and Web of Science databases were searched. Two independent reviewers participated in the article selection and attributed a Level of Evidence score to each article to account for quality based on participant selection, intervention and analysis. A score combining both frequency and number of articles was calculated. Correlations were carried out between the Level of Evidence score, Journal Impact Factor and the frequency of biomechanical parameters.

                          Results: Spatio-temporal parameters were found to be the most often measured biomechanical parameters and reported by the greatest number of articles; walking velocity, cadence and step/stride length appearing to be the most relevant biomechanical parameters for gait analysis in the healthy adult population. No correlation was found between Level of Evidence score and Journal Impact Factor, nor between the frequency of parameters and Level of Evidence score.

                          Conclusion: This systematic review provides recommendations for variables to assess in future gait evaluations in healthy adults.
                          Keywords: Gait, biomechanics, gait analysis, healthy, adult


                          Introduction


                          Walking is the most common form of locomotion and it is part of almost all activities of daily living [1,2]; therefore, the ability to walk is an indicator of overall health as it dictates autonomy [3]. Although walking is usually learned at a young age, the mechanics of walking are not as simple as they may appear [1].

                          From the first studies of human walking elaborated through a series of photographic images, by early Biomechanics enthusiasts Edweard Muybridge and Étienne-Jules Marey, gait analysis as it is known today has evolved significantly [4]. The walking pattern of individuals has become an area of broad interest and the focus of much research as seen by the numerous journals and articles published. The importance of gait analysis lies in its application; through years of research and experimentation, gait analysis has become widely used as a means to diagnose pathology, set a prognosis and establish and evaluate a treatment plan [5,6]. Today, a variety of different parameters of various types exist and are readily used to examine and explain human gait [7-10].

                          In clinical settings, gait analysis is often carried out solely through clinician observation [11]. Although clinicians have developed good expertise through many years of practice and training, these observations remain subjective [12]. Principal reason for main, and perhaps sole use of clinician observation as means of gait analysis, is ease of measurement [8,13,14].


                          Jo Bowyer
                          Chartered Physiotherapist Registered Osteopath.
                          "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                          Comment


                          • Longitudinal sequencing in intramuscular coordination: A new hypothesis of dynamic functions in the human rectus femoris muscle


                            http://journals.plos.org/plosone/art...l.pone.0183204

                            Abstract


                            The punctum fixum-punctum mobile model has been introduced in previous publications. It describes general principles of intersegmental neuromuscular succession patterns to most efficiently generate specific movement intentions. The general hypothesis of this study is that these principles—if they really do indicate a fundamental basis for efficient movement generation—should also be found in intramuscular coordination and should be indicated by “longitudinal sequencing” between fibers according to the principles of the punctum fixum-punctum mobile model. Based on this general hypothesis an operationalized model was developed for the rectus femoris muscle (RF), to exemplarily scrutinize this hypothesis for the RF. Electromyography was performed for 14 healthy male participants by using two intramuscular fine wire electrodes in the RF (placed proximal and distal), three surface electrodes over the RF (placed proximal, middle, and distal), and two surface electrodes over the antagonists (m. biceps femoris and m. semitendinosus). Three movement tasks were measured: kicking movements; deceleration after sprints; and passively induced backward accelerations of the leg. The results suggest that proximal fibers can be activated independently from distal fibers within the RF. Further, it was shown that the hypothesized function of “intramuscular longitudinal sequencing” does exist during dynamic movements. According to the punctum fixum-punctum mobile model, the activation succession between fibers changes direction (from proximal to distal or inversely) depending on the intentional context. Thus, the results seem to support the general hypothesis for the RF and could be principally in line with the operationalized “inter-fiber to tendon interaction model”.
                            Jo Bowyer
                            Chartered Physiotherapist Registered Osteopath.
                            "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                            Comment


                            • Timing and extent of finger force enslaving during a dynamic force task cannot be explained by EMG activity patterns


                              http://journals.plos.org/plosone/art...l.pone.0183145


                              Abstract


                              Finger enslaving is defined as the inability of the fingers to move or to produce force independently. Such finger enslaving has predominantly been investigated for isometric force tasks. The aim of this study was to assess whether the extent of force enslaving is dependent on relative finger movements. Ten right-handed subjects (22–30 years) flexed the index finger while counteracting constant resistance forces (4, 6 and 8 N) orthogonal to the fingertip. The other, non-instructed fingers were held in extension. EMG activities of the mm. flexor digitorum superficialis (FDS) and extensor digitorum (ED) in the regions corresponding to the index, middle and ring fingers were measured. Forces exerted by the non-instructed fingers increased substantially (by 0.2 to 1.4 N) with flexion of the index finger, increasing the enslaving effect with respect to the static, pre-movement phase. Such changes in force were found 260–370 ms after the initiation of index flexion. The estimated MCP joint angle of the index finger at which forces exerted by the non-instructed fingers started to increase varied between 4° and 6°. In contrast to the finger forces, no significant changes in EMG activity of the FDS regions corresponding to the non-instructed fingers upon index finger flexion were found. This mismatch between forces and EMG of the non-instructed fingers, as well as the delay in force development are in agreement with connective tissue linkages being slack when the positions of the fingers are similar, but pulled taut when one finger moves relative to the others. Although neural factors cannot be excluded, our results suggest that mechanical connections between muscle-tendon structures were (at least partly) responsible for the observed increase in force enslaving during index finger flexion.
                              Jo Bowyer
                              Chartered Physiotherapist Registered Osteopath.
                              "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                              Comment


                              • A cross-sectional study comparing lateral and diagonal maximum weight shift in people with stroke and healthy controls and the correlation with balance, gait and fear of falling


                                http://journals.plos.org/plosone/art...l.pone.0183020


                                Abstract


                                Impaired balance is common post stroke and can be assessed by means of force-platforms measuring center of pressure (COP) displacements during static standing, or more dynamically during lateral maximum weight shift (MWS). However, activities of daily life also include diagonal MWS and since force platforms are nowadays commercially available, investigating lateral and diagonal MWS in a clinical setting might be feasible and clinically relevant. We investigated lateral and diagonal MWS while standing in patients with stroke (PwS) and healthy controls (HC), evaluated MWS towards the affected and the non-affected side for PwS and correlated MWS with measures of balance, gait and fear of falling. In a cross-sectional observational study including 36 ambulatory sub-acute inpatients and 32 age-matched HC, a force platform (BioRescue, RM Ingénierie, France) was used to measure lateral and diagonal MWS in standing. Clinical outcome measures collected were Berg Balance Scale and Community Balance and Mobility Scale (CBMS) for balance, 10-meter walk test (10MWT) for gait speed and Falls Efficacy Scale–international version for fear of falling. MWS for PwS towards the affected side was significantly smaller compared to HC (lateral: p = 0.029; diagonal-forward: p = 0.000). MWS for PwS was also significantly reduced towards the affected side in the diagonal-forward direction (p = 0.019) compared to the non-affected side of PwS. Strong correlations were found for MWS for PwS in the diagonal-forward direction towards the affected side, and clinical measures of balance (CBMS: r = 0.66) and gait speed (10MWT: r = 0.66). Our study showed that ambulatory sub-acute PwS, in comparison to HC, have decreased ability to shift their body weight diagonally forward in standing towards their affected side. This reduced ability is strongly related to clinical measures of balance and gait speed. Our results suggest that MWS in a diagonal-forward direction should receive attention in rehabilitation of ambulatory sub-acute PwS in an inpatient setting.
                                Jo Bowyer
                                Chartered Physiotherapist Registered Osteopath.
                                "Out beyond ideas of wrongdoing and rightdoing,there is a field. I'll meet you there." Rumi

                                Comment

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