Effort matching between arms depends on relative limb geometry and personal control.

Proprioception encompasses our sense of position and movement of our limbs, as well as the effort with which we engage in voluntary actions. Historically, sense of effort has been linked to centrally generated signals that elicit voluntary movements. We were interested in determining the effect of differences in limb geometry and personal control on sense of effort. In experiment 1, subjects exerted either extension or flexion torques to resist a torque applied by a robot exoskeleton to their reference elbow. They attempted to match this torque by exerting an equal effort torque (in a congruent direction with the reference arm) with their opposite (matching) arm in different limb positions (±15°). Subjects produced greater matching torque when their matching arm exerted effort toward the mirrored position of the reference (e.g., reference/matching arms at 90°/105° elbow flexion) vs. away (e.g., 90°/75° flexion). In experiment 2, a larger angular difference between arms (30°) resulted in a larger discrepancy in matched torques. Furthermore, in both experiments 1 and 2, subjects tended to overestimate the reference arm torque. This motivated a third experiment to determine whether providing more personal control might influence perceived effort and reduce the overestimation of the reference torques that we observed ( experiments 3a and 3b). Overestimation of the matched torques decreased significantly when subjects self-selected the reference torque that they were matching. Collectively, our data suggest that perceived effort between arms can be influenced by signals relating to the relative geometry of the limbs and the personal control of motor output during action. NEW & NOTEWORTHY This work highlights how limb geometry influences our sense of effort during voluntary motor actions. It also suggests that loss of personal control during motor actions leads to an increase in perceived effort.

Proceedings from the 9th Annual University of Calgary Leaders in Medicine Research Symposium.

On November 3, 2017 the Leaders in Medicine (LIM) program at the University of Calgary's Cumming School of Medicine hosted the 9th Annual Leaders in Medicine (LIM) Symposium. This year's event commemorated 20 years of the LIM program and its dedication to the training of clinician- scientists.

Proceedings from the 8th Annual University of Calgary Leaders in Medicine Research Symposium.

On November 14, 2016, the Leaders in Medicine (LIM) program at the Cumming School of Medicine, University of Calgary hosted its 8th Annual Research Symposium. Professor Stephen Sawcer, Professor of Neurological Genetics at the University of Cambridge and an Honorary Consultant Neurologist at Addenbrooke's Hospital, was the keynote speaker and presented a lecture entitled, "Multiple sclerosis genetics - prospects and pitfalls". This was not only a cutting edge address on genetics but also a thoughtful overview on Dr. Sawcer's career and career choices. We were extremely grateful for the opportunity to have Dr. Sawcer participate in our annual symposium.

Using Robotics to Quantify Impairments in Sensorimotor Ability, Visuospatial Attention, Working Memory, and Executive Function After Traumatic Brain Injury.

OBJECTIVE: To investigate the use of a robotic assessment tool to quantify sensorimotor, visuospatial attention, and executive function impairments in individuals with traumatic brain injury (TBI). SETTING: Foothills Hospital (Calgary, Canada). PARTICIPANTS: Twenty-three subjects with first-time TBI in the subacute to chronic phase participated in this study. Normative data were collected from 275 to 494 neurologically intact control subjects for each robotic task. DESIGN: A prospective observational case series. Subjects with TBI completed brief clinical cognitive and motor assessments followed by robotic assessments of upper limb reaching, position sense, bimanual motor ability, attention, and visuospatial skills. Scores of subjects with TBI were compared with normative data. MAIN MEASURES: Robotic task performance was computed for each subject on each task, as well as performance on specific task parameters. Clinical assessments included the Montreal Cognitive Assessment, Fugl-Meyer upper extremity assessment, and Purdue Peg Board. RESULTS: Subjects with TBI demonstrated a variety of deficits on robotic tasks. The proportion of TBI subjects who were significantly different from controls ranged from 36% (dominant arm reaching) to 60% (bimanual object hitting task). CONCLUSION: Robotic measures allowed us to quantify a range of impairments specific to each subject, and offer an objective tool with which to examine these abilities after TBI.

Pandemic-associated mental health changes in youth with neuroinflammatory disorders.

BACKGROUND: Children with neuroinflammatory disorders have high rates of anxiety and depression, alongside low rates of physical activity. Given general concerns for mental and physical health in children during the COVID-19 pandemic lockdown, here we sought to understand how sleep, anxiety, depression, and physical activity changed with the lockdown in children with neuroinflammatory disorders. We hypothesized that outcomes would worsen during the lockdown, and that they would differ by underlying disorder category and age. METHODS: Patients attending a specialized neuroinflammatory clinic (n = 314) completed questionnaires (n = 821 responses; Jan 2017-Aug 2020) assessing sleep, anxiety, depression, and physical activity. Respondents had either: childhood-onset chronic or recurrent neuroinflammatory disorders (CRNI), a history of Autoimmune Encephalitis (AE) or Monophasic Acquired Demyelinating Syndromes (monoADS). We performed linear mixed models to examine the association between our outcome measures (sleep, anxiety, depression, and physical activity) and categories of disorder type, sex, age, physical activity, relapses, and time (pre- vs. post- COVID-19 lockdown). Participant ID acted as a random effect, to account for repeated measures. RESULTS: Sleep significantly increased in the first 6 months of the COVID-19 lockdown (F(1, 544)=56.85, P<0.001,). Across the whole group, anxiety and depression did not change with the pandemic, but we found differing trends by age category. Anxiety decreased in teenagers (≥13y) (Z = 3.96, P<0.001), but not for pre-teens. Depression remained higher in teenagers than preteens across both timepoints (F(1, 597)=6.30, p = 0.012). Physical activity levels did not change with the pandemic in comparison to pre-pandemic (F(1, 629)=1.92, P = 0.166). Anxiety was higher in inactive individuals regardless of timing (F(2, 547)=3.74, p = 0.024). CONCLUSION: For youth with neuroinflammatory disorders, the COVID-19 pandemic lockdown resulted in increased hours of nighttime sleep but did not result in significant overall changes in self-reported anxiety or depression. Pre-lockdown, teenagers had higher depression and anxiety scores than preteens. Post-lockdown, anxiety and depression scores decreased in teenagers compared to pre-teens. Physical activity was low both pre- and post-lockdown, and rates of anxiety were higher for inactive participants at both timepoints. Differences based on age suggest that younger children (<13 years) were more negatively affected by the pandemic than older children (≥ 13 years).

Creating space for Indigenous healing practices in patient care plans.

BACKGROUND: The Truth and Reconciliation Commission of Canada's Calls to Action ask that those who can effect change within the Canadian healthcare system recognize the value of Indigenous healing practices and support them in the treatment of Indigenous patients. METHODS: We distributed a survey to the Canadian Rheumatology Association membership to assess awareness of Indigenous healing practices, and attitudes informing their acceptance in patient care plans. RESULTS: We received responses from 77/514 members (15%), with most (73%) being unclear or unaware of what Indigenous healing practices were. Nearly all (93%) expressed interest in the concept of creating space for Indigenous healing practices in rheumatology care plans. The majority of support was for the use in preventive or symptom management strategies, and less as adjuncts to disease activity control. Themes identified through qualitative analysis of free-text responses included a desire for patient-centered care and support for reconciliation in medicine, but with a colonial construct of medicine, demonstration of an evidence bias, and hierarchy of medicines. CONCLUSIONS: Overall, respondents were open to the idea of inclusion of Indigenous healing practices in patient's car plans, emphasizing importance for patient empowerment and patient-centered care. However, they cited concerns that provide the indication for further learning and reconciliation in medicine.

CONTEXTE: Les appels à l'action de la Commission de vérité et réconciliation du Canada demandent à ceux qui peuvent effectuer des changements au sein du système de soins de santé canadien de reconnaître la valeur des pratiques de guérison autochtones et de les soutenir dans le traitement des patients autochtones. MÉTHODES: Nous avons distribué un sondage aux membres de la Société canadienne de rhumatologie pour évaluer leurs connaissances des pratiques de guérison autochtones et leurs positions quant à l'acceptation de ces pratiques dans les plans de soins des patients. RÉSULTATS: Nous avons reçu des réponses de 77 membres sur 514 (15 %). La plupart (73 %) étaient incertains ou pas au courant de ce que sont les pratiques de guérison autochtones. Presque tous (93 %) ont exprimé un intérêt dans le concept de création d'un espace pour les pratiques de guérison autochtones dans les plans de soins en rhumatologie. La plus grande partie du soutien avait trait davantage à leur utilisation dans des stratégies de prévention ou de gestion des symptômes, et moins comme des auxiliaires dans le contrôle de l'activité de la maladie. Les thèmes relevés par une analyse qualitative des réponses en texte libre comprenaient un désir pour des soins centréssur le patient et un soutien pour une réconciliation en médecine, mais avec un concept colonial de médecine, une démonstration de l'existence d'un biais et une hiérarchie des médicaments. CONCLUSIONS: Dans l'ensemble, les répondants demeuraient ouverts à l'idée d'inclure des pratiques de guérison autochtones dans les plans de soinsdes patients, mettant l'accent sur l'importance de la capacité d'agirdu patient et des soins centréssur le patient. Toutefois, ils mentionnaient des préoccupations qui donnent une indication pour un plus grand besoin d'apprentissage et de réconciliation en médecine.

Severe bilateral Legg-Calvé-Perthes resolved with pamidronate in combination with casts, physiotherapy and adductor tenotomy: a pictorial essay over 11 years.

We describe an 11-year prospective clinical and radiologic course of a 6-year-old boy with bilateral Legg-Calvé-Perthes disease, who was treated with intravenous pamidronate (IV-PAM). His baseline radiographs showed grade IV avascular necrosis/Catterall stage IV, and at worst he progressed to lateral pillar/Herring stage C bilaterally. His disease initially was extremely functionally limiting with expected poor outcome with eventual joint replacement. Because IV-PAM stops bone breakdown and allows for ongoing bone formation while revascularisation of bone occurs, we hypothesised that IV-PAM could act as an adjunct to traditional treatment to help heal the femoral heads. Our patient received nine once monthly doses of IV-PAM (1 mg/kg/dose) over 13 months, along with Petrie/broomstick casts and physiotherapy. Remarkably, over time, his femoral heads healed. Now, at 11-year follow-up, he has excellent functional and radiologic outcome with congruence between femoral head and acetabulum, no residual osteonecrosis and minimal loss of femoral head sphericity.

Parallel specification of competing sensorimotor control policies for alternative action options.

Recent theory proposes that the brain, when confronted with several action possibilities, prepares multiple competing movements before deciding among them. Psychophysical supporting evidence for this idea comes from the observation that when reaching towards multiple potential targets, the initial movement is directed towards the average location of the targets, consistent with multiple prepared reaches being executed simultaneously. However, reach planning involves far more than specifying movement direction; it requires the specification of a sensorimotor control policy that sets feedback gains shaping how the motor system responds to errors induced by noise or external perturbations. Here we found that, when a subject is reaching towards multiple potential targets, the feedback gain corresponds to an average of the gains specified when reaching to each target presented alone. Our findings provide evidence that the brain, when presented with multiple action options, computes multiple competing sensorimotor control policies in parallel before implementing one of them.