Paulina J. M. Bank

Motor consequences of experimentally induced limb pain: a systematic review.

Compelling evidence exists that pain may affect the motor system, but it is unclear if different sources of peripheral limb pain exert selective effects on motor control. This systematic review evaluates the effects of experimental (sub)cutaneous pain, joint pain, muscle pain and tendon pain on the motor system in healthy humans. The results show that pain affects many components of motor processing at various levels of the nervous system, but that the effects of pain are largely irrespective of its source. Pain is associated with inhibition of muscle activity in the (painful) agonist and its non‐painful antagonists and synergists, especially at higher intensities of muscle contraction. Despite the influence of pain on muscle activation, only subtle alterations were found in movement kinetics and kinematics. The performance of various motor tasks mostly remained unimpaired, presumably as a result of a redistribution of muscle activity, both within the (painful) agonist and among muscles involved in the task. At the most basic level of motor control, cutaneous pain caused amplification of the nociceptive withdrawal reflex, whereas insufficient evidence was found for systematic modulation of other spinal reflexes. At higher levels of motor control, pain was associated with decreased corticospinal excitability. Collectively, the findings show that short‐lasting experimentally induced limb pain may induce immediate changes at all levels of motor control, irrespective of the source of pain. These changes facilitate protective and compensatory motor behaviour, and are discussed with regard to pertinent models on the effects of pain on motor control.

Walking to the beat of different drums: Practical implications for the use of acoustic rhythms in gait rehabilitation

Acoustic rhythms are frequently used in gait rehabilitation, with positive instantaneous and prolonged transfer effects on various gait characteristics. The gait modifying ability of acoustic rhythms depends on how well gait is tied to the beat, which can be assessed with measures of relative timing of auditory-motor coordination. We examined auditory-motor coordination in 20 healthy elderly individuals walking to metronome beats with pacing frequencies slower than, equal to, and faster than their preferred cadence. We found that more steps were required to adjust gait to the beat, the more the metronome rate deviated from the preferred cadence. Furthermore, participants anticipated the beat with their footfalls to various degrees, depending on the metronome rate; the faster the tempo, the smaller the phase advance or phase lead. Finally, the variability in the relative timing between footfalls and the beat was smaller for metronome rates closer to the preferred cadence, reflecting superior auditory-motor coordination. These observations have three practical implications. First, instantaneous effects of acoustic stimuli on gait characteristics may typically be underestimated given the considerable number of steps required to attune gait to the beat in combination with the usual short walkways. Second, a systematic phase lead of footfalls to the beat does not necessarily reflect a reduced ability to couple gait to the metronome. Third, the efficacy of acoustic rhythms to modify gait depends on metronome rate. Gait is coupled best to the beat for metronome rates near the preferred cadence.

Deficient muscle activation in patients with Complex Regional Pain Syndrome and abnormal hand postures: An electromyographic evaluation

OBJECTIVE Motor abnormalities in Complex Regional Pain Syndrome (CRPS) are common and often characterized by a restricted active range of motion (AROM) and an increased resistance to passive movements, whereby the affected body part preferably adopts an abnormal posture. The objective of the present study was to obtain a better understanding of the factors that are associated with these abnormal postures and limitations of the AROM, and to investigate whether these motor impairments reflect dystonia. METHODS We evaluated characteristics of surface EMG of the flexor carpi radialis and extensor carpi radialis muscles during active maintenance of various flexion-extension postures of the wrist of the affected and unaffected side in 15 chronic CRPS patients, and in 15 healthy controls. RESULTS Deviant joint postures in chronic CRPS - at least in those patients with some range of active movement - were not characterized by sustained muscle contractions, and limitations of the AROM were not attributable to excessive co-contraction. Rather, the agonistic muscle and its antagonist were activated in normal proportions, albeit over a limited range. CONCLUSIONS The AROM limitations and abnormal postures that are often observed in chronic CRPS patients are not associated with excessive muscle activity and hence do not exhibit the characteristics typical of dystonia. SIGNIFICANCE We hypothesize that structural alterations in skeletal muscle tissue and pain-induced adaptations of motor function may contribute to the observed motor impairments. Our findings may have important clinical implications, since commonly prescribed treatments are aimed at reducing excessive muscle contraction.

Serious Gaming in Augmented Reality using HMDs for Assessment of Upper Extremity Motor Dysfunctions

Abstract For a better understanding of how different disorders affect motor function, a uniform, standardized and objective evaluation is a desirable goal for the clinical community. We explore the potential of Augmented Reality (AR) combined with serious gaming and free hand tracking to facilitate objective, cost-effective and patient-friendly methods for evaluation of upper extremity motor dysfunction in different patient groups. In this paper, we describe the design process of the game and the system architecture of the AR framework to meet these requirements. Furthermore, we report our findings from two pilot studies we conducted with healthy people aged over 50. First, we present a usability study (n = 5) on three different modalities of visual feedback for natural hand interaction with AR objects (i. e., no augmented hand, partial augmented hand and a full augmented hand model). The results show that a virtual representation of the fingertips or hand improves the usability of natural hand interaction. Secondly, a study about game engagement is presented. The results of this experiment (n = 8) show that there might be potential for engagement, but usability needs to be improved before it can emerge.

Intended and unintended (sensory-)motor coupling between the affected and unaffected upper limb in complex regional pain syndrome

Motor dysfunction in complex regional pain syndrome (CRPS) has been associated with bilateral malfunction of sensory and motor circuits, which hints at abnormal coupling between the affected and the contralateral unaffected limb. In addition, clinical observations suggest that motor performance may depend on the (voluntary or automatic) context in which movements are executed. The present study aimed to examine the role of voluntary and automatic aspects of interlimb coupling in CRPS.

Force modulation deficits in complex regional pain syndrome: a potential role for impaired sense of force production.

Compelling evidence points at both impaired proprioception and disturbed force control in patients with chronic complex regional pain syndrome (CRPS). Because force modulation at least partly relies on proprioception, we evaluated if impaired sense of force production contributes to disturbances of force control in patients with CRPS.

Optical Hand Tracking: A Novel Technique for the Assessment of Bradykinesia in Parkinson's Disease

Evaluation of therapies for Parkinsons disease (PD) may benefit from objective quantification of the separate movement components of bradykinesia (i.e., velocity, amplitude, and rhythm). This study evaluated the sensitivity and reliability of parameters derived from recently available optical hand tracking techniques for patient‐friendly, automated quantification of bradykinesia of the upper extremity in PD.

A Haptic Serious Augmented Reality Game for Motor Assessment of Parkinson's Disease Patients

In the clinical community there is a need for assessment tools that allow for objective, quantitative and valid measures of motor dysfunction. In this paper, we report on the design and evaluation of a serious game that engages patients with Parkinsons disease in upper extremity (hand/arm) movements. The game employs augmented reality to show virtual movement targets, i.e. candies falling from a conveyor belt, and a haptic game controller to catch the candies, that is able to acquire quantitative data about the patients movement. This paper first describes the design process of the game and the system components. Secondly, we present results of our small quantitative evaluation study (N11, age: 26–60, healthy persons) regarding the usability of the system, the task load and user experience of the game. Our findings show that the system has a relatively good usability and the game is engaging, but there is still need for technical improvement with regard to tracking the controller in 3D space.

Designing for Engagement in Augmented Reality Games to Assess Upper Extremity Motor Dysfunctions

We present a Markerless 3D Augmented Reality Application for virtual accessory try-on applications around human arm. The system is based on a Kinect sensor and a multi-layer rendering framework to render RGB, depth data and 3D model of accessories simultaneously. The aim is to support realistic visualization of virtual objects around human arm, by detecting wrist pose and handling occlusion for various interactive marketing and retail applications, such as virtual watch try-on.My research focus is on posthumanism: future biomorphic transformations and sculptural reconstruction of the human body. I work with digital—physical sculpture, data art, performance and contemporary technology and materials, such as 3D printing, attempting to bridge the gap between art, science, design and technology. My work investigates a presently topical discourse on the aspects of posthumanism theories, such as bioengineering, gender issues and outer space exploration. Philosophically, I lean on posthumanism theories, uncovered by Cary Wolfe, Daryl Wennemann, N. Katherine Hayles, et al. I further these ideas into sculptural surfaces, enmeshing future skin concept and biomorphic transformations of the skin based on the data from the human body. Current research eventually will result in a multi sensorial experience with mixed reality scenarios — exhibition and performances with augmented to body 3D printed sculptures — a visualisation of humans personal data. The work contributes articulating future possibilities of the relationship of technology and the body. The contribution can be important to the postgender related discussion in relation to digital technologies, data and bodies; to the augmented and mixed reality issues relating to the body and also the themes of embodiment, bodies of matter and data bodies. The objects encapsulate different layers of information and might encourage different perspective on posthumanism.

[POSTER] Affording Visual Feedback for Natural Hand Interaction in AR to Assess Upper Extremity Motor Dysfunction

For the clinical community, there is great need for objective, quantitative and valid measures of the factors contributing to motor dysfunction. Currently, there are no standard protocols to assess motor dysfunction in various patient groups, where each medical discipline uses subjectively scored clinical tests, qualitative video analysis, or marker-based motion capturing. We investigate the potential of Augmented Reality (AR) combined with serious gaming and marker-less tracking of the hand to facilitate efficient, cost-effective and patient-friendly methods for evaluation of upper extremity motor dysfunction in different patient groups. First, the design process of the game and the system architecture of the AR framework are described. To provide unhindered assessment of motor dysfunction, patients should operate with the system in a natural way and be able to understand their actions in the virtual AR world. To test this in our system, we conducted a usability study with five healthy people (aged between 57-63) on three different modalities of visual feedback for natural hand interaction with AR objects. These modalities are: no augmented hand, partial augmented hand (tip of index finger and tip of thumb) and a full augmented hand model. The results of the study show that a virtual representation of the fingertips or hand improves the usability of natural hand interaction.