Nazirah Hasnan

Strategies for Rapid Muscle Fatigue Reduction during FES Exercise in Individuals with Spinal Cord Injury: A Systematic Review

Background Rapid muscle fatigue during functional electrical stimulation (FES)-evoked muscle contractions in individuals with spinal cord injury (SCI) is a significant limitation to attaining health benefits of FES-exercise. Delaying the onset of muscle fatigue is often cited as an important goal linked to FES clinical efficacy. Although the basic concept of fatigue-resistance has a long history, recent advances in biomedical engineering, physiotherapy and clinical exercise science have achieved improved clinical benefits, especially for reducing muscle fatigue during FES-exercise. This review evaluated the methodological quality of strategies underlying muscle fatigue-resistance that have been used to optimize FES therapeutic approaches. The review also sought to synthesize the effectiveness of these strategies for persons with SCI in order to establish their functional impacts and clinical relevance. Methods Published scientific literature pertaining to the reduction of FES-induced muscle fatigue was identified through searches of the following databases: Science Direct, Medline, IEEE Xplore, SpringerLink, PubMed and Nature, from the earliest returned record until June 2015. Titles and abstracts were screened to obtain 35 studies that met the inclusion criteria for this systematic review. Results Following the evaluation of methodological quality (mean (SD), 50 (6) %) of the reviewed studies using the Downs and Black scale, the largest treatment effects reported to reduce muscle fatigue mainly investigated isometric contractions of limited functional and clinical relevance (n = 28). Some investigations (n = 13) lacked randomisation, while others were characterised by small sample sizes with low statistical power. Nevertheless, the clinical significance of emerging trends to improve fatigue-resistance during FES included (i) optimizing electrode positioning, (ii) fine-tuning of stimulation patterns and other FES parameters, (iii) adjustments to the mode and frequency of exercise training, and (iv) biofeedback-assisted FES-exercise to promote selective recruitment of fatigue-resistant motor units. Conclusion Although the need for further in-depth clinical trials (especially RCTs) was clearly warranted to establish external validity of outcomes, current evidence was sufficient to support the validity of certain techniques for rapid fatigue-reduction in order to promote FES therapy as an integral part of SCI rehabilitation. It is anticipated that this information will be valuable to clinicians and other allied health professionals administering FES as a treatment option in rehabilitation and aid the development of effective rehabilitation interventions.

Mechanomyographic parameter extraction methods: An appraisal for clinical applications

The research conducted in the last three decades has collectively demonstrated that the skeletal muscle performance can be alternatively assessed by mechanomyographic signal (MMG) parameters. Indices of muscle performance, not limited to force, power, work, endurance and the related physiological processes underlying muscle activities during contraction have been evaluated in the light of the signal features. As a non-stationary signal that reflects several distinctive patterns of muscle actions, the illustrations obtained from the literature support the reliability of MMG in the analysis of muscles under voluntary and stimulus evoked contractions. An appraisal of the standard practice including the measurement theories of the methods used to extract parameters of the signal is vital to the application of the signal during experimental and clinical practices, especially in areas where electromyograms are contraindicated or have limited application. As we highlight the underpinning technical guidelines and domains where each method is well-suited, the limitations of the methods are also presented to position the state of the art in MMG parameters extraction, thus providing the theoretical framework for improvement on the current practices to widen the opportunity for new insights and discoveries. Since the signal modality has not been widely deployed due partly to the limited information extractable from the signals when compared with other classical techniques used to assess muscle performance, this survey is particularly relevant to the projected future of MMG applications in the realm of musculoskeletal assessments and in the real time detection of muscle activity.

Exergaming for individuals with neurological disability: a systematic review

Abstract Introduction: Exergames have the potential to enable persons with disabilities to take part in physical activities that are of appropriate “dose-potency” and enjoyable within a relatively safe home environment. It overcomes some of the challenges regarding transportation difficulties in getting to commercial gymnasium facilities, reducing physical activities perceived as “boring” or getting access into the built environment that may be “wheelchair unfriendly”. Objective: This systematic review assessed available evidence whether “exergaming” could be a feasible modality for contributing to a recommended exercise prescription according to current ACSM™ or WHO guidelines for physical activity. Methods: Strategies used to search for published articles were conducted using separate search engines (Google Scholar™, PubMed™ and Web of Science™) on cardiometabolic responses and perceived exertion during exergaming among neurologically-disabled populations possessing similar physical disabilities. Each study was categorized using the SCIRE-Pedro evidence scale. Results: Ten of the 144 articles assessed were identified and met specific inclusion criteria. Key outcome measures included responses, such as energy expenditure, heart rate and perceived exertion. Twelve out of the 17 types of exergaming interventions met the ACSM™ or WHO recommendations of “moderate intensity” physical activity. Exergames such as Wii Jogging, Bicycling, Boxing, DDR and GameCycle reported moderate physical activity intensities. While Wii Snowboarding, Skiing and Bowling only produced light intensities. Conclusion: Preliminary cross-sectional evidence in this review suggested that exergames have the potential to provide moderate intensity physical activity as recommended by ACSM™ or WHO in populations with neurological disabilities. However, more research is needed to document exergaming’s efficacy from longitudinal observations before definitive conclusions can be drawn. Implications for Rehabilitation Exergaming can be deployed as physical activity or exercise using commercially available game consoles for neurologically disabled individuals in the convenience of their home environment and at a relatively inexpensive cost Moderate-to-vigorous intensity exercises can be achieved during exergaming in this population of persons with neurological disabilities. Exergaming can also be engaging and enjoyable, yet achieve the recommended physical activity guidelines proposed by ACSM™ or WHO for health and fitness benefits. Exergaming as physical activity in this population is feasible for individuals with profound disabilities, since it can be used even in sitting position for wheelchair-dependent users, thus providing variability in terms of exercise options. In the context of comprehensive rehabilitation, exergaming should be viewed by the clinician as “at least as good as” (and likely more enjoyable) than traditional arm-exercise modalities, with equivalent aerobic dose-potency as “traditional” exercise in clinic or home environments.

www.elearnSCI.org: a global educational initiative of ISCoS

Objective:To develop a web-based educational resource for health professionals responsible for the management of spinal cord injury (SCI).The resource:www.elearnSCI.org is comprised of seven learning modules, each subdivided into various submodules. Six of the seven modules address the educational needs of all disciplines involved in comprehensive SCI management. The seventh module addresses prevention of SCI. Each submodule includes an overview, activities, self-assessment questions and references.Development of the resource:Three hundred and thirty-two experts from The International Spinal Cord Society (ISCoS) and various affiliated societies from 36 countries were involved in developing the resource through 28 subcommittees. The content of each submodule was reviewed and approved by the Education and Scientific Committees of ISCoS and finally by an Editorial Committee of 23 experts.Key features:The content of the learning modules is relevant to students and to new as well as experienced SCI healthcare professionals. The content is applicable globally, has received consumer input and is available at no cost. The material is presented on a website underpinned by a sophisticated content-management system, which allows easy maintenance and ready update of all the content. The resource conforms to key principles of e-learning, including appropriateness of curriculum, engagement of learners, innovative approaches, effective learning, ease of use, inclusion, assessment, coherence, consistency, transparency, cost effectiveness and feedback.Conclusion:www.elearnSCI.org provides a cost effective way of training healthcare professionals that goes beyond the textbook and traditional face-to-face teaching.

Study Protocol of the International Spinal Cord Injury (InSCI) Community Survey

Objective The Learning Health System for Spinal Cord Injury (LHS-SCI) is an initiative embedded in the World Health Organizations (WHOs) Global Disability Plan and requires the statistical collection of data on the lived experience of persons with SCI to consequently formulate recommendations and policies. The International Spinal Cord Injury (InSCI) community survey has been developed as an initial step to gain information about the lived experience of persons with SCI within and across diverse nations. Design InSCI is a multinational community survey based on the International Classification of Functioning, Disability and Health Core Sets for SCI and involves 28 countries from all six WHO regions. The study will be implemented in 2017. Overall aims, guiding principles on sampling strategies, data collection modes, and reminder management are described. Conclusions InSCI will be the first survey to be conducted simultaneously in many countries and in all six WHO world regions that identifies the factors associated with functioning, health, and well-being of persons living with SCI. Expected results of the survey will be used for the basis of conducting stakeholder dialogs for policy reforms designed to improve the functioning, health maintenance, and well-being of persons with SCI.

Estimation of Electrically-Evoked Knee Torque from Mechanomyography Using Support Vector Regression

The difficulty of real-time muscle force or joint torque estimation during neuromuscular electrical stimulation (NMES) in physical therapy and exercise science has motivated recent research interest in torque estimation from other muscle characteristics. This study investigated the accuracy of a computational intelligence technique for estimating NMES-evoked knee extension torque based on the Mechanomyographic signals (MMG) of contracting muscles that were recorded from eight healthy males. Simulation of the knee torque was modelled via Support Vector Regression (SVR) due to its good generalization ability in related fields. Inputs to the proposed model were MMG amplitude characteristics, the level of electrical stimulation or contraction intensity, and knee angle. Gaussian kernel function, as well as its optimal parameters were identified with the best performance measure and were applied as the SVR kernel function to build an effective knee torque estimation model. To train and test the model, the data were partitioned into training (70%) and testing (30%) subsets, respectively. The SVR estimation accuracy, based on the coefficient of determination (R2) between the actual and the estimated torque values was up to 94% and 89% during the training and testing cases, with root mean square errors (RMSE) of 9.48 and 12.95, respectively. The knee torque estimations obtained using SVR modelling agreed well with the experimental data from an isokinetic dynamometer. These findings support the realization of a closed-loop NMES system for functional tasks using MMG as the feedback signal source and an SVR algorithm for joint torque estimation.

Return to work after spinal cord injury in Malaysia

Study design:Cross-sectional survey.Objectives:To determine the employment outcomes of persons with spinal cord injury (SCI) and to investigate the impact of various demographic, injury-related and work-related variables on these outcomes.Setting:People living with SCI in Malaysia who are members of a disability support organization.Methods:A total of 84 members of the Malaysian Spinal Injury Association, who have had traumatic SCI for at least 2 years and were between 15 and 64 years of age at the time of study, were interviewed through phone using a questionnaire to identify the association between demographic, injury-related and work-related variables and employment outcomes.Results:The return to work rate in this study was 57.1% (employed at the time of study). The overall employment rate after SCI was 76.2% (worked at some point after injury). Those who were younger at time of injury (<20 years of age), able to drive a modified vehicle, independent in personal care and mobility were positively related to being employed. On the other hand, being hospitalized in the preceding 1 year and receiving financial incentives were negatively related to employment.Conclusion:Functional independence, especially ability to drive, was strongly associated with return to work and should be one of the priority goals of comprehensive rehabilitation of persons with SCI. The negative impact of recent hospitalization as well as financial compensation needs to be probed further.

Development of biocompatible hydroxyapatite–poly(ethylene glycol) core–shell nanoparticles as an improved drug carrier: structural and electrical characterizations

Hydroxyapatite–5 wt% poly(ethylene glycol) (HA–PEG) core–shell composite nanoparticles (NPs) were synthesized using a coprecipitation technique. For the first time, the NPs are characterized for potential drug delivery applications using structural, electrical and in vitro kinetic studies. Phase quantification and the crystal structures of the NPs were analyzed using X-ray diffraction and Fourier transform infrared spectroscopy and the morphology was determined using scanning electron and transmission electron microscopies. Dielectric spectroscopy was used to analyze the polarization behaviour of the HA and HA–PEG core–shell NPs as potential drug carriers by applying an oscillating (100 Hz to 2.5 MHz) electric field. The increased intra-particle interfacial interactions in the HA–PEG NPs confirmed the significant enhancement in interfacial or space charge polarization owing to the reduction in mobility and accumulation of charge-carriers at the interfaces. Thus, HA–PEG showed better aceclofenac drug releasing properties than pristine HA NPs. An in vitro cell study confirmed that the HA and HA–PEG core–shell nanocarriers showed excellent biocompatibility on human dermis fibroblast (HDF) cells. The interaction within the HA–PEG core–shell was stronger than with pristine HA and the biodegradable PEG from the shell-layer neutralized the composite-surroundings path. Hence, it would reduce the direct interaction of aceclofenac drug with the surrounding biomolecules of the delivery paths and enhance the ability for carrying the drug precisely to the target organs.

Torque and mechanomyogram relationships during electrically-evoked isometric quadriceps contractions in persons with spinal cord injury

The interaction between muscle contractions and joint loading produces torques necessary for movements during activities of daily living. However, during neuromuscular electrical stimulation (NMES)-evoked contractions in persons with spinal cord injury (SCI), a simple and reliable proxy of torque at the muscle level has been minimally investigated. Thus, the purpose of this study was to investigate the relationships between muscle mechanomyographic (MMG) characteristics and NMES-evoked isometric quadriceps torques in persons with motor complete SCI. Six SCI participants with lesion levels below C4 [(mean (SD) age, 39.2 (7.9) year; stature, 1.71 (0.05) m; and body mass, 69.3 (12.9) kg)] performed randomly ordered NMES-evoked isometric leg muscle contractions at 30°, 60° and 90° knee flexion angles on an isokinetic dynamometer. MMG signals were detected by an accelerometer-based vibromyographic sensor placed over the belly of rectus femoris muscle. The relationship between MMG root mean square (MMG-RMS) and NMES-evoked torque revealed a very high association (R(2)=0.91 at 30°; R(2)=0.98 at 60°; and R(2)=0.97 at 90° knee angles; P<0.001). MMG peak-to-peak (MMG-PTP) and stimulation intensity were less well related (R(2)=0.63 at 30°; R(2)=0.67 at 60°; and R(2)=0.45 at 90° knee angles), although were still significantly associated (P≤0.006). Test-retest interclass correlation coefficients (ICC) for the dependent variables ranged from 0.82 to 0.97 for NMES-evoked torque, between 0.65 and 0.79 for MMG-RMS, and from 0.67 to 0.73 for MMG-PTP. Their standard error of measurements (SEM) ranged between 10.1% and 31.6% (of mean values) for torque, MMG-RMS and MMG-PTP. The MMG peak frequency (MMG-PF) of 30Hz approximated the stimulation frequency, indicating NMES-evoked motor unit firing rate. The results demonstrated knee angle differences in the MMG-RMS versus NMES-isometric torque relationship, but a similar torque related pattern for MMG-PF. These findings suggested that MMG was well associated with torque production, reliably tracking the motor unit recruitment pattern during NMES-evoked muscle contractions. The strong positive relationship between MMG signal and NMES-evoked torque production suggested that the MMG might be deployed as a direct proxy for muscle torque or fatigue measurement during leg exercise and functional movements in the SCI population.

Evoked EMG versus Muscle Torque during Fatiguing Functional Electrical Stimulation-Evoked Muscle Contractions and Short-Term Recovery in Individuals with Spinal Cord Injury

This study investigated whether the relationship between muscle torque and m-waves remained constant after short recovery periods, between repeated intervals of isometric muscle contractions induced by functional electrical stimulation (FES). Eight subjects with spinal cord injury (SCI) were recruited for the study. All subjects had their quadriceps muscles group stimulated during three sessions of isometric contractions separated by 5 min of recovery. The evoked-electromyographic (eEMG) signals, as well as the produced torque, were synchronously acquired during the contractions and during short FES bursts applied during the recovery intervals. All analysed m-wave variables changed progressively throughout the three contractions, even though the same muscle torque was generated. The peak to peak amplitude (PtpA), and the m-wave area (Area) were significantly increased, while the time between the stimulus artefact and the positive peak (PosT) were substantially reduced when the muscles became fatigued. In addition, all m-wave variables recovered faster and to a greater extent than did torque after the recovery intervals. We concluded that rapid recovery intervals between FES-evoked exercise sessions can radically interfere in the use of m-waves as a proxy for torque estimation in individuals with SCI. This needs to be further investigated, in addition to seeking a better understanding of the mechanisms of muscle fatigue and recovery.