RESUMEN
An increment in peak tibial acceleration (PTA) may be related to an increased risk of running-rated injury. Many authors believe that reducing PTA through improved shock-absorption could, therefore, help prevent injury. The aim of the current study was, therefore, to investigate the individual responses of participants to a biofeedback intervention aimed at reducing PTA.11 participants (two females, nine males; 43⯱â¯10â¯years; stature: 1.74⯱â¯0.07â¯m; body mass: 74⯱â¯11â¯kg; distance running a week: 19⯱â¯14â¯km; 5â¯km time: 24⯱â¯3â¯min) received an intervention of six sessions of multisensory biofeedback aimed at reducing PTA. Mean PTA and kinematic patterns were measured at baseline, directly after the feedback intervention and a month after the end of the intervention. Group as well as single-subject analyses were performed to quantify differences between the sessions. A significant decrease of 26 per cent (effect size: Hedges' gâ¯=â¯0.94) in mean PTA was found a month after the intervention. No significant changes or large effect sizes were found for any group differences in the kinematic variables. However, on an individual level, shock-absorbing solutions differed both within and between participants. The data suggest participants did not learn a specific solution to reduce PTA but rather learned the concept of reducing PTA. These results suggest future research in gait retraining should investigate individual learning responses and focus on the different strategies participants use both between and within sessions. For training purposes, participants should not focus on learning one running strategy, but they should explore several strategies.
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Biorretroalimentación Psicológica , Tibia , Masculino , Femenino , Humanos , Tibia/fisiología , Aceleración , Marcha/fisiología , Aprendizaje , Fenómenos Biomecánicos/fisiologíaRESUMEN
BACKGROUND: Biofeedback seems to be a promising tool to improve gait outcomes for both healthy individuals and patient groups. However, due to differences in study designs and outcome measurements, it remains uncertain how different forms of feedback affect gait outcomes. Therefore, the aim of this study is to review primary biomechanical literature which has used biofeedback to alter gait-related outcomes in human participants. METHODS: Medline, Cinahl, Cochrane, SPORTDiscus and Pubmed were searched from inception to December 2017 using various keywords and the following MeSHterms: biofeedback, feedback, gait, walking and running. From the included studies, sixteen different study characteristics were extracted. FINDINGS: In this mapping review 173 studies were included. The most common feedback mode used was visual feedback (42%, nâ¯=â¯73) and the majority fed-back kinematic parameters (36%, nâ¯=â¯62). The design of the studies was poor: only 8% (nâ¯=â¯13) of the studies had both a control group and a retention test; 69% (nâ¯=â¯120) of the studies had neither. A retention test after 6â¯months was performed in 3% (nâ¯=â¯5) of the studies, feedback was faded in 9% (nâ¯=â¯15) and feedback was given in the field rather than the laboratory in 4% (nâ¯=â¯8) of the studies. INTERPRETATION: Further work on biofeedback and gait should focus on the direct comparison between different modes of feedback or feedback parameters, along with better designed and field based studies.
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Biorretroalimentación Psicológica , Trastornos Neurológicos de la Marcha/rehabilitación , Marcha/fisiología , Fenómenos Biomecánicos , Retroalimentación Sensorial , Trastornos Neurológicos de la Marcha/fisiopatología , Humanos , Proyectos de InvestigaciónRESUMEN
Functional electrical stimulation has been shown to be a safe and effective means of correcting foot drop of central neurological origin. Current surface-based devices typically consist of a single channel stimulator, a sensor for determining gait phase and a cuff, within which is housed the anode and cathode. The cuff-mounted electrode design reduces the likelihood of large errors in electrode placement, but the user is still fully responsible for selecting the correct stimulation level each time the system is donned. Researchers have investigated different approaches to automating aspects of setup and/or use, including recent promising work based on iterative learning techniques. This paper reports on the design and clinical evaluation of an electrode array-based FES system for the correction of drop foot, ShefStim. The paper reviews the design process from proof of concept lab-based study, through modelling of the array geometry and interface layer to array search algorithm development. Finally, the paper summarises two clinical studies involving patients with drop foot. The results suggest that the ShefStim system with automated setup produces results which are comparable with clinician setup of conventional systems. Further, the final study demonstrated that patients can use the system without clinical supervision. When used unsupervised, setup time was 14min (9min for automated search plus 5min for donning the equipment), although this figure could be reduced significantly with relatively minor changes to the design.
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Terapia por Estimulación Eléctrica/instrumentación , Anciano , Electrodos , Diseño de Equipo , Estudios de Factibilidad , Femenino , Trastornos Neurológicos de la Marcha/terapia , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The aim of this study was to compare the seven following commercially available activity monitors in terms of step count detection accuracy: Movemonitor (Mc Roberts), Up (Jawbone), One (Fitbit), ActivPAL (PAL Technologies Ltd.), Nike+ Fuelband (Nike Inc.), Tractivity (Kineteks Corp.) and Sensewear Armband Mini (Bodymedia). Sixteen healthy adults consented to take part in the study. The experimental protocol included walking along an indoor straight walkway, descending and ascending 24 steps, free outdoor walking and free indoor walking. These tasks were repeated at three self-selected walking speeds. Angular velocity signals collected at both shanks using two wireless inertial measurement units (OPAL, ADPM Inc) were used as a reference for the step count, computed using previously validated algorithms. Step detection accuracy was assessed using the mean absolute percentage error computed for each sensor. The Movemonitor and the ActivPAL were also tested within a nine-minute activity recognition protocol, during which the participants performed a set of complex tasks. Posture classifications were obtained from the two monitors and expressed as a percentage of the total task duration. The Movemonitor, One, ActivPAL, Nike+ Fuelband and Sensewear Armband Mini underestimated the number of steps in all the observed walking speeds, whereas the Tractivity significantly overestimated step count. The Movemonitor was the best performing sensor, with an error lower than 2% at all speeds and the smallest error obtained in the outdoor walking. The activity recognition protocol showed that the Movemonitor performed best in the walking recognition, but had difficulty in discriminating between standing and sitting. Results of this study can be used to inform choice of a monitor for specific applications.
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Monitoreo Ambulatorio/instrumentación , Monitoreo Ambulatorio/métodos , Actividad Motora/fisiología , Caminata , Adulto , Exactitud de los Datos , HumanosRESUMEN
OBJECTIVE: To investigate the feasibility of unsupervised community use of an array-based automated setup functional electrical stimulator for current foot-drop functional electrical stimulation (FES) users. DESIGN: Feasibility study. SETTING: Gait laboratory and community use. PARTICIPANTS: Participants (N=7) with diagnosis of unilateral foot-drop of central neurologic origin (>6mo) who were regular users of a foot-drop FES system (>3mo). INTERVENTION: Array-based automated setup FES system for foot-drop (ShefStim). MAIN OUTCOME MEASURES: Logged usage, logged automated setup times for the array-based automated setup FES system and diary recording of problems experienced, all collected in the community environment. Walking speed, ankle angles at initial contact, foot clearance during swing, and the Quebec User Evaluation of Satisfaction with Assistive Technology version 2.0 (QUEST version 2.0) questionnaire, all collected in the gait laboratory. RESULTS: All participants were able to use the array-based automated setup FES system. Total setup time took longer than participants' own FES systems, and automated setup time was longer than in a previous study of a similar system. Some problems were experienced, but overall, participants were as satisfied with this system as their own FES system. The increase in walking speed (N=7) relative to no stimulation was comparable between both systems, and appropriate ankle angles at initial contact (N=7) and foot clearance during swing (n=5) were greater with the array-based automated setup FES system. CONCLUSIONS: This study demonstrates that an array-based automated setup FES system for foot-drop can be successfully used unsupervised. Despite setup's taking longer and some problems, users are satisfied with the system and it would appear as effective, if not better, at addressing the foot-drop impairment. Further product development of this unique system, followed by a larger-scale and longer-term study, is required before firm conclusions about its efficacy can be reached.
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Terapia por Estimulación Eléctrica/instrumentación , Trastornos Neurológicos de la Marcha/terapia , Autocuidado , Caminata/fisiología , Adulto , Anciano , Articulación del Tobillo/fisiología , Terapia por Estimulación Eléctrica/métodos , Electrodos , Falla de Equipo , Estudios de Factibilidad , Femenino , Marcha/fisiología , Trastornos Neurológicos de la Marcha/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Monitoreo Ambulatorio/instrumentación , Satisfacción del Paciente , Factores de TiempoRESUMEN
Functional electrical stimulation is commonly used to correct drop foot following stroke or multiple sclerosis. This technique is successful for many patients, but previous studies have shown that a significant minority have difficulty identifying correct sites to place the electrodes in order to produce acceptable foot movement. Recently there has been some interest in the use of 'virtual electrodes', the process of stimulating a subset of electrodes chosen from an array, thus allowing the site of stimulation to be moved electronically rather than physically. We have developed an algorithm for automatically determining the best site of stimulation and tested it on a computer linked to a small, battery-powered prototype stimulator with 64 individual output channels. Stimulation was delivered via an 8×8 array adhered to the leg by high-resistivity self-adhesive hydrogel. Ten participants with stroke (ages 53-71 years) and 11 with MS (ages 40-80 years) were recruited onto the study and performed two walks of 10 m for each of the following conditions: own setup (PS), clinician setup (CS), automated setup (AS) and no stimulation (NS). The PS and CS conditions used the participant's own stimulator with two conventional electrodes; the AS condition used the new stimulator and algorithm. Outcome measures were walking speed, foot angle at initial contact and the Borg Rating of Perceived Exertion. Mean walking speed with no stimulation was 0.61 m/s; all FES setups significantly increased speed relative to this (AS p<0.05, PS p<0.01, CS p<0.01). Speed for PS (0.72 m/s) was faster than both AS (0.65 m/s, p<0.01) and CS (0.68 m/s, p<0.05). Frontal plane foot orientation at heel-strike was more neutral for AS (0.3° everted) than in the NS (11.2° inverted, p<0.01), PS (4.5° inverted, p<0.05) and CS (3.1° inverted, p<0.05) conditions. Dorsiflexion angles for AS (4.2°) were larger than NS (-3.0°, p<0.01), not different to PS (4.3°, p>0.05) and less dorsiflexed than CS (6.0°, p<0.05). This proof of principle study has demonstrated that automated setup of an array stimulator produces results broadly comparable to clinician setup. Slower walking speed for automated and clinician setups compared to the participants' own setup may be due to the participants' lack of familiarity with responses different to their usual setups. Automated setup using the method described here seems sufficiently reliable for future longer-term investigation outside the laboratory and may lead to FES becoming more viable for patients who, at present, have difficulty setting up conventional stimulators.
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Estimulación Eléctrica/instrumentación , Trastornos Neurológicos de la Marcha/fisiopatología , Trastornos Neurológicos de la Marcha/terapia , Marcha , Laboratorios , Adulto , Anciano , Anciano de 80 o más Años , Automatización , Electrodos , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Functional electrical stimulation (FES) applied to the common peroneal nerve is commonly prescribed to correct both equinus and excessive foot inversion in swing and initial contact. This paper presents the development of a simple shoe model, to allow quantification of 3-D shoe (foot and footwear) kinematics in clinical situations when footwear is required, e.g. with FES systems requiring footswitches. To preliminarily validate the shoe model, barefoot 'normal' adult data (n=11) processed using validated 3-D foot models, were reprocessed with the shoe model. Outputs were compared through calculation of waveform similarity and correlation. Clinical utility of the shoe model is demonstrated through the presentation of 3-D shoe kinematics, calculated from a cohort of existing unilateral common peroneal FES users (n=16), both with and without FES. A trend of reduced inversion at mid-swing and initial contact was seen, although this was not found to be statistically significant (p≤0.0125). The shoe model was found to be practical to use in a clinical environment, and has potential to contribute to the evidence base for interventions such as common peroneal FES.
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Deformidades Adquiridas del Pie/rehabilitación , Trastornos Neurológicos de la Marcha/rehabilitación , Neuroestimuladores Implantables , Zapatos , Adulto , Fenómenos Biomecánicos , Estudios de Casos y Controles , Femenino , Marcha/fisiología , Trastornos Neurológicos de la Marcha/etiología , Trastornos Neurológicos de la Marcha/fisiopatología , Humanos , Imagenología Tridimensional , Masculino , Modelos Anatómicos , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/diagnóstico , Esclerosis Múltiple/rehabilitación , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico , Rehabilitación de Accidente Cerebrovascular , Adulto JovenRESUMEN
Functional electrical stimulation is commonly used to restore function in post-stroke patients in upper and lower limb applications. Location of the electrodes can be a problem hence some research groups have begun to experiment with electrode arrays. Electrode arrays are interfaced with a thin continuous hydrogel sheet which is high resistivity to reduce transverse currents between electrodes in the array. Research using electrode arrays has all been conducted in a laboratory environment over short time periods but it is suspected that this approach will not be feasible over longer time periods due to changes in hydrogel resistivity. High resistivity hydrogel samples were tested by leaving them in contact with the skin over a seven day period. The samples became extremely conductive with resistivities reaching around 10-50 Ωm. The effect of these resistivity changes was studied using finite element analysis to solve for the stationary current quasi-static electric field gradient in the tissue. Electrical stimulation efficiency and focality were calculated for both a high and low resistivity electrode-skin interface layer at different tissue depths. The results showed that low resistivity hydrogel produced significant decreases in stimulation efficiency and focality compared to high resistivity hydrogel.
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Estimulación Eléctrica/instrumentación , Análisis de Elementos Finitos , Hidrogeles , Piel , Impedancia Eléctrica , Electrodos , Humanos , Masculino , Factores de TiempoRESUMEN
Discomfort experienced during surface functional electrical stimulation (FES) is thought to be partly a result of localized high current density in the skin underneath the stimulating electrode. This article describes a finite element (FE) model to predict skin current density distribution in the region of the electrode during stimulation and its application to the identification of electrode properties that may act to reduce sensation. The FE model results show that the peak current density was located in an area immediately under the stratum corneum, adjacent to a sweat duct. A simulation of surface FES via a high-resistivity electrode showed a reduction in this peak current density, when compared to that with a low-resistivity electrode.