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Pantall A.,Georgia Institute of Technology | Pantall A.,University of Surrey | Ewins D.,University of Surrey | Ewins D.,Douglas Bader Rehabilitation Center
Journal of Rehabilitation Research and Development | Year: 2013

A recent development in prosthetics is the osseoin-tegrated fixation (OF), with improvements in comfort, fatigue, hip movement, and ease of prosthetic attachment reported. However, little information is available regarding muscle function. This study reports on selected gait parameters of the residual limb during the stance phase of level overground walking, focusing on muscle activity. Five males with trans-femoral amputation (TFA) with OFs were recruited. Ground reaction force (GRF), lower-limb kinematics, and surface elec-tromyography (sEMG) from residual-limb muscles were recorded. sEMG data were also collected from a group of 10 nondisabled male subjects. Interstance variability of gait parameters was assessed by coefficient of multiple correlations. Repeatability of GRF and hip kinematics was high, whereas repeatability of the sEMG was low for four of the five individuals with TFA. Interstance variability of the sEMG for gluteus medius (GMED) was significantly greater in the group with TFA. The main difference in sEMG between the groups was the phase, with GMED and adductor magnus displaying greater differences than their counterparts in the nondisabled group. Results demonstrate that muscles in the residual limb retain aspects of their previous functional pattern.

Wright P.A.,Salisbury District Hospital | Durham S.,Douglas Bader Rehabilitation Center | Ewins D.J.,Douglas Bader Rehabilitation Center | Ewins D.J.,University of Surrey | And 2 more authors.
Archives of Disease in Childhood | Year: 2012

The aim of this review paper is to consider the application of neuromuscular electrical stimulation (NMES) to improve gait or upper limb function in children with cerebral palsy (CP). Although most NMES research has been directed at adults with neurological conditions, there is a growing body of evidence supporting its use in children with CP. In line with a recent meta-analysis, the use of electrical stimulation to minimise impairment and activity limitations during gait is cautiously advocated. A detailed commentary on one of the most common lower limb NMES applications, tibialis anterior stimulation (either with or without gastrocnemius stimulation) is given. Although there is a lack of randomised controlled trials and a predominance of mainly small studies, this review further concludes that the balance of available evidence is in favour of upper limb exercise NMES offering benefi ts such as increased muscle strength, range of motion and function in children with CP. The use of dynamic splinting with NMES has been shown to be more effective than either treatment on its own in improving function and posture. There is at present little published work to support the application of botulinum toxin type A to temporarily reduce muscle tone as an adjunct intervention to NMES in this population, although the presence of parallel applications to manage similar symptoms in other muscular disorders is noted.

Pantall A.,Georgia Institute of Technology | Durham S.,Douglas Bader Rehabilitation Center | Ewins D.,University of Surrey | Ewins D.,Douglas Bader Rehabilitation Center
Clinical Biomechanics | Year: 2011

Background: Femoral osseointegrated implants represent a new development in amputee rehabilitation, eliminating socket pressure discomfort, improving hip range of movement and facilitating prosthetic limb attachment. A clinical aspect that has not previously been reported on is the function of muscles in the residuum with implications concerning energy expenditure, hip-hiking and viability of the electrogram as a myoprocessor. Typically, amputees fitted with osseointegrated fixation have shorter residuums and weaker attachment of cleaved muscles. Function of muscle can be assessed by surface electromyography through changes in amplitude and median frequency of the signal. Methods: Five male transfemoral amputees with osseointegrated fixations participated together with a control group comprised of ten adult males. Electrodes recorded surface electromyographic activity of five residual limb muscles or left lower limb muscles of control subjects. Isometric contractions were performed against resistance. The increase in mean rectified amplitude from resting to maximally contracting was calculated and median frequencies estimated. Findings: The amputees were unable to maintain a maximum voluntary contraction of constant amplitude. Amplitude increase was lowest for rectus femoris and adductor magnus. The median frequency of adductor magnus was significantly greater (P = 0.02) for the amputees than intact subjects and there was a significant difference (P < 0.01) between gluteus maximus and adductor magnus for amputee subjects. Interpretation: High electromyographic amplitude variability suggests that using residuum muscles singly as a myoprocessor might be challenging. Adductor magnus displayed a different sEMG profile compared to intact subjects indicating decreased function and neuromuscular changes. Further work into optimal muscle anchorage is required to ensure maximal mechanical performance. © 2011 Elsevier Ltd.

Catalfamo P.,CONICET | Catalfamo P.,National University of Entre Rios | Catalfamo P.,University of Surrey | Acevedo R.,National University of Entre Rios | And 3 more authors.
Footwear Science | Year: 2014

Purpose: A variety of methods have been proposed for detection of initial contact (IC) and foot off (FO) and some comparative analysis is reported in the literature. Pressure measurement insoles and kinematic systems are often part of footwear analysis. Although gait event detection algorithms using these systems have been proposed and evaluated against kinetic data (KN) from force platforms (typically used as a 'gold standard'), they have not been compared directly. The objective of this work was to undertake this comparison using the same volunteer dataset and test conditions.Methods: Data from 10 healthy adults walking at self-selected normal speed were collected. Two kinematic algorithms (one using a fixed threshold, KM, and the other using high pass-filtering, HPA) and one algorithm using pressure measurement data from an insole (Contact Area Detection, AD) were tested and compared with the detection provided by KN. All data were synchronised and sampled at 200 Hz. Six basic spatio-temporal parameters were also calculated.Results: The absolute mean difference (AMD) in event detection between the three methods and KN was below 25 ms. However, the methods presented tendencies to detect events earlier or later than KN and this influenced the AMD between the methods, which increased to 47 ms for IC detection between HPA and AD. The spatio-temporal parameters showed no statistically significant differences between AD and KM, but differences reached statistical significance between AD and HPA.Conclusion: It is possible to compare gait events and basic spatio-temporal parameters detected using data from pressure measurement insoles and kinematic algorithms; however the kinematic algorithm used will influence the results. Hence the comparison of findings from alternative detection methods is an important issue for which information about the behaviour of the method used is required. © 2014 © 2014 Taylor & Francis.

Pratt E.,Douglas Bader Rehabilitation Center | Pratt E.,University of Surrey | Durham S.,Douglas Bader Rehabilitation Center | Ewins D.,Douglas Bader Rehabilitation Center | Ewins D.,University of Surrey
Journal of Prosthetics and Orthotics | Year: 2011

An angle of 10° to 12° incline between the anterior border of the tibia (shank) and the vertical (SAV) at mid-midstance has been recommended as a starting point from which the "moment arm" at the knee can be optimized (tuned) in children wearing fixed ankle-foot orthoses. The aim of this study was to document the SAV and "moment arm" at the knee throughout stance in normally developing children. Data were collected from 11 healthy children aged 5 to 16 years, and SAV and "moment arm" at the knee plotted throughout stance, both barefoot and shod. The mean (standard deviation) SAV at mid-midstance was 11.4° (3.4°) barefoot and 10.5° (3.6°) shod. The mean (standard deviation) "moment arm" at the knee (normalized to leg length) at mid-midstance was 2.5% (1.7%) barefoot and 1.3% (2.4%) shod. The study provides preliminary evidence for current tuning techniques. © 2011 American Academy of Orthotists & Prosthetists.

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