Advanced tuning of below knee prosthesis using the MOTEK CAREN system

A transtibial prosthetic alignment is described as a spatial three dimensions with six degrees of freedom of interrelationship between socket and foot. Moreover, dynamic alignment, a crucial step in aligning prosthesis, aims to achieve the most suitable limb position to achieve desire function and comfort. Misalignment may result in walking difficulty, skin abrasion and uneven forces acting on the residual limb within the socket, which could lead to wound, and even more serious skin and joint trauma. However, the optimal alignment in traditional practice can take one day to several weeks from the starting to finalize in dynamic alignment, depends on prosthetist’s skill and experience. The alignment optimization, a very time- consuming process, is accomplished by subjective judgment of the prosthetist based on visual observation of gait and feedback from the patient. Furthermore, a prosthesis aligned in the traditional subjective practice seems to be lacked of any scientific biomechanical systematics

Investigating ramp gradients for humps on railway platforms

Horizontal and vertical gaps between the train and the platform are a major safety concern for railway passengers, especially for disabled passengers. London Underground is implementing a programme to install platform humps to remove vertical differences between the train and the platform. In order to properly design platform humps, this study empirically investigated the effects of the design factors of the ramps, namely the slope and cross-fall gradients, on disabled passengers. The investigation consisted of two experiments: one where 20 participants were asked to walk on simulated slopes, and the other where 25 participants were asked to board or alight from the simulated train from or onto the slopes. The slope gradients tested were 3·0% (1:33), 5·2% (1:19) and 6·9% (1:14) with the cross-fall gradients 1·5% (1:67), 2·0% (1:50) and 2·5% (1:40). The results showed that the slope gradient does not largely affect the participants’ performance of longitudinal walking on the slopes or their subjective safety evaluation, but would cause additional difficulty for them to board/alight from the train from/onto the slope. This suggests that train doors should not stop next to the ramp. There was little evidence concerning the effects of the cross-fall gradient. The results provide useful information for designing platform humps

A Strathclyde cluster model for gait kinematic measurement using functional methods : a study of inter-assessor reliability analysis with comparison to anatomical models

A major source of error in reliability of gait analysis arises from the palpation of anatomical landmarks (ALs). The purpose of this study was to investigate whether less reliance on manually identifying ALs could improve inter-assessor reliability of joint kinematics compared to two anatomical models. It was hypothesised that the Strathclyde Functional Cluster Model (SFCM), in which the hip, knee and ankle joint centres and knee and ankle flexion axes were determined by functional methods, would obtain greater inter-assessor reliability. Ten able-bodied participants and seven assessors were recruited. Each participant completed three trials conducted by different assessors on non-consecutive days. Agreement and inter-assessor reliability between the models were compared and analysed, whilst factor effects of assessor experience and body mass index (BMI) were investigated. The SFCM obtained excellent agreement with anatomical models for all sagittal angles and hip ab/adduction angle, and it showed slightly higher inter-assessor reliability with smaller variations in the knee and ankle. The assessor experience was not a significant factor, but the BMI had a significant effect on the inter-assessor reliability. The results demonstrate that the SFCM may be more beneficial for less experienced assessors

Clinical usability of a stability-based package using visualisation : a retrospective analysis

The utility of a new clinical system and user interaction, are important given that these may influence clinical use and incorporation into routine practice, as well as patient experience and engagement. As a result, rehabilitative outcome will be affected [1]. The stability-based package was designed and developed as a hybrid tool to enhance rehabilitative outcomes and experience using a game-development approach. By incorporating optoelectronic cameras for accurate motion tracking, a cluster-based model, pointer calibration and visualisation software for a simplified user-interface and real-time feedback, the package focused on addressing complexity and time efficiency to create more clinically appropriate motion analysis system. The feasibility and efficacy of the package has already been reported [2]. This study aimed to retrospectively analyse the usability of the package with respect to time efficiency. A retrospective analysis was completed to eliminate bias of completing training quickly, which would have shifted central attention away from the participant. This aimed to achieve an unbiased representation of the system usability for clinical practice

Is treadmill walking with virtual reality an acceptable and plausible training modality for stroke survivors?

Introduction and Objectives: For many stroke survivors recovering independent walking is an important objective, however, although most survivors recover some walking ability it is often insufficient to meet the challenges of community walking[1]. Treadmill walking, through forced use of the paretic side, has some evidence as an intervention but lacks transfer to community walking[2]. With the rationale of providing a more realistic, variable walking experience, the addition of virtual reality (VR) to treadmills is a recent, promising, development. This aim of this study, therefore, was to investigate the credibility and acceptability of treadmill training with VR among stroke survivors. Methods: This was a feasibility study testing the validity of treadmill training with and without VR through comparison with overground walking. User acceptability was assessed through independent interviews. Six ambulant stroke survivors (aged 56.5±10.6years, 116±93.3months post stroke) were recruited from local stroke clubs. They attended an introductory session for baseline measurements (over ground gait biomechanics, functional mobility and cognition) and familiarisation with the treadmill VR system (MOTEKMedical, Netherlands) including wearing a harness. They then participated in two training sessions, one week apart, each session included treadmill walking without VR (TW) and treadmill walking with VR (TWVR) e.g. road and forest paths visualisations. The final session included a second measurement of gait biomechanics which provided the data for statistical comparison. Each individual was independently interviewed before and after their participation. Results: In general minor, non-significant, differences were observed for TM, TMVR and overground walking. There was, however, a consistent, and statistically significant (p= 0.032) finding of greater hip flexion for TWVR, see table for details. Universally, participants found the experience acceptable and enjoyable, although “challenging”. Conclusion: This feasibility study found treadmill walking (with and without VR) to be similar enough to overground walking to justify it as a training modality for chronic stroke survivors who had already attained some independence in walking. One possible difference, greater hip flexion during treadmill walking, may be a product of harness wearing, and/or relate to the setup of the visualisations. Participants found the experience of treadmill walking acceptable. Although they preferred walking with the visualisations there were few biomechanical differences to simple treadmill walking. Further exploration of individual variability, however, should be undertaken as this may be a factor in ranslating gains from treadmill training to community walking. In conclusion, similarities between overground and treadmill walking (with and without VR) support its use as a training modality in stroke rehabilitation. No great advantage was evident from the use of visualisation other than participant’s preference, however these findings require further testing

Evaluation of functional methods of joint centre determination for quasi-planar movement

Functional methods identify joint centres as the centre of rotation (CoR) of two adjacent movements during an ad-hoc movement. The methods have been used for functionally determining hip joint centre in gait analysis and have revealed advantages compared to predictive regression techniques. However, the current implementation of functional methods hinders its application in clinical use when subjects have difficulties performing multi-plane movements over the required range. In this study, we systematically investigated whether functional methods can be used to localise the CoR during a quasi-planar movement. The effects of the following factors were analysed: the algorithms, the range and speed of the movement, marker cluster location, marker cluster size and distance to the joint centre. A mechanical linkage was used in our study to isolate the factors of interest and give insight to variation in implementation of functional methods. Our results showed the algorithms and cluster locations significantly affected the estimate results. For all algorithms, a significantly positive relationship between CoR errors and the distance of proximal cluster coordinate location to the joint centre along the medial-lateral direction was observed while the distal marker clusters were best located as close as possible to the joint centre. By optimising the analytical and experimental factors, the transformation algorithms achieved a root mean square error (RMSE) of 5.3 mm while the sphere fitting methods yielded the best estimation with an RMSE of 2.6 mm. The transformation algorithms performed better in presence of random noise and simulated soft tissue artefacts

Efficacy of using the pelvic method to estimate centre of mass position in response to gait perturbations

During gait the centre of mass (COM) should be maintained relative to the base of support for optimal efficiency of movement, and reduced risk of falling. The ability to control the COM position is challenged for every step, and is therefore an important tool in clinical practice to predict dynamic stability. To ensure accuracy and precision of COM estimation, motion analysis equipment and full body (FB) tracking is required. Difficulty implementing this due to time and expertise limitations causes clinicians to favour the pelvic model (P), assuming the COM can be represented by the centre point of the pelvis. This may trade accuracy and precision for clinical applicability. The aim of this study was to investigate COM representation during unperturbed and perturbed gait using a reduced kinematic model

Efficacy of stability-based training with visualisation in people with chronic ankle instability

Background Chronic ankle instability (CAI) is associated with recurrent ankle sprains, mechanical laxity and/or perceived instability. Stability-based rehabilitative training has been found to prevent further injury, however poor programme compliance can hinder the programme’s effectiveness. Virtual reality (VR) systems have been shown to provide a stimulating and motivational environment that may be more conducive to rehabilitation adherence. An emerging technique, visualisation, is the connection of biomechanical analysis and VR. Visualisation produces real-time feedback, by accurately monitoring movement and progress, using VR to create a diverse, challenging, and controllable environment, representative of real-world situations. Objective The aim of this study was to determine the feasibility of incorporating visualisation into stability training for people with chronic ankle instability. Specifically, the effect of visualisation on performance of the Star Excursion Balance Test (SEBT), as well as participant’s enjoyment of the experience. Design and Methods Individuals with CAI were randomly allocated to the 4-week stability-based training programme with visualisation (VIS), or without (NO-VIS). Balance exercises were based on standard practice, with adaptations for visualisation. Participants completed the SEBT and Cumberland Ankle Instability Tool (CAIT) prior to, and after training. Participants recorded enjoyment of training using the Physical Activity Enjoyment Scale (PACES-8). The Strathclyde Cluster Model and pointer calibration were applied to all participants. Movement was tracked using Vicon Tracker (Vicon, Oxford, UK), with testing controlled and recorded using D-Flow (Motek Medical, Amsterdam, The Netherlands). Effect size (d) was calculated and interpreted using Hopkin’s recommendations. Results Of 17 participants (Vis=10,No-Vis=7), there were 2 drop outs (Vis=1,No-Vis=1). No adverse events were reported and participant drop-out was due to injury unrelated to the study. There were no between-group differences in population demographics and pre-training CAIT scores (p⩾0.2). Following training there was a non-significant but small effect (d=0.6,p=0.3) favouring the NO-VIS group for an increase in CAIT score. There was a non-significant but moderate effect (d=1,p=0.20) favouring the VIS group for an increase in average reach distance on the SEBT. There was a non-significant but large effect (d=1.4,p=0.16) for higher enjoyment of training in the VIS group. Conclusions Results of this study support the feasibility and safety of stability training with visualisation in those with CAI. Observations of a more enjoyable experience, alongside improved postural control suggest visualisation may enhance stability-based training. Implications of this will be discussed, along with the practicalities and logistics of running such programmes

Functional quadriceps reconstruction : 3D gait analysis, EMG and environmental simulator outcomes

Limited objective evidence exists on the benefits of functional muscle transfers following quadriceps resection in sarcoma. In particular, no studies have compared patients with functional transfers to those without. In this study, objective and subjective assessments were performed with 3D Gait Analysis, Environmental Simulator, Electromyography (EMG) and Patient-Reported Outcomes. Thirty-four patients at the Scottish Sarcoma Network Glasgow Centre/ Canniesburn Plastic Surgery Unit underwent quadriceps resection for sarcoma between 2009 - 2019, including 24 patients with functional reconstruction and 10 without. Both groups were equivalent for the extent of quadriceps resection (2.58 versus 2.85 components, p=0.47). Primary outcome measure was 3D Gait Analysis and Gait Profile Score (GPS), and secondary outcome was the Toronto Extremity Salvage Score (TESS) score. Ancillary analyses included environmental simulation with the Motek CAREN system and EMG of transferred muscles. Outcomes measures were better in functional reconstruction patients when compared to those without - the GPS score was 8.04 versus 10.2 (p=0.0019), and the TESS score was 81.85 versus 71.17 (p=0.028). Environmental simulator tasks found that functional reconstruction patients could complete activities of daily living including shopping and collision avoidance tasks, without significantly slowing their walking speed. Patients without a functional reconstruction could not complete weighted shopping tasks. EMG showed that transferred hamstrings co-activated with the ipsilateral rectus femoris during the gait cycle. These are the first objective data demonstrating the superiority of muscle transfers for functional restoration in quadriceps resection versus patients without functional transfers. Critically, these also provide answers to patient-oriented questions relating to the recovery of function and activities of daily living. [Abstract copyright: Copyright © 2022 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.