Comparison between passive vision-based system and a wearable inertial-based system for estimating temporal gait parameters related to the GAITRite electronic walkway.

Quantitative gait analysis allows clinicians to assess the inherent gait variability over time which is a functional marker to aid in the diagnosis of disabilities or diseases such as frailty, the onset of cognitive decline and neurodegenerative diseases, among others. However, despite the accuracy achieved by the current specialized systems there are constraints that limit quantitative gait analysis, for instance, the cost of the equipment, the limited access for many people and the lack of solutions to consistently monitor gait on a continuous basis. In this paper, two low-cost systems for quantitative gait analysis are presented, a wearable inertial system that relies on two wireless acceleration sensors mounted on the ankles; and a passive vision-based system that externally estimates the measurements through a structured light sensor and 3D point-cloud processing. Both systems are compared with a reference clinical instrument using an experimental protocol focused on the feasibility of estimating temporal gait parameters over two groups of healthy adults (five elders and five young subjects) under controlled conditions. The error of each system regarding the ground truth is computed. Inter-group and intra-group analyses are also conducted to transversely compare the performance between both technologies, and of these technologies with respect to the reference system. The comparison under controlled conditions is required as a previous stage towards the adaptation of both solutions to be incorporated into Ambient Assisted Living environments and to provide continuous in-home gait monitoring as part of the future work.

[Feasibility of the construction of a magnetorheological joint for a lower limb orthosis in valve configuration]. / Viabilidad de la construcción de articulación magnetoreológica para ortesis de miembro inferior en configuración de válvula.

Ortheses are devices that assist in the function of the limbs, contributing with stability and support to the involved joints. KAFOs (knee-ankle-foot orthosis) are mainly indicated for people with muscular or neural diseases that affect the lower limbs. The actual designs of knee hinges for KAFOs compromise the stability and mobility of the limb. In this work, it was tested the feasibility of a design for a knee hinge for KAFO that should be able to modify its mechanical resistance depending on the gait phase. Orthotics biomechanical criteria and gait biomechanical requirements were considered. It was proposed an electromagnetic system in order to modify the hinge damping. In the future, the system will be interacting with a magnetorheological fluid (MR) which can change its rheological properties when a magnetic field is applied, thus, reaching different damping constants with the designed hinge. The diameter of the internal pipes required for the MR fluid to freely circulate within the orthosis was established. It was observed that the original design of the proposed orthotic hinge is feasible; however, some proposals are presented in order to achieve a better performance of the orthosis.

Preliminary study of an in vitro development of new tissue applying mechanical stimulation with a bioreactor as an alternative for ligament reconstruction.

Complete rupture of the anterior cruciate ligament (ACL) is a common problem in orthopedics. At present, there are many techniques to reconstruct ligaments, which include the use of autografts, allografts, and, in some cases, artificial ligaments. The latter have not provided good results in the short, medium, and long term. The purpose of present study was to engineer functional biological tissue that could potentially be used to replace the knee ligaments by applying tissue engineering techniques and mechanical stimulation with a bioreactor, promoting cellular differentiation and matrix synthesis. In this preliminary study, the new tissue was characterized with mechanical tests and biological tests (viability and immunochemistry), comparing their behavior with that of the native tissue. Mechanical and biological tests proved that mechanical stimulation administered with a bioreactor maintains the ligament fibroblast phenotype and promotes synthesis of the extracellular matrix.

[Familiarization to treadmill walking in unimpaired Parkinson's disease patients]. / Familiarización de la marcha en banda sinfin de individuos con enfermedad de Parkinson.

Familiarization to treadmill walking in unimpaired Parkinson's disease (PD) patients is assessed, across multiple treadmill walking sessions. Thirteen PD subjects were enrolled into the study (Eight were in a moderate stage of the disease, and 5 in an advanced stage). PD subjects attended a progressive program consisting of 12 sessions of 20 min. Walking speed, cadence, step length and coefficient of variation were assessed. ANOVA test were used to evaluate progression of disease and time influence over familiarization. PD Subjects baseline characteristics did not differ significantly between both groups and typical dependencies over progression of disease and velocity were found for cadence, step length and coefficient of variation. However, we showed that some PD subjects may require longer familiarization times and that familiarization is an adaptation process which involves parameters as velocity, cadence and gait stability. A better definition of familiarization to treadmill is needed since some parameters such as step length does not change significantly while others such as cadence, coefficient of variation and intraclass correlation coefficient does. Therefore familiarization to treadmill walking should remain on measures of velocity, cadence, reliability and variability. However, a bigger sample size is needed in order to improve the results of the present study.

Evidence-based design and development of a VR-based treadmill system for gait research and rehabilitation of patients with Parkinson's disease.

Virtual reality (VR) in neurorehabilitation allows to reduce patient's risk and allows him to learn on a faster way. Up to now VR has been used in patients with Parkinson disease (PD) as a research tool and none of the developed systems are used in clinical practice. The goal of this project is to develop a VR-based system for gait therapy, and gait research of patients with PD designed based on published evidence. The developed system uses a digital camera to measure spatiotemporal gait parameters. The software was developed in C#, using Open-Source libraries that facilitates VR programming. The system has potential uses in clinical and research settings.

[Dynamic plantar pressure distribution after percutaneous hallux valgus correction using the Reverdin-Isham osteotomy]. / Distribución de la presión plantar dinámica después del tratamiento corrective de hallux valgus mediante la ténica de Reverdin-Isham.

Percutaneous surgical techniques are suitable for the correction of the hallux valgus deformity. Satisfactory aesthetic and functional results obtained with the Reverdin- Isham osteotomy have been reported. The aim of this study was to describe dynamic plantar pressure redistribution after the correction of the deformity using this technique. A sample of 20 feet with mild or moderate hallux valgus was conformed and surgically treated using the Reverdin-Isham osteotomy. Clinical, radiological, surface and pressure assessments were performed pre and postoperatively. Postoperative mean (± SD) values of the American Orthopaedic Foot and Ankle Society (AOFAS) score, metatarsophalangeal, first intermetatarsal and proximal articular sect angles were 95.7 (3.3), 15.5° (5.4), 9.5° (1.5) y 5.3° (3.0), respectively. A significant decrease was observed in surface values of both lateral (P = 0.003) and medial (P = 0.001) masks of the forefoot. Mean pressure values of the lateral forefoot region denoted a significant increase (P < 0.001) while the medial forefoot region showed no change (P = 0.137). There is evidence that this particular surgical technique promotes a new plantar pressure pattern in the foot that might significantly favour the increase of the pressure observed under the lesser metatarsal heads and might not induce meaningful changes in the mean pressure registered under the first metatarsal head and hallux.

Sensing and Control Strategies Used in FES Systems Aimed at Assistance and Rehabilitation of Foot Drop: A Systematic Literature Review.

Functional electrical stimulation (FES) is a rehabilitation and assistive technique used for stroke survivors. FES systems mainly consist of sensors, a control algorithm, and a stimulation unit. However, there is a critical need to reassess sensing and control techniques in FES systems to enhance their efficiency. This SLR was carried out following the PRISMA 2020 statement. Four databases (PubMed, Scopus, Web of Science, Wiley Online Library) from 2010 to 2024 were searched using terms related to sensing and control strategies in FES systems. A total of 322 articles were chosen in the first stage, while only 60 of them remained after the final filtering stage. This systematic review mainly focused on sensor techniques and control strategies to deliver FES. The most commonly used sensors reported were inertial measurement units (IMUs), 45% (27); biopotential electrodes, 36.7% (22); vision-based systems, 18.3% (11); and switches, 18.3% (11). The control strategy most reported is closed-loop; however, most of the current commercial FES systems employ open-loop strategies due to their simplicity. Three main factors were identified that should be considered when choosing a sensor for gait-oriented FES systems: wearability, accuracy, and affordability. We believe that the combination of computer vision systems with artificial intelligence-based control algorithms can contribute to the development of minimally invasive and personalized FES systems for the gait rehabilitation of patients with FDS.

Wheelchair users' satisfaction after provision using the WHO 8-step guidelines: A pilot study.

BACKGROUND: Wheelchairs are vital for the successful rehabilitation and inclusion of people with mobility disabilities; 10% of the population with disabilities needs a wheelchair, but only 15% have access to an adequate one. Not user-configured wheelchairs may lead to postural deformities and pressure ulcers, thus negatively impact user satisfaction, wheelchair skills, and quality of life. OBJECTIVE: To assess the impact of the 8-step "Guidelines on the provision of manual wheelchairs in less-resourced settings" from the World Health Organization (WHO) on user satisfaction, wheelchair skills, and quality of life of Mexican manual wheelchair users. METHODS: 12 wheelchair users with spinal cord injury that received rehabilitation were recruited. Volunteers were provided a wheelchair and cushion following the WHO 8-step guidelines. Assessment of QUEST, WHOQOL-Bref, and WST-Q was performed at the beginning of the study and 12 months later. RESULTS: Significant improvement was observed in terms of satisfaction (QUEST; P = 0.009) after receiving the wheelchair and the foam cushion (QUEST; P = 0.004). WHOQol-Bref did not denote significant differences. For the dimensions assessed by the WST-Q scores, a significant 10.9% improvement was observed in both, capacity (P = 0.022) and performance (P = 0.009). CONCLUSIONS: The application of the WHO 8-step guidelines for wheelchair provision may contribute to increase user satisfaction regarding the wheelchair and cushion devices as well as the prescription process as determined by the QUEST. According to the WST-Q, functional capacity and mobility may also be improved by following the 8-step guidelines.

Design and Implementation of a Rehabilitation Upper-limb Exoskeleton Robot Controlled by Cognitive and Physical Interfaces.

This paper presents an upper limb exoskeleton that allows cognitive (through electromyography signals) and physical user interaction (through load cells sensors) for passive and active exercises that can activate neuroplasticity in the rehabilitation process of people who suffer from a neurological injury. For the exoskeleton to be easily accepted by patients who suffer from a neurological injury, we used the ISO9241-210:2010 as a methodology design process. As the first steps of the design process, design requirements were collected from previous usability tests and literature. Then, as a second step, a technological solution is proposed, and as a third step, the system was evaluated through performance and user testing. As part of the technological solution and to allow patient participation during the rehabilitation process, we have proposed a hybrid admittance control whose input is load cell or electromyography signals. The hybrid admittance control is intended for active therapy exercises, is easily implemented, and does not need musculoskeletal modeling to work. Furthermore, electromyography signals classification models and features were evaluated to identify the best settings for the cognitive human-robot interaction.

Comparing Machine Learning Methods to Improve Fall Risk Detection in Elderly with Osteoporosis from Balance Data.

Falls are a multifactorial cause of injuries for older people. Subjects with osteoporosis are particularly vulnerable to falls. We study the performance of different computational methods to identify people with osteoporosis who experience a fall by analysing balance parameters. Balance parameters, from eyes open and closed posturographic studies, and prospective registration of falls were obtained from a sample of 126 community-dwelling older women with osteoporosis (age 74.3 ± 6.3) using World Health Organization Questionnaire for the study of falls during a follow-up of 2.5 years. We analyzed model performance to determine falls of every developed model and to validate the relevance of the selected parameter sets. The principal findings of this research were (1) models built using oversampling methods with either IBk (KNN) or Random Forest classifier can be considered good options for a predictive clinical test and (2) feature selection for minority class (FSMC) method selected previously unnoticed balance parameters, which implies that intelligent computing methods can extract useful information with attributes which otherwise are disregarded by experts. Finally, the results obtained suggest that Random Forest classifier using the oversampling method to balance the data independent of the set of variables used got the best overall performance in measures of sensitivity (>0.71), specificity (>0.18), positive predictive value (PPV >0.74), and negative predictive value (NPV >0.66) independent of the set of variables used. Although the IBk classifier was built with oversampling data considering information from both eyes opened and closed, using all variables got the best performance (sensitivity >0.81, specificity >0.19, PPV = 0.97, and NPV = 0.66).

Effect of mechanical vibration on transcutaneous oxygen levels in the feet of type 2 diabetes mellitus patients. / Efecto de la vibración mecánica sobre los niveles de oxígeno transcutáneo medidos en el pie de pacientes con diabetes mellitus tipo 2.

BACKGROUND AND OBJECTIVE: Foot conditions in patients with diabetes mellitus (DM) are major causes of morbidity and disability. Whole body vibration may promote blood circulation in the lower limbs, hence facilitating perfusion and promoting the supply of nutrients and oxygen to comprised tissues. Transcutaneous oxygen levels (TcPO2)>40mmHg in cases of diabetic foot syndrome are associated with a good prognosis in the resolution of ulcers. The objective of this study was to determine whether whole body vibration favors some parameters of interest related to complications associated with the diabetic foot syndrome. PATIENTS AND METHODS: Fifty-four patients with DM were included in a 12-week exercise program based on whole body vibration. Glycemic control was determined on the basis of the patients' levels of glycated hemoglobin (HbA1c); sensitivity and TcPO2 levels of each foot were also recorded. Assessments were performed prior to initiating the whole body vibration program and at the end of it. RESULTS: No significant changes were observed in the patients' HbA1c (P=.442) levels or sensitivity (P=.07). A significant 7mmHg increase (P<.0001; effect size: d=0.53) was observed in the concentration of TcPO2. CONCLUSIONS: Whole body vibration may increase TcPO2 levels with useful implications for the prevention or management of complications associated with restricted blood perfusion in the diabetic foot syndrome.

Temporal and spatial gait parameters analysis in non-pathological Mexican children.

OBJECTIVE: To examine temporal and spatial gait parameters in Mexican healthy pediatric subjects to describe normal values which could serve as reference data to eventually compare pathological patterns of the Mexican infant gait. MATERIALS AND METHODS: Descriptive study that analyzed the gait of 120 children (61 boys and 59 girls) between the ages of 6 and 13 years old. Modifying factors (age, gender, and footwear) were recorded and its impact over temporal and spatial gait parameters was assessed. The data was stratified according to the modifying factors. A GAITRite System was used for recording the gait data. RESULTS: Significant differences were noted for the following factors: age and the use of footwear. As the individual advances in age, a decrease in number of steps, normalized velocity, velocity, cadence, normalized cadence, normalized step and stride length was observed. In contrast, step and stride length increased. Use of footwear increased velocity (normalized and non-normalized), normalized cadence, step and stride length (normalized and non-normalized), and percentage of stance GC phase; cadence and swing GC percentage diminished. Gender stratification showed no significant differences in any temporal and spatial gait parameters. There were also found significant differences with those reported for normal adult and pediatric gait in the literature. CONCLUSION: Age and footwear modified gait pattern in the studied sample, while gender apparently did not exert any influence on it.