Effects of physiotherapy and home-based training in parkinsonian syndromes: protocol for a randomised controlled trial (MobilityAPP)

INTRODUCTION

Gait and mobility impairment are pivotal signs of parkinsonism, and they are particularly severe in atypical parkinsonian disorders including multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). A pilot study demonstrated a significant improvement of gait in patients with MSA of parkinsonian type (MSA-P) after physiotherapy and matching home-based exercise, as reflected by sensor-based gait parameters. In this study, we aim to investigate whether a gait-focused physiotherapy (GPT) and matching home-based exercise lead to a greater improvement of gait performance compared with a standard physiotherapy/home-based exercise programme (standard physiotherapy, SPT).

METHODS AND ANALYSIS

This protocol was deployed to evaluate the effects of a GPT versus an active control undergoing SPT and matching home-based exercise with regard to laboratory gait parameters, physical activity measures and clinical scales in patients with Parkinson's disease (PD), MSA-P and PSP. The primary outcomes of the trial are sensor-based laboratory gait parameters, while the secondary outcome measures comprise real-world derived parameters, clinical rating scales and patient questionnaires. We aim to enrol 48 patients per disease group into this double-blind, randomised-controlled trial. The study starts with a 1 week wearable sensor-based monitoring of physical activity. After randomisation, patients undergo a 2 week daily inpatient physiotherapy, followed by 5 week matching unsupervised home-based training. A 1 week physical activity monitoring is repeated during the last week of intervention.

ETHICS AND DISSEMINATION

This study, registered as 'Mobility in Atypical Parkinsonism: a Trial of Physiotherapy (Mobility_APP)' at clinicaltrials.gov (NCT04608604), received ethics approval by local committees of the involved centres. The patient's recruitment takes place at the Movement Disorders Units of Innsbruck (Austria), Erlangen (Germany), Lausanne (Switzerland), Luxembourg (Luxembourg) and Bolzano (Italy). The data resulting from this project will be submitted to peer-reviewed journals, presented at international congresses and made publicly available at the end of the trial.

TRIAL REGISTRATION NUMBER

NCT04608604.

Lower extremity muscle patterns and frontal plane biomechanics are altered in the contralateral knee of adults with osteoarthritis compared to asymptomatic adults

PURPOSE

To compare knee joint muscle activity during gait between the contralateral limb of individuals with knee osteoarthritis (OA) and an asymptomatic older adult group. A secondary objective was to compare frontal and sagittal plane moment and sagittal plane motion features between groups.

SCOPE

84 individuals with moderate knee OA (61 ± 6 years, 43 % female, BMI 29.2 ± 5.7 kg/m2), and 45 asymptomatic older adults (61 ± 7 years, 49 % female, BMI 25.0 ± 3.4 kg/m2) participated. Participants walked at a self-selected pace on a dual belt treadmill. Surface electromyograms of the quadriceps, hamstrings, and gastrocnemius, segment motions and ground reaction forces were recorded. Principal component analyses identified amplitude and temporal electromyogram features. Sagittal plane motion and net external sagittal and frontal plane moments were calculated. Analysis of Variance models using Bonferroni corrections determined between and within group differences in these gait features.

CONCLUSIONS

The contralateral knee showed prolonged lateral hamstring activation and altered temporal features of the gastrocnemius and greater knee adduction moments compared to asymptomatic adults. Group, muscle, or interaction effects were not found for the quadriceps. These findings highlight the importance of exploring the implications of contralateral knee function of individuals with moderate knee OA, particularly considering the altered antagonist muscle activations, and heightened frontal plane moments.

Local Dynamic Stability of Trunk During Gait is Responsive to Rehabilitation in Subjects with Primary Degenerative Cerebellar Ataxia

This study aimed to assess the responsiveness to the rehabilitation of three trunk acceleration-derived gait indexes, namely the harmonic ratio (HR), the short-term longest Lyapunov's exponent (sLLE), and the step-to-step coefficient of variation (CV), in a sample of subjects with primary degenerative cerebellar ataxia (swCA), and investigate the correlations between their improvements (∆), clinical characteristics, and spatio-temporal and kinematic gait features. The trunk acceleration patterns in the antero-posterior (AP), medio-lateral (ML), and vertical (V) directions during gait of 21 swCA were recorded using a magneto-inertial measurement unit placed at the lower back before (T0) and after (T1) a period of inpatient rehabilitation. For comparison, a sample of 21 age- and gait speed-matched healthy subjects (HSmatched) was also included. At T1, sLLE in the AP (sLLEAP) and ML (sLLEML) directions significantly improved with moderate to large effect sizes, as well as SARA scores, stride length, and pelvic rotation. sLLEML and pelvic rotation also approached the HSmatched values at T1, suggesting a normalization of the parameter. HRs and CV did not significantly modify after rehabilitation. ∆sLLEML correlated with ∆ of the gait subscore of the SARA scale (SARAGAIT) and ∆stride length and ∆sLLEAP correlated with ∆pelvic rotation and ∆SARAGAIT. The minimal clinically important differences for sLLEML and sLLEAP were ≥ 36.16% and ≥ 28.19%, respectively, as the minimal score reflects a clinical improvement in SARA scores. When using inertial measurement units, sLLEAP and sLLEML can be considered responsive outcome measures for assessing the effectiveness of rehabilitation on trunk stability during walking in swCA.

Acute effects of robot-assisted body weight unloading on biomechanical movement patterns during overground walking

Body weight unloading (BWU) is used in rehabilitation/training settings to reduce kinetic requirements, however different BWU methods may be unequally capable of preserving biomechanical movement patterns. Biomechanical analysis of both kinetic and kinematic movement trajectories rather than discrete variables has not previously been performed to describe the effect of BWU on gait patterns during horizontal walking. The aim of the present study was to investigate how robot-assisted BWU producing an dynamic unloading force on the body centre of mass, affects kinematic, kinetic, and spatiotemporal gait parameters in healthy young adults by use of time-continuous analysis. Twenty participants walked overground in a 3-D motion-capture lab at 0, 10, 20, 30, 40, and 50 % BWU at a self-selected speed. Vertical and anterior-posterior ground reaction forces (GRFs) and lower limb internal joint moments were obtained during the stance phase, while joint angles were obtained during entire strides. Time-continuous data were analysed using Statistical Parametric Mapping (SPM) and discrete data using conventional statistics to compare different BWU conditions by means of One-Way Repeated Measures Anova. With increasing BWU, corresponding reductions were observed for GRFs, internal joint moments, joint angles, walking speed, stride/step length and cadence. Observed effects were partially caused by decreased walking speed and increased BWU. While amplitude reductions were observed for kinetic and kinematic variables, trajectory shapes were largely preserved. In conclusion, dynamic robot-assisted BWU enables reduced kinetic requirements without distorting biomechanically normal gait patterns during overground walking in young healthy adults.

Fine-Grained Intoxicated Gait Classification Using a Bilinear CNN

Consuming excessive amounts of alcohol causes impaired mobility and judgment and driving accidents, resulting in more than 800 injuries and fatalities each day. Passive methods to detect intoxicated drivers beyond the safe driving limit can facilitate Just-In-Time alerts and reduce Driving Under the Influence (DUI) incidents. Popularly-owned smartphones are not only equipped with motion sensors (accelerometer and gyroscope) that can be employed for passively collecting gait (walk) data but also have the processing power to run computationally expensive machine learning models. In this paper, we advance the state-of-the-art by proposing a novel method that utilizes a Bi-linear Convolution Neural Network (BiCNN) for analyzing smartphone accelerometer and gyroscope data to determine whether a smartphone user is over the legal driving limit (0.08) from their gait. After segmenting the gait data into steps, we converted the smartphone motion sensor data to a Gramian Angular Field (GAF) image and then leveraged the BiCNN architecture for intoxication classification. Distinguishing GAF-encoded images of the gait of intoxicated vs. sober users is challenging as the differences between the classes (intoxicated vs. sober) are subtle, also known as a fine-grained image classification problem. The BiCNN neural network has previously produced state-of-the-art results on fine-grained image classification of natural images. To the best of our knowledge, our work is the first to innovatively utilize the BiCNN to classify GAF encoded images of smartphone gait data in order to detect intoxication. Prior work had explored using the BiCNN to classify natural images or explored other gait-related tasks but not intoxication Our complete intoxication classification pipeline consists of several important pre-processing steps carefully adapted to the BAC classification task, including step detection and segmentation, data normalization to account for inter-subject variability, data fusion, GAF image generation from time-series data, and a BiCNN classification model. In rigorous evaluation, our BiCNN model achieves an accuracy of 83.5%, outperforming the previous state-of-the-art and demonstrating the feasibility of our approach.

Gait analysis after total hip arthroplasty by direct minimally invasive anterolateral approach: A controlled study

INTRODUCTION

Clinical and functional improvement after minimally invasive total hip arthroplasty (THA) has become increasingly controversial. The minimally invasive anterolateral approach (MIALA) allows rapid recovery resulting in a reduced need for rehabilitation. Alterations in muscle and static balance have previously been demonstrated. Results in the context of quantified gait analysis (QGA) and MIALA compared to an asymptomatic population remain unknown beyond one year postoperatively. Thus, the main objective of this controlled study was to compare the spatiotemporal parameters of gait, obtained using a QGA, beyond one year postoperatively in subjects operated on for THA by MIALA, with a group of asymptomatic subjects of the same age. The secondary objectives of the study were to compare the other QGA and EMG data acquired in operated subjects with asymptomatic subjects.

HYPOTHESIS

We hypothesized that QGA and EMG parameters would not normalize beyond one year postoperatively.

PATIENTS AND METHODS

Thirty-one subjects were recruited, including 16 patients (68 years old; IQR: 65-70) who underwent MIALA, at 15.5 months postoperatively (IQR: 13-17) and 15 asymptomatic subjects (62 years old; IQR: 61-71). Subjects underwent QGA and maximal isometric muscle force tests on the gluteus medius, gluteus maximus, Tensor Fascia Lata (TFL) and Sartorius muscles. Spatiotemporal gait parameters were the primary endpoint. The other QGA parameters: kinetics (characteristic values of vertical ground reaction forces, peak hip moments) and kinematics (hip joint amplitudes and pelvic mobility in the frontal and sagittal plane) constituted the secondary criteria.

RESULTS

Five subjects were excluded for unrestored offset. Walking speed was lower in operated patients (1.03m/s versus 1.18m/s, p=0.005). Maximal isometric muscle force moments were lower in patients operated on for the gluteus maximus and medius as well as the TFL (p<0.005). The vertical ground reaction forces were lower for the operated patients for the loading phase (FzFCmax, p=0.001), the single stance phase (FzSPmin, p=5.05.10-2) and the swing phase (FzTOmax, p=0.0002). The moments were lower in the sagittal plane for the operated patients (0.6N.m for the operated versus 1.1N.m for the asymptomatic, p=0.02). The pelvic amplitudes in the sagittal plane were lower for operated patients (3.3° versus 7.2°, p=0.05).

DISCUSSION

Our hypothesis appears to be validated. Gait deficits persisted beyond one year postoperatively after THA with MIALA. A decrease in walking speed, maximal isometric muscle force of the gluteus medius and gluteus maximus and TFL was observed, as well as a decrease in propulsive force and peak hip moment. Functionally, these results could signify muscle damage following surgery, requiring rehabilitation for improved muscle function.

LEVEL OF PROOF

III: Non-randomized controlled trial.

Validation of a Wearable System for Lower Extremity Assessment

OBJECTIVE

Remote assessment and diagnosis of functional impairment caused by osteoarthritis (OA) of the knee can achieve early intervention of patients' functional impairment, prevent the deterioration of OA of the knee, and provide functional remote screening for patients with knee OA. This study introduced an inertial measurement unit (IMU) sensor-based system to assess lower extremity function and perform gait analysis. Then, we compared its accuracy to gold-standard motion capture and gait measurement systems.

METHODS

Nine adults were selected to participate in a comparative study of gait assessment outcomes using an IMU sensor-based wearable system, a gold-standard motion capture system, and a pressure-based gait analysis system. The subject walked on a path that incorporated all three systems. Data analysis was performed on spatiotemporal gait parameters, including velocity, cycle time, cadence, and stride length. This was followed by gait phases, including stance, swing, double stance, and single limb support phases. Data were processed using the data processing software of each system. An independent sample t-test was conducted for inter-group comparison to analyze the data.

RESULTS

The spatiotemporal gait parameters of the systems demonstrated excellent consistency, and the gait phases showed high consistency. Compared to the gold-standard pressure-based gait analysis system (the GATERite system), the mean gait cycle time results were 1.124 s vs. 1.127 s (p = 0.404); cadence was 93.333 steps/min vs. 94.189 steps/min (p = 0.482); stance phase was 60.89% vs. 63.26% (p < 0.001); swing phase was 39.11% vs. 36.74% (p < 0.001); stride length was 1.404 m vs. 1.420 m (p = 0.743); speed was 1.093 m/s vs. 1.110 m/s (p = 0.725). Compared to the gold-standard video-based motion capture system, the root mean square error was 2.7° for the hip angle and 2.6° for the knee angle.

CONCLUSIONS

This IMU-based wearable system delivered precise measuring results to evaluate patients with knee OA. This technology can also be used to guide rehabilitation exercises for patients with knee OA.

A comparison of three-dimensional kinematics between markerless and marker-based motion capture in overground gait

Vision-based methods using RGB inputs for human pose estimation have grown in recent years but have undergone limited testing in clinical and biomechanics research areas like gait analysis. The purpose of the present study was to compare lower extremity kinematics during overground gait between a traditional marker-based approach and a commercial multi-view markerless system in a sample of subjects including young adults, older adults, and adults diagnosed with Parkinson's disease. A convenience sample of 35 adults between the age of 18-85 years were included in this study, yielding a total of 114 trials and 228 gait cycles that were compared between systems. A total of 30 time normalized waveforms, including three-dimensional joint centers, segment angles, and joint angles were compared between systems using root mean-squared error (RMSE), range of motion difference (ΔROM), Pearson correlation coefficients (r), and interclass correlation coefficients (ICC). RMSEs for joint center positions were less than 28 mm in all joints with correlations indicating good to excellent agreement. RMSEs for segment and joint angles were in range of previous results, with highest agreement between systems in the sagittal plane. ΔROM differences were within reference values that characterize clinical groups like Parkinson's disease, stroke, or knee osteoarthritis. Further improvements in pelvis tracking, markerless keypoint model definitions, and standardization of comparison study protocols are needed. Nevertheless, markerless solutions seem promising toward unrestricted motion analysis in biomechanics research and clinical settings.

Effect of Ankle-Foot Orthoses in Pediatric Patients with Hereditary Motor-Sensory Neuropathy: A Case Series Study

(1) Aims: to evaluate the effect on gait performance and standing stability of ankle-foot orthoses (AFO) in pediatric patients with hereditary motor-sensory neuropathy (HMSN). (2) Methods: a retrospective case-series study including three adolescents (S1, S2, S3, mean age 14 years) with HMSN. The subjects were evaluated barefoot, with carbon AFO (Botter) and with solid AFO (SAFO) by means of: gait analysis, stabilometry and gait functional tests (10 Meter Walk Test, 2 Minute Walk Test). Finally, the CSD-OPUS questionnaire was administered to the assess satisfaction and impact of the orthoses on life quality. (3) Results: orthoses improved gait and stability performance. Botter allowed greater ankle movement than SAFO and provided greater push-off power. This, combined with the carbon elastic energy return, might explain better performances in the 2MWT, with a larger distance traveled compared to SAFO for both S1 (110 m vs. 72 m) and S2 (170 m vs. 155 m) and, compared to barefoot walking, also for S3 (211 m vs. 160 m), for which SAFO analysis was not available. Both orthoses improved performance at the stabilometric analysis. The CSD-OPUS questionnaire showed a significantly higher level of satisfaction with Botter for the subjects (S1, S2) who completed the comparison. (4) Conclusions: Both orthoses improved gait and standing, though Botter proved to be better tolerated and more effective in improving gait endurance.

[Analysis of movement disorders in paediatric and adolescent rheumatology]

Rheumatic diseases in childhood and adolescence like juvenile idiopathic arthritis can cause movement disorders due to pain, swelling and limited range of motion. This article describes different possibilities and results of movement analysis for rheumatic diseases. The influence of JIA on specific movements in individual joints and complex movements such as gait is examined. The results of gait analyses show a great influence of the disease on spatiotemporal parameters such as gait speed, cadence and stride length, on joint angles during walking and on torques and forces. Furthermore, the importance of gait analysis for estimating the efficacy of interventions like intra-articular steroids is described. This article provides a summary of current studies on the effects of rheumatic diseases on movement disorders in children and adolescents, as well as an outlook on the increasing importance of movement analysis for therapy monitoring and optimisation.

Verification of Reliability and Validity of Trunk Forward Tilt Angle Measurement During Gait Using 2-Dimensional Motion Analysis

Objective

The purpose of this study was to verify the reliability and validity of trunk forward tilt angle measurement during gait using the 2-dimensional motion analysis, open-source software Kinovea.

Methods

The participants were 48 healthy people (23.3 ± 3.7 years of age), and the measurement task was normal gait. Two-dimensional motion analysis using Kinovea and measurement using a 3-dimensional motion analyzer were performed synchronously to calculate the forward tilt angle of the trunk during gait. The maximum and minimum values ​​of the trunk forward tilt angle in 1 gait cycle were used as representative values. The intraclass correlation coefficient and the minimum detectable change amount in Kinovea were calculated. We also verified the correlation with the measured values ​​using the 3-dimensional motion analyzer and the error by Bland-Altman analysis.

Results

The intraclass correlation coefficient for Kinovea was 0.925 (95% confidence interval, 0.866-0.958) at the maximum and 0.918 (95% confidence interval, 0.854-0.954) at the minimum. The maximum value of the minimum detectable change amount was 2.7°, and the minimum value was 2.9°. The correlation coefficient between the methods was the maximum value r = 0.964 (R² = 0.929) and the minimum value r = 0.970 (R² = 0.941). The average difference between the methods (d) was -0.55 to -0.51° and the standard deviation of the difference between the measured values was 0.66 to 0.84°, and the minimum value was d = -0.59 to -0.54° and SDd = 0.63 to 0.91°.

Conclusion

The reliability and validity of the measurement by 2-dimensional motion analysis of the trunk forward tilt angle in young adults were confirmed.

Reliability of IMU-Derived Gait Parameters in Foot Drop Patients

Foot drop is a deficit in foot dorsiflexion causing difficulties in walking. Passive ankle-foot orthoses are external devices used to support the drop foot improving gait functions. Foot drop deficits and therapeutic effects of AFO can be highlighted using gait analysis. This study reports values of the major spatiotemporal gait parameters assessed using wearable inertial sensors on a group of 25 subjects suffering from unilateral foot drop. Collected data were used to assess the test-retest reliability by means of Intraclass Correlation Coefficient and Minimum Detectable Change. Excellent test-retest reliability was found for all the parameters in all walking conditions. The analysis of Minimum Detectable Change identified the gait phases duration and the cadence as the most appropriate parameters to detect changes or improvements in subject gait after rehabilitation or specific treatment.

A gait functional classification of adolescent idiopathic scoliosis (AIS) based on spatio-temporal parameters (STP)

BACKGROUND

Therapeutic decisions for patients with adolescent idiopathic scoliosis (AIS) are mostly based on static measurements performed on two-dimensional standing full-spine radiographs. However, the trunk plays an essential role in the human locomotion, and the functional consequences during daily activities of this specific and common spinal deformity are not factored in.

RESEARCH QUESTION

Does patients with AIS have specific gait patterns based on spatio-temporals parameters measurements ?

METHODS

90 AIS patients (aged 10-18 years) with preoperative simplified gait analysis were retrospectively included for analysis between 2017 and 2020. Spatio-temporal parameters (STP) were measured on a 3-m baropodometric gaitway and included the measurement of 15 normalized gait parameters. A hierarchical cluster analysis was performed to identify group of patients based on the similarities of their gait patterns, and functional variables' inter-group differences were also measured. The subject distribution was calculated to identify the structural characteristics of the subjects according to their gait patterns.

RESULTS

Three gait patterns were identified. Cluster 1 (46%) was defined by asymmetry, Cluster 2 (16%) by instability, and Cluster 3 (36%) by variability. Each cluster was significantly different from the other ones on at least 6 different parameters (p < 0.05). Furthermore, each cluster was associated with one type of curve: Lenke 1 for Cluster 1 (57.5%), Lenke 6 for Cluster 2 (40%) and Lenke 5 for Cluster 3 (43.5%).

SIGNIFICANCE

Patients with severe AIS have a dynamic signature during gait identified on STP. Understanding consequences of this deformity on gait may be an interesting avenue to study the pathological mechanisms involved in their dynamic motor organization. Furthermore, these results might also be a first step to study the effectiveness of the different therapies.

Mechanographic analysis of the timed 4 stair climb test - methodology and reference data of healthy children and adolescents

OBJECTIVES

The timed 4 stair climb test (4SC) is an accepted and widely used tool to assess motor function of patients with neuromuscular diseases. We aimed to establish reference data for the 4SC, and for mechanographic analysis of ascent (4SC-Up) and descent (4SC-Dn) in healthy children and adolescents.

METHODS

We used a custom-made staircase measuring device to assess force, power and velocity during the ascent of 4 stairs in healthy subjects. Secondary outcome measures included mechanographic analyses such as the Chair-Rising-test and the myometric Grip Force-test.

RESULTS

Data of 288 participants aged 4 to 16 years (144 males, 144 females) were analyzed. A simple algorithm integrating the minimal applied force was used to compensate for different movement strategies. Percentiles for average power, force and horizontal velocity were calculated. While results of the 4SC-Up test showed no age or gender dependency, we found 4SC-Dn results to be age dependent. Mean device measured times were significantly shorter than manually measured times (mean difference -0.19 s; p<0.001).

CONCLUSIONS

Mechanographic analysis of the 4SC appears to be a promising tool for evaluation of muscle strength and function of the lower extremities as it enables physically exact measurements of a highly relevant activity of daily living.

Individuals with a COVID-19 history exhibit asymmetric gait patterns despite full recovery

COVID-19 is a multisystem infectious disease affecting the body systems. Its neurologic complications include -but are not limited to headache, loss of smell, encephalitis, and cerebrovascular accidents. Even though gait analysis is an objective measure of the neuro-motor system and may provide significant information about the pathophysiology of specific diseases, no studies have investigated the gait characteristics in adults after full recovery from COVID-19. This was a cross-sectional, controlled study that included 12 individuals (mean age, 23.0 ± 4.1 years) with mild-to-moderate COVID-19 history (COVD) and 20 sedentary controls (CONT; mean age, 24.0 ± 3.6 years). Gait was evaluated using inertial sensors on a motorized treadmill. Spatial-temporal gait parameters and gait symmetry were calculated by using at least 512 consecutive steps for each participant. The effect-size analyses were utilized to interpret the impact of the results. Spatial-temporal gait characteristics were comparable between the two groups. The COVD group showed more asymmetrical gait patterns than the CONT group in the double support duration symmetry (p = 0.042), single support duration symmetry (p = 0.006), loading response duration symmetry (p = 0.042), and pre-swing duration symmetry (p = 0.018). The effect size analyses of the differences showed large effects (d = 0.68-0.831). Individuals with a history of mild-to-moderate COVID-19 showed more asymmetrical gait patterns than individuals without a disease history. Regardless of its severity, the multifaceted long-term effects of COVID-19 need to be examined and the scope of clinical follow-up should be detailed.

An insight into Transfemoral Prostheses: Materials, modelling, simulation, fabrication, testing, clinical evaluation and performance perspectives

INTRODUCTION

A Transfemoral prosthesis restores any limb amputated above the knee. Designing and developing a transfemoral prosthesis that is consistent with human performance is a tough task. While prosthetic components are widely available in the market, ongoing research is being conducted to develop parts that would restore the lost capability, taking into account numerous social, economic and technological considerations.

AREAS COVERED

The present paper provides a comprehensive review about the mechanical aspects and performance of transfemoral prosthesis in recent years based on the research findings on materials, manufacturing methods and evaluations for suitability of the prostheses. The fundamental terminologies as well as technical advancements are covered in order to impart a better knowledge in the area of Lower Limb prostheses. This review also provides a concise description on the role of computers, advanced software packages, sensors and other hardware components for the design, fabrication and testing of transfemoral prosthetic devices in the current environment.

EXPERT OPINION

The current state of lower limb prostheses and future research opportunities are summarised to address upcoming challenges. Based on survey of various research works, adapting modern technology may aid in the development of functional and cost-efficient prosthetic components with superior safety, comfort and quality.

Wearable Sensor Gait Analysis of Fall Detection using Attention Network

The statistical data from the National Council on Aging indicates that a senior adult dies in the US from a fall every 19 minutes. The care of elderly people can be improved by enabling the detection of falling events, especially if it triggers the pneumatic actuation of a protective airbag. This work focuses on detecting impending fall risk of senior subjects within the geriatric population, towards a planned approach to mitigating fall injuries through pneumatic airbag deployment. With the widespread adoption of wearable sensors, there is an increased emphasis on fall prediction models that effectively cope with accelerometry signal data. Fall detection and gait classification are challenging tasks, especially in differentiating falls from near falls. We propose to apply attention to the deep neural network (DNN) analysis of acceleration data where a fall is known to have occurred. We take the maximum value of the sensor signals to define the observation window of the detector. Powered by a transformer DNN with word embedding, attention networks have achieved a state-of-the-art in natural language processing (NLP) tasks. Besides the success of the transformer for efficiently processing long sequences, it supports parallel computing with fast computation. In this paper, we propose a novel transformer attention network for gait analysis of fall detection modeling with Time2Vec positional encoding- founded on a Masked Transformer Network. Using our dataset, we demonstrate that the proposed approach achieves better specificity and sensitivity than the present models.

Gait Analysis Platform for Measuring Surgery Recovery

Gait analysis has evolved significantly during last years due to the great development of the Medical Internet of Things (MIoT) platforms that allow an easy integration of sensors (inertial, magnetic and pressure in our case) to the complex analytics required to compute, not only relevant parameters, but also meaningful indexes. In this paper, we extend a previous development based on a fully wireless pair of insoles by implementing an updated version with more reliable and user-friendly devices, smartphone app and web front-end and back-end. We also extend previous work focused on fall analysis (with the corresponding fall risk index or FRI) with the proposal of a new surgery recovery index (SRI) to account for the individual speed recovery speed that can be measured either at clinical facilities or at home in a telemedicine environment or while doing daily life activities. This new index can be personalized for different types of surgeries that affect gait such as hip, knee, etc. This paper presents the case of hip recovery and is built on top of the clinical standard SPPB test and allows obtaining quantitative parameters directly from the sensors.

The Hybrid Subischial Socket for Persons With Transfemoral Amputation: Gait Parameters and Clinical Assessment of a Case Series

BACKGROUND

The subischial socket interface design is a promising new shape of socket for persons with transfemoral amputation. Typically, the proximal trim line is located distal to the ischial tuberosity, improving comfort in prosthetic users without interfering with gait parameters compared to Ischial Containment Socket (ICS). No studies have investigated the performances of a subischial sockets with suction suspension system. A new subischial socket (Hybrid Subischial Socket - HySS) combined with a hypobaric passive suspension system has been recently developed.

OBJECTIVE

To assess the effects of HySS in terms of comfort, hip range-of-motion and gait parameters.

METHODOLOGY

Three persons with transfemoral amputation were tested first using their usual ICS and then after one month of continuous use of HySS.

FINDINGS

The following parameters improved in all participants using HySS: 1) hip range-of-motion, 2) walking speed and distance, 3) Timed-Up-and-Go-Test time, 4) stride length, 5) double support duration, 6) peak value of hip extension during stance, 7) satisfaction with the prosthesis.

CONCLUSION

These findings suggest that the use of HySS could allow improvements for prosthetic use.

The effect of scoliosis support orthosis bracing on adult spinal deformity patients: evaluation of gait and dynamic balance

Non-operative treatment is regarded as the first-line therapy for patients with adult spinal deformity (ASD) without neurologic deficits or significant impairment. While there is high-level evidence supporting the use of rigid bracing in adolescent idiopathic scoliosis, there is a paucity of literature pertaining to the use of scoliosis support orthosis (SSO) in ASD patients. To investigate the impact of an SSO on pain, gait parameters, and functional balance measures in symptomatic ASD patients. Thirty ASD patients (26 Females, Age: 72.7, Cobb Angle: 47.1°) were evaluated on 3 different occasions: first day of bracing: baseline (Pre), and 45-min post fitting (Post45m), and after 8-weeks of bracing for 4 hours a day (Post8w). Each patient performed a 6-minute walk (over-ground gait), a dynamic balance test, and completed VAS, ODI, and SRS22r. Significant short- and long-term improvements using SSO were found in the 6-minute walk (Pre: 278.6; Post45m: 322.2; Post8w: 338.8 m, p<0.001), walking speed (Pre: 0.88; Post45m: 0.97; Post8w: 0.97 m/s, p<0.001), head total sway distance during the balance test (Pre: 81.33; Post45m: 68.63; Post8w: 60.72 cm, p=0.048), low-back pain (VAS: Pre: 5.5; Post45m: 3.5; Post8w: 3.3, p<0.001), and for the ODI (Pre: 41.9; Post45m: 32.9; Post8w: 30.1, p=0.005).This study demonstrated clinically significant improvements in PROMs, spatiotemporal gait measures, and functional balance measures after continuous use of a SSO. These improvements were observed immediately following brace-fitting and maintained at an 8-week follow-up. Given these results, it is reasonable to consider a SSO for conservative management of patients with mild symptoms of pain and deformity, and who have not yet progressed to meet surgical indications.

Machine Learning Approaches in Parkinson's Disease

BACKGROUND

Parkinson's disease is the second most frequent neurodegenerative disorder. Its diagnosis is challenging and mainly relies on clinical aspects. At present, no biomarker is available to obtain a diagnosis of certainty in vivo.

OBJECTIVE

The present review aims at describing machine learning algorithms as they have been variably applied to different aspects of Parkinson's disease diagnosis and characterization.

METHODS

A systematic search was conducted on PubMed in December 2019, resulting in 230 publications obtained with the following search query: "Machine Learning" "AND" "Parkinson Disease".

RESULTS

the obtained publications were divided into 6 categories, based on different application fields: "Gait Analysis - Motor Evaluation", "Upper Limb Motor and Tremor Evaluation", "Handwriting and typing evaluation", "Speech and Phonation evaluation", "Neuroimaging and Nuclear Medicine evaluation", "Metabolomics application", after excluding the papers of general topic. As a result, a total of 166 articles were analyzed, after elimination of papers written in languages other than English or not directly related to the selected topics.

CONCLUSION

Machine learning algorithms are computer-based statistical approaches which can be trained and are able to find common patterns from big amounts of data. The machine learning approaches can help clinicians in classifying patients according to several variables at the same time.

The Effects of Knee Orthosis with Two Degrees of Freedom Joint Design on Gait and Sit-to-Stand Task in Patients with Medial Knee Osteoarthritis

Objectives

Knee bracing as a conservative treatment option for patients with medial knee osteoarthritis (KOA) is of great interest to health practitioners and patients alike. Optimal orthotic knee joint structure is essential to achieve biomechanical and clinical effectiveness. Therefore, this study aimed to identify the effects of a knee orthosis with a new two-degrees-of-freedom (DOF) joint design on selected gait parameters and in a sit-to-stand task in patients with mild-to-moderate medial KOA.

Methods

This study was conducted both at the Physical Medicine and Rehabilitation Clinic in Shahid Modarres Academic Hospital and the Biomechanical Laboratory of Rehabilitation Faculty of Iran University of medical Sciences in Tehran, Iran from September 2015 to October 2017. The gait performance of 16 patients was assessed without an orthosis, using a common one-DOF (DOF) knee orthosis and using the same knee orthosis with a two-DOF orthotic joint design. The interactive shearing force between limb and brace in the shell area during a sit-to-stand test was also identified. Repeated measures analysis of variance was used to analyse the data.

Results

Compared with walking with no orthosis, both orthosis conditions reduced the external knee adduction moment significantly (P ≤0.05). A significant increase between the one-DOF and two-DOF conditions in terms of walking speed (P = 0.041 and P = 0.009, respectively) and stride length (P = 0.028 and P = 0.038, respectively) was observed. In a sit-to-stand test, wearing the orthosis significantly decreased knee transverse plane range of motion (P ≤0.05). There was a 41.31 ± 8.34 Newtons reduction in knee flexion constraint force.

Conclusion

The two-DOF knee orthosis was more comfortable compared to the one-DOF knee orthosis during deep knee flexion. Otherwise, the one-DOF- and two-DOF-braces performed similarly.

Vision-based Estimation of MDS-UPDRS Gait Scores for Assessing Parkinson's Disease Motor Severity

Parkinson's disease (PD) is a progressive neurological disorder primarily affecting motor function resulting in tremor at rest, rigidity, bradykinesia, and postural instability. The physical severity of PD impairments can be quantified through the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), a widely used clinical rating scale. Accurate and quantitative assessment of disease progression is critical to developing a treatment that slows or stops further advancement of the disease. Prior work has mainly focused on dopamine transport neuroimaging for diagnosis or costly and intrusive wearables evaluating motor impairments. For the first time, we propose a computer vision-based model that observes non-intrusive video recordings of individuals, extracts their 3D body skeletons, tracks them through time, and classifies the movements according to the MDS-UPDRS gait scores. Experimental results show that our proposed method performs significantly better than chance and competing methods with an F 1-score of 0.83 and a balanced accuracy of 81%. This is the first benchmark for classifying PD patients based on MDS-UPDRS gait severity and could be an objective biomarker for disease severity. Our work demonstrates how computer-assisted technologies can be used to non-intrusively monitor patients and their motor impairments. The code is available at https://github.com/mlu355/PD-Motor-Severity-Estimation.

Opioid-Induced Reductions in Gait Variability in Healthy Volunteers and Individuals with Knee Osteoarthritis

OBJECTIVE

To investigate differences in gait variability induced by two different single-dose opioid formulations and an inert placebo in healthy volunteers and knee osteoarthritis patients.

DESIGN

Experimental, randomized, double-blinded, crossover study of inert placebo (calcium tablets), 50 mg of tapentadol, and 100 mg of tramadol.

SETTING

Laboratory setting.

SUBJECTS

Healthy volunteers and knee osteoarthritis patients.

METHODS

At three visits, separated by seven days, one tablet was administered per visit according to the randomization code. At each visit, a baseline measurement was done before tablet administration, after which hourly measurements were performed for six hours, yielding a total of seven measurements per visit. Gait variability was measured by three-dimensional gait analysis, recorded during six minutes of continuous treadmill walking at self-selected speed. One hundred seventy gait cycles were identified from detection of clear events of the knee joint angle trajectories. Gait variability was assessed as average standard deviations over a gait cycle of the sacrum displacements and accelerations; sagittal plane ankle, knee, and hip joint angles; step widths; and stride times.

RESULTS

Twenty-four opioid-naïve and neurologically intact participants (12 healthy volunteers and 12 knee osteoarthritis patients) were included and completed the experiment. Tapentadol reduced the variability of sacrum displacements and accelerations compared with placebo and tramadol. There were no differences between experimental conditions regarding the variability in lower-extremity joint angle variability, step widths, or stride times.

CONCLUSIONS

In opioid-naïve and neurologically intact individuals, tapentadol seems to reduce movement variability during treadmill walking, compared with placebo and tramadol. This can be interpreted as a loss of adaptability that might increase the risk of falling if the system is perturbed.

Disadvantage during Perioperative Period of Total Hip Arthroplasty Using the Direct Anterior Approach: a Network Meta-Analysis

BACKGROUND

The purpose of this study was to analyze complications of complete hip arthroplasty through systematic review and network meta-analysis of comparative studies of direct anterior approach (DAA), anterolateral approach (LA), and posterolateral approach (PA).

METHODS

Prospective randomized controlled trials (RCTs) or quasi-experimental designs evaluating clinical outcomes of DAA, LA, and PA for complete hip arthroplasty are valid if they meet the following criteria: 1) Comparison of clinical outcomes between the three methods for main complete hip arthroplasty (total hip arthroplasty, THA); 2) Compared at least one of the following outcomes: blood loss, operating time, and transfusion volume; 3) Sufficient data were available to extract and pool, i.e., mean reported, standard deviation and number of subjects. A network meta-analysis was used to determine the results of treatment across various surgical approaches. Indirect comparisons between the two surgical approaches was made by borrowing details from the standard comparator (i.e., the posterior approach).

RESULTS

Eight prospective RCTs were included in the meta-analysis of the network. The operation time of the LA was longer than that of PA (standardized mean difference [SMD], 0.96; 95% confidence interval [CI], 0.74-1.18; P < 0.001). DAA also had significantly longer operation time than PA (SMD, 0.45; 95% CI, 0.24-0.66; P < 0.001). However, blood loss of the DAA was the highest compared to other approaches (SMD, 0.60; 95% CI, 0.39-0.82; P = 0.002).

CONCLUSION

When performing THA with DAA, we should pay attention to increased operation time and blood loss.

Walking while Talking in Older Adults with Chronic Kidney Disease

BACKGROUND AND OBJECTIVES

Walking while talking is a dual cognitive-motor task that predicts frailty, falls, and cognitive decline in the general elderly population. Adults with CKD have gait abnormalities during usual walking. It is unknown whether they have greater gait abnormalities and cognitive-motor interference during walking while talking.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Community-dwelling, nondisabled adults (n=330) ≥65 years of age underwent quantitative gait analysis, including walking while talking. Differences in walking-while-talking performance by CKD status were evaluated, and relative changes between walking-while-talking and walking alone performance were computed to quantify cognitive-motor interference (dual-task cost). Associations were tested using multivariable linear spline regression models, and independent gait domains were derived using factor analysis. CKD was defined as an eGFR<60 ml/min per 1.73 m2.

RESULTS

CKD was present in 134 (41%) participants. Participants with CKD had slower gait speed along with various gait cycle abnormalities during walking while talking: among those with CKD, every 10-ml/min per 1.73 m2 lower eGFR was associated with 3.3-cm/s (95% confidence interval, 0.4 to 6.1) slower gait speed, 1.8-cm (95% confidence interval, 0.6 to 3.0) shorter step length, 1.1% (95% confidence interval, 0.6 to 1.7) less time in the swing phase, and 1.4% (95% confidence interval, 0.5 to 2.3) greater time in double support after multivariable adjustment. When comparing walking while talking with walking alone, every 10-ml/min per 1.73 m2 lower eGFR was associated with 1.8% (95% confidence interval, 0.5 to 3.2) greater decrease in time in the swing phase and 0.9% (95% confidence interval, 0.2 to 1.5) greater increase in time in the stance phase. Factor analysis identified three walking-while-talking domains and three dual-task cost domains: eGFR was associated specifically with the rhythm domain for both walking-while-talking and dual-task cost. Every 10-ml/min per 1.73 m2 lower eGFR was associated with a poorer performance of 0.2 SD (95% confidence interval, 0.1 to 0.3) for walking while talking and 0.2 SD (95% confidence interval, 0.03 to 0.3) for dual-task cost.

CONCLUSIONS

During walking while talking, CKD is associated with gait abnormalities, possibly due to increased cognitive-motor interference.

The Influence of Hydraulic Ankles and Microprocessor-control on the Biomechanics of Trans-tibial Amputees During Quiet Standing on a 5° Slope

BACKGROUND

Lower limb amputees have a high incidence of comorbidities, such as osteoarthritis, which are believed to be caused by kinetic asymmetries. A lack of prosthetic adaptation to different terrains requires kinematic compensations, which may influence these asymmetries.

METHOD

Six SIGAM grade E-F trans-tibial amputees (one bilateral) wore motion capture markers while standing on force plates, facing down a 5° slope. The participants were tested under three prosthetic conditions; a fixed attachment foot (FIX), a hydraulic ankle (HYD) and a microprocessor foot with a 'standing support' mode (MPF). The resultant ground reaction force (GRF) and support moment for prosthetic and sound limbs were chosen as outcome measures. These were compared between prosthetic conditions and to previously captured able-bodied control data.

RESULTS

The distribution of GRF between sound and prosthetic limbs was not significantly affected by foot type. However, the MPF condition required fewer kinematic compensations, leading to a reduction in sound side support moment of 59% (p=0.001) and prosthetic side support moment of 43% (p=0.02) compared to FIX. For the bilateral participant, only the MPF positioned the GRF vector anterior to the knees, reducing the demand on the residual joints to maintain posture.

CONCLUSIONS

For trans-tibial amputees, loading on lower limb joints is affected by prosthetic foot technology, due to the kinematic compensations required for slope adaptation. MPFs with 'standing support' might be considered reasonable and necessary for bilateral amputees, or amputees with stability problems due to the reduced biomechanical compensations evident.

High day-to-day repeatability of lower extremity muscle activation patterns and joint biomechanics of dual-belt treadmill gait: A reliability study in healthy young adults

PURPOSE

The reliability of lower extremity muscle activation patterns has not been clearly studied in a dual-belt instrumented treadmill environment. The primary study objective was to quantify the day-to-day reliability of quadriceps, hamstrings, gastrocnemius and gluteus medius activation patterns in healthy young adult gait. Secondarily, the reliability of spatiotemporal, and knee/hip motion and moment-based gait outcomes was assessed.

SCOPE

20 young adults were recruited and tested on two separate days. Using standardized procedures, participants were prepared for surface electromyography and lower extremity motion capture. All individuals walked on a dual-belt instrumented treadmill while muscle activation, segment motions and ground reaction forces were recorded. Sagittal plane motion and net external sagittal and frontal plane moments were calculated. Discrete biomechanical and muscle activation measures were calculated, and non-negative matrix factorization extracted amplitude and temporal muscle activation features. Intraclass Correlation Coefficients, Standard Error of Measurement and Minimum Detectable Change were calculated.

CONCLUSIONS

High to excellent Intraclass correlation coefficients were found between visits for most primary and secondary outcomes. The absolute and relative reliability, including Minimum Detectable Change values, provided in this study support the use of dual-belt instrumented treadmill walking as an acceptable medium to collect biomechanical and lower extremity EMG outcomes for future studies.

Gait Characteristics of Transtibial Amputees on Level Ground in a Cohort of 53 Amputees - Comparison of Kinetics and Kinematics With Non-amputees

STUDY DESIGN

Retrospective analysis.

BACKGROUND

The gait characteristics of transtibial amputees (TTs) have been described many times. In general, the literature reported nearly consistent results for the kinematic and kinetic parameters of the prosthetic side. However, the literature revealed inconsistent findings on kinetic parameters for determining the risk of developing knee osteoarthritis, such as the peak knee adduction moment, knee flexion moment and vertical ground reaction forces.

OBJECTIVES

The objective of our study was to describe the sagittal kinetic and kinematic gait characteristics of the ankle and residual knee joint of the prosthetic limb and the knee loading parameters of the sound side of unilateral TTs. This specific consideration may contribute to resolving the controversy of these parameters in the literature.

METHODS

We analysed our database containing gait analyses from 53 unilateral TTs and compared data to a control group (CG), also taken from our database. The sagittal kinetic and kinematic gait characteristics of the ankle and residual knee joint of the prosthetic limb, and selected knee loading parameters of the sound side (the peak knee adduction moment, knee flexion moment and vertical ground reaction forces) were evaluated. Beside these parameters we reported typical spatiotemporal gait parameters as gait velocity, step length, step length asymmetry, stance phase duration and asymmetry of stance phase duration.

RESULTS

The TTs walked slower and more asymmetrically than the CG. The kinematic pattern of the prosthetic ankle differed from that found in the CG. The largest difference was observed for the range of motion of the plantarflexion at push-off, which was significantly reduced for the prosthetic foot. The residual knee joint was generally affected with respect to decreased moments and reduced knee flexion during stance phase. The peaks of the vertical ground reaction forces and knee adduction moments showed no differences between the sound side of amputees and the CG. The peak knee flexion moment at midstance was significantly reduced for the sound side of amputees in comparison with the CG.

CONCLUSION

The biomechanical data measured for the prosthetic side in a cohort of 53 unilateral TT amputees conformed with the literature. The parameters determining the risk of developing knee osteoarthritis investigated in our retrospective analysis were not increased on the sound side in comparison with non-amputees. We deem it reasonable to assume that an appropriate prosthesis will reduce the likelihood of overloading the knee on the sound side during normal walking.

Automatic force plate contact detection protocol for computerized gait analysis

BACKGROUND

The usability and evaluability of a computerized gait analysis requires correct force plate foot contact, with the force measuring plates embedded in the ground, in order to obtain kinetic data.

RESEARCH QUESTION

This article describes a technical development that facilitates the process flow of computerized gait analysis. Software has been developed that automatically recognizes, counts and documents the correct force plate foot contacts METHODS: A software program has been developed. Programming was done in Microsoft® C# using the ViconDatastreemSDK.dotNet® Dynamic Link Library (DLL) developed by Vicon®. The program queries the positions of the foot markers and the electrical signals of the force plates.

RESULTS AND SIGNIFICANCE

The program, which runs parallel to the Vicon® data acquisition software, simultaneously displays the information about the correct force plate foot contacts in a graphical user interface (GUI). After the measurement, an automatically generated protocol of the evaluable walks is available in tabular form.

A Deep Learning-Based Approach for Gait Analysis in Huntington Disease

Huntington Disease (HD) is a genetic neurodegenerative disease which leads to involuntary movements and impaired balance. These changes have been quantified using footstep pressure sensor mats such as Protokinetics' Zeno Walkway. Drawing from distances between recorded footsteps, patients' disease severity have been measured in terms of high level gait characteristics such as gait width and stride length. However, little attention has been paid to the pressure data collected during formation of individual footsteps. This work investigates the potential of classifying patient disease severity based on individual footstep pressure data using deep learning techniques. Using the Motor Subscale of the Unified HD Rating Scale (UHDRS) as the gold standard, our experiments showed that using VGG16 and similar modules can achieve classification accuracy of 89%. Image pre-processing are key steps for better model performance. This classification accuracy is compared to results based on 3D CNN (82%) and SVM (86.9%).

Percentage Contribution of Lower Limb Moments to Vertical Ground Reaction Force in Normal Gait

Objective

The purpose of this study was to investigate how the hip, knee, and ankle moments in the sagittal plane contribute to the vertical ground reaction force (GRF) in healthy participants during normal speed of walking.

Methods

Forty healthy male individuals volunteered to participate in this study. They were filmed using 6 high-speed (120 Hz) Pro-Reflex infrared cameras (Qualisys) while walking on an Advanced Mechanical Technology Incorporation force platform. The data collected were the percentage contribution of the moments of the hip, knee, and ankle joints in the sagittal plane at the instant of occurrence of the first peak, second peak, and trough of the vertical GRF.

Results

The results revealed that at the first peak of the GRF (loading response), the highest contribution was generated from the knee extension moment followed by the hip extension moment. Knee flexion and ankle plantar flexion moments produced a high contribution to the trough of the GRF (midstance) with approximately equal values. The second peak of the GRF was mainly produced by the ankle plantar flexion moment.

Conclusion

The role of hip extension moment is secondary to knee extension moment in the first peak of GRF. Knee flexion moment is secondary to ankle plantar flexion moment in the second peak of GRF. Both knee flexion and ankle plantar flexion moments have equal contribution during midstance.

Effects of an Articulated Ankle Foot Orthosis on Gait Biomechanics in Adolescents with Traumatic Brain Injury: A Case-Series Report

PURPOSE

To quantify the effects of an articulated ankle foot orthosis on genu recurvatum gait in adolescents with traumatic brain injury (TBI).

METHODS

Gait analysis was conducted in 2 individuals with TBI during over ground ambulation with (braced condition) and without (barefoot condition) the AAFO. For each participant, stride-by-stride gait data were compared to assess differences between barefoot and braced walking conditions.

RESULTS

During the braced versus barefoot condition, both participants demonstrated reduced plantar flexion at initial contact, increased knee flexion at initial contact, reduced peak knee extension during stance, and reduced peak and integral of internal knee flexor moment during stance.

CONCLUSIONS

The data suggest that the AAFO reduced plantar flexion during stance, therefore attenuating the anterior displacement of the ground reaction force vector (GRFV) relative to the ankle and knee joint axes, and leading to a reduction in knee hyperextension and the internal knee flexor moment during stance. We posit that the reduction in internal knee flexor moment may lead to a more sustainable gait pattern with less potential for mechanical stress on the posterior knee joint capsule.

Spatiotemporal Gait Variables Using Wavelets for an Objective Analysis of Parkinson Disease

Parkinson's disease generates a special interest in factors such as gait patterns, posture patterns, and risk of falls. The human gait pattern has a basic unit called the gait cycle, composed of two phases: stance and swing. Using gait analysis it is possible to get spatiotemporal variables as walking speed and step number derived from stance and swing phases. In this paper, we explore the feasibility of wavelet techniques to analyze gait signals, we use a member of Daubechies family to distinguish automatically gait phases, this approach allowed us to estimate spatiotemporal variables that shows significant differences between Parkinson patients and non-Parkinson patients, this result aims to allow clinical experts to easily diagnose and assess Parkinson patients, with short evaluation times and with non-invasive technologies.

Real-Time Constant Monitoring of Fall Risk Index by Means of Fully-Wireless Insoles

Constant monitoring of gait in real life conditions is considered the best way to assess Fall Risk Index (FRI) since most falls happen out of the ideal conditions in which clinicians are currently analyzing the patient's behavior. This paper presents the WIISEL platform and results obtained through the use of the first full-wireless insole devices that can measure almost all gait related data directly on the feet (not in the upper part of the body as most existing wearable solutions). The platform consists of a complete tool-chain: insoles, smartphone &amp; app, server &amp; analysis tool, FRI estimation and user access. Results are obtained by combining parameters in a personalized way to build individual fall risk index assessed by experts with the help of data analytics. New FRI has been compared with standards that validate the quality of its prediction in a statistically significant way. That qualitatively relevant information is being provided to the platform users, being either end-users/patients, relatives or caregivers and the related clinicians to ideally assess about their long term evolution.

Performing gait analysis within the timed up & go assessment test: comparison of aTUG to a marker-based tracking system

Results from a technical validation of the aTUG (ambient Timed Up & Go) system are presented. The approach's gait analysis capabilities were compared to a gold standard: SIMI Motion, a marker-based motion tracking system. Seven people participated and computation of step length and step duration happened with a median error of 3 cm (IQR 3 cm) respectively 0.08 s (IQR 0.07 s). These results show that aTUG has a measurement precision which is sufficient for use in clinical gait analysis and enables the use of the device without a gold standard, i.e. in hospitals outside laboratories or in the homes of patients. aTUG is an approach and system that utilizes only ambient sensor technologies to support the execution of geriatric mobility assessment tests and to perform a gait analysis simultaneously. Such capabilities are strongly demanded in order to support physicians in executing the geriatric assessment tests frequently and objectively in professional and domestic environments. The latter may enable more early prevention and more sustainable rehabilitation.

Hip abductor function in individuals with medial knee osteoarthritis: Implications for medial compartment loading during gait

BACKGROUND

Hip abductor muscles generate moments of force that control lower extremity frontal plane motion. Strengthening these muscles has been a recent trend in therapeutic intervention studies for knee osteoarthritis. The current study investigated the relationship between hip abductor muscle function (strength and activation) and the net external knee adduction moment during gait in those with medial compartment knee osteoarthritis.

METHODS

54 individuals with moderate knee osteoarthritis walked at their self-selected velocity while gluteus medius electromyograms, segment motions and ground reaction forces were recorded. Net external knee adduction moment (KAM) and linear enveloped electromyographic profiles were calculated. Peak KAM was determined and then principal component analyses (PCA) were applied to KAM and electromyographic profiles. Isometric hip abductor strength, anthropometrics and gait velocity were measured. Multiple regression models evaluated the relationship between walking velocity, hip abductor strength, electromyographic variables recorded during gait and KAM waveform characteristics.

FINDINGS

Minimal peak KAM variance was explained by abductor strength (R(2)=9%, P=0.027). PCA-based KAM waveform characteristics were not explained by abductor strength. Overall gluteus medius amplitude (PP1-scores) was related to a reduction in the bi-modal KAM (PP3-scores) pattern (R(2)=16%, P=0.003).

INTERPRETATION

There was no clear relationship between hip abductor muscle strength and specific amplitude and temporal KAM characteristics. Higher overall gluteus medius activation amplitude was related to a sustained KAM during mid-stance. 84 to 90% of the variance in KAM waveform characteristics was not explained by hip abductor muscle function showing hip abductor muscle function has minimal association to KAM characteristics.