Does visuospatial neglect contribute to standing balance within the first 12 weeks post-stroke? A prospective longitudinal cohort study.

BACKGROUND: Visuospatial neglect (VSN) has been suggested to limit standing balance improvement post-stroke. However, studies investigating this association longitudinally by means of repeated within-subject measurements early post-stroke are lacking. This prospective longitudinal cohort study evaluates the longitudinal association of egocentric and allocentric VSN severity with 1) standing balance independence and 2) postural control and weight-bearing asymmetry (WBA) during quiet standing, in the first 12 weeks post-stroke. METHODS: Thirty-six hemiplegic individuals after a first-ever unilateral stroke were evaluated at weeks 3, 5, 8 and 12 post-stroke. Egocentric and allocentric VSN severity were evaluated using the Broken Hearts Test. The standing unperturbed item of the Berg Balance Scale (BBS-s) was used to clinically evaluate standing independence. Posturographic measures included measures of postural control (mediolateral (ML)/anteroposterior (AP) net center-of-pressure velocities (COPvel)) and WBA during quiet standing. A linear mixed model was used to examine longitudinal associations between egocentric and allocentric VSN, and BBS-s, COPvel-ML, COPvel-AP and WBA within the first 12 weeks post-stroke. RESULTS: Egocentric (ß = -0.08, 95%CI[-0.15;-0.01], P = .029) and allocentric VSN severity (ß = -0.09, 95%CI[-0.15; -0.04], P = .002) were significant independent factors for BBS-s scores in the first 12 weeks post-stroke. Egocentric and allocentric VSN were no significant independent factors for COPvel-ML, COPvel-AP and WBA in the first 12 weeks post-stroke. CONCLUSIONS: Allocentric and egocentric VSN severity were significantly associated with decreased standing independence, but not impaired postural control or greater asymmetric weight-bearing, in the early subacute post-stroke phase. This may involve traditional VSN measures being not sensitive enough to detect fine-grained VSN deficits due to a ceiling effect between 5 and 8 weeks post-stroke, once the individual regains standing ability. Future studies may require more sensitive VSN measurements to detect such deficits. Trial registration Clinicaltrials.gov. unique identifier NCT05060458.

Experimental Comparison between 4D Stereophotogrammetry and Inertial Measurement Unit Systems for Gait Spatiotemporal Parameters and Joint Kinematics.

(1) Background: Traditional gait assessment methods have limitations like time-consuming procedures, the requirement of skilled personnel, soft tissue artifacts, and high costs. Various 3D time scanning techniques are emerging to overcome these issues. This study compares a 3D temporal scanning system (Move4D) with an inertial motion capture system (Xsens) to evaluate their reliability and accuracy in assessing gait spatiotemporal parameters and joint kinematics. (2) Methods: This study included 13 healthy people and one hemiplegic patient, and it examined stance time, swing time, cycle time, and stride length. Statistical analysis included paired samples t-test, Bland-Altman plot, and the intraclass correlation coefficient (ICC). (3) Results: A high degree of agreement and no significant difference (p > 0.05) between the two measurement systems have been found for stance time, swing time, and cycle time. Evaluation of stride length shows a significant difference (p < 0.05) between Xsens and Move4D. The highest root-mean-square error (RMSE) was found in hip flexion/extension (RMSE = 10.99°); (4) Conclusions: The present work demonstrated that the system Move4D can estimate gait spatiotemporal parameters (gait phases duration and cycle time) and joint angles with reliability and accuracy comparable to Xsens. This study allows further innovative research using 4D (3D over time) scanning for quantitative gait assessment in clinical practice.

Accuracy, Validity, and Reliability of Markerless Camera-Based 3D Motion Capture Systems versus Marker-Based 3D Motion Capture Systems in Gait Analysis: A Systematic Review and Meta-Analysis.

(1) Background: Marker-based 3D motion capture systems (MBS) are considered the gold standard in gait analysis. However, they have limitations for which markerless camera-based 3D motion capture systems (MCBS) could provide a solution. The aim of this systematic review and meta-analysis is to compare the accuracy, validity, and reliability of MCBS and MBS. (2) Methods: A total of 2047 papers were systematically searched according to PRISMA guidelines on 7 February 2024, in two different databases: Pubmed (1339) and WoS (708). The COSMIN-tool and EBRO guidelines were used to assess risk of bias and level of evidence. (3) Results: After full text screening, 22 papers were included. Spatiotemporal parameters showed overall good to excellent accuracy, validity, and reliability. For kinematic variables, hip and knee showed moderate to excellent agreement between the systems, while for the ankle joint, poor concurrent validity and reliability were measured. The accuracy and concurrent validity of walking speed were considered excellent in all cases, with only a small bias. The meta-analysis of the inter-rater reliability and concurrent validity of walking speed, step time, and step length resulted in a good-to-excellent intraclass correlation coefficient (ICC) (0.81; 0.98). (4) Discussion and conclusions: MCBS are comparable in terms of accuracy, concurrent validity, and reliability to MBS in spatiotemporal parameters. Additionally, kinematic parameters for hip and knee in the sagittal plane are considered most valid and reliable but lack valid and accurate measurement outcomes in transverse and frontal planes. Customization and standardization of methodological procedures are necessary for future research to adequately compare protocols in clinical settings, with more attention to patient populations.

Physical functioning factors predicting a return home after stroke rehabilitation: A systematic review and meta-analysis.

OBJECTIVES: This systematic review and meta-analysis sought to identify the physical functioning factors associated with home discharge after inpatient stroke rehabilitation. DATA SOURCES: A search of PubMed, Embase, CINHAL, The Cochrane Library (Trials), Web of Science, and PEDro were conducted up until May 2023. METHODS: Two independent reviewers selected studies for population (patients with stroke), predictive factors (physical functioning), outcome (discharge destination), setting (inpatient rehabilitation), and study designs (observational and experimental studies). Predictive factors were identified among assessments of the "body function" and "activity" components of the International Classification of Functioning. Methodological quality was assessed with the Newcastle-Ottawa Scale. The findings used quantitative and narrative syntheses. Meta-analyses were performed with the inverse variance method and the random-effects model using included studies with sufficient data. RESULTS: Forty-five studies were included with 204,787 participants. Included studies assessed the association of independence in activities of daily living, walking, rolling, transferring, and balance on admission with a probability of returning home. Motor (odds ratio = 1.23, 95% confidence interval: 1.12-1.35, p < .001) and total (odds ratio = 1.34, 95% confidence interval: 1.14-1.57, p < .001) Functional Independence Measure scores on admission were significantly associated with home discharge in meta-analyses. Additionally, included studies showed that independence in motor activities, such as sitting, transferring, and walking, and scores above thresholds for the Functional Independence Measure and Berg Balance Scale on admission were associated with discharge destination. CONCLUSION: This review showed that higher independence in activities of daily living on admission is associated with home discharge after inpatient stroke rehabilitation.

Effect of Music Based Therapy Rhythmic Auditory Stimulation (RAS) Using Wearable Device in Rehabilitation of Neurological Patients: A Systematic Review.

(1) Background: Even though music therapy is acknowledged to have positive benefits in neurology, there is still a lack of knowledge in the literature about the applicability of music treatments in clinical practice with a neurological population using wearable devices. (2) Methods: a systematic review was conducted following PRISMA 2020 guidelines on the 29 October 2022, searching in five databases: PubMed, PEDro, Medline, Web of Science, and Science Direct. (3) Results: A total of 2964 articles were found, including 413 from PubMed, 248 from Web of Science, 2110 from Science Direct, 163 from Medline, and none from PEDro. Duplicate entries, of which there were 1262, were eliminated. In the first screening phase, 1702 papers were screened for title and abstract. Subsequently, 1667 papers were removed, based on population, duplicate, outcome, and poor study design. Only 15 studies were considered after 35 papers had their full texts verified. Results showed significant values of spatiotemporal gait parameters in music-based therapy rhythmic auditory stimulation (RAS), including speed, stride length, cadence, and ROM. (4) Conclusions: The current findings confirm the value of music-based therapy RAS as a favorable and effective tool to implement in the health care system for the rehabilitation of patients with movement disorders.

Gait Stride Length Estimation Using Embedded Machine Learning.

INTRODUCTION: Spatiotemporal gait parameters, e.g., gait stride length, are measurements that are classically derived from instrumented gait analysis. Today, different solutions are available for gait assessment outside the laboratory, specifically for spatiotemporal gait parameters. Such solutions are wearable devices that comprise an inertial measurement unit (IMU) sensor and a microcontroller (MCU). However, these existing wearable devices are resource-constrained. They contain a processing unit with limited processing and memory capabilities which limit the use of machine learning to estimate spatiotemporal gait parameters directly on the device. The solution for this limitation is embedded machine learning or tiny machine learning (tinyML). This study aims to create a machine-learning model for gait stride length estimation deployable on a microcontroller. MATERIALS AND METHOD: Starting from a dataset consisting of 4467 gait strides from 15 healthy people, measured by IMU sensor, and using state-of-the-art machine learning frameworks and machine learning operations (MLOps) tools, a multilayer 1D convolutional float32 and int8 model for gait stride length estimation was developed. RESULTS: The developed float32 model demonstrated a mean accuracy and precision of 0.23 ± 4.3 cm, and the int8 model demonstrated a mean accuracy and precision of 0.07 ± 4.3 cm. The memory usage for the float32 model was 284.5 kB flash and 31.9 kB RAM. The int8 model memory usage was 91.6 kB flash and 13.6 kB RAM. Both models were able to be deployed on a Cortex-M4F 64 MHz microcontroller with 1 MB flash memory and 256 kB RAM. CONCLUSIONS: This study shows that estimating gait stride length directly on a microcontroller is feasible and demonstrates the potential of embedded machine learning, or tinyML, in designing wearable sensor devices for gait analysis.

Prevalence, associated factors and predictors of post stroke pneumonia in a Nigerian population: A retrospective study.

OBJECTIVES: Stroke can trigger an immune response that can raise the risk of infection, alter tracheal epithelium, reduce pulmonary clearance and impair secretions drainage capacity. Infection, altered tracheal epithelium, reduced pulmonary clearance, impaired secretions drainage capacity and aspiration can cause pneumonia after stroke. The aim of this study is to find out the prevalence of post stroke pneumonia in a Nigerian population and factors that are associated with it. MATERIALS AND METHOD: Study data was extracted from the case files of patients with stroke who were managed between 1st January, 2011 and 1st February, 2021 in the study setting. RESULTS: The result showed that, there was a record of only 591 patients with stroke (mean age, 62.78 ± 14.86 years) who were managed in the two hospitals during the period of the study. Out of this number, only 102 (17.3 %) had pneumonia. Presence of the pneumonia was only significantly (p < 0.05) associated with sex, type of stroke, lower limb muscle power, and outcome (died or alive). However, only those with ischaemic stroke are less likely to have pneumonia (Odds ratio=  0.467; CI: 0.275 to 0.791, p=  0.005), and patients who survived the stroke and are alive are less likely to develop pneumonia (Odds ratio=  0.150; CI: 0.092 to 0.245, p < 0.001). CONCLUSIONS: Pneumonia occurs to a large extent after stroke. Therefore, it is important measures are taken to prevent it or complications arising from it especially in those with a hemorrhagic stroke.

Effect of home-based virtual reality training and telerehabilitation on balance in individuals with Parkinson disease, multiple sclerosis, and stroke: a systematic review and meta-analysis.

OBJECTIVE: In the last decade, there is a growing interest in the use of virtual reality for rehabilitation in clinical and home settings. The aim of this systematic review is to do a summary of the current evidence on the effect of home-based virtual reality training and telerehabilitation on postural balance in individuals with central neurological disorders. METHODS: Literature was searched in PubMed, Web of Science, PEDro, ScienceDirect, and MEDLINE. Randomized controlled trials (RCTs) evaluating the effect of home-based virtual reality (VR) training and telerehabilitation (TR) on postural balance in patients with Parkinson's disease, Multiple sclerosis or stroke. Studies were imported to EndNote and Excel to perform two screening phases by four reviewers. Risk of bias was assessed using PEDro scale and Cochrane assessment tool for risk of bias. Synthesis of the data on comparative outcomes was performed using RevMan software. RESULTS: Seven RCTs were included, with all three pathologies represented. VR and TR consisted of a training device (e.g., Nintendo Wii or Xbox 360) and a monitoring device (e.g., Skype or Microsoft Kinect). Five studies used the Berg Balance Scale (BBS) for measuring postural balance. Across studies, there was an improvement in BBS scores over time in both experimental and control groups, and the effect remained at follow-up for both groups. However, there was no significant difference between  groups post-intervention (MD = 0.74, p = 0.45). CONCLUSION: Home-based VR and TR can be used as prolongation to conventional therapy.

Vagus nerve stimulation for the treatment of epilepsy: things to note on the protocols, the effects and the mechanisms of action.

Epilepsy is a chronic brain disorder that is characterized by repetitive un-triggered seizures that occur severally within 24 h or more. Non-pharmacological methods for the management of epilepsy were discussed. The non-pharmacological methods include the vagus nerve stimulation (VNS) which is subdivided into invasive and non-invasive techniques. For the non-invasive techniques, the auricular VNS, stimulation of the cervical branch of vagus nerve in the neck, manual massage of the neck, and respiratory vagal nerve stimulation were discussed. Similarly, the stimulation parameters used and the mechanisms of actions through which VNS improves seizures were also discussed. Use of VNS to reduce seizure frequency has come a long way. However, considering the cost and side effects of the invasive method, non-invasive techniques should be given a renewed attention. In particular, respiratory vagal nerve stimulation should be considered. In doing this, the patients should for instance carry out slow-deep breathing exercise 6 to 8 times every 3 h during the waking hours. Slow-deep breathing can be carried out by the patients on their own; therefore this can serve as a form of self-management.HIGHLIGHTSEpilepsy can interfere with the patients' ability to carry out their daily activities and ultimately affect their quality of life.Medications are used to manage epilepsy; but they often have their serious side effects.Vagus nerve stimulation (VNS) is gaining ground especially in the management of refractory epilepsy.The VNS is administered through either the invasive or the non-invasive methodsThe invasive method of VNS like the medication has potential side effects, and can be costly.The non-invasive method includes auricular VNS, stimulation of the neck muscles and skin and respiratory vagal nerve stimulation via slow-deep breathing exercises.The respiratory vagal nerve stimulation via slow-deep breathing exercises seems easy to administer even by the patients themselves.Consequently, it is our opinion that patients with epilepsy be made to carry out slow-deep breathing exercise 6-8 times every 3 h during the waking hours.

Determination of hand grip strength and its correlates during pregnancy: a cross-sectional study.

BACKGROUND: Pregnancy results in many changes, including reduced hand grip strength (HGS). However, good HGS is required for physical functions such as carrying and breastfeeding the baby after birth. The aim of this study was to determine the factors that may predict HGS during pregnancy. METHODS: The study was a cross-sectional study approved by the Research Ethics Committees of Kano State Ministry of Health and Aminu Kano Teaching Hospital in Kano, north-west, Nigeria. Pregnant women at the designated hospitals were included in the study if they had no serious comorbidities or any known neurological condition that affects the hands and the neck. Demographic characteristics and independent (predictor) variables (age, weight, height, BMI, maternity leave status, number of full-term deliveries, number of preterm deliveries, number of live births, number of abortuses, gravidity, trimester, systolic blood pressure, diastolic blood pressure, inter arm systolic BP difference [IASBP], inter arm diastolic BP difference [IADBP], and heart rate) of each of the participants were recorded by experienced therapists. The data were analysed using descriptive statistics, t-test, Pearson correlation coefficient and standard multiple regression. RESULT: One hundred and sixty-one pregnant women with mean age, 25.04 ± 4.83 years participated in the study. In the dominant hand, 120 participants (74.5%) had weak grip strength. In the non-dominant hand, 135 participants (83.9%) had weak grip strength. For the dominant hand, the total variance explained by the whole model was significant, 28.5%, F(11, 161) = 1.187, R2 = 0.081, p = 0.300 . In the final model, none of the variables significantly predicted HGS. However, systolic blood pressure contributed to the model more than any other variable (Beta = -0.155). For the non-dominant hand, the total variance explained by the whole model was not significant, 33.1%, F(11, 161) = 1.675, R2 = 0.111, p = 0.089 . In the final model, only systolic blood pressure (Beta = -0.254, p = 0.023) significantly predicted hand grip strength. CONCLUSION: Cardiovascular events or changes during pregnancy (such as change in systolic blood pressure) may be related to HGS in pregnant women. It is therefore, important for clinicians to pay attention to this, in planning rehabilitation strategies for pregnant women.

Constraint-induced movement therapy protocols using the number of repetitions of task practice: a systematic review of feasibility and effects.

BACKGROUND: High repetitions of task practice is required for the recovery of the motor function during constraint-induced movement therapy (CIMT). This can be achieved into ways: when the task practice is measured in hours of practice or when the number of repetitions is counted. However, it has been argued that using hours of task practice as a measure of practice does not provide a clear instruction on the dose of practice. AIM: The aim of this study is to determine the feasibility and effects of the CIMT protocol that uses the number of repetitions of task practice. MATERIALS/METHOD: The study was a systematic review registered in PROSPERO (CRD42020142140). Five databases, PubMED, CENTRAL, PEDro, OTSeeker and Web of Science, were searched. Studies of any designs in adults with stroke were included if they used the number of repetitions of task practice as a measure of dose. The methodological quality of the included studies was assessed using Modified McMaster critical review form. The results were analysed using qualitative synthesis. RESULTS: Eight studies (n = 205) were included in the study. The number of task repetitions in the studies ranges between 45 and 1280 per day. The results showed that CIMT protocol using the number of repetitions of task practice was feasible and improved outcomes such as motor function, quality of life, functional mobility and spasticity. CONCLUSION: The number of repetitions of task practice as a measure of CIMT dose can be used in place of the existing protocol that uses the number of hours of task practice.

Comparing Two Different Modes of Task Practice during Lower Limb Constraint-Induced Movement Therapy in People with Stroke: A Randomized Clinical Trial.

Background: Constraint-induced movement therapy (CIMT) is used for the rehabilitation of motor function after stroke. Objectives: The aim of this study was to compare the effects of lower limb CIMT that uses number of repetition of tasks with the one that uses number of hours of practice. Method: The study was a randomized clinical trial approved by the Ethics Committee of Kano State Ministry of Health. Fifty-eight people with stroke participated in the study. Groups 1 and 2 performed daily 600 repetitions and 3 hours of task practice, respectively, 5 times weekly for 4 weeks. Motor impairment (primary outcome), balance, functional mobility, knee extensor spasticity, walking speed and endurance, and exertion before and after commencement of activities were assessed at baseline and postintervention. The data was analyzed using Friedmann and Mann-Whitney U tests. Result: The results showed that there was only significant difference (p < 0.05) in knee extensor spasticity (group 1 (median = 0(0), mean rank = 27.50); group 2 (median = 0(0), mean rank = 31.64)), exertion before commencement of activities (group 1 (median = 0(0.5), mean rank = 21.90); group 2 (median = 1(0.5), mean rank = 37.64)), and exertion after commencement of activities (group 1 (median = 1(1), mean rank = 20.07); group 2 (median = 1(0), mean rank = 39.61) postintervention in favour of the experimental group (group 1)). Conclusion: The group 1 protocol is more effective at improving outcomes after stroke.

Neurobiology of Recovery of Motor Function after Stroke: The Central Nervous System Biomarker Effects of Constraint-Induced Movement Therapy.

Recovery of motor function after stroke involves many biomarkers. This review attempts to identify the biomarker effects responsible for recovery of motor function following the use of Constraint-Induced Movement Therapy (CIMT) and discuss their implications for research and practice. From the studies reviewed, the biomarker effects identified include improved perfusion of motor areas and brain glucose metabolism; increased expression of proteins, namely, Brain-Derived Neurotrophic Factor (BDNF), Vascular Endothelial Growth Factor (VEGF), and Growth-Associated Protein 43 (GAP-43); and decreased level of Gamma-Aminobutyric Acid (GABA). Others include increased cortical activation, increased motor map size, and decreased interhemispheric inhibition of the ipsilesional hemisphere by the contralesional hemisphere. Interestingly, the biomarker effects correlated well with improved motor function. However, some of the biomarker effects have not yet been investigated in humans, and they require that CIMT starts early on poststroke. In addition, one study seems to suggest the combined use of CIMT with other rehabilitation techniques such as Transcortical Direct Stimulation (tDCs) in patients with chronic stroke to achieve the biomarker effects. Unfortunately, there are few studies in humans that implemented CIMT during early poststroke. Thus, it is important that more studies in humans are carried out to determine the biomarker effects of CIMT especially early on poststroke, when there is a greater opportunity for recovery. Furthermore, it should be noted that these effects are mainly in ischaemic stroke.

Vibrotactile feedback for correcting aerodynamic position of a cyclist.

Guidance to maintain an optimal aerodynamic position is currently unavailable during cycling. This study used real-time vibrotactile feedback to guide cyclists to a reference position with minimal projected frontal area as an indicator of aerodynamic drag, by optimizing torso, shoulder, head and elbow position without compromising comfort when sitting still on the bike. The difference in recapturing the aerodynamic reference position during cycling after predefined deviations from the reference position at different intensities was analysed for 14 participants between three interventions, consisting of 1) vibrotactile feedback with a margin of error of 1.5% above the calibrated reference projected frontal area, 2) vibrotactile feedback with a margin of 3%, and 3) no feedback. The reference position is significantly more accurately achieved using vibrotactile feedback compared to no feedback (p < 0.001), but there is no significant difference between the 1.5% and 3% margin (p = 0.11) in terms of relative projected frontal area during cycling compared to the calibrated reference position (1.5% margin -0.46 ± 1.76%, 3% margin -0.01 ± 2.01%, no feedback 2.59 ± 3.29%). The results demonstrate that vibrotactile feedback can have an added value in assisting and correcting cyclists in recapturing their aerodynamic reference position.

The effectiveness of trunk training on trunk control, sitting and standing balance and mobility post-stroke: a systematic review and meta-analysis.

OBJECTIVE: To investigate the effectiveness of trunk training on trunk control, sitting and standing balance and mobility. DATA SOURCES: PubMed/MEDLINE, Web of Science, Physiotherapy Evidence Database (PEDro), Cochrane Library, Rehab+ and ScienceDirect were searched until January 2019. REVIEW METHODS: Randomized controlled trials were included if they investigated the effect of trunk exercises on balance and gait after stroke. Four reviewers independently screened and performed data extraction and risk of bias assessment with the PEDro scale. Disagreements were resolved by a fifth independent reviewer. A meta-analysis was performed to quantitatively describe the results. RESULTS: After screening of 1881 studies, 22 studies and 394 participants met the inclusion criteria. Trunk training was executed as core stability, reaching, weight-shift or proprioceptive neuromuscular facilitation exercises. The amount of therapy varied from a total of 3-36 hours between studies. The median PEDro score was 6 out of 10 which corresponds with a low risk of bias. Meta-analysis was performed with a random-effects model due to differences in study population, interventions received and follow-up length. The overall treatment effect was large for trunk control standardized mean differences (SMD) 1.08 (95% confidence interval (CI): 0.96-1.31), standing balance SMD 0.84 (95% CI: 0.04-0.98) and mobility SMD 0.88 (95% CI: 0.67-1.09). CONCLUSIONS: In patients suffering from stroke, there is a strong amount of evidence showing that trunk training is able to improve trunk control, sitting and standing balance and mobility.

Vibrotactile Feedback During Physical Exercise: Perception of Vibrotactile Cues in Cycling.

The aim of this study was to investigate the perception of vibrotactile signals during physical exercise by comparing differences in recognition between stationary and cycling positions. The impact of physical exercise on the ability to perceive vibrotactile cues is unknown, whereas the recognition in stationary position has been shown previously. Vibrating elements were positioned at 3 locations on the thighs and spine of 9 athletes to apply various vibrotactile cues. Subjects performed at 0, 50, 70 and 90% of their maximal cycling power output and denoted the interpretation of the vibration signals on a touchscreen. The results show a similarity in correct recognition between stationary position and physical exercise for the thighs and spine (p>0.1) and demonstrate a decrease in response time for 70 and 90% levels of physical exercise compared to 0 and 50% (p<0.001). Furthermore, vibrotactile signals at the spine are noticed more accurately and more rapidly compared to the thighs (p<0.01). These results suggest that vibrotactile feedback also has potential in applications during physical exercise. The potential use of vibrotactile feedback can be in cycling for, among other, correcting the aerodynamic position. Applications in other sports and health-related domains are feasible as well.

Posture normalisation of 3D body scans.

For product developers that design near-body products, virtual mannequins that represent realistic body shapes, are valuable tools. With statistical shape modelling, the variability of such body shapes can be described. Shape variation captured by statistical shape models (SSMs) is often polluted by posture variations, leading to less compact models. In this paper, we propose a framework that has low computational complexity to build a posture invariant SSM, by capturing and correcting the posture of an instance. The posture-normalised SSM is shown to be substantially more compact than the non-posture-normalised SSM. Practitioner summary: Statistical shape modelling is a technique to map out the variability of (body) shapes. This variability is often polluted by variations in posture. In this paper, we propose a framework to build a posture invariant statistical shape model. Abbreviations: SSM: statistical shape model; 1D: one-dimensional; 3D: three-dimensional; DHM: digital human model; LBS: linear blend skinning; PCA: princial component analysis; PC: principal component; TTR: thumb tip reach.

Assessment of Forces in Intradermal Injection Devices: Hydrodynamic Versus Human Factors.

PURPOSE: The force that has to be exerted on the plunger for administering a given amount of fluid in a given time, has an important influence on comfort for the subject and usability for the administrator in intradermal drug delivery. The purpose of this study is to model those forces that are subject-independent, by linking needle and syringe geometry to the force required for ejecting a given fluid at a given ejection rate. MATERIAL AND METHODS: We extend the well-known Hagen-Poiseuille formula to predict pressure drop induced by a fluid passing through a cylindrical body. The model investigates the relation between the pressure drop in needles and the theoretic Hagen-Poiseuille prediction and is validated in fifteen needles from 26G up to 33G suited for intradermal drug delivery. We also provide a method to assess forces exerted by operators in real world conditions. RESULTS: The model is highly linear in each individual needle with R-square values ranging from 75% up to 99.9%. Ten out of fifteen needles exhibit R-square values above 99%. A proof-of-concept for force assessment is provided by logging forces in operators in real life conditions. CONCLUSIONS: The force assessment method and the model can be used to pinpoint needle geometry for intradermal injection devices, tuning comfort for subjects and usability for operators.

Inter- and Intrarater Reliability of Clinical Tests Associated With Functional Lumbar Segmental Instability and Motor Control Impairment in Patients With Low Back Pain: A Systematic Review.

OBJECTIVES: To provide a comprehensive overview of clinical tests associated with functional lumbar segmental instability and motor control impairment in patients with low back pain (LBP), and to investigate their intrarater reliability, interrater reliability, or both. DATA SOURCES: A systematic computerized search was conducted on December 1, 2015, in 4 different databases (starting search year is indicated in parentheses, with articles included from that year until December 1, 2015): PubMed (1972-), Web of Science (1955-), Embase (1947-), and MEDLINE (1946-). STUDY SELECTION: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed during design, search, and reporting stages of this review. The included population comprised patients with primary LBP. DATA EXTRACTION: Data were extracted as follows: (1) description and scoring of the clinical tests; (2) population characteristics; (3) inclusion and exclusion criteria; (4) description of the used procedures; (5) results for both intra- and interrater reliability; and eventually (6) notification on used statistical method. The risk of bias of the included articles was assessed with the use of the COnsensus-based Standards for the selection of health Measurement INstruments checklist. DATA SYNTHESIS: A total of 16 records were eligible, and 30 clinical tests were identified. All included studies investigated interrater reliability, and 3 studies investigated intrarater reliability. The identified interrater reliability scores ranged from poor to very good (κ=-.09 to .89; intraclass correlation coefficient, .72-.96), and the intrarater reliability scores ranged from fair to very good (κ=.51-.86). CONCLUSIONS: Three clinical tests (aberrant movement pattern, prone instability test, Beighton Scale) could be identified as having an adequate interrater reliability. No conclusions could be made for intrarater reliability. However, further research should focus on better study designs, provide an overall agreement for uniformity and interpretation of clinical tests, and should implement research regarding validity.

Effectiveness of Active Cycling in Subacute Stroke Rehabilitation: A Randomized Controlled Trial.

OBJECTIVE: To examine the effects of 3 months of aerobic training (AT) followed by coaching on aerobic capacity, strength, and gait speed after subacute stroke. DESIGN: Randomized controlled trial. SETTING: Inpatient rehabilitation center. PARTICIPANTS: Patients (N=59; mean age ± SD, 65.4±10.3y; 21 women (36%); Barthel Index ≤50 in 64% of patients) with first stroke and able to cycle at 50 revolutions/min were enrolled in the study 3 to 10 weeks after stroke onset. INTERVENTIONS: Patients were randomly allocated to a 3-month active cycling group (ACG, n=33) and education, or to a control group (CG, n=26). Afterward, patients in the ACG were randomly assigned either to a coaching (n=15) or to a noncoaching group (n=16) for 9 months. MAIN OUTCOME MEASURES: Aerobic capacity, isometric knee extension strength, and gait ability and speed were measured before and after intervention and during follow-up at 6 and 12 months. RESULTS: A nonsignificant difference was found in workload (Wattpeak) (P=.078) between ACG and CG after 3 months. Furthermore, after 3 months of cycling and after 9 months of coaching, all groups showed significant changes over time (P≤.027) in peak oxygen consumption, Wattpeak, leg strength, and gait speed. Also, significant changes over time (P<.001) were found in the ACG and the CG in patients with walking inability at baseline. CONCLUSIONS: No significant differences between training groups were found over time. Although our study did not have objective exercise data from the training device during follow-up, the 3-month active cycling (AC) program combined with education sessions seemed an applicable method in subacute stroke rehabilitation. New long-term AT interventions should focus on coaching approaches to facilitate training after a supervised AC program.