Walking orientation randomness metric (WORM) score: pilot study of a novel gait parameter to assess walking stability and discriminate fallers from non-fallers using wearable sensors.

BACKGROUND: Musculoskeletal disorders can contribute to injurious falls and incur significant societal and healthcare burdens. Identification of fallers from non-fallers through wearable-based gait analysis can facilitate timely intervention to assist mobility and prevent falls whilst improving care and attention for high fall-risk patients. In this study, we use wearable sensor-based gait analysis to introduce a novel variable to assess walking stability in fallers and non-fallers - the Walking Orientation Randomness Metric. The WORM score quantifies the stability, or 'figure-of-eight' motion of a subject's trunk during walking as an indicator of a falls-predictive (pathological) gait. METHODS: WORM is calculated as the 'figure-of-eight' oscillation mapped out in the transverse-plane by the upper body's centre-point during a walking bout. A sample of patients presenting to the Prince of Wales Hospital (Sydney, Australia) with a primary diagnosis of "falls for investigation" and age-matched healthy controls (non-fallers) from the community were recruited. Participants were fitted at the sternal angle with the wearable accelerometer, MetaMotionC (Mbientlab Inc., USA) and walked unobserved (at self-selected pace) for 5-50 m along an obstacle-free, carpeted hospital corridor. RESULTS: Participants comprised of 16 fallers (mean age: 70 + 17) and 16 non-fallers (mean age: 70 + 9) based on a recent fall(s) history. The (median) WORM score was 17-fold higher (p < 0.001) in fallers (3.64 cm) compared to non-fallers (0.21 cm). ROC curve analyses demonstrate WORM can discriminate fallers from non-fallers (AUC = 0.97). Diagnostic analyses (cut-off > 0.51 cm) show high sensitivity (88%) and specificity (94%). CONCLUSION: In this pilot study we have introduced the WORM score, demonstrating its discriminative performance in a preliminary sample size of 16 fallers. WORM is a novel gait metric assessing walking stability as measured by truncal way during ambulation and shows promise for objective and clinical evaluation of fallers.

The use of carbon fiber/polyetheretherketone (CF/PEEK) in pedicle screw fixation for spinal neoplasms-potential advantages in postoperative imaging and radiotherapy planning.

Background: Titanium pedicle screw fixation complicates postoperative care in patients with spinal neoplasms due to postoperative imaging artefacts and dose perturbation. This study aims to measure the benefits of using carbon fiber/polyetheretherketone (CF/PEEK) pedicle fixation compared to titanium in postoperative imaging, radiotherapy planning and delivery for spinal neoplasms treated with conventional external beam radiotherapy with a commercial treatment planning system. Methods: The properties of CF/PEEK pedicle fixation systems were compared to titanium in radiotherapy dose planning accuracy and postoperative computed tomography (CT) image quality. Dose profiles through the screw, tulip and longitudinal axis of the screw were acquired with radiochromic films and compared to a collapsed cone algorithm simulation, to measure dose agreement. The image quality of postoperative CTs were compared by defining four regions of interest around the vertebrae and screws in water phantom models and previous planning CTs, and comparing calculated artefact indexes (AIs). Results: CF/PEEK screws have non-inferior dosimetric prediction accuracy up to 50 mm beneath the screw for collapsed-cone algorithm planning systems. There is a statistically significant reduction in the absolute difference between calculated and measured dose at a depth of 2 mm beneath the screw. There is minimal attenuation with CF/PEEK relative to the surrounding dose, extending to 50 mm beneath the screw. There is a statistically significant improvement in CT imaging quality with reduced AIs in CF/PEEK fixation compared to titanium in both model and patient CT plans. Conclusions: CF/PEEK pedicle fixation can provide benefits in postoperative imaging and photon radiotherapy planning and delivery to patients with spinal neoplasms.

Analysing gait patterns in degenerative lumbar spine diseases: a literature review.

Objectives: To collate the current state of knowledge and explore differences in the spatiotemporal gait patterns of degenerative lumbar spine diseases: lumbar spinal stenosis (LSS), lumbar disc herniation (LDH) and low back pain (LBP). Background: LBP is common presenting complaint with degenerative lumbar spine disease being a common cause. In particular, the gait patterns of LSS, LDH and mechanical-type (facetogenic and discogenic) LBP is not established. Methods: A search of the literature was conducted to determine the changes in spatial and temporal gait metrics involved with each type of degenerative lumbar spine disease. A search of databases including Medline, Embase and PubMed from their date of inception to April 18th, 2021 was performed to screen, review and identify relevant studies for qualitative synthesis. Seventeen relevant studies were identified for inclusion in the present review. Of these, 5 studies investigated gait patterns in LSS, 10 studies investigated LBP and 2 studies investigated LDH. Of these, 4 studies employed wearable accelerometry in LSS (2 studies) and LBP (2 studies). Conclusions: Previous studies suggest degenerative diseases of the lumbar spine have unique patterns of gait deterioration. LSS is characterised by asymmetry and variability. Spatiotemporal gait deterioration in gait velocity, cadence with increased double-support duration and gait variability are distinguishing features in LDH. LBP involves marginal abnormalities in temporal and spatial gait metrics. Previous studies suggest degenerative diseases of the lumbar spine have unique patterns of gait deterioration. Gait asymmetry and variability, may be relevant metrics for distinguishing between the gait profiles of lumbar spine diseases.

Proposed objective scoring algorithm for walking performance, based on relevant gait metrics: the Simplified Mobility Score (SMoS™)-observational study.

BACKGROUND: Walking is a fundamental part of living, and its importance is not limited by age or medical status. Reduced walking speed (WS), or gait velocity, is a sign of advancing age, various disease states, cognitive impairment, mental illness and early mortality. Activity levels, as defined in the literature as "daily step count" (DSC), is also a relevant measure of health status. A deterioration in our walking metrics, such as reduced WS and DSC, is associated with poor health outcomes. These objective measures are of such importance, that walking speed has been dubbed "the 6th vital sign". We report a new objective measure that scores walking using the relevant metrics of walking speed and daily step count, into an easy-to-understand score from 0 (nil mobility) to 100 (excellent mobility), termed the Simplified Mobility Score (SMoS™). We have provided equal weighting to walking speed and daily step count, using a simple algorithm to score each metric out of 50. METHODS: Gait data was collected from 182 patients presenting to a tertiary hospital spinal unit with complaints of pain and reduced mobility. Walking speed was measured from a timed walk along an unobstructed pathway. Daily step count information was obtained from patients who had enabled step count tracking on their devices. The SMoS of the sample group were compared to expected population values calculated from the literature using 2-tailed Z tests. RESULTS: There were significantly reduced SMoS in patients who presented to the spinal unit than those expected at each age group for both genders, except for the 50-59 age bracket where no statistically significant reduction was observed. Even lower scores were present in those that went on to have surgical management. There was a significant correlation of SMoS scores with subjective disability scores such as the Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) in this cohort. CONCLUSIONS: The SMoS is a simple and effective scoring tool which is demonstrably altered in spinal patients across age and gender brackets and correlates well with subjective disability scores. The SMoS has the potential to be used as a screening tool in primary and specialised care settings.

Objectifying clinical gait assessment: using a single-point wearable sensor to quantify the spatiotemporal gait metrics of people with lumbar spinal stenosis.

BACKGROUND: Wearable accelerometer-containing devices have become a mainstay in clinical studies which attempt to classify the gait patterns in various diseases. A gait profile for lumbar spinal stenosis (LSS) has not been developed, and no study has validated a simple wearable system for the clinical assessment of gait in lumbar stenosis. This study identifies the changes to gait patterns that occur in LSS to create a preliminary disease-specific gait profile. In addition, this study compares a chest-based wearable sensor, the MetaMotionC© device and inertial measurement unit python script (MMC/IMUPY) system, against a reference-standard, videography, to preliminarily assess its accuracy in measuring the gait features of patients with LSS. METHODS: We conduct a cross-sectional observational study examining the walking patterns of 25 LSS patients and 33 healthy controls. To construct a preliminary disease-specific gait profile for LSS, the gait patterns of the 25 LSS patients and 25 healthy controls with similar ages were compared. To assess the accuracy of the MMC/IMUPY system in measuring the gait features of patients with LSS, its results were compared with videography for the 21 LSS and 33 healthy controls whose walking bouts exceeded 30 m. RESULTS: Patients suffering from LSS walked significantly slower, with shorter, less frequent steps and higher asymmetry compared to healthy controls. The MMC/IMUPY system had >90% agreement with videography for all spatiotemporal gait metrics that both methods could measure. CONCLUSIONS: The MMC/IMUPY system is a simple and feasible system for the construction of a preliminary disease-specific gait profile for LSS. Before clinical application in everyday living conditions is possible, further studies involving the construction of a more detailed disease-specific gait profile for LSS by disease severity, and the validation of the MMC/IMUPY system in the home environment, are required.

Objective falls-risk prediction using wearable technologies amongst patients with and without neurogenic gait alterations: a narrative review of clinical feasibility.

OBJECTIVES: The present narrative review aims to collate the literature regarding the current use of wearable gait measurement devices for falls-risk assessment in neurological and non-neurological populations. Thereby, this review seeks to determine the extent to which the aforementioned barriers inhibit clinical use. BACKGROUND: Falls contribute a significant disease burden in most western countries, resulting in increased morbidity and mortality with substantial therapeutic costs. The recent development of gait analysis sensor technologies has enabled quantitative measurement of several gait features related to falls risk. However, three main barriers to implementation exist: accurately measuring gait-features associated with falls, differentiating between fallers and non-fallers using these gait features, and the accuracy of falls predictive algorithms developed using these gait measurements. METHODS: Searches of Medline, PubMed, Embase and Scopus were screened to identify 46 articles relevant to the present study. Studies performing gait assessment using any wearable gait assessment device and analysing correlation with the occurrence of falls during a retrospective or prospective study period were included. Risk of Bias was assessed using the Centre for Evidence Based Medicine (CEBM) Criteria. CONCLUSIONS: Falls prediction algorithms based entirely, or in-part, on gait data have shown comparable or greater success of predicting falls than existing stratification scoring systems such as the 10-meter walk test or timed-up-and-go. However, data is lacking regarding their accuracy in neurological patient populations. Inertial measurement units (IMU) have displayed competency in obtaining and interpreting gait metrics relevant to falls risk. They have the potential to enhance the accuracy and efficiency of falls risk assessment in inpatient and outpatient setting.

Analysis of Patterns of Gait Deterioration in Patients with Lumbar Spinal Stenosis.

OBJECTIVE: Quantitative gait analysis has been established as a valuable tool for functional assessment and evaluation of intervention efficacy in lumbar spinal stenosis (LSS). We aimed to bolster the limited evidence on the specific aspects of gait that are altered in LSS. METHODS: Fifteen patients with LSS and 15 healthy subjects performed a 30-m-long walk. Gait was assessed by video recording. Four spatiotemporal parameters were compared between groups: cadence, gait velocity, step length, and step duration. RESULTS: Compared with healthy subjects, gait of patients with LSS demonstrated significant differences for all spatiotemporal parameters. Differences in mean cadence, step length, gait velocity, and step duration were -14%, -24%, -37%, and +16% between patients with LSS and healthy subjects. CONCLUSIONS: This study demonstrated significant alterations in clinically measurable gait parameters in patients with LSS compared with healthy subjects. Future studies should assess the value of these gait parameters for objective clinical assessment of functional status and intervention efficacy through correlation with currently used subjective tools and comparison at preoperative and postoperative time points. Specific gait alterations identified in patients with LSS may be valuable for clinical objective assessment of functional status and intervention efficacy.

mHealth Apps for Enhanced Management of Spinal Surgery Patients: A Review.

mHealth (mobile health) refers to mobile technologies that aid medical and public health practices. As of February 2019, 81% of Americans own a smartphone, and mHealth applications (apps) have become increasingly common with more than 400,000 mHealth applications currently available. Advancements in mobile technology now allow us to provide personalized up-to-date information, track personal health data, remind and engage patients, and communicate in a cost-effective way. There are new opportunities for healthcare providers to integrate mHealth into clinical practice. We discuss the current scientific evidence, and research into mHealth technology.

Assessment and Post-Intervention Recovery After Surgery for Lumbar Disk Herniation Based on Objective Gait Metrics from Wearable Devices Using the Gait Posture Index.

OBJECTIVE: Surgery for lumbar disk herniation (LDH) presents an option for patients when conservative measures fail. The objective of this clinical study is to investigate a novel, objective outcome measure in patients undergoing lumbar microdiscectomy. METHODS: Twenty-four patients were evaluated pre- and postoperatively using the Oswestry Disability Index (ODI), and a novel objective scoring tool, the Gait Posture index (GPi). The score is calculated from 4 key physical health metrics: daily step count, walking speed, step length, and walking posture. The GPi ranges from 0 (nonambulant) to 100 (excellent walking performance). Wearable accelerometers and observational recordings were used to evaluate the components of the GPi. The GPi was calculated and compared with the ODI, pre- and postintervention. The study was designed as a proof of concept and confirmation of validity for use of the GPi in LDH. RESULTS: At follow-up (average 66 ± 36 days), 23 of 24 patients had an improvement in their GPi after surgery. The average GPi of the cohort improved from 59.33 ± 16.06 to 85.75 ± 9.22 with P < 0.001, with significant changes in all 4 components. The average preoperative ODI was 54.54 ± 20.70, improving to 16.33 ± 14.095 with P < 0.001. The Pearson correlation coefficient was r = 0.56, indicating a correlation between change in ODI and change in GPi. CONCLUSIONS: The GPi score is a new, objective descriptor of mobility in spinal surgery which can be used to augment traditional subjective outcome scoring surveys such as the ODI. Significant changes are seen in the GPi and its constituent metrics in patients undergoing surgery for LDH.