Wearable motion-based platform for functional spine health assessment.

INTRODUCTION: Low back pain is a significant burden to society and the lack of reliable outcome measures, combined with a prevailing inability to quantify the biopsychosocial elements implicated in the disease, impedes clinical decision-making and distorts treatment efficacy. This paper aims to validate the utility of a biopsychosocial spine platform to provide standardized wearable sensor-derived functional motion assessments to assess spine function and differentiate between healthy controls and patients. Secondarily, we explored the correlation between these motion features and subjective biopsychosocial measures. METHODS: An observational study was conducted on healthy controls (n=50) and patients with low back pain (n=50) to validate platform utility. The platform was used to conduct functional assessments along with patient-reported outcome assessments to holistically document cohort differences. Our primary outcomes were motion features; and our secondary outcomes were biopsychosocial measures (pain, function, etc). RESULTS: Our results demonstrated statistically significant differences in motion features between healthy and patient cohorts across anatomical planes. Importantly, we found velocity and acceleration in the axial plane showed the largest difference, with healthy controls having 49.7% and 55.7% higher values, respectively, than patients. In addition, we found significant correlations between motion features and biopsychosocial measures for pain, physical function and social role only. CONCLUSIONS: Our study validated the use of wearable sensor-derived functional motion metrics in differentiating healthy controls and patients. Collectively, this technology has the potential to facilitate holistic biopsychosocial evaluations to enhance spine care and improve patient outcomes. TRIAL REGISTRATION NUMBER: NCT05776771.

Reliability of a Wearable Motion Tracking System for the Clinical Evaluation of a Dynamic Cervical Spine Function.

Neck pain is a common cause of disability worldwide. Lack of objective tools to quantify an individual's functional disability results in the widespread use of subjective assessments to measure the limitations in spine function and the response to interventions. This study assessed the reliability of the quantifying neck function using a wearable cervical motion tracking system. Three novice raters recorded the neck motion assessments on 20 volunteers using the device. Kinematic features from the signals in all three anatomical planes were extracted and used as inputs to repeated measures and mixed-effects regression models to calculate the intraclass correlation coefficients (ICCs). Cervical spine-specific kinematic features indicated good and excellent inter-rater and intra-rater reliability for the most part. For intra-rater reliability, the ICC values varied from 0.85 to 0.95, and for inter-rater reliability, they ranged from 0.7 to 0.89. Overall, velocity measures proved to be more reliable compared to other kinematic features. This technique is a trustworthy tool for evaluating neck function objectively. This study showed the potential for cervical spine-specific kinematic measurements to deliver repeatable and reliable metrics to evaluate clinical performance at any time points.

Reliability of a Wearable Motion System for Clinical Evaluation of Dynamic Lumbar Spine Function.

Background: Low back pain is the leading cause of disability worldwide. Subjective assessments are often used to assess extent of functional limitations and treatment response. However, these measures have poor sensitivity and are influenced by the patient's perception of their condition. Currently, there are no objective tools to effectively assess the extent of an individual's functional disability and inform clinical decision-making. Objective: The purpose of this study was to evaluate the reliability of a wearable motion system based on Inertial Measurement Unit (IMU) sensors for use in quantifying low back function. Methods: Low back motion assessments were conducted by 3 novice raters on 20 participants using an IMU-based motion system. These assessments were conducted over 3 days with 2 days of rest in between tests. A total of 37 kinematic parameters were extracted from the low back motion assessment in all three anatomical planes. Intra-rater and inter-rater reliability were assessed using Intraclass Correlation Coefficients (ICCs) calculated from repeated measures, mixed-effects regression models. Results: Lumbar spine-specific kinematic parameters showed moderate to excellent reliability across all kinematic parameters. The ICC values ranged between 0.84-0.93 for intra-rater reliability and 0.66 - 0.83 for inter-rater reliability. In particular, velocity measures showed higher reliabilities than other kinematic variables. Conclusion: The IMU-based wearable motion system is a valid and reliable tool to objectively assess low back function. This study demonstrated that lumbar spine-specific kinematic metrics have the potential to provide good, repeatable metrics to assess clinical function over time.

A physiological and biomechanical investigation of three passive upper-extremity exoskeletons during simulated overhead work.

The objective of this study was to evaluate three passive upper-extremity exoskeletons relative to a control condition. Twelve subjects performed an hour-long, simulated occupational task in a laboratory setting. Independent measures of exoskeleton, exertion height (overhead, head height), time, and their interactions were assessed. Dependent measures included changes in tissue oxygenation (ΔTSI) in the anterior deltoid and middle trapezius, peak resultant lumbar spine loading, and subjective discomfort in various body regions. A statistically significant reduction in ΔTSI between exoskeleton and control was only observed in one instance. Additionally, neither increases in spinal loading nor increases in subjective discomfort ratings were observed for any of the exoskeletons. Ultimately, the exoskeletons offered little to no physiological benefit for the conditions tested. However, the experimental task was not highly fatiguing to the subjects, denoted by low ΔTSI values across conditions. Results may vary for tasks requiring constant arm elevation or higher force demands. Practitioner summary This study quantified the benefits of upper-extremity exoskeletons using NIRS, complementary to prior studies using EMG. The exoskeletons offered little to no physiological benefit for the conditions tested. However, the experimental task was not highly fatiguing, and results may vary for an experimental task with greater demand on the shoulders. Abbreviations: WMSD: work-related musculoskeletal disorder; EMG: electromyography; NIRS: near-infrared spectroscopy; NIR: near-infrared; Hb: haemoglobin; Mb: myoglobin; TSI: tissue saturation index; ATT: adipose tissue thickness.