Accelerometers for objective evaluation of physical activity following spine surgery

Data Analytics in Physical Activity Studies With Accelerometers: Scoping Review

BACKGROUND

Monitoring free-living physical activity (PA) through wearable devices enables the real-time assessment of activity features associated with health outcomes and provision of treatment recommendations and adjustments. The conclusions of studies on PA and health depend crucially on reliable statistical analyses of digital data. Data analytics, however, are challenging due to the various metrics adopted for measuring PA, different aims of studies, and complex temporal variations within variables. The application, interpretation, and appropriateness of these analytical tools have yet to be summarized.

OBJECTIVE

This research aimed to review studies that used analytical methods for analyzing PA monitored by accelerometers. Specifically, this review addressed three questions: (1) What metrics are used to describe an individual's free-living daily PA? (2) What are the current analytical tools for analyzing PA data, particularly under the aims of classification, association with health outcomes, and prediction of health events? and (3) What challenges exist in the analyses, and what recommendations for future research are suggested regarding the use of statistical methods in various research tasks?

METHODS

This scoping review was conducted following an existing framework to map research studies by exploring the information about PA. Three databases, PubMed, IEEE Xplore, and the ACM Digital Library, were searched in February 2024 to identify related publications. Eligible articles were classification, association, or prediction studies involving human PA monitored through wearable accelerometers.

RESULTS

After screening 1312 articles, 428 (32.62%) eligible studies were identified and categorized into at least 1 of the following 3 thematic categories: classification (75/428, 17.5%), association (342/428, 79.9%), and prediction (32/428, 7.5%). Most articles (414/428, 96.7%) derived PA variables from 3D acceleration, rather than 1D acceleration. All eligible articles (428/428, 100%) considered PA metrics represented in the time domain, while a small fraction (16/428, 3.7%) also considered PA metrics in the frequency domain. The number of studies evaluating the influence of PA on health conditions has increased greatly. Among the studies in our review, regression-type models were the most prevalent (373/428, 87.1%). The machine learning approach for classification research is also gaining popularity (32/75, 43%). In addition to summary statistics of PA, several recent studies used tools to incorporate PA trajectories and account for temporal patterns, including longitudinal data analysis with repeated PA measurements and functional data analysis with PA as a continuum for time-varying association (68/428, 15.9%).

CONCLUSIONS

Summary metrics can quickly provide descriptions of the strength, frequency, and duration of individuals' overall PA. When the distribution and profile of PA need to be evaluated or detected, considering PA metrics as longitudinal or functional data can provide detailed information and improve the understanding of the role PA plays in health. Depending on the research goal, appropriate analytical tools can ensure the reliability of the scientific findings.

Adaptive Control Method for Gait Detection and Classification Devices with Inertial Measurement Unit

Cueing and feedback training can be effective in maintaining or improving gait in individuals with Parkinson's disease. We previously designed a rehabilitation assist device that can detect and classify a user's gait at only the swing phase of the gait cycle, for the ease of data processing. In this study, we analyzed the impact of various factors in a gait detection algorithm on the gait detection and classification rate (GDCR). We collected acceleration and angular velocity data from 25 participants (1 male and 24 females with an average age of 62 ± 6 years) using our device and analyzed the data using statistical methods. Based on these results, we developed an adaptive GDCR control algorithm using several equations and functions. We tested the algorithm under various virtual exercise scenarios using two control methods, based on acceleration and angular velocity, and found that the acceleration threshold was more effective in controlling the GDCR (average Spearman correlation -0.9996, p < 0.001) than the gyroscopic threshold. Our adaptive control algorithm was more effective in maintaining the target GDCR than the other algorithms (p < 0.001) with an average error of 0.10, while other tested methods showed average errors of 0.16 and 0.28. This algorithm has good scalability and can be adapted for future gait detection and classification applications.

Let’s Get Physical! A Comprehensive Review of Pre- and Post-Surgical Interventions Targeting Physical Activity to Improve Pain and Functional Outcomes in Spine Surgery Patients

The goal of this comprehensive review was to synthesize the recent literature on the efficacy of perioperative interventions targeting physical activity to improve pain and functional outcomes in spine surgery patients. Overall, research in this area does not yet permit definitive conclusions. Some evidence suggests that post-surgical interventions may yield more robust long-term outcomes than preoperative interventions, including large effect sizes for disability reduction, although there are no studies directly comparing these surgical approaches. Integrated treatment approaches that include psychosocial intervention components may supplement exercise programs by addressing fear avoidance behaviors that interfere with engagement in activity, thereby maximizing the short- and long-term benefits of exercise. Efforts should be made to test brief, efficient programs that maximize accessibility for surgical patients. Future work in this area should include both subjective and objective indices of physical activity as well as investigating both acute postoperative outcomes and long-term outcomes.

The Effect of the Severity of Preoperative Leg Pain on Patient-Reported Outcomes, Minimum Clinically Important Difference Achievement, and Patient Satisfaction After Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

To compare patient-reported outcome measures (PROMs), satisfaction, and minimum clinically important difference (MCID) achievement after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in patients stratified by preoperative leg pain.

METHODS

Patients undergoing MIS-TLIF were collected through retrospective review of a prospectively maintained single-surgeon database. PROMs administered preoperatively/postoperatively included Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), visual analog scale (VAS) back/leg pain, Oswestry Disability Index (ODI), and 12-Item Short Form (SF-12) Physical/Mental Component Score (PCS/MCS). Patients were grouped based on preoperative VAS leg scores: VAS leg ≤7 or VAS leg >7. Inferential statistics were used to compare PROMs, MCID achievement rates, and postoperative satisfaction between groups.

RESULTS

A total of 562 patients were eligible (168 VAS leg score ≤7; 394 VAS leg score >7). Significant differences between cohorts in postoperative mean PROMs were noted for PROMIS-PF at 6 weeks/2 years, SF-12 PCS at 6 weeks/2 years, SF-12 MCS at 6 weeks/12 weeks/6 months/1 year, VAS back score at 6 weeks/12 weeks/6 months, VAS leg score at 6 weeks/12 weeks/6 months/2 years and ODI at all postoperative time points (P < 0.045, all). In the VAS leg score >7 cohort, a greater proportion achieving MCID for VAS leg score at all postoperative time points and ODI at 12 weeks (P < 0.010, all). Postoperative satisfaction was greater in VAS back score ≤7 cohort for VAS leg score at 6 weeks/12 weeks/6 months/2 years, VAS back score at 12 weeks/2 years, and ODI at 6 weeks/12 weeks/6 months/2 years (P < 0.046, all).

CONCLUSIONS

Patients with severe preoperative leg pain showed worse postoperative PROM scores and patient satisfaction for disability and back/leg pain. MCID achievement rates across cohorts were similar. Patients with severe leg pain may have expectations for surgical benefits incongruent with their postoperative outcomes, and physicians may seek to manage the preoperative expectations of their patients to reflect likely outcomes after MIS-TLIF.

Translating Data Analytics Into Improved Spine Surgery Outcomes: A Roadmap for Biomedical Informatics Research in 2021

STUDY DESIGN

Narrative review.

OBJECTIVES

There is growing interest in the use of biomedical informatics and data analytics tools in spine surgery. Yet despite the rapid growth in research on these topics, few analytic tools have been implemented in routine spine practice. The purpose of this review is to provide a health information technology (HIT) roadmap to help translate data assets and analytics tools into measurable advances in spine surgical care.

METHODS

We conducted a narrative review of PubMed and Google Scholar to identify publications discussing data assets, analytical approaches, and implementation strategies relevant to spine surgery practice.

RESULTS

A variety of data assets are available for spine research, ranging from commonly used datasets, such as administrative billing data, to emerging resources, such as mobile health and biobanks. Both regression and machine learning techniques are valuable for analyzing these assets, and researchers should recognize the particular strengths and weaknesses of each approach. Few studies have focused on the implementation of HIT, and a variety of methods exist to help translate analytic tools into clinically useful interventions. Finally, a number of HIT-related challenges must be recognized and addressed, including stakeholder acceptance, regulatory oversight, and ethical considerations.

CONCLUSIONS

Biomedical informatics has the potential to support the development of new HIT that can improve spine surgery quality and outcomes. By understanding the development life-cycle that includes identifying an appropriate data asset, selecting an analytic approach, and leveraging an effective implementation strategy, spine researchers can translate this potential into measurable advances in patient care.

Developing a Prediction Model for Identification of Distinct Perioperative Clinical Stages in Spine Surgery With Smartphone-Based Mobility Data

BACKGROUND

Spine surgery outcomes assessment currently relies on patient-reported outcome measures, which satisfy established reliability and validity criteria, but are limited by the inherently subjective and discrete nature of data collection. Physical activity measured from smartphones offers a new data source to assess postoperative functional outcomes in a more objective and continuous manner.

OBJECTIVE

To present a methodology to characterize preoperative mobility and gauge the impact of surgical intervention using objective activity data garnered from smartphone-based accelerometers.

METHODS

Smartphone mobility data from 14 patients who underwent elective lumbar decompressive surgery were obtained. A time series analysis was conducted on the number of steps per day across a 2-year perioperative period. Five distinct clinical stages were identified using a data-driven approach and were validated with clinical documentation.

RESULTS

Preoperative presentation was correctly classified as either a chronic or acute mobility decline in 92% of patients, with a mean onset of acute decline of 11.8 ± 2.9 weeks before surgery. Postoperative recovery duration demonstrated wide variability, ranging from 5.6 to 29.4 weeks (mean: 20.6 ± 4.9 weeks). Seventy-nine percentage of patients ultimately achieved a full recovery, associated with an 80% ± 33% improvement in daily steps compared with each patient's preoperative baseline (P = .002). Two patients subsequently experienced a secondary decline in mobility, which was consistent with clinical history.

CONCLUSION

The perioperative clinical course of patients undergoing spine surgery was systematically classified using smartphone-based mobility data. Our findings highlight the potential utility of such data in a novel quantitative and longitudinal surgical outcome measure.

Gait metrics analysis utilizing single-point inertial measurement units: a systematic review

BACKGROUND

Wearable sensors, particularly accelerometers alone or combined with gyroscopes and magnetometers in an inertial measurement unit (IMU), are a logical alternative for gait analysis. While issues with intrusive and complex sensor placement limit practicality of multi-point IMU systems, single-point IMUs could potentially maximize patient compliance and allow inconspicuous monitoring in daily-living. Therefore, this review aimed to examine the validity of single-point IMUs for gait metrics analysis and identify studies employing them for clinical applications.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA) were followed utilizing the following databases: PubMed; MEDLINE; EMBASE and Cochrane. Four databases were systematically searched to obtain relevant journal articles focusing on the measurement of gait metrics using single-point IMU sensors.

RESULTS

A total of 90 articles were selected for inclusion. Critical analysis of studies was conducted, and data collected included: sensor type(s); sensor placement; study aim(s); study conclusion(s); gait metrics and methods; and clinical application. Validation research primarily focuses on lower trunk sensors in healthy cohorts. Clinical applications focus on diagnosis and severity assessment, rehabilitation and intervention efficacy and delineating pathological subjects from healthy controls.

DISCUSSION

This review has demonstrated the validity of single-point IMUs for gait metrics analysis and their ability to assist in clinical scenarios. Further validation for continuous monitoring in daily living scenarios and performance in pathological cohorts is required before commercial and clinical uptake can be expected.

The Effect of the Severity of Preoperative Disability on Patient-Reported Outcomes and Patient Satisfaction Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

To compare patient-reported outcomes (PROMs), satisfaction, and minimum clinically important difference (MCID) achievement following minimally invasive transforaminal lumbar interbody fusion stratified by preoperative disability.

METHODS

Minimally invasive transforaminal lumbar interbody fusions were grouped by preoperative Oswestry Disability Index (ODI) score: ODI <41 or ODI ≥41. PROMs administered pre/postoperatively included Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF), visual analog scale (VAS) back/leg, ODI, and 12-Item Short-Form Physical Composite Score (SF-12 PCS)/12-Item Short-Form Mental Composite Score (SF-12 MCS). Satisfaction scores were collected for VAS back/leg and ODI. Coarsened exact match controlled for differences between cohorts. T tests compared mean PROMs and postoperative improvement/satisfaction between cohorts. Simple logistic regression compared MCID achievement.

RESULTS

After coarsened exact matching, there were 118 patients in the ODI ≤41 and 377 patients in the ODI >41 cohort. The ODI >41 cohort saw greater postoperative inpatient VAS pain score and narcotic consumption on days 0/1 (P < 0.018, all). PROMs differed between cohorts: PROMIS-PF, SF-12 PCS, ODI, VAS back/leg at all postoperative time points and SF-12 MCS at 6 weeks/12 weeks/6 months/1 year (P < 0.045, all). Patients in the ODI >41 cohort demonstrated greater proportion achieving MCID for ODI at all postoperative time points and for SF-12 MCS 6-week/12-week/6-month/1-year (P < 0.040, all). The ODI ≤41 cohort demonstrated greater MCID achievement for overall PROMIS-PF and SF-12 PCS 6 months (P < 0.047, all). Postoperative satisfaction was greater in the ODI ≤41 cohort for VAS leg 6 weeks/12 weeks, VAS back 6 weeks/12 weeks, and ODI all postoperative time points (P < 0.048, all).

CONCLUSIONS

Preoperative disability associated with worse postoperative PROMs and patient satisfaction for disability, back/leg pain at multiple time points. MCID achievement rates across cohorts were similar for most PROMs at most postoperative time points. Patients with severe disability may have unrealistic expectations for surgical benefits, influencing corresponding postoperative satisfaction.

The Effect of the Severity of Preoperative Back Pain on Patient-Reported Outcomes, Recovery Ratios, and Patient Satisfaction Following Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF)

BACKGROUND

Limited literature has addressed impact of preoperative back pain severity on patient-reported outcome measures (PROMs), recovery ratios (RRs), and patient satisfaction following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

METHODS

MIS TLIFs were retrospectively identified and grouped: preoperative visual analog scale (VAS) back ≤7 or VAS back >7. PROMs, including PROMIS-PF, VAS back and leg, Oswestry Disability Index (ODI), and SF-12 Physical Composite Score and Mental Composite Score (MCS), were collected pre- and postoperatively. A PROM's RR was calculated as proportion of postoperative improvement to overall potential improvement.

RESULTS

In total, 740 patients were included: 359 patients with VAS back ≤7 and 381 patients with VAS back >7. The VAS back >7 cohort reported significantly greater postoperative inpatient pain (P ≤ .003, both). All preoperative and the following postoperative PROMs favored the VAS back ≤7 cohort: PROMIS-PF 2-years, VAS back overall, SF-12 Physical Composite Score 12 weeks and 1 year, SF-12 MCS 6 weeks/12 weeks, VAS leg 6 weeks, 12 weeks, 6 months, and 2 years, and ODI overall (P ≤ 0.048, all). The VAS back >7 cohort demonstrated greater delta PROMs for all VAS back and ODI except 2 years (P ≤ 0.021, all). A greater proportion of patients in the VAS back >7 group achieved minimal clinically important difference for VAS back overall, ODI 6 weeks/12 weeks, PROMIS-PF 6 weeks, and SF-12 MCS 6 weeks/6 months (P ≤ 0.044, all). The VAS back>7 cohort RR was significantly greater for VAS back 6 months and VAS leg 6 months/2 years (P ≤ 0.034, all). The VAS back ≤7 cohort's postoperative satisfaction was significantly greater for VAS back 12 weeks, VAS leg 12 weeks, and ODI 6 weeks/12 weeks (P ≤ 0.046, all).

CONCLUSIONS

Patients with greater preoperative back pain demonstrated significantly worse postoperative scores for most PROMs at most time points and significantly worse patient satisfaction for disability, back and leg pain at multiple time points.

Technological advancements in the analysis of human motion and posture management through digital devices

Technological development of motion and posture analyses is rapidly progressing, especially in rehabilitation settings and sport biomechanics. Consequently, clear discrimination among different measurement systems is required to diversify their use as needed. This review aims to resume the currently used motion and posture analysis systems, clarify and suggest the appropriate approaches suitable for specific cases or contexts. The currently gold standard systems of motion analysis, widely used in clinical settings, present several limitations related to marker placement or long procedure time. Fully automated and markerless systems are overcoming these drawbacks for conducting biomechanical studies, especially outside laboratories. Similarly, new posture analysis techniques are emerging, often driven by the need for fast and non-invasive methods to obtain high-precision results. These new technologies have also become effective for children or adolescents with non-specific back pain and postural insufficiencies. The evolutions of these methods aim to standardize measurements and provide manageable tools in clinical practice for the early diagnosis of musculoskeletal pathologies and to monitor daily improvements of each patient. Herein, these devices and their uses are described, providing researchers, clinicians, orthopedics, physical therapists, and sports coaches an effective guide to use new technologies in their practice as instruments of diagnosis, therapy, and prevention.

Monitoring Patient Recovery After THA or TKA Using Mobile Technology

BACKGROUND

Smartphones offer the possibility of assessing recovery of mobility after total hip or knee arthroplasty (THA or TKA) passively and reliably, as well as facilitating the collection of patient-reported outcome measures (PROMs) with greater frequency.

QUESTIONS/PURPOSES

We investigated the feasibility of using mobile technology to collect daily step data and biweekly PROMs to track recovery after total joint arthroplasty.

METHODS

Pre- and post-operative daily steps were recorded in prospectively enrolled patients (128 THA and 139 TKA) via an app, which uses the phone's accelerometer. During 6-month follow-up, patients also completed PROMs (the pain numeric rating scale, the Hip Disability and Osteoarthritis Outcome Score Joint Replacement [HOOS JR] and the Knee Injury and Osteoarthritis Outcome Score Joint Replacement [KOOS JR]), and HOOS or KOOS JR quality of life domain via a mobile-enabled web link.

RESULTS

At least 6 months of follow-up was completed by 65% for THA and 68% for TKA patients. Reasons for non-completion included time commitment, phone battery, app issues, and health complications. Responses from 78% of requested PROMs were returned with 96% of patients returning at least one post-operative PROM. Step data were available from 92% of days from male patients and 86% of days from female patients. The most robust recovery occurred early, within the first 2 months. The groups with higher pre-operative steps were more likely to recover their maximum daily steps at an earlier time point. Correlations between step counts and PROMs scores were modest.

CONCLUSION

Assessing large amounts of post-TKA and post-THA step data using mobile technology is feasible. Completion rates were good, making the technology very useful for collecting frequent PROMs. Being unable to ensure that patients always carried their phones limited our analysis of the step counts.

Early postoperative physical activity and function: a descriptive case series study of 53 patients after lumbar spine surgery

BACKGROUND

The purpose of this prospective case series study was to compare changes in early postoperative physical activity and physical function between 6 weeks and 3 and 6 months after lumbar spine surgery.

METHODS

Fifty-three patients (mean [95% confidence interval; CI] age = 59.2 [56.2, 62.3] years, 64% female) who underwent spine surgery for a degenerative lumbar condition were assessed at 6 weeks and 3- and 6-months after surgery. The outcomes were objectively-measured physical activity (accelerometry) and patient-reported and objective physical function. Physical activity was assessed using mean steps/day and time spent in moderate to vigorous physical activity (MVPA) over a week. Physical function measures included Oswestry Disability Index (ODI), 12-item Short Form Health Survey (SF-12), Timed Up and Go (TUG), and 10-Meter Walk (10 MW). We compared changes over time in physical activity and function using generalized estimating equations with robust estimator and first-order autoregressive covariance structure. Proportion of patients who engaged in meaningful physical activity (e.g., walked at least 4400 and 6000 steps/day or engaged in at least 150 min/week in MVPA) and achieved clinically meaningful changes in physical function were compared at 3 and 6 months.

RESULTS

After surgery, 72% of patients initiated physical therapy (mean [95%CI] sessions =8.5 [6.6, 10.4]) between 6 weeks and 3 months. Compared to 6 weeks post-surgery, no change in steps/day or time in MVPA/week was observed at 3 or 6 months. From 21 to 23% and 9 to 11% of participants walked at least 4400 and 6000 steps/day at 3 and 6 months, respectively, while none of the participants spent at least 150 min/week in MVPA at these same time points. Significant improvements were observed on ODI, SF-12, TUG and 10 MW (p <  0.05), with over 43 to 68% and 62 to 87% achieving clinically meaningful improvements on these measures at 3 and 6 months, respectively.

CONCLUSION

Limited improvement was observed in objectively-measured physical activity from 6 weeks to 6 months after spine surgery, despite moderate to large function gains. Early postoperative physical therapy interventions targeting physical activity may be needed.

Using Wearable Devices to Monitor Physical Activity in Patients Undergoing Aortic Valve Replacement: Protocol for a Prospective Observational Study

Background

In last few decades, several tools have been developed to measure physical function objectively; however, their use has not been well established in clinical practice.

Objective

This study aims to describe the preoperative physical function and to assess and compare 6-month postoperative changes in the physical function of patients undergoing treatment for aortic stenosis with either surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR). The study also aims to evaluate the feasibility of wearable devices in assessing physical function in such patients.

Methods

This is a prospective observational study. The enrollment will be conducted 1 month before patients’ SAVR/TAVR. Patients will be provided with the wearable device at baseline (activity tracker device, Garmin vívoactive 3). They will be trained in the use of the device, and they will be requested to wear it on the wrist of their preferred hand until 12 months after SAVR/TAVR. After baseline assessment, they will undergo 4 follow-up assessments at 1, 3, 6, and 12 months after SAVR/TAVR. At baseline and each follow-up, they will undergo a set of standard and validated tests to assess physical function, health-related quality of life, and sleep quality.

Results

The ethics committee of Vicenza in Veneto Region in Italy approved the study (Protocol No. 943; January 4, 2019). As of October 2020, the enrollment of participants is ongoing.

Conclusions

The use of the wearable devices for real-time monitoring of physical activity of patients undergoing aortic valve replacement is a promising opportunity for improving the clinical management and consequently, the health outcomes of such patients.

Trial Registration

Clinicaltrials.gov NCT03843320; https://tinyurl.com/yyareu5y

International Registered Report Identifier (IRRID)

DERR1-10.2196/20072

Wearable Technology in Spine Surgery

Although patient-reported outcome measures (PROMs) provide valuable insight into the effectiveness of spine surgery, there still remain limitations on measuring outcomes in this manner. Among other deficiencies, PROMs do not always correlate with more objective measures of surgery success. Wearable technology, such as pedometers, tri-axis accelerometer, or wearable cameras, may allow physicians to track patient progress following spine surgery more objectively. Recently, there has been an emphasis on using wearable devices to measure physical activity and limb and spine function. Wearable devices could play an important role as a supplement to PROMs, although they might have to be substantiated through adequate controlled studies to identify normative data for patients presenting with common spine disorders. This review will detail the current state of wearable technology applications in spine surgery and its direction as its utilization expands.

Use of accelerometer-based activity monitoring in orthopaedics: benefits, impact and practical considerations

Studies of the effectiveness of orthopaedic interventions do not generally measure physical activity (PA). Applying accelerometer-based activity monitoring in orthopaedic studies will add relevant information to the generally examined physical function and pain assessment.Accelerometer-based activity monitoring is practically feasible in orthopaedic patient populations, since current day activity sensors have battery time and memory to measure continuously for several weeks without requiring technical expertise.The ongoing development in sensor technology has made it possible to combine functional tests with activity monitoring.For clinicians, the application of accelerometer-based activity monitoring can provide a measure of PA and can be used for clinical comparisons before and after interventions.In orthopaedic rehabilitation, accelerometer-based activity monitoring may be used to help patients reach their targets for PA and to coach patients towards a more active lifestyle through direct feedback. Cite this article: EFORT Open Rev 2019;4:678-685. DOI: 10.1302/2058-5241.4.180041.

Commercial Postural Devices: A Review

Wearables are devices worn on the human body and are able to measure various health parameters, such as physical activity, energy expenditure and gait. With the advancement of technology, the general population are now spending more hours craning our necks and slouching over smartphones, tablets and computers, et cetera. Bodily posture is representative of physical and mental health. Poor posture can lead to spinal complications and the same can be said vice versa. As the standard of living increases, there is an increase in consumerism and the expectation to maintain such a lifestyle even in the aging population. Therefore, many are able to afford small luxuries in life, such as a piece of technology that could potentially improve their health in the long run. Wearable technology is a promising alternative to laboratory systems for movement and posture analysis. This article reviews commercial wearable devices with a focus on postural analysis. The clinical applicability of posture wearables, particularly in preventing, monitoring and treating spinal and musculoskeletal conditions, along with other purposes in healthcare, will be discussed.

The role of wearable devices and objective gait analysis for the assessment and monitoring of patients with lumbar spinal stenosis: systematic review

Background

The purpose of this systematic review was to evaluate the accuracy and reliability of wearable devices for objective gait measurement of Lumbar Spinal Stenosis (LSS) patients, with a focus on relevant gait metrics.

Methods

Systematic searches were conducted of five electronic databases to identify studies that assessed gait metrics by wearable or portable technology. Data was collected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines.

Results

Four articles were identified for inclusion in this review. The objectives, methodology and quality of the studies varied. No single gait metric was investigated in all four studies, making comparison difficult. The most relevant metrics reported included gait cycle, gait velocity, step length and cadence, which were reported in two studies. Two studies explored gait symmetry. Differences between LSS patients and normal healthy subjects are demonstrable using wearable technology.

Conclusions

The measurements of gait cycle, cadence, step length, gait velocity, and number of steps with wearable devices can be used in the gait measurement of LSS patients for initial assessment, and objective outcomes following interventions. However, data and analysis are limited, and further studies are necessary to comment on reliability.

The role of wearables in spinal posture analysis: a systematic review

Background

Wearables consist of numerous technologies that are worn on the body and measure parameters such as step count, distance travelled, heart rate and sleep quantity. Recently, various wearable systems have been designed capable of detecting spinal posture and providing live biofeedback when poor posture is sustained. It is hypothesised that long-term use of these wearables may improve spinal posture.

Research questions

To (1) examine the capabilities of current devices assessing spine posture, (2) to identify studies implementing such devices in the clinical setting and (3) comment on the clinical practicality of integration of such devices into routine care where appropriate.

Methods

A comprehensive systematic review was conducted in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA) across the following databases: PubMed; MEDLINE; EMBASE; Cochrane; and Scopus. Articles related to wearables systems able to measure spinal posture were selected amongst all published studies dated from 1980 onwards. Extracted data was collected as per a predetermined checklist including device types, study objectives, findings and limitations.

Results

A total of 37 articles were extensively reviewed and analysed in the final review. The proposed wearables most commonly used Inertial Measurement Units (IMUs) as the underlying technology. Wearables measuring spinal posture have been proposed to be used in the following settings: post-operative rehabilitation; treatment of musculoskeletal disorders; diagnosis of pathological spinal posture; monitoring of progression of Parkinson’s Disease; detection of falls; workplace occupational health and safety; comparison of interventions.

Conclusions

This is the first and only study to specifically review wearable devices that monitor spinal posture. Our findings suggest that currently available devices are capable of assessing spinal posture with good accuracy in the clinical setting. However, further validation regarding the long-term use of these technologies and improvements regarding practicality is required for commercialisation.

Initial Experience With Real-Time Continuous Physical Activity Monitoring in Patients Undergoing Spine Surgery

STUDY DESIGN

Multicenter prospective pilot study.

OBJECTIVE

To evaluate if continuous physical activity monitoring by a personal electronic 3-dimensional accelerometer device is feasible and can provide objective data that correlates with patient-reported outcomes following spine surgery.

SUMMARY OF BACKGROUND DATA

Self-reported health-related quality-of-life (HRQOL) metrics are inherently limited by being very subjective, having a low frequency of data collection, and inconsistent follow-up.

METHODS

Inclusion criteria: adults (18+), thoracolumbar deformity or degenerative disease, and regular access to a computer with internet connection. Physical activity parameters included: number of daily steps, maximum hourly steps, and activity intensity. Patients completed the Oswestry Disability Index (ODI), the Short-Form Health Survey 36 (SF-36), and the Scoliosis Research Society-22r (SRS22) preoperatively and postoperatively at 6 weeks, 3 months, and 6 months.

RESULTS

Thirty-two patients were enrolled, 8 (25%) withdrew, 1 (3.1%) died, and 1 (3.1%) did not end up undergoing surgery resulting in 22 (68.8%) available patients. Mean preoperative and postoperative step ranges were 1278±767 to 17,800±6464 and 891±587 to 12,655±7038, respectively. Eleven patients improved in mean total daily steps at the final postoperative month with 2 having significant improvements (P<0.05). Five patients did not significantly change (P>0.05) and 6 patients had significantly lower mean total daily steps at 6 months (P<0.05). The entire cohort significantly improved in ODI, SF-36 Physical Component Summary, SRS Activity, SRS Appearance, SRS Mental, SRS Satisfaction, and SRS Total score at 6 months postoperative (P<0.05 for all). Both ODI and Physical Component Summary were significantly correlated with preoperative average total daily steps (r=-0.61, P=0.0058 and r=0.60, P=0.0114, respectively). No other HRQOL metrics were significantly correlated at baseline or at 6 months postoperative (P>0.05).

CONCLUSIONS

A prospective pilot study for continuous real-time physical activity monitoring was successfully completed. This is the first study of its kind and demonstrates a foundation to continuous physical activity monitoring following spine surgery. A larger and longer prospective study is needed to confirm long-term results and its relationship with HRQOL scores.

Validation of the baseline severity stratification of objective functional impairment in lumbar degenerative disc disease

OBJECTIVE

The Timed Up and Go (TUG) test is a simple, objective, and standardized method to measure objective functional impairment (OFI) in patients with lumbar degenerative disc disease (DDD). The objective of the current work was to validate the OFI baseline severity stratification (BSS; with levels of “none,” “mild,” “moderate,” and “severe”).

METHODS

Data were collected in a prospective IRB-approved 2-center study. Patients were assessed with a comprehensive panel of scales for measuring pain (visual analog scale [VAS] for back and leg pain), functional impairment (Roland-Morris Disability Index [RMDI] and Oswestry Disability Index [ODI]), and health-related quality of life (HRQOL; EQ-5D and SF-12). OFI BSS was determined using age- and sex-adjusted cutoff values.

RESULTS

A total of 375 consecutive patients scheduled for lumbar spine surgery were included. Each 1-step increase on the OFI BSS corresponded to an increase of 0.53 in the back pain VAS score, 0.69 in the leg pain VAS score, 1.81 points in the RMDI, and 5.93 points in the ODI, as well as to a decrease in HRQOL of −0.073 in the EQ-5D, −1.99 in the SF-12 physical component summary (PCS), and −1.62 in the SF-12 mental component summary (MCS; all p < 0.001). Patients with mild, moderate, and severe OFI had increased leg pain by 0.90 (p = 0.044), 1.54 (p < 0.001), and 1.94 (p < 0.001); increased ODI by 7.99 (p = 0.004), 12.64 (p < 0.001), and 17.13 (p < 0.001); and decreased SF-12 PCS by −2.57 (p = 0.049), −3.63 (p = 0.003), and −6.23 (p < 0.001), respectively.

CONCLUSIONS

The OFI BSS is a valid measure of functional impairment for use in daily clinical practice. The presence of OFI indicates the presence of significant functional impairment on subjective outcome measures.