An adaptive prosthetic socket for people with transtibial amputation.

It is essential that people with limb amputation maintain proper prosthetic socket fit to prevent injury. Monitoring and adjusting socket fit, for example by removing the prosthesis to add prosthetic socks, is burdensome and can adversely affect users' function and quality-of-life. This study presents results from take-home testing of a motor-driven adaptive socket that automatically adjusted socket size during walking. A socket fit metric was calculated from inductive sensor measurements of the distance between the elastomeric liner surrounding the residual limb and the socket's inner surface. A proportional-integral controller was implemented to adjust socket size. When tested on 12 participants with transtibial amputation, the controller was active a mean of 68% of the walking time. In general, participants who walked more than 20 min/day demonstrated greater activity, less doff time, and fewer manual socket size adjustments for the adaptive socket compared with a locked non-adjustable socket and a motor-driven socket that participants adjusted with a smartphone application. Nine of 12 participants reported that they would use a motor-driven adjustable socket if it were available as it would limit their socket fit issues. The size and weight of the adaptive socket were considered the most important variables to improve.

Mortality with concurrent treatment with gabapentin and opioids among people with spine diagnoses in the U.S. Medicare population: a propensity-matched cohort study.

IMPORTANCE: Given the negative impact of opioid use on population health, prescriptions for alternative pain-relieving medications, including gabapentin, have increased. Concurrent gabapentin and opioid prescriptions are commonly reported in retrospective studies of opioid-related overdose deaths. OBJECTIVE: To determine whether people who filled gabapentin and opioid prescriptions concurrently ('gabapentin + opioids') had greater mortality than those who filled an active control medication (tricyclic antidepressants [TCAs] or duloxetine) and opioids concurrently ('TCAs/duloxetine + opioids'). We hypothesized that people treated with gabapentin + opioids would have higher mortality rates compared to people treated with TCAs/duloxetine + opioids. DESIGN: Propensity score-matched cohort study with an incident user, active control design. The median (maximum) follow-up was 45 (1093) days. SETTING: Population-based. PARTICIPANTS: Medicare beneficiaries with spine-related diagnoses 2017-2019. The primary analysis included those who concurrently (within 30 days) filled at least 1 incident gabapentin + at least 1 opioid or at least 1 incident TCA/duloxetine + at least 1 opioid. EXPOSURES: People treated with gabapentin + opioids (n=67,133) were matched on demographic and clinical factors in a 1:1 ratio to people treated with TCAs/duloxetine + opioids (n=67,133). MAIN OUTCOMES AND MEASURES: The primary outcome was mortality at any time. A secondary outcome was occurrence of a major medical complication at any time. RESULTS: Among 134,266 participants (median age 73.4 years; 66.7% female), 2360 died before the end of follow-up. No difference in mortality was observed between groups (adjusted hazard ratio (HR) and 95% confidence interval (CI) for gabapentin + opioids was 0.98 (0.90, 1.06); p=0.63). However, people treated with gabapentin + opioids were at slightly increased risk of a major medical complication (1.02 (1.00, 1.04); p=0.03) compared to those treated with TCAs/duloxetine + opioids. Results were similar in analyses (a) restricted to less than or = 30-day follow-up and (b) that required at least 2 fills of each prescription. CONCLUSIONS AND RELEVANCE: When treating pain in older adults taking opioids, the addition of gabapentin did not increase mortality risk relative to addition of TCAs or duloxetine. However, providers should be cognizant of a small increased risk of major medical complications among opioid users initiating gabapentin compared to those initiating TCAs or duloxetine.

The effects of telehealth-delivered mindfulness meditation, cognitive therapy, and behavioral activation for chronic low back pain: a randomized clinical trial.

BACKGROUND: Chronic low back pain (CLBP) is a significant problem affecting millions of people worldwide. Three widely implemented psychological techniques used for CLBP management are cognitive therapy (CT), mindfulness meditation (MM), and behavioral activation (BA). This study aimed to evaluate the relative immediate (pre- to post-treatment) and longer term (pre-treatment to 3- and 6-month follow-ups) effects of group, videoconference-delivered CT, BA, and MM for CLBP. METHODS: This is a secondary analysis of a three-arm, randomized clinical trial comparing the effects of three active treatments-CT, BA, and MM-with no inert control condition. Participants were N = 302 adults with CLBP, who were randomized to condition. The primary outcome was pain interference, and other secondary outcomes were also examined. The primary study end-point was post-treatment. Intent-to-treat analyses were undertaken for each time point, with the means of the changes in outcomes compared among the three groups using an analysis of variance (ANOVA). Effect sizes and confidence intervals are also reported. RESULTS: Medium-to-large effect size reductions in pain interference were found within BA, CT, and MM (ds from - .71 to - 1.00), with gains maintained at both follow-up time points. Effect sizes were generally small to medium for secondary outcomes for all three conditions (ds from - .20 to - .71). No significant between-group differences in means or changes in outcomes were found at any time point, except for change in sleep disturbance from pre- to post-treatment, improving more in BA than MM (d = - .49). CONCLUSIONS: The findings from this trial, one of the largest telehealth trials of psychological treatments to date, critically determined that group, videoconference-delivered CT, BA, and MM are effective for CLBP and can be implemented in clinical practice to improve treatment access. The pattern of results demonstrated similar improvements across treatments and outcome domains, with effect sizes consistent with those observed in prior research testing in-person delivered and multi-modal psychological pain treatments. Thus, internet treatment delivery represents a tool to scale up access to evidence-based chronic pain treatments and to overcome widespread disparities in healthcare. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03687762.

The Moderating Effects of Cognitive Processes on Pain-related Outcomes.

Although evidence supports the importance of pain-related thoughts (ie, cognitive content, or what people think) as predictors of pain and pain-related function, evidence regarding the role of cognitive processes (ie, how people think about pain, eg, by accepting pain, not making judgments about pain, or being absorbed by the pain experience) in adjustment to chronic pain is in its early stages. Using baseline data from a clinical trial of individuals with chronic low back pain (N = 327), the study aimed to increase knowledge regarding the associations between cognitive processes, pain intensity, pain interference, and depression. The results indicate that a number of cognitive processes are significantly related to pain intensity when controlling for catastrophizing, although the pattern of associations found was opposite to those anticipated. One cognitive process (pain absorption) was found to be significantly associated with pain interference, and 9 of 10 cognitive processes were significantly associated with depression when controlling for catastrophizing. In each case, the processes thought to be adaptive were negatively associated with pain interference and depression, and processes thought to be maladaptive evidenced the opposite pattern. The findings are consistent with-but do not prove, given the cross-sectional nature of the data-the possibility that cognitive processes play an important role in adjustment to chronic pain. The potential role these variables play in depression was particularly noteworthy. Longitudinal and experimental studies to evaluate the causal nature of the associations identified are warranted. PERSPECTIVE: The study findings highlight the potential importance of cognitive process variables (ie, how people think) in adjustment to chronic pain. Research to evaluate cognitive processes as potential mechanism variables in pain treatment is warranted.

A technology-enabled multi-disciplinary team-based care model for the management of Long COVID and other fatiguing illnesses within a federally qualified health center: protocol for a two-arm, single-blind, pragmatic, quality improvement professional cluster randomized controlled trial.

BACKGROUND: The clinical burden of Long COVID, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and other post-infectious fatiguing illnesses (PIFI) is increasing. There is a critical need to advance understanding of the effectiveness and sustainability of innovative approaches to clinical care of patients having these conditions. METHODS: We aim to assess the effectiveness of a Long COVID and Fatiguing Illness Recovery Program (LC&FIRP) in a two-arm, single-blind, pragmatic, quality improvement, professional cluster, randomized controlled trial in which 20 consenting clinicians across primary care clinics in a Federally Qualified Health Center system in San Diego, CA, will be randomized at a ratio of 1:1 to either participate in (1) weekly multi-disciplinary team-based case consultation and peer-to-peer sharing of emerging best practices (i.e., teleECHO (Extension for Community Healthcare Outcomes)) with monthly interactive webinars and quarterly short courses or (2) monthly interactive webinars and quarterly short courses alone (a control group); 856 patients will be assigned to participating clinicians (42 patients per clinician). Patient outcomes will be evaluated according to the study arm of their respective clinicians. Quantitative and qualitative outcomes will be measured at 3- and 6-months post-baseline for clinicians and every 3-months post assignment to a participating clinician for patients. The primary patient outcome is change in physical function measured using the Patient-Reported Outcomes Measurement Information System (PROMIS)-29. Analyses of differences in outcomes at both the patient and clinician levels will include a linear mixed model to compare change in outcomes from baseline to each post-baseline assessment between the randomized study arms. A concurrent prospective cohort study will compare the LC&FIRP patient population to the population enrolled in a university health system. Longitudinal data analysis approaches will allow us to examine differences in outcomes between cohorts. DISCUSSION: We hypothesize that weekly teleECHO sessions with monthly interactive webinars and quarterly short courses will significantly improve clinician- and patient-level outcomes compared to the control group. This study will provide much needed evidence on the effectiveness of a technology-enabled multi-disciplinary team-based care model for the management of Long COVID, ME/CFS, and other PIFI within a federally qualified health center. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05167227 . Registered on December 22, 2021.

Postacute Sequelae of SARS-CoV-2: Musculoskeletal Conditions and Pain.

Musculoskeletal and pain sequelae of COVID-19 are common in both the acute infection and patients experiencing longer term symptoms associated with recovery, known as postacute sequelae of COVID-19 (PASC). Patients with PASC may experience multiple manifestations of pain and other concurrent symptoms that complicate their experience of pain. In this review, the authors explore what is currently known about PASC-related pain and its pathophysiology as well as strategies for diagnosis and management.

Combining Procedural and Behavioral Treatments for Chronic Low Back Pain: A Pilot Feasibility Randomized Controlled Trial.

Individual treatments for chronic low back pain (CLBP) have small magnitude effects. Combining different types of treatments may produce larger effects. This study used a 2×2 factorial randomized controlled trial (RCT) design to combine procedural and behavioral treatments for CLBP. The study aims were to: (1) assess feasibility of conducting a factorial RCT of these treatments; and (2) estimate individual and combined treatment effects of (a) lumbar radiofrequency ablation (LRFA) of the dorsal ramus medial branch nerves (vs. a simulated LRFA control procedure) and (b) Activity Tracker-Informed Video-Enabled Cognitive Behavioral Therapy program for CLBP (AcTIVE-CBT) (vs. an educational control treatment) on back-related disability at 3 months post-randomization. Participants (n=13) were randomized in a 1:1:1:1 ratio. Feasibility goals included an enrollment proportion ≥30%, a randomization proportion ≥80%, and a ≥80% proportion of randomized participants completing the 3-month Roland-Morris Disability Questionnaire (RMDQ) primary outcome endpoint. An intent-to-treat analysis was used. The enrollment proportion was 62%, the randomization proportion was 81%, and all randomized participants completed the primary outcome. Though not statistically significant, there was a beneficial, moderate-magnitude effect of LRFA vs. control on 3-month RMDQ (-3.25 RMDQ points; 95% CI: -10.18, 3.67). There was a significant, beneficial, large-magnitude effect of AcTIVECBT vs. control (-6.29, 95% CI: -10.97, -1.60). Though not statistically significant, there was a beneficial, large effect of LRFA+AcTIVE-CBT vs. control (-8.37; 95% CI: -21.47, 4.74). We conclude that it is feasible to conduct an RCT combining procedural and behavioral treatments for CLBP.

Short partial doffs of release/relock sockets may effectively stabilize limb fluid volume in prosthesis users with transtibial amputation.

BACKGROUND: A challenge often faced by people with lower extremity amputation is management of prosthetic socket fit due to changes in fluid volume within their residual limb. Prior research suggests that intermittently doffing the prosthetic socket may help stabilize daily residual limb fluid volume. METHODS: To assess the effects of partial doff duration on residual limb fluid volume retention, participants with transtibial amputation were tested by walking on a treadmill in a controlled, laboratory setting under three conditions. An automated system to release the locking pin and enlarge the socket was used to produce the partial doffing. Percent limb fluid volume changes after partial doffing for 4 min (Short Rest) and for 10 min (Long Rest) were compared with no partial doffing (No Release). Limb fluid volume was monitored using bioimpedance analysis. FINDINGS: Mean percent fluid volume changes in the posterior region were  -1.2% for No Release, 2.7% for Short Rest, and 1.0% for Long Rest. Short and Long Rests had larger increases than No Release (P = 0.005 and 0.03, respectively); Short and Long Rests were not statistically different (P = 0.10). Eight of the thirteen participants experienced a higher percent fluid volume gain for both release protocols while four experienced a higher percent fluid volume gain for only one release protocol. INTERPRETATION: A partial doff duration as short as 4 min may be an effective strategy to stabilize limb fluid volume in prosthesis users with transtibial amputation. Trials in at-home settings should be pursued.

Targeted muscle reinnervation and regenerative peripheral nerve interfaces for pain prophylaxis and treatment: A systematic review.

OBJECTIVE: Nerve pain frequently develops following amputations and peripheral nerve injuries. Two innovative surgical techniques, targeted muscle reinnervation (TMR) and regenerative peripheral nerve interfaces (RPNI), are rapidly gaining popularity as alternatives to traditional nerve management, but their effectiveness is unclear. LITERATURE SURVEY: A review of literature pertaining to TMR and RPNI pain results was conducted. PubMed and MEDLINE electronic databases were queried. METHODOLOGY: Studies were included if pain outcomes were assessed after TMR or RPNI in the upper or lower extremity, both for prophylaxis performed at the time of amputation and for treatment of postamputation pain. Data were extracted for evaluation. SYNTHESIS: Seventeen studies were included, with 14 evaluating TMR (366 patients) and three evaluating RPNI (75 patients). Of these, one study was a randomized controlled trial. Nine studies had a mean follow-up time of at least 1 year (range 4-27.6 months). For pain treatment, TMR and RPNI improved neuroma pain in 75%-100% of patients and phantom limb pain in 45%-80% of patients, averaging a 2.4-6.2-point reduction in pain scores on the numeric rating scale postoperatively. When TMR or RPNI was performed prophylactically, many patients reported no neuroma pain (48%-100%) or phantom limb pain (45%-87%) at time of follow-up. Six TMR studies reported Patient-Reported Outcomes Measurement Information System (PROMIS) scores assessing pain intensity, behavior, and interference, which consistently showed a benefit for all measures. Complication rates ranged from 13% to 31%, most frequently delayed wound healing. CONCLUSIONS: Both TMR and RPNI may be beneficial for preventing and treating pain originating from peripheral nerve dysfunction compared to traditional techniques. Randomized trials with longer term follow-up are needed to directly compare the effectiveness of TMR and RPNI with traditional nerve management techniques.

Treatment With Opioids Is Not Associated With Poor Outcomes Among Older Adults With Lumbar Spinal Stenosis Receiving Epidural Injections.

STUDY DESIGN: Secondary analysis of a randomized controlled trial. OBJECTIVE: To assess how baseline treatment with opioids is associated with pain and function in older adults with lumbar spinal stenosis who receive epidural injections. SUMMARY OF BACKGROUND DATA: Data were obtained from the Lumbar Epidural Steroid injections for Spinal Stenosis trial, a double-blind, multisite, randomized controlled trial. METHODS: Baseline treatment with opioids was assessed from electronic medical record prescription pharmacy data or from health utilization records collected from patients. We calculated adjusted changes in back pain numerical rating scale, leg pain numerical rating scale, and back-related disability (Roland Morris Disability Questionnaire scores) from baseline to three weeks and to six weeks among patients treated and not treated with opioids at baseline using generalized linear regression. RESULTS: Baseline treatment with opioids was not significantly associated with back pain intensity (adjusted difference in means at three weeks of follow-up between patients treated with opioids at baseline versus not [±95% CI, 0.1 (-0.7, 0.7)], leg pain intensity [-0.2 (-0.9, 0.4)], or back-related function [-0.8 (-2.1, 0.4)]. We found similar results at six weeks of follow-up. CONCLUSIONS: Among older adults with lumbar spinal stenosis who are receiving epidural injections, those treated with opioids at baseline had similar outcomes to those who were not.

Predicting decompression surgery by applying multimodal deep learning to patients' structured and unstructured health data.

BACKGROUND: Low back pain (LBP) is a common condition made up of a variety of anatomic and clinical subtypes. Lumbar disc herniation (LDH) and lumbar spinal stenosis (LSS) are two subtypes highly associated with LBP. Patients with LDH/LSS are often started with non-surgical treatments and if those are not effective then go on to have decompression surgery. However, recommendation of surgery is complicated as the outcome may depend on the patient's health characteristics. We developed a deep learning (DL) model to predict decompression surgery for patients with LDH/LSS. MATERIALS AND METHOD: We used datasets of 8387 and 8620 patients from a prospective study that collected data from four healthcare systems to predict early (within 2 months) and late surgery (within 12 months after a 2 month gap), respectively. We developed a DL model to use patients' demographics, diagnosis and procedure codes, drug names, and diagnostic imaging reports to predict surgery. For each prediction task, we evaluated the model's performance using classical and generalizability evaluation. For classical evaluation, we split the data into training (80%) and testing (20%). For generalizability evaluation, we split the data based on the healthcare system. We used the area under the curve (AUC) to assess performance for each evaluation. We compared results to a benchmark model (i.e. LASSO logistic regression). RESULTS: For classical performance, the DL model outperformed the benchmark model for early surgery with an AUC of 0.725 compared to 0.597. For late surgery, the DL model outperformed the benchmark model with an AUC of 0.655 compared to 0.635. For generalizability performance, the DL model outperformed the benchmark model for early surgery. For late surgery, the benchmark model outperformed the DL model. CONCLUSIONS: For early surgery, the DL model was preferred for classical and generalizability evaluation. However, for late surgery, the benchmark and DL model had comparable performance. Depending on the prediction task, the balance of performance may shift between DL and a conventional ML method. As a result, thorough assessment is needed to quantify the value of DL, a relatively computationally expensive, time-consuming and less interpretable method.

Estimating individualized treatment effects using a risk-modeling approach: an application to epidural steroid injections for lumbar spinal stenosis.

ABSTRACT: Conventional "1-variable-at-a-time" analyses to identify treatment effect modifiers are often underpowered and prone to false-positive results. This study used a "risk-modeling" approach guided by the Predictive Approaches to Treatment effect Heterogeneity (PATH) Statement framework: (1) developing and validating a multivariable model to estimate predicted future back-related functional limitations as measured by the Roland-Morris Disability Questionnaire (RMDQ) and (2) stratifying patients from a randomized controlled trial (RCT) of lumbar epidural steroid injections (LESIs) for the treatment of lumbar spinal stenosis into subgroups with different individualized treatment effects on RMDQ scores at the 3-week follow-up. Model development and validation were conducted in a cohort (n = 3259) randomly split into training and testing sets in a 4:1 ratio. The model was developed in the testing set using linear regression with least absolute shrinkage and selection regularization and 5-fold cross-validation. The model was then applied in the testing set and subsequently in patients receiving the control treatment in the RCT of LESI. R2 values in the training set, testing set, and RCT were 0.38, 0.32, and 0.34, respectively. There was statistically significant modification ( P = 0.03) of the LESI treatment effect according to predicted risk quartile, with clinically relevant LESI treatment effect point estimates in the 2 quartiles with greatest predicted risk (-3.7 and -3.3 RMDQ points) and no effect in the lowest 2 quartiles. A multivariable risk-modeling approach identified subgroups of patients with lumbar spinal stenosis with a clinically relevant treatment effect of LESI on back-related functional limitations.

Improving Power and Accuracy in Randomized Controlled Trials of Pain Treatments by Accounting for Concurrent Analgesic Use.

The 0 to 10 numeric rating scale of pain intensity is a standard outcome in randomized controlled trials (RCTs) of pain treatments. For individuals taking analgesics, there may be a disparity between "observed" pain intensity (pain intensity with concurrent analgesic use) and pain intensity without concurrent analgesic use (what the numeric rating scale would be had analgesics not been taken). Using a contemporary causal inference framework, we compare analytic methods that can potentially account for concurrent analgesic use, first in statistical simulations, and second in analyses of real (non-simulated) data from an RCT of lumbar epidural steroid injections. The default analytic method was ignoring analgesic use, which is the most common approach in pain RCTs. Compared to ignoring analgesic use and other analytic methods, simulations showed that a quantitative pain and analgesia composite outcome based on adding 1.5 points to pain intensity for those who were taking an analgesic (the QPAC1.5) optimized power and minimized bias. Analyses of real RCT data supported the results of the simulations, showing greater power with analysis of the QPAC1.5 as compared to ignoring analgesic use and most other methods examined. We propose alternative methods that should be considered in the analysis of pain RCTs. PERSPECTIVE: This article presents the conceptual framework behind a new quantitative pain and analgesia composite outcome, the QPAC1.5, and the results of statistical simulations and analyses of trial data supporting improvements in power and bias using the QPAC1.5. Methods of this type should be considered in the analysis of pain RCTs.

A novel portable sensor to monitor bodily positions and activities in transtibial prosthesis users.

BACKGROUND: Step activity monitors provide insight into the amount of physical activity prosthesis users conduct but not how they use their prosthesis. The purpose of this research was to help fill this void by developing and testing a technology to monitor bodily position and type of activity. METHODS: Thin inductive distance sensors were adhered to the insides of sockets of a small group of transtibial prosthesis users, two at proximal locations and two at distal locations. An in-lab structured protocol and a semi-structured out-of-lab protocol were video recorded, and then participants wore the sensing system for up to 7 days. A data processing algorithm was developed to identify sit, seated shift, stand, standing weight-shift, walk, partial doff, and non-use. Sensed distance data from the structured and semi-structured protocols were compared against the video data to characterize accuracy. Bodily positions and activities during take-home testing were tabulated to characterize participants' use of the prosthesis. FINDINGS: Sit and walk detection accuracies were above 95% for all four participants tested. Stand detection accuracy was above 90% for three participants and 62.5% for one participant. The reduced accuracy may have been due to limited stand data from that participant. Step count was not proportional to active use time (sum of stand, walk, and standing weight-shift times). INTERPRETATION: Step count may provide an incomplete picture of prosthesis use. Larger studies should be pursued to investigate how bodily position and type of activity may facilitate clinical decision-making and improve the lives of people with lower limb amputation.

The Lumbar Stenosis Prognostic Subgroups for Personalizing Care and Treatment (PROSPECTS) study: protocol for an inception cohort study.

BACKGROUND: Lumbar spinal stenosis (LSS) is a common degenerative condition that contributes to back and back-related leg pain in older adults. Most patients with symptomatic LSS initially receive non-operative care before surgical consultation. However, there is a scarcity of data regarding prognosis for patients seeking non-surgical care. The overall goal of this project is to develop and evaluate a clinically useful model to predict long-term physical function of patients initiating non-surgical care for symptomatic LSS. METHODS: This is a protocol for an inception cohort study of adults 50 years and older who are initiating non-surgical care for symptomatic LSS in a secondary care setting. We plan to recruit up to 625 patients at two study sites. We exclude patients with prior lumbar spine surgeries or those who are planning on lumbar spine surgery. We also exclude patients with serious medical conditions that have back pain as a symptom or limit walking. We are using weekly, automated data pulls from the electronic health records to identify potential participants. We then contact patients by email and telephone within 21 days of a new visit to determine eligibility, obtain consent, and enroll participants. We collect data using telephone interviews, web-based surveys, and queries of electronic health records. Participants are followed for 12 months, with surveys completed at baseline, 3, 6, and 12 months. The primary outcome measure is the 8-item PROMIS Physical Function (PF) Short Form. We will identify distinct phenotypes using PROMIS PF scores at baseline and 3, 6, and 12 months using group-based trajectory modeling. We will develop and evaluate the performance of a multivariable prognostic model to predict 12-month physical function using the least absolute shrinkage and selection operator and will compare performance to other machine learning methods. Internal validation will be conducted using k-folds cross-validation. DISCUSSION: This study will be one of the largest cohorts of individuals with symptomatic LSS initiating new episodes of non-surgical care. The successful completion of this project will produce a cross-validated prognostic model for LSS that can be used to tailor treatment approaches for patient care and clinical trials.

Performance of an auto-adjusting prosthetic socket during walking with intermittent socket release.

Introduction: A challenge in the engineering of auto-adjusting prosthetic sockets is to maintain stable operation of the control system while users change their bodily position and activity. The purpose of this study was to test the stability of a socket that automatically adjusted socket size to maintain fit. Socket release during sitting was conducted between bouts of walking. Methods: Adjustable sockets with sensors that monitored distance between the liner and socket were fabricated. Motor-driven panels and a microprocessor-based control system adjusted socket size during walking to maintain a target sensed distance. Limb fluid volume was recorded continuously. During eight sit/walk cycles, the socket panels were released upon sitting and then returned to position for walking, either the size at the end of the prior bout or a size 1.0% larger in volume. Results: In six transtibial prosthesis users, the control system maintained stable operation and did not saturate (move to and remain at the end of the actuator's range) during 98% of the walking bouts. Limb fluid volume changes generally matched the panel position changes executed by the control system. Conclusions: Stable operation of the control system suggests that the auto-adjusting socket is ready for testing in users' at-home settings.

Cyclic socket enlargement and reduction during walking to minimize limb fluid volume loss in transtibial prosthesis users.

The purpose of this research was to pursue an innovative cyclic panel-pull strategy during ambulation to minimize limb fluid volume loss in transtibial prosthesis users. Participants' traditional socket shapes were duplicated, and test sockets prepared with three adjustable motor-driven panels that were controlled by a microprocessor. After donning the prosthesis, participants' liners were fastened to the panels. During a 40 min test session, participants conducted three cycles of sitting (5 min) and walking (8 min). During the 5th and 6th min of each cycle of walking, the panels were cyclically pulled outward in late stance phase, decreasing pressure on the residual limb. Panels were returned to their original position in swing phase. Eight of twelve participants gained more fluid volume while walking when panel-pull was added than when it was removed. When the liner was uncoupled from the panels and panel-pull was executed, eight of twelve participants gained less fluid volume compared to when the liner was fastened to the panels. Panel-pull may facilitate limb fluid volume retention in transtibial prosthesis users. Efforts to simplify the design so that it can be implemented in long-term testing during at-home use should be considered.

Long-term effectiveness of epidural steroid injections after new episodes of low back pain in older adults.

BACKGROUND: There is limited research on the long-term effectiveness of epidural steroid injections (ESI) in older adults despite the high prevalence of back and leg pain in this age group. We tested the hypotheses that older adults undergoing ESI, compared to patients not receiving ESI: (1) have worse pain, disability and quality of life ('outcomes') pre-ESI, (2) have improved outcomes after ESI and (3) have improved outcomes due to a specific ESI effect. METHODS: We prospectively studied patients ≥65 years old presenting to primary care with new episodes of back pain in three US healthcare systems (BOLD registry). Outcomes were leg and back pain intensity, disability and quality of life, assessed at baseline and 3-, 6-, 12- and 24-month follow-ups. We categorized participants as: (1) ESI within 6 months from the index visit (n = 295); (2) no ESI within 6 months (n = 4809); (3) no ESI within 6 months, propensity-score matched to group 1 (n = 483). We analysed the data using linear regression and Generalized Estimating Equations. RESULTS: Pain intensity, disability and quality of life at baseline were significantly worse at baseline in ESI patients (group 1) than in group 2. The improvement from baseline to 24 months in all outcomes was statistically significant for group 1. However, no statistically significant differences were observed between outcome trajectories for the propensity-score matched groups 1 and 3. CONCLUSIONS: Older adults treated with ESI have long-term improvement. However, the improvement is unlikely the result of a specific ESI effect. SIGNIFICANCE: In this large, two-year, prospective study in older adults with a new episode of low back pain, back pain, leg pain, disability and quality of life improved after epidural steroid injections; however, propensity-score matching revealed that the improvement was unlikely the result of a specific effect of the injections, indicating that epidural steroids are unlikely to provide long-term benefits in older adults with new episodes of back and leg pain.

The Flares of Low back pain with Activity Research Study (FLAReS): study protocol for a case-crossover study nested within a cohort study.

BACKGROUND: Although it is generally accepted that physical activity and flares of low back pain (LBP) are related, evidence for the directionality of this association is mixed. The Flares of Low back pain with Activity Research Study (FLAReS) takes a novel approach to distinguish the short-term effects of specific physical activities on LBP flares from the cumulative effects of such activities, by conducting a longitudinal case-crossover study nested within a cohort study. The first aim is to estimate the short-term effects (≤ 24 h) of specific physical activities on LBP flares among Veterans in primary care in the Veterans Affairs healthcare system. The second aim is to estimate the cumulative effects of specific activities on LBP-related functional limitations at 1-year follow-up. METHODS: Up to 550 adults of working age (18-65 years) seen for LBP in primary care complete up to 36 "Scheduled" surveys over 1-year follow-up, and also complete unscheduled "Flare Window" surveys after the onset of new flares. Each survey asks about current flares and other factors associated with LBP. Surveys also inquire about activity exposures over the 24 h, and 2 h, prior to the time of survey completion (during non-flare periods) or prior to the time of flare onset (during flares). Other questions evaluate the number, intensity, duration, and/or other characteristics of activity exposures. Other exposures include factors related to mood, lifestyle, exercise, concurrent treatments, and injuries. Some participants wear actigraphy devices for weeks 1-4 of the study. The first aim will examine associations between 10 specific activity categories and participant-reported flares over 1-year follow-up. The second aim will examine associations between the frequency of exposure to 10 activity categories over weeks 1-4 of follow-up and long-term functional limitations at 12 months. All analyses will use a biopsychosocial framework accounting for potential confounders and effect modifiers. DISCUSSION: FLAReS will provide empirically derived estimates of both the short-term and cumulative effects of specific physical activities for Veterans with LBP, helping to better understand the role of physical activities in those with LBP. TRIAL REGISTRATION: ClinicalTrials.gov NCT04828330 , registered April 2, 2021.