Preliminary Characterization of Age and Chronic Low Back Pain Effects on Multimodal Pain Sensitivity: A Comparison Study in Older Adults with and Without Chronic Low Back Pain.

Though pain sensitivity impairments contribute to chronic pain in younger adults, it is unclear if pain hypersensitivity manifests with aging and is heightened in the geriatric chronic low back pain population. The cross-sectional study preliminarily addressed this gap by measuring pain sensitivity in older adults with chronic low back pain (n = 25) as well as pain-free sex-matched older (n = 25) and younger adults (n = 25). Pain sensitivity was quantified by 8 distinct measures that were subdivided as static (ie, pressure pain thresholds, heat pain thresholds, fixed mechanical pain, and fixed cold pain) and dynamic pain sensitivity (ie, mechanical temporal summation, thermal ramp and hold, heat pain aftersensations, and conditioned pain modulation). Test-retest reliability values for pain sensitivity ranged from moderate to excellent (intraclass correlation coefficients ≥ .500; p's < .05). The main effect for the group was significant (partial η2 = .413, P < .001), revealing between-group differences in pain sensitivity on 5 out of 8 tests (p's ≤ .043). Predominantly, both older adult groups demonstrated increased pain facilitation and decreased pain inhibition during dynamic pain sensitivity testing compared to pain-free younger adults (p's ≤ .044). Despite qualitative differences, static and dynamic pain sensitivity responses were statistically similar between older adults with and without chronic LBP (p's > .05). Findings suggest pain sensitivity can be reliably measured in older adults and that pain hypersensitivity develops with chronological aging, providing partial support for the theory that pain hypersensitivity may impact geriatric chronic pain populations. Further study is needed to more definitively parse out whether pain hypersensitivity is comparatively heightened in older adults with chronic LBP beyond the influence of chronological aging. PERSPECTIVE: This article establishes that surrogate measures of centrally mediated pain sensitization are heightened with aging. Impaired endogenous pain modulation may influence chronic pain development, maintenance, treatment efficacy, and/or ensuing disability, necessitating research to comprehensively characterize how pain hypersensitivity contributes to geriatric chronic pain conditions.

Through the Lens of Movement-Evoked Pain: A Theoretical Framework of the "Pain-Movement Interface" to Guide Research and Clinical Care for Musculoskeletal Pain Conditions.

Over 120 million Americans report experiencing pain in the past 3 months. Among these individuals, 50 million report chronic pain and 17 million report pain that limits daily life or work activities on most days (ie, high-impact chronic pain). Musculoskeletal pain conditions in particular are a major contributor to global disability, health care costs, and poor quality of life. Movement-evoked pain (MEP) is an important and distinct component of the musculoskeletal pain experience and represents an emerging area of study in pain and rehabilitation fields. This focus article proposes the "Pain-Movement Interface" as a theoretical framework of MEP that highlights the interface between MEP, pain interference, and activity engagement. The goal of the framework is to expand knowledge about MEP by guiding scientific inquiry into MEP-specific pathways to disability, high-risk clinical phenotypes, and underlying individual influences that may serve as treatment targets. This framework reinforces the dynamic nature of MEP within the context of activity engagement, participation in life and social roles, and the broader pain experience. Recommendations for MEP evaluation, encompassing the spectrum from high standardization to high patient specificity, and MEP-targeted treatments are provided. Overall, the proposed framework and recommendations reflect the current state of science in this emerging area of study and are intended to support future efforts to optimize musculoskeletal pain management and enhance patient outcomes. PERSPECTIVE: Movement-evoked pain (MEP) is a distinct component of the musculoskeletal pain experience and emerging research area. This article introduces the "Pain-Movement Interface" as a theoretical framework of MEP, highlighting the interface between MEP, pain interference, and activity engagement. Evaluating and treating MEP could improve rehabilitation approaches and enhance patient outcomes.

A Clinical Measure of Trunk Neuromuscular Function Predicts Falling in Older Adults With Chronic Low Back Pain.

BACKGROUND AND PURPOSE: Older adults with low back pain (LBP) are at risk for falling, but condition-specific mechanisms are unknown. Trunk neuromuscular function is critical for maintaining balance during mobility tasks and is often impaired in older adults with LBP. The purpose of this study was to assess whether aberrant lumbopelvic movements (or aberrant movements), a clinical index of trunk neuromuscular function, were associated with increased fall risk among older adults with chronic LBP over a 12-month follow-up period. METHODS: This study analyzed data from a prospective cohort study of 250 community-dwelling older adults with chronic LBP. Participants were screened for 4 aberrant movements during 3 trials of forward flexion from a standing position: instability catch, painful arc, altered lumbopelvic rhythm, and Gower's sign. Aberrant movements were totaled to yield a summary score (ie, 0-4). Prospective falls were monitored via monthly fall calendars for 12 months. A generalized linear model with Poisson distribution and log link function was used to evaluate the association between aberrant movements and prospective fall risk. Age, sex, body mass index, LBP intensity, dynamic balance performance, prior falls, anxiolytic medication usage, and hip osteoarthritis characteristics were included as covariates in the model. RESULTS: Baseline aberrant movements were independently associated with greater fall risk (risk ratio = 1.249, 95% CI = 1.047-1.491, P = .014); each 1-unit increase in aberrant movement score imparted a 24.9% increase in the risk of falling. CONCLUSIONS: Aberrant movements increased the risk of falling among older adults with chronic LBP over a 1-year span.

Examining Psychological Factors as Contributors to Pain, Disability, and Physical Function in Geriatric Chronic Low Back Pain: A Prospective Analysis of the Delaware Spine Studies Cohort.

In younger populations, risk factors from psychologically-focused theoretical models have become accepted as primary drivers behind the persistence of low back pain (LBP), but these risk factors have not been thoroughly assessed in older adult populations (60-85 years). To address this knowledge gap, we sought to examine longitudinal associations between both general and pain-related psychological risk factors and future pain intensity, LBP-related disability, and physical function (gait speed) outcomes in older adults with chronic LBP (n = 250). Questionnaires for general (ie, depressive symptoms) and pain-related psychological risk factors (ie, fear-avoidance beliefs, pain catastrophizing, and kinesiophobia) were collected at baseline. Questionnaire values were entered into principal component analysis to yield a combined psychological component score. LBP intensity (pain thermometers), LBP-related disability (Quebec Back Pain Disability Scale), and gait speed were measured at baseline and 12-month follow-up. Multiple linear regression was used to examine adjusted associations between baseline psychological component scores and each prospective outcome. The baseline psychological component score failed to independently predict 12-month LBP-related disability and gait speed after adjustment for baseline outcomes. Though the psychological component score was associated with 12-month LBP intensity after adjusting for baseline LBP intensity, this association diminished with full adjustment for other baseline characteristics. Cumulatively, general and pain-related psychological risk factors did not independently predict longitudinal pain, disability, and physical function outcomes in this cohort. Compared to younger populations with this condition, general and pain-related psychological risk factors may have less influence on the maintenance of chronic LBP in older adults. PERSPECTIVE: This article failed to establish consistent independent relationships between psychological factors and worse longitudinal pain, disability, and physical function outcomes in older adults with chronic LBP. The findings highlight a need to determine other age-specific biopsychosocial risk factors that may impact the maintenance of chronic pain in this patient population.

Construct validity of movement-evoked pain operational definitions in older adults with chronic low back pain.

OBJECTIVE: Movement-evoked pain (MeP) may predispose the geriatric chronic low back pain (LBP) population to health decline. As there are differing operational definitions for MeP, the question remains as to whether these different definitions have similar associations with health outcomes in older adults with chronic LBP. DESIGN: Cross-sectional analysis of an observational study. SETTING: Clinical research laboratory. SUBJECTS: 226 older adults with chronic LBP. METHODS: This secondary analysis used baseline data from a prospective cohort study (n = 250). LBP intensity was collected before and after the repeated chair rise test, stair climbing test, and 6-minute walk test; MeP change scores (ie, sum of pretest pain subtracted from posttest pain) and aggregated posttest pain (ie, sum of posttest pain) variables were calculated. LBP-related disability and self-efficacy were measured by the Quebec Back Pain Disability Scale (QBPDS) and Low Back Activity Confidence Scale (LOBACS), respectively. Physical function was measured with the Health ABC Performance Battery. Robust regression with HC3 standard errors was used to evaluate adjusted associations between both MeP variables and disability, self-efficacy, and physical function. RESULTS: Greater aggregated posttest MeP was independently associated with worse disability (b = 0.593, t = 2.913, P = .004), self-efficacy (b = -0.870, t = -3.110, P = .002), and physical function (b = -0.017, t = -2.007, P = .039). MeP change scores were not associated with any outcome (all P > .050). CONCLUSIONS: Aggregate posttest MeP was linked to poorer health outcomes in older adults with chronic LBP, but MeP change scores were not. Future studies should consider that the construct validity of MeP paradigms partially depends on the chosen operational definition.

Movement-Evoked Pain Versus Widespread Pain: A Longitudinal Comparison in Older Adults With Chronic Low Back Pain From the Delaware Spine Studies.

It is currently unknown which pain-related factors contribute to long-term disability and poorer perceived health among older adults with chronic low back pain (LBP). This investigation sought to examine the unique influence of movement-evoked pain (MeP) and widespread pain (WP) on longitudinal health outcomes (ie, gait speed, perceived disability, and self-efficacy) in 250 older adults with chronic LBP. MeP was elicited with 3 standardized functional tests, while presence of WP was derived from the McGill Pain Map. Robust regression with HC3 standard errors was used to examine associations between these baseline pain variables and health outcomes at 12-month follow-up. Covariates for these models included age, sex, body mass index, resting and recall LBP intensity, LBP duration, depression, pain catastrophizing, and baseline outcome (eg, baseline gait speed). Greater MeP was independently associated with worse 12-month LBP-related disability (b = .384, t = 2.013, P = .046) and poorer self-efficacy (b = -.562, t = -2.074, P = .039); but not gait speed (P > .05). In contrast, WP and resting and recall LBP intensity were not associated with any prospective health outcome after adjustment (all P > .05). Compared to WP and resting and recall LBP intensity, MeP is most strongly related to longitudinal health outcomes in older adults with chronic LBP. PERSPECTIVE: This article establishes novel independent associations between MeP and worse perceived disability and self-efficacy at 12-months in older adults with chronic LBP. MeP likely has biopsychosocial underpinnings and consequences and may therefore be an important determinant of health outcomes in LBP and other geriatric chronic pain populations.

Trajectories of Physical Function and Disability Over 12 Months in Older Adults With Chronic Low Back Pain.

BACKGROUND AND PURPOSE: Understanding prognosis is critical for clinical care and health policy initiatives. The purpose of this study was to determine whether distinct prognostic trajectories of physical function and disability exist in a cohort of 245 community-dwelling older adults with chronic low back pain (LBP), and to characterize the demographic, health, and pain-related profiles of each trajectory subgroup. METHODS: All participants underwent standard clinic examinations at baseline, 3 months, 6 months, and 12 months. At each time point, the Late Life Function & Disability Instrument (LLFDI) was used to measure general physical function (LLFDI Function) and disability (LLFDI Disability-Limitation); the Quebec LBP Disability Questionnaire was used to measure disability due to pain. Growth mixture modeling (GMM) was performed on each outcome to identify distinct trajectory classes/subgroups; baseline demographic (eg, age and sex), health (eg, comorbidities, depressive symptoms, and physical activity level), and pain-related (eg, LBP intensity, pain-related fear, and pain catastrophizing) characteristic profiles were compared across subgroups. RESULTS: GMM statistics revealed an optimal number of 3 to 4 trajectory subgroups, depending on the outcome examined. Subgroups differed across demographic, health, and pain-related characteristics; the classes with the most favorable prognoses had consistent profile patterns: fewer depressive symptoms, fewer comorbidities, higher physical activity levels, lower LBP intensities, less pain-related fear, and less pain catastrophizing. CONCLUSION: Our findings indicate that several distinct trajectory subgroups exist that would have been masked by observing mean cohort change alone. Furthermore, subgroup characteristic profiles may help clinicians identify likely prognostic trajectories for their patients. Future research should focus on identifying modifiable risk factors that best predict group membership, and tailoring interventions to mitigate the risk of poor prognosis.

Aberrant Lumbopelvic Movements Predict Prospective Functional Decline in Older Adults with Chronic Low Back Pain.

OBJECTIVE: To investigate if clinically observable aberrant lumbopelvic movements are associated with physical function at 12-month follow-up in older adults with chronic low back pain (CLBP), both directly and indirectly through baseline physical function. DESIGN: Secondary analysis of a yearlong prospective cohort study. SETTING: Clinical Research Laboratory. PARTICIPANTS: Community-dwelling older adults with CLBP (N=250). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Data from 239 participants were analyzed. Participants were screened at baseline for aberrant lumbopelvic movements during active trunk flexion; total observable aberrant movements were recorded and summed (range 0-4). Latent constructs of physical function were developed from an array of perception-based and performance-based outcome measures at baseline and 12 months, respectively. Structural Equation Modeling was used to assess the direct effect of baseline aberrant movement score on the latent construct of 12-month physical function, and its indirect effect through baseline physical function. RESULTS: Aberrant movements were present in most participants (64.7%) and had a significant negative total effect on 12-month physical function (γ= -0.278, P<.001). Aberrant movement score's direct effect and indirect effect, through baseline functioning, were significantly negatively associated with physical function at 12-months, after adjusting for covariates (γ=-0.068, P=.038; γ= -0.210, P<.001, respectively). CONCLUSIONS: Aberrant lumbopelvic movements are associated with decreased physical function at 12-month follow-up in older adults with CLBP, independent of baseline physical function and covariates. Future studies should evaluate if screening for aberrant movements may inform prognostic and interventional efforts in this patient population.

The Manual Therapy and Strengthening for the Hip (MASH) Trial: Protocol for a Multisite Randomized Trial of a Subgroup of Older Adults With Chronic Back and Hip Pain.

OBJECTIVE: Chronic low back pain (CLBP) is a disabling and costly condition for older adults that is difficult to properly classify and treat. In a cohort study, a subgroup of older adults with CLBP who had elevated hip pain and hip muscle weakness was identified; this subgroup differentiated itself by being at higher risk for future mobility decline. The primary purpose of this clinical trial is to evaluate whether a hip-focused low back pain (LBP) treatment provides better disability and physical performance outcomes for this at-risk group compared with a spine-focused LBP treatment. METHODS: This study is a multisite, single-blinded, randomized controlled, parallel arm, Phase II trial conducted across 3 clinical research sites. A total of 180 people aged between 60 and 85 years with CLBP and hip pain are being recruited. Participants undergo a comprehensive baseline assessment and are randomized into 1 of 2 intervention arms: hip-focused or spine-focused. They are treated twice weekly by a licensed physical therapist for 8 weeks and undergo follow-up assessments at 8 weeks and 6 months after randomization. Primary outcome measures include the Quebec Low Back Disability Scale and the 10-Meter Walk Test, which are measures of self-report and performance-based physical function, respectively. IMPACT: This multicenter, randomized clinical trial will determine whether a hip-focused or spine-focused physical therapist intervention results in improved disability and physical performance for a subgroup of older adults with CLBP and hip pain who are at increased risk of mobility decline. This trial will help further the development of effective interventions for this subgroup of older adults with CLBP.

A Standardized Assessment of Movement-evoked Pain Ratings Is Associated With Functional Outcomes in Older Adults With Chronic Low Back Pain.

OBJECTIVE: Despite high prevalence estimates, chronic low back pain (CLBP) remains poorly understood among older adults. Movement-evoked pain (MeP) is an understudied factor in this population that may importantly contribute to disability. This study investigated whether a novel MeP paradigm contributed to self-reported and performance-based function in older adults with CLBP. MATERIALS AND METHODS: This secondary analysis includes baseline data from 230 older adults with CLBP in the context of a prospective cohort study. The Repeated Chair Rise Test, Six Minute Walk Test, and Stair Climbing Test were used to elicit pain posttest LBP ratings were aggregated to yield the MeP variable. Self-reported and performance-based function were measured by the Late Life Function and Disability Index (LLFDI) scaled function score and Timed Up-and-Go Test (TUG), respectively. Robust regression with HC3 standard errors was used to model adjusted associations between MeP and both functional outcomes; age, sex, body mass index, and pain characteristics (ie, intensity, quality, and duration) were utilized as covariates. RESULTS: MeP was present in 81.3% of participants, with an average rating of 5.09 (SD=5.4). Greater aggregated posttest MeP was associated with decreased LLFDI scores (b=-0.30, t=-2.81, P=0.005) and poorer TUG performance (b=0.081, t=2.35, P=0.020), independent of covariates. LBP intensity, quality and duration were not associated with the LLFDI or TUG, (all P>0.05). DISCUSSION: Aggregated posttest MeP independently contributed to worse self-reported and performance-based function among older adults with CLBP. To understand long-term consequences of MeP, future studies should examine longitudinal associations between MeP and function in this population.

Hip Range of Motion and Strength Predict 12-Month Physical Function Outcomes in Older Adults With Chronic Low Back Pain: The Delaware Spine Studies.

OBJECTIVE: The objective of this study was to investigate whether poor hip range of motion (ROM) and strength predict 12-month physical function decline among older adults with chronic low back pain (LBP) and whether hip osteoarthritis modifies those relationships. METHODS: At baseline, passive ROM and strength measurements were taken for hip flexion, extension, abduction, adduction, internal rotation, and external rotation; ultrasound images and self-reported symptoms were used to evaluate hip osteoarthritis presence (eg, osteophytes and hip pain). At baseline and 12 months, performance-based (repeated chair rise, self-selected gait speed, 6-minute walk test [6MWT]) and self-reported (Quebec LBP Disability Questionnaire, Late-Life Function & Disability Instrument [LLFDI] basic and advanced lower extremity scales) physical function outcomes were assessed. Regression models were constructed for each outcome predicted by baseline hip ROM and strength measures, with adjustment for potential covariates. To avoid collinearity, hip ROM and strength measures with the strongest unadjusted correlations were included in final models. The hip osteoarthritis presence by hip ROM/strength interaction was also explored. RESULTS: Hip abduction strength predicted repeated chair rise (ß = -0.297, P < 0.001), gait speed (ß = 0.160, P = 0.003), 6MWT (ß = 0.159, P ≤ 0.001), Quebec LBP Disability Questionnaire (ß = -0.152, P = 0.003), and LLFDI basic lower extremity scale (ß = 0.171, P = 0.005) outcomes. Regarding hip ROM, extension predicted repeated chair rise (ß = -0.110, P = 0.043) and LLFDI advanced lower extremity scale (ß = 0.090, P = 0.007) outcomes, external rotation predicted gait speed (ß = 0.122, P = 0.004) outcomes, and abduction predicted LLFDI basic lower extremity scale (ß = 0.114, P = 0.026) outcomes. The hip osteoarthritis interaction was not significant for any model. CONCLUSION: Reduced hip strength and ROM predict physical function decline; hip osteoarthritis presence may not modify these relationships.

Hip osteoarthritis signs and symptoms are associated with increased fall risk among community-dwelling older adults with chronic low back pain: a prospective study.

BACKGROUND: Older adults with concurrent low back and hip pain are predisposed to reductions in physical performance and health-related quality of life. Yet no study to date has assessed whether or not coexisting hip impairments increase fall risk in older adults with chronic low back pain (CLBP). The objective of this study was to determine if hip osteoarthritis (OA) signs and symptoms per American College of Rheumatology (ACR) criteria are associated with fall risk over a 1-year span. METHODS: Falls were prospectively monitored for 1 year via fall calendars. Age, sex, body mass index (BMI), anxiolytic use, balance confidence, LBP-related disability, and prior fall history were identified as covariates. Hip pain, pain with hip internal rotation (IR), hip IR range of motion (ROM) ≥ 15°, and morning stiffness lasting ≤ 60 min were evaluated at baseline and summed to represent hip OA impairment burden. A generalized linear model with a Poisson distribution and log link function assessed the association between ACR criteria and fall risk beyond established covariates. As a secondary analysis, binary logistic regression assessed ACR criteria and the odds of falling two or more times within a year. RESULTS: Data from two-hundred and ten participants were analyzed. Hip OA signs and symptoms were present in 97.1% of the participants, and hip OA impairment burden was significantly greater (p < 0.050) in participants who fell ≥ 2 times compared to single and non-fallers. Higher hip OA impairment burden was associated with significantly increased fall risk (p = 0.001, risk ratio = 1.23, 95% CI 1.09-1.38) and odds of falling multiple times (p < 0.05, odds ratio = 1.41, 95% CI 1.01-1.95) after adjustment for covariates. CONCLUSIONS: Older adults with CLBP and concomitant hip impairments are an at-risk group for falling. Healthcare professionals should employ falls screening and preventive measures to avoid negative sequelae in this vulnerable population.