20 research outputs found
Dual Goals of Trunk Restriction and Stability are Prioritized by Individuals with Chronic Low Back Pain During a Volitional Movement
Background Individuals with chronic low back pain demonstrate impaired responses to volitional and externally-generated postural perturbations that may impact stability whilst performing activities of daily living. Understanding how balance may be impaired by strategy selection is an important consideration during rehabilitation from low back pain to prevent future injurious balance loss. Research question This cross-sectional study explored the influence of an active pain episode on volitional movement patterns and stability during a sit-to-stand task in individuals with chronic low back pain compared to those with no low back pain history. Methods Thirteen participants with low back pain who were in an active flare-up and 13 without pain sat on a height-adjusted chair and performed 5 sit-to-stand movements. Sagittal plane kinematics, kinetics, and surface electromyography were used to compute neuromuscular variables across Acceleration, Transition and Deceleration phases. Stability was assessed using times to contact of body centers of mass and pressure to base of support boundaries. Independent samples t-tests were used to examine group effects, and repeated measures analyses of variance assessed within-subjects effects across movement phases. Results Individuals with low back pain tended to restrict proximal joint motions through heightened muscle activity while increasing distal joint movement and distal muscle contributions. Individuals with low back pain used a greater driving force, indicated by a longer time to contact of the center of pressure, to achieve comparable center of mass stability. Individuals with low back pain may prioritize trunk restriction and stability through the sit-to-stand movement, possibly related to fear of pain or movement. Significance The tendency for individuals with active low back pain to restrict trunk movements may require additional effort to maintain stability. Further research should examine whether trunk restriction is related to pain-related fear of movement and whether additional cognitive resources are required to maintain movement stability
Individuals with Non-Specific Low Back Pain in an Active Episode Demonstrate Temporally Altered Torque Responses and Direction-Specific Enhanced Muscle Activity Following Unexpected Balance Perturbations
Individuals with a history of non-specific low back pain (LBP) while in a quiescent pain period demonstrate altered automatic postural responses (APRs) characterized by reduced trunk torque contributions and increased co-activation of trunk musculature. However, it is unknown whether these changes preceded or resulted from pain. To further delineate the relationship between cyclic pain recurrence and APRs, we quantified postural responses following multi-directional support surface translations, in individuals with non-specific LBP, following an active pain episode. Sixteen subjects with and 16 without LBP stood on two force plates that were translated unexpectedly in 12 directions. Net joint torques of the ankles, knees (sagittal only), hips, and trunk, in the frontal and sagittal planes, were quantified and the activation of 12 muscles of the lower limb unilaterally and the dorsal and ventral trunk, bilaterally, were recorded using surface electromyography (EMG). Peaks and latencies to peak joint torques, rates of torque development (slopes), and integrated EMGs characterizing baseline and active muscle contributions were analyzed for group by perturbation direction (torques) and group by perturbation by epoch interaction (EMG) effects. In general, the LBP cohort demonstrated APRs that were of similar torque magnitude and rate but peaked earlier compared to individuals without LBP. Individuals with LBP also demonstrated increased muscle activity following perturbation directions in which the muscle was acting as a prime mover and reduced muscle activity in opposing directions, proximally and distally, with some proximal asymmetries. These altered postural responses may reflect increased muscle spindle sensitivity. Given that these motor alterations are demonstrated proximally and distally, they likely reflect the influence of central nervous system processing in this cohort
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Responses to Multi-Directional Surface Translations Involve Redistribution of Proximal Versus Distal Strategies to Maintain Upright Posture
Evaluation of postural control in multiple planes is necessary to determine the movement strategies used to respond to unexpected perturbations. The present study quantified net joint torques of the lower limbs and trunk in the sagittal and frontal planes following multi-directional surface translations. Twenty-one healthy subjects stood with feet on separate force plates mounted on a moveable platform, translated unexpectedly in one of 12 directions. Peak net torque magnitudes and latencies following perturbation onset were determined as were the relative contributions of each joint to total torque production. Magnitude of net torque generated by each leg varied by perturbation direction, with the largest individual joint magnitude elicited in directions of limb loading. Relative contributions of individual joint torques to the total response were dependent upon perturbation direction. Results suggest that a redistribution of the relative contributions of hip/trunk versus ankle strategies occurs dependent on perturbation direction, with a significant contribution by the knee joint in response to forward perturbations. Direction-specific redistribution of proximal versus distal strategies appears to depend upon the biomechanical constraints imposed by a given perturbation direction. Thus, it appears that sagittal and frontal plane posture-righting responses may not be uniquely controlled, and may instead be governed similarly, with modulation of relative torque contributions among joints when necessary, given direction-specific anatomical constraints
A History of Low Back Pain Associates With Altered Electromyographic Activation Patterns in Response to Perturbations of Standing Balance
People with a history of low back pain (LBP) exhibit altered responses to postural perturbations, and the central neural control underlying these changes in postural responses remains unclear. To characterize more thoroughly the change in muscle activation patterns of people with LBP in response to a perturbation of standing balance, and to gain insight into the influence of early- vs. late-phase postural responses (differentiated by estimates of voluntary reaction times), this study evaluated the intermuscular patterns of electromyographic (EMG) activations from 24 people with and 21 people without a history of chronic, recurrent LBP in response to 12 directions of support surface translations. Two-factor general linear models examined differences between the 2 subject groups and 12 recorded muscles of the trunk and lower leg in the percentage of trials with bursts of EMG activation as well as the amplitudes of integrated EMG activation for each perturbation direction. The subjects with LBP exhibited 1) higher baseline EMG amplitudes of the erector spinae muscles before perturbation onset, 2) fewer early-phase activations at the internal oblique and gastrocnemius muscles, 3) fewer late-phase activations at the erector spinae, internal and external oblique, rectus abdominae, and tibialis anterior muscles, and 4) higher EMG amplitudes of the gastrocnemius muscle following the perturbation. The results indicate that a history of LBP associates with higher baseline muscle activation and that EMG responses are modulated from this activated state, rather than exhibiting acute burst activity from a quiescent state, perhaps to circumvent trunk displacements
Individuals With Non-Specific Low Back Pain Use a Trunk Stiffening Strategy to Maintain Upright Posture
There is increasing evidence that individuals with non-specific low back pain (LBP) have altered movement coordination., however, the relationship of this neuromotor impairment to recurrent pain episodes is unknown. To assess coordination while minimizing the confounding influences of pain we characterized automatic postural responses to multi-directional support surface translations in individuals with a history of LBP who were not in an active episode of their pain. Twenty subjects with and 21 subjects without non-specific LBP stood on a platform that was translated unexpectedly in 12 directions. Net joint torques of the ankles, knees, hips and trunk in the frontal and sagittal planes as well as surface electromyographs of 12 lower leg and trunk muscles were compared across perturbation directions to determine if individuals with LBP responded using a trunk stiffening strategy. Individuals with LBP demonstrated reduced peak trunk torques, and enhanced activation of the trunk and ankle muscle responses following perturbations. These results suggest that individuals with LBP use a strategy of trunk stiffening achieved through co-activation of trunk musculature, aided by enhanced distal responses, to respond to unexpected support surface perturbations. Notably, these neuromotor alterations persisted between active pain periods and could represent either movement patterns that have developed in response to pain or could reflect underlying impairments that may contribute to recurrent episodes of LBP
Development and validation of a measure of primary care behavioral health integration
INTRODUCTION: We developed the Practice Integration Profile (PIP) to measure the degree of behavioral health integration in clinical practices with a focus on primary care (PC). Its 30 items, completed by providers, managers, and staff, provide an overall score and 6 domain scores derived from the Lexicon of Collaborative Care. We describe its history and psychometric properties.
METHOD: The PIP was tested in a convenience sample of practices. Linear regression compared scores across integration exemplars, PC with behavioral services, PC without behavioral services, and community mental health centers without PC. An additional sample rated 4 scenarios describing practices with varying degrees of integration.
RESULTS: One hundred sixty-nine surveys were returned. Mean domain scores ran from 49 to 65. The mean total score was 55 (median 58; range 0-100) with high internal consistency (Cronbach\u27s alpha = .95). The lowest total scores were for PC without behavioral health (27), followed by community mental health centers (44), PC with behavioral health (60), and the exemplars (86; p \u3c .001). Eleven respondents rerated their practices 37 to 194 days later. The mean change was + 1.5 (standard deviation = 11.1). Scenario scores were highly correlated with the degree of integration each scenario was designed to represent (Spearman\u27s rho = -0.71; P = 0.0005).
DISCUSSION: These data suggest that the PIP is useful, has face, content, and internal validity, and distinguishes among types of practices with known variations in integration. We discuss how the PIP may support practices and policymakers in their integration efforts and researchers assessing the degree to which integration affects patient health outcomes
The Practice Integration Profile: Rationale, development, method, and research
Insufficient knowledge exists regarding how to measure the presence and degree of integrated care. Prior estimates of integration levels are neither grounded in theory nor psychometrically validated. They provide scant guidance to inform improvement activities, compare integration efforts, discriminate among practices by degree of integration, measure the effect of integration on quadruple aim outcomes, or address the needs of clinicians, regulators, and policymakers seeking new models of health care delivery and funding. We describe the development of the Practice Integration Profile (PIP), a novel instrument designed to measure levels of integrated behavioral health care within a primary care clinic. The PIP draws upon the Agency for Health care Research and Quality\u27s (AHRQ) Lexicon of Collaborative Care which provides theoretic justification for a paradigm case of collaborative care. We used the key clauses of the Lexicon to derive domains of integration and generate measures corresponding to those key clauses. After reviewing currently used methods for identifying collaborative care, or integration, and identifying the need to improve on them, we describe a national collaboration to describe and evaluate the PIP. We also describe its potential use in practice improvement, research, responsiveness to multiple stakeholder needs, and other future directions
Further Experience with the Practice Integration Profile: A Measure of Behavioral Health and Primary Care Integration
Valid measures of behavioral health integration have the potential to enable comparisons of various models of integration, contribute to the overall development of high-quality care, and evaluate outcomes that are strategically aligned with standard improvement efforts. The Practice Integration Profile has proven to discriminate among clinic types and integration efforts. We continued the validation of the measure\u27s internal consistency, intra-rater consistency, and inter-rater consistency with a separate and larger sample from a broader array of practices. We found that the Practice Integration Profile demonstrated a high level of internal consistency, suggesting empirically sound measurement of independent attributes of integration, and high reliability over time. The Practice Integration Profile provides internally consistent and interpretable results and can serve as both a quality improvement and health services research tool
Promoting scholarship in improvement science: A model for academic clinical departments
Abstract Introduction Clinical departments at academic medical centers strive to deliver clinical care, provide education and training, support faculty development, and promote scholarship. These departments have experienced increasing demands to improve the quality, safety, and value of care delivery. However, many academic departments lack a sufficient number of clinical faculty members with expertise in improvement science to lead initiatives, teach, and generate scholarship. In this article, we describe the structure, activities, and early outcomes of a program within an academic department of medicine to promote scholarly improvement work. Methods The Department of Medicine at the University of Vermont Medical Center launched a Quality Program with three primary goals: (a) improve care delivery, (b) provide education and training, and (c) promote scholarship in improvement science. The program serves as a resource center for students, trainees and faculty, offering education and training, analytic support, consultation in design and methodology, and project management. It strives to integrate education, research, and care delivery to learn, apply evidence and improve health care. Results Over the first 3 years of full implementation, the Quality Program supported an average of 123 projects annually, including prospective clinical quality improvement initiatives, retrospective assessment of clinical programs and practices, and curriculum development and evaluation. The projects have yielded a total of 127 scholarly products, defined as peer‐reviewed publications and abstracts, posters, and oral presentations at local, regional, and national conferences. Conclusions The Quality Program may serve as a practical model for promoting care delivery improvement, training, and scholarship in improvement science while advancing the goals of a learning health system at the level of an academic clinical department. Dedicated resources within such departments offer the potential to enhance care delivery while promoting academic success for faculty and trainees in improvement science