Allan J. Kozlowski

Reliability of the lumbar flexion, lumbar extension, and passive straight leg raise test in normal populations embedded within a complete physical examination

Study Design. The study measured the reliability of the passive straight leg raise (SLR) test and lumbar range of motion (LROM) tests measured as continuous variables embedded within a comprehensive physical examination. Objectives. To determine the reliability of the SLR and LROM test scores when they are measured with a Cybex electronic inclinometer (Lumex, Inc., New York, NY) within a physical examination. Summary of Background Data. Good published empirical reliability exists for the Cybex and for SLR and LROM tests when the measurements are taken in isolation from other physical examination procedures. Reliability of the Cybex for continuous SLR and LROM measurement within a physical examination has not been assessed, however. Methods. Forty-five participants were seen by one of two physician/physiotherapist teams. Participants were examined by both team members. The first examiner conducted the first tests and retested 1 week later (intrarater reliability). The second examined the participants the day after their first appointment (inter-rater reliability). Results. Only two scores showed substantial reliability (defined as r ≥ 0.60). These scores were left (r = 0.81) and right (r = 0.79) SLR intrarater reliability. All other scores fell below the specified cutoff. Conclusions. SLR and LROM scores used clinically are collected during comprehensive physical examinations. Most scores gathered under these conditions were not reliable. These findings have implications for the use of clinically derived SLR and LROM scores.

Time and Effort Required by Persons with Spinal Cord Injury to Learn to Use a Powered Exoskeleton for Assisted Walking

BACKGROUND Powered exoskeletons have been demonstrated as being safe for persons with spinal cord injury (SCI), but little is known about how users learn to manage these devices. OBJECTIVE To quantify the time and effort required by persons with SCI to learn to use an exoskeleton for assisted walking. METHODS A convenience sample was enrolled to learn to use the first-generation Ekso powered exoskeleton to walk. Participants were given up to 24 weekly sessions of instruction. Data were collected on assistance level, walking distance and speed, heart rate, perceived exertion, and adverse events. Time and effort was quantified by the number of sessions required for participants to stand up, walk for 30 minutes, and sit down, initially with minimal and subsequently with contact guard assistance. RESULTS Of 22 enrolled participants, 9 screen-failed, and 7 had complete data. All of these 7 were men; 2 had tetraplegia and 5 had motor-complete injuries. Of these, 5 participants could stand, walk, and sit with contact guard or close supervision assistance, and 2 required minimal to moderate assistance. Walk times ranged from 28 to 94 minutes with average speeds ranging from 0.11 to 0.21 m/s. For all participants, heart rate changes and reported perceived exertion were consistent with light to moderate exercise. CONCLUSIONS This study provides preliminary evidence that persons with neurological weakness due to SCI can learn to walk with little or no assistance and light to somewhat hard perceived exertion using a powered exoskeleton. Persons with different severities of injury, including those with motor complete C7 tetraplegia and motor incomplete C4 tetraplegia, may be able to learn to use this device.

Analysis of the convergent and discriminant validity of published lumbar flexion, extension, and lateral flexion scores.

Study Design. Articles reflecting the convergent or discriminant validity of the lumbar range of motion tests were reviewed and compared. Mean scores and standard deviations for lumber range of motion from healthy control subjects were plotted against those from patients with low back injuries. Objective. To use published research to analyze the convergent and discriminant validity of lumbar range of motion tests for the characterization of low back pain and injury. Summary of Background Data. Several publications have addressed lumbar range of motion validity. Individual studies suggest that the tests possess convergent validity, but that their discriminant validity is indeterminate. Methods. English-language journals were searched on Medline using “region,” “lumbar,” “range of motion,” “validity of results,” “observer variation,” and “low back pain” as title and subject search terms. The study methods approximating the specifications of the American Medical Association Guides to the Evaluation of Permanent Impairment were included in the analysis. Results. Convergent validity research showed inconsistent relations between inclinometric and radiographic lumbar range of motion measurements. Some studies showed strong relation, whereas others showed essentially no relation between the two techniques. Correlations between lumbar range of motion scores and spinal disability and function were similarly inconclusive. Studies reporting mean scores and standard deviations for lumbar range of motion measurements showed a high degree of overlap between the scores of participants with low back injuries and those without such injuries. Conclusions. Convergent and discriminant validities of the lumbar range of motion tests currently require further substantiation. Absolute lumbar range of motion scores may not be suitable as the sole determinants of low back pathology diagnosis. Implications for using the lumbar range of motion tests to characterize low back injuries in medicolegal situations are discussed.

An introduction to applying individual growth curve models to evaluate change in rehabilitation: a National Institute on Disability and Rehabilitation Research Traumatic Brain Injury Model Systems report.

The abundance of time-dependent information contained in the Spinal Cord Injury and the Traumatic Brain Injury Model Systems National Databases, and the increased prevalence of repeated-measures designs in clinical trials highlight the need for more powerful longitudinal analytic methodologies in rehabilitation research. This article describes the particularly versatile analytic technique of individual growth curve (IGC) analysis. A defining characteristic of IGC analysis is that change in outcome such as functional recovery can be described at both the patient and group levels, such that it is possible to contrast 1 patient with other patients, subgroups of patients, or a group as a whole. Other appealing characteristics of IGC analysis include its flexibility in describing how outcomes progress over time (whether in linear, curvilinear, cyclical, or other fashion), its ability to accommodate covariates at multiple levels of analyses to better describe change, and its ability to accommodate cases with partially missing outcome data. These features make IGC analysis an ideal tool for investigating longitudinal outcome data and to better equip researchers and clinicians to explore a multitude of hypotheses. The goal of this special communication is to familiarize the rehabilitation community with IGC analysis and encourage the use of this sophisticated research tool to better understand temporal change in outcomes.

Descriptive Modeling of Longitudinal Outcome Measures in Traumatic Brain Injury: A National Institute on Disability and Rehabilitation Research Traumatic Brain Injury Model Systems Study

Establishing accurate mathematical models of outcome measures is essential in understanding change throughout the rehabilitation process. The goal of this study is to identify the best-fitting descriptive models for a set of commonly adopted outcome measures found within the Traumatic Brain Injury Model Systems National Database where the modeling is based on data submission through 2011 and the complete range of recorded time points since injury for each individual, where time points range from admission to rehabilitation to 20 years postinjury. The statistical methodology and the application of the methodology contained herein may be used to assist researchers and clinicians in (1) modeling the outcome measures considered, (2) modeling various portions of these outcomes by stratification and/or truncating time periods, (3) modeling longitudinal outcome measures not considered, and (4) establishing models as a necessary precursor in conducting individual growth curve analysis.

Using Individual Growth Curve Models to Predict Recovery and Activities of Daily Living After Spinal Cord Injury: An SCIRehab Project Study

OBJECTIVE To evaluate change in functional outcomes over 1 year after spinal cord injury (SCI). DESIGN Observational longitudinal secondary analysis. SETTING Six rehabilitation facilities participating in the SCIRehab project. PARTICIPANTS Patients (N=1146) with SCI enrolled from 2007 to 2010. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES FIM instrument 13-item and 11-item motor, 3-item transfer, 6-item self-care, 3-item self-care upper-extremity, and 3-item self-care lower-extremity subscores modeled as trajectories of change. RESULTS Patients were on average 37 years old, non-Hispanic white, with high school or higher education, a body mass index of 25, and a Comprehensive Severity Index score of 20. Most were men with paraplegia (37%) or high tetraplegia (27%). Median time frames were 22 days from injury to admission, 46 days from admission to discharge, 407 days from admission to follow-up, and 44 days for rehabilitation length of stay. The motor subscores were higher on admission for paraplegia and American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade D groups, and recovered faster for the AIS grade D group. Lower function at admission was associated with older age, higher Comprehensive Severity Index score, longer length of stay, fewer physical therapy and therapeutic recreation hours, and more occupational therapy hours. Slower recovery rates were associated with older age, more days from injury to admission, and fewer physical therapy hours per week. CONCLUSIONS Longitudinal outcomes modeled as individual trajectories of change are clinically meaningful. Individual growth curve models could facilitate recovery prediction and outcome evaluation at individual and group levels. However, assessment of the effects of treatment on outcome trajectories will require the addition of outcome measures at time points during intervention and may require the use of outcome measures specific to aspects of rehabilitation, such as mobility and self-care.

Commentary on the American Medical association guides' lumbar impairment validity checks

Study Design. The American Medical Association’s (AMA) Guides to the Evaluation of Permanent Impairment range of motion-based (ROM) lumbar impairment model validity checks were reviewed. Published literature of lumbar ROM (LROM) testing also was reviewed for application of the AMA validity checking protocols. Objective. The utility and feasibility of use of the AMA Guides’ ROM lumbar impairment ratings were examined. Summary of Background Data. Although they appear to be essential components of the ROM model, few published studies report use of these validity checks. Of at least 22 reviewed studies of LROM testing, only six studies included at least three measurements (the bare minimum) of LROM. Furthermore, only two (9.1%) reported performance of the LROM validity check. Only one, however, reported the results. Methods. English language journals were searched on Medline using “region, lumbar,” “range of motion,” “validity of results,” “observer variation,” and “low back pain” as title and subject search terms. The study methodologies approximating the AMA Guides’ specifications were included in the analysis. Results. Under normal conditions of ROM measurement, 33% of three consecutive lumbar flexion and 27% of three consecutive lumbar extension measurements failed the LROM validity check. In addition, across three different experimental sessions (each with more than three consecutive LROM measurements taken) only 15 participants (33%) had valid flexion scores and only 24 participants (53%) had valid extension scores across all three sessions. Conclusion. Technical complications inherent in the ROM-based impairment-rating model render the validity checks difficult to perform satisfactorily and thus rarely used.

Agreement between responses from community-dwelling persons with stroke and their proxies on the NIH Neurological Quality of Life (Neuro-QoL) Short Forms

OBJECTIVE To examine agreement between patient and proxy responses on the Quality of Life in Neurological Disorders (Neuro-QoL) instruments after stroke. DESIGN Cross-sectional observational substudy of the longitudinal, multisite, multicondition Neuro-QoL validation study. SETTING In-person, interview-guided, patient-reported outcomes. PARTICIPANTS Convenience sample of dyads (N=86) of community-dwelling persons with stroke and their proxy respondents. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Dyads concurrently completed short forms of 8 or 9 items for the 13 Neuro-QoL adult domains using the patient-proxy perspective. Agreement was examined at the scale-level with difference scores, intraclass correlation coefficients (ICCs), effect size statistics, and Bland-Altman plots, and at the item-level with kappa coefficients. RESULTS We found no mean differences between patients and proxies on the Applied Cognition-General Concerns, Depression, Satisfaction With Social Roles and Activities, Stigma, and Upper Extremity Function (Fine Motor, activities of daily living) short forms. Patients rated themselves more favorably on the Applied Cognition-Executive Function, Ability to Participate in Social Roles and Activities, Lower Extremity Function (Mobility), Positive Affect and Well-Being, Anxiety, Emotional and Behavioral Dyscontrol, and Fatigue short forms. The largest mean patient-proxy difference observed was 3 T-score points on the Lower Extremity Function (Mobility). ICCs ranged from .34 to .59. However, limits of agreement showed dyad differences exceeding ±20 T-score points, and item-level agreement ranged from not significant to weighted kappa=.34. CONCLUSIONS Proxy responses on Neuro-QoL short forms can complement responses of moderate- to high-functioning community-dwelling persons with stroke and augment group-level analyses, but do not substitute for individual patient ratings. Validation is needed for other stroke populations.

Framework for Assessment of the Usability of Lower-Extremity Robotic Exoskeletal Orthoses.

ABSTRACTPersons with neurologic conditions such as spinal cord injury, stroke, and multiple sclerosis often lose the ability to stand and walk. Robotic hip-knee-ankle-foot exoskeletal orthoses have become commercially available and may allow some of these people to stand and walk again. These devices may also have applications beyond mobility, such as exercise, amelioration of secondary complications related to lack of ambulation, and the promotion of neuroplasticity. The authors present a framework for assessment of the usability of robotic exoskeletal orthoses available now or in the near future. The framework contains six modules: Functional applications, Personal factors, Device factors, External factors, Activities, and Health outcomes. Metrics and measures are suggested for each framework factor.

Functional recovery after severe traumatic brain injury: an individual growth curve approach.

OBJECTIVE To examine person, injury, and treatment characteristics associated with recovery trajectories of people with severe traumatic brain injury (TBI) during inpatient rehabilitation. DESIGN Observational prospective longitudinal study. SETTING TBI rehabilitation units. PARTICIPANTS Adults (N=206) with severe nonpenetrating TBI admitted directly to inpatient rehabilitation from acute care. Participants were excluded for prior disability and intentional etiology of injury. INTERVENTIONS Naturally occurring treatments delivered within comprehensive multidisciplinary teams were recorded daily in 15-minute units provided to patients and family members, separately. MAIN OUTCOME MEASURES Motor and cognitive FIM were measured on admission, discharge, and every 2 weeks in between and were analyzed with individual growth curve methodology. RESULTS Inpatient recovery was best modeled with linear, cubic, and quadratic components: relatively steep recovery was followed by deceleration of improvement, which attenuated prior to discharge. Slower recovery was associated with older age, longer coma, and interruptions to rehabilitation. Patients admitted at lower functional levels received more treatment, and more treatment was associated with slower recovery, presumably because treatment was allocated according to need. Therefore, effects of treatment on outcome could not be disentangled from effects of case mix factors. CONCLUSIONS FIM gain during inpatient recovery from severe TBI is not a linear process. In observational studies, the specific effects of treatment on rehabilitation outcomes are difficult to separate from case mix factors that are associated with both outcome and allocation of treatment.