Sara R. Piva

Responsiveness of the numeric pain rating scale in patients with low back pain

Study Design. Cohort study of patients with low back pain (LBP) receiving physical therapy. Objective. To examine the responsiveness characteristics of the numerical pain rating scale (NPRS) in patients with LBP using a variety of methods. Summary of Background Data. Although several studies have assessed the reliability and validity of the NPRS, few studies have characterized its responsiveness in patients with LBP. Methods. Determination of change on the NPRS during 1 and 4 weeks was examined by calculating mean change, standardized effect size, Guyatt Responsiveness Index, area under a receiver operating characteristic curve, minimum clinically important difference, and minimum detectable change. Change in the NPRS from baseline to the 1 and 4-week follow-up was compared to the average of the patient and therapist’s perceived improvement using the 15-point Global Rating of Change scale. Results. The majority of patients had clinically meaningful improvement after both 1 and 4 weeks of rehabilitation. The standard error of measure was equal to 1.02, corresponding to a minimum detectable change of 2 points. The area under the curve at the 1 and 4-week follow-up was 0.72 (0.62, 0.81) and 0.92 (0.86, 0.97), respectively. The minimum clinically important difference at the 1 and 4-week follow-up corresponded to a change of 2.2 and 1.5 points, respectively. Conclusions. Clinicians can be confident that a 2-point change on the NPRS represents clinically meaningful change that exceeds the bounds of measurement error.

Relationships of Fear, Anxiety, and Depression With Physical Function in Patients With Knee Osteoarthritis

OBJECTIVES To explore whether the psychologic variables anxiety, depression, and fear-avoidance beliefs, and interactions between these variables, are associated with physical function in patients with knee osteoarthritis (OA). We hypothesized lower levels of function would be related to higher anxiety, higher depression, and higher fear-avoidance beliefs, and that high levels of 2 of these factors simultaneously might interact to have a greater adverse effect on physical function. DESIGN Cross-sectional, correlational design. SETTING Institutional practice. PARTICIPANTS Subjects included patients with knee OA (N=182; age, mean +/- SD, 63.9+/-8.8y; 122 women). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Self-report measures of function included the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, the Lower Extremity Function Scale (LEFS), and the Knee Outcome Survey-Activity of Daily Living Scale. The Get Up and Go test was used as a physical performance measure of function. Self-report measures for psychologic variables included the Beck Anxiety Inventory, the Center for Epidemiological Studies Depression Scale, and the Fear Avoidance Belief Questionnaire-Physical Activity Scale modified for the knee. RESULTS Higher anxiety was related to poorer function on the WOMAC physical function. Both high anxiety and fear-avoidance beliefs were related to poorer function on the LEFS and Knee Outcome Survey-Activity of Daily Living Scale. There was no association between the psychologic variables and the Get Up and Go test. The anxiety x depression interaction was associated with the LEFS. CONCLUSIONS Anxiety and fear-avoidance beliefs are associated with self-report measures of function in patients with knee OA. Depression may influence scores on the LEFS under conditions of low anxiety.

A Balance Exercise Program Appears to Improve Function for Patients With Total Knee Arthroplasty: A Randomized Clinical Trial

Background Patients with total knee arthroplasty (TKA) have impaired balance and movement control. Exercise interventions have not targeted these impairments in this population. Objectives The purposes of this study were: (1) to determine the feasibility of applying a balance exercise program in patients with TKA, (2) to investigate whether a functional training (FT) program supplemented with a balance exercise program (FT+B program) could improve physical function compared with an FT program alone in a small group of individuals with TKA, and (3) to test the methods and calculate sample size for a future randomized trial with a larger study sample. Design This study was a double-blind, pilot randomized clinical trial. Setting The study was conducted in the clinical laboratory of an academic center. Participants The participants were 43 individuals (30 female, 13 male; mean age=68 years, SD=8) who underwent TKA 2 to 6 months prior to the study. Interventions The interventions were 6 weeks (12 sessions) of a supervised FT or FT+B program, followed by a 4-month home exercise program. Measurements Feasibility measures included pain, stiffness, adherence, and attrition. The primary outcome measure was a battery of physical performance tests: self-selected gait speed, chair rise test, and single-leg stance time. Secondary outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index and the Lower Extremity Functional Scale. Results Feasibility of the balance training in people with TKA was supported by high exercise adherence, a relatively low dropout rate, and no adverse events. Both groups demonstrated clinically important improvements in lower-extremity functional status. The degree of improvement seemed higher for gait speed, single-leg stance time, and stiffness in the FT+B group compared with the FT group. Limitations Due to the pilot nature of the study, differences between groups did not have adequate power to show statistical significance. Conclusions There is a need for conducting a larger randomized controlled trial to test the effectiveness of an FT+B program after TKA.

Walking Skill Can Be Assessed in Older Adults: Validity of the Figure-of-8 Walk Test

Background The Figure-of-8 Walk Test (F8W) involves straight and curved paths and was designed to represent walking skill in everyday life. Objective The purposes of this study were to validate the measure in older adults with walking difficulties and to explore correlates of the curved-path walking measure not represented by a straight-path walking measure. Design Fifty-one community-dwelling older adults with mobility disability participated in 2 baseline visits as part of an intervention study. Methods The F8W time, steps, and smoothness and measures of gait (gait speed, modified Gait Abnormality Rating Scale [GARS-M]), physical function (Late Life Function and Disabilities Index [LLFDI], Survey of Activities and Fear of Falling in the Elderly [SAFFE], Gait Efficacy Scale [GES], Physical Performance Test [PPT], and fall history), and movement control and planning (gait variability, Trail Making Test B [Trails B]) were recorded in each test session. Bivariate correlations for the F8W with each variable were conducted to examine concurrent and construct validity. Adjusted linear regression analyses were performed to explore the variance in mobility explained by F8W independent of gait speed. Results Figure-of-8 Walk Test time correlated with gait (gait speed, r=−.570; GARS-M, r=.281), physical function (LLFDI function, r=−.469; SAFFE restriction subscale, r=.370; PPT, r=−.353), confidence in walking (GES, r=−.468), and movement control (step length coefficient of variation, r=.279; step width coefficient of variation, r=−.277; Trails B, r=.351). Figure-of-8 Walk Test steps correlated with step width variability (r=−.339) and was related to fear of falling (t=−2.50). All correlations were significant (P<.05). Limitations This pilot study had a small sample size, and further research is needed. Conclusions The F8W is a valid measure of walking skill among older adults with mobility disability and may provide information complementary to gait speed.

Agility and Perturbation Training Techniques in Exercise Therapy for Reducing Pain and Improving Function in People With Knee Osteoarthritis: A Randomized Clinical Trial

Background Impairment-based exercise programs have yielded only small to moderate benefits in reducing pain and improving function in people with knee osteoarthritis (OA). It has previously been proposed that adding agility and perturbation training to exercise programs for people with knee OA may improve treatment effects for pain and function. Objective The purpose of this study was to examine the effectiveness of adding agility and perturbation techniques to standard exercise therapy compared with the standard exercise program alone for people with knee OA. Design This was a single-blinded randomized controlled trial. Setting The study was conducted in the outpatient physical therapy clinic of a large, university-based health center. Participants One hundred eighty-three people with knee OA (122 women, 61 men) participated. Interventions Participants were randomly assigned to either a group that received agility and perturbation training with standard exercise therapy or a group that received only the standard exercise program. Measurements The outcome measures were self-reported knee pain and function, self-reported knee instability, a performance-based measure of function, and global rating of change. Results Although both groups exhibited improvement in self-reported function and in the global rating of change at the 2-, 6-, and 12-month follow-up periods, there were no differences between groups on these outcomes. There was no reduction in knee pain or improvement in performance-based function in either group. Limitations It is possible that more-intense application of the interventions or application of the interventions to participants with knee OA who were at greater risk for falling may have yielded additive effects of the agility and perturbation training approach. Conclusions Both intervention groups exhibited improvement in self-reported function and the global rating of change. Our results, however, did not support an additive effect of agility and perturbation training with standard exercise therapy in our sample of individuals with knee OA. Further study is needed to determine whether there are subgroups of individuals who might achieve an added benefit with this approach.

Physical Activity Measured by the SenseWear Armband in Women With Rheumatoid Arthritis

Background Individuals with rheumatoid arthritis (RA) often are sedentary and have an increased risk of developing comorbid conditions. Women with RA are more likely to experience challenges in maintaining an active lifestyle over their life span than men with RA or people who are healthy. As the benefits of physical activity (PA) are well known, measuring PA accurately in this population is important. Objectives The purposes of this study were: (1) to characterize PA as measured with the SenseWear Armband (SWA) in women with RA and (2) to determine the measurement time frame to obtain consistent estimates of PA and daily energy expenditure (EE) in women with RA. Design This was a cross-sectional study. Methods Participants wore the SWA for 7 days. Measurements of daily total energy expenditure (TEE), physical activity energy expenditure (PAEE) during activities at or above 1 metabolic equivalent (MET) level (PAEE≥1MET), PAEE during activities at or above 2 METs (PAEE≥2METs), PAEE during activities at or above 3 METs (PAEE≥3METs), and number of steps were obtained. Results Fifty-three women participated. Complete data were obtained for 47 participants (89%). Daily usage of the SWA was 98% of the time (23:31 hours/24 hours). Means (SD) were 2,099 (340) kcal/d for TEE, 1,050 (331) kcal/d for PAEE≥1MET, 642 (309) kcal/d for PAEE≥2METs, 239 (178) kcal/d for PAEE≥3METs, and 7,260 (2,710) for number of steps. Results of intraclass correlation coefficient analyses and multiple linear regressions indicated that 2 days were needed to reliably estimate TEE; 3 days for PAEE≥1MET, PAEE≥2METs, and number of steps; and 4 days for PAEE≥3METs. Limitations The sample was composed of well-educated women with RA who had mild to moderate difficulty performing daily activities. Conclusion The SWA may be useful to quantify PA in women with RA and to monitor effectiveness of interventions aiming to increase PA levels. Minimizing the number of days necessary for data collection will reduce the individuals burden and may improve adherence in studies of PA behaviors.

Interrater Reliability and Validity of the Stair Ascend/Descend Test in Subjects With Total Knee Arthroplasty

OBJECTIVE (1) To determine the interrater reliability and measurement error of an 11-step stair ascend/descend test (STTotal-11) and stair up (ascend) test (STUp-11); (2) to seek evidence for the STTotal-11 and STUp-11 as valid measures of physical function by determining if they relate to measures of physical function and do not relate to measures not of physical function; and (3) to explore if the STTotal-11 and STUp-11 scores relate to lower-extremity muscle weakness and knee range of motion (ROM) in subjects with total knee arthroplasty (TKA). DESIGN Cross-sectional study. SETTING Academic center. PARTICIPANTS Subjects (N=43, 30 women; mean age, 68+/-8y) with unilateral TKA. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES STTotal-11 and STUp-11 were performed twice, and scores were compared with scores on 4 lower extremity performance-based tasks, 2 patient-reported questionnaires of physical function, 3 psychologic factors, knee ROM, and strength of quadriceps, hip extensors, and abductors. RESULTS Intraclass correlation coefficient was .94 for both the STTotal-11 and STUp-11, standard error of measurements were 1.14 seconds and .82 seconds, and minimum detectable change associated with 90% confidence interval was 2.6 seconds and 1.9 seconds, respectively. Correlations between stair tests and performance-based measures and knee and hip muscle strength ranged from Pearson correlation coefficient (r)=.40 to .78. STTotal-11 and STUp-11 had a small correlation with one of the patient-reported measures of physical function. Stair tests were not associated with psychologic factors and knee extension ROM and were associated with knee flexion ROM. CONCLUSIONS STTotal-11 and STUp-11 have good interrater reliability and minimum detectable changes adequate for clinical use. The pattern of associations supports the validity of the stair tests in TKA.

Contribution of Hip Abductor Strength to Physical Function in Patients With Total Knee Arthroplasty

Background Investigating modifiable factors that contribute to functional limitations in patients with total knee arthroplasty (TKA) may guide changes in rehabilitation protocols and improve functional outcomes. Whereas quadriceps muscle weakness has been demonstrated to contribute to functional limitations in TKA, the role of hip abductor weakness has not received attention. Objective The purpose of this study was to determine whether hip abductor strength (force-generating capacity) contributes to physical function beyond what can be explained by quadriceps muscle strength in patients after a TKA. Design A cross-sectional design was used in the study. Setting The study was conducted in a clinical laboratory at an academic center. Patients Thirty-one people with TKA (74% female; mean age=68 years, SD=8; mean body mass index=31 kg/m2, SD=5) participated in the study. Measurements Strength of quadriceps muscles and hip abductors was measured using an isokinetic dynamometer. Performance-based physical function was assessed with 4 measures: self-selected walking speed, the Figure-of-8 Walk Test, the Stair Ascend/Descend Test, and the 5-Chair Rise Test. Self-reported physical function was assessed with the Western Ontario and McMaster Universities Osteoarthritis Index Physical Function Subscale. Results In hierarchical regression models, after accounting for demographic and anthropometric factors, quadriceps muscle strength was associated with performance on the Stair Ascend/Descend Test. After accounting for demographic, anthropometric, and quadriceps strength, hip abductor strength was associated with performance on the Stair Ascend/Descend Test, the Figure-of-8 Walk Test, and the 5-Chair Rise Test. Limitations The study design precluded ascertainment of causal relationships. Conclusions After TKA, hip abductor strength influenced physical function in participants more than did demographic or anthropometric measures or quadriceps strength. Longitudinal studies with larger samples are warranted. If findings are replicated, they will justify targeting the hip abductors during rehabilitation after TKA.

Associates of Physical Function and Pain in Patients with Patellofemoral Pain Syndrome

OBJECTIVES To explore whether impairment of muscle strength, soft tissue length, movement control, postural and biomechanic alterations, and psychologic factors are associated with physical function and pain in patients with patellofemoral pain syndrome (PFPS). DESIGN Cross-sectional study. SETTING Rehabilitation outpatient. PARTICIPANTS Seventy-four patients diagnosed with PFPS. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Measurements were self-reported function and pain; strength of quadriceps, hip abduction, and hip external rotation; length of hamstrings, quadriceps, plantar flexors, iliotibial band/tensor fasciae latae complex, and lateral retinaculum; foot pronation; Q-angle; tibial torsion; visual observation of quality of movement during a lateral step-down task; anxiety; and fear-avoidance beliefs. RESULTS After controlling for age and sex, anxiety and fear-avoidance beliefs about work and physical activity were associated with function, while only fear-avoidance beliefs about work and physical activity were associated with pain. CONCLUSIONS Psychologic factors were the only associates of function and pain in patients with PFPS. Factors related to physical impairments did not associate to function or pain. Our results should be validated in other samples of patients with PFPS. Further studies should determine the role of other psychologic factors, and how they relate to anxiety and fear-avoidance beliefs in these patients.

Physical Impairment Index : Reliability, Validity, and Responsiveness in Patients with Acute Low Back Pain

Study Design. Cohort study of patients with acute low back pain undergoing physical therapy. Objectives. Examine the reliability and validity of the Physical Impairment Index in a group of patients with acute low back pain and determine the responsiveness and minimum detectable change of the index and its component tests. Summary of the Background Data. The Physical Impairment Index was originally described as a reliable and valid means of assessing physical impairment in patients with low back pain. The psychometric properties of the index have not been reported in patients with acute low back pain, nor has its responsiveness been examined. Methods. Seventy-eight patients with acute (<3 weeks duration) low back pain participating in a clinical trial were assessed at baseline and after 4 weeks. Interrater reliability of the index was examined in a subgroup of 20 patients. Validity was examined through correlations with concurrent measures of pain, disability, and psychosocial variables. Changes in the index over 4 weeks were used to assess responsiveness and minimum detectable change. Results. Interrater reliability of the index was high (intraclass correlation coefficient = 0.89), and its validity was generally supported by the pattern of correlations. The index was more responsive to change than any of its component tests but was less responsive than the Oswestry disability score. The minimum detectable change on the index was approximately 1 point. Conclusions. The Physical Impairment Index appears to be a reliable and valid measure of physical impairment for patients with acute low back pain and may be useful as an adjunct outcome measure for studies involving these patients. Further research on patients with chronic pain is needed before it can be advocated for outcomes research with this population.