Quantification of walking ability in subjects with neurogenic claudication from lumbar spinal stenosis--a comparative study.

BACKGROUND CONTEXT: Walking limitations caused by neurogenic claudication (NC) are typically assessed with self-reported measures, although objective evaluation of walking using motorized treadmill test (MTT) or self-paced walking test (SPWT) has periodically appeared in the lumbar spinal stenosis (LSS) literature. PURPOSE: This study compared the validity and responsiveness of MTT and SPWT for assessing walking ability before and after common treatments for NC. STUDY DESIGN: Prospective observational cohort study. PATIENT SAMPLE: Fifty adults were recruited from an urban spine center if they had LSS and substantial walking limitations from NC and were scheduled to undergo surgery (20%) or conservative treatment (80%). OUTCOME MEASURES: Walking times, distances, and speeds along with the characteristics of NC symptoms were recorded for MTT and SPWT. Self-reported measures included back and leg pain intensity assessed with 0 to 10 numeric pain scales, disability assessed with Oswestry Disability Index, walking ability assessed with estimated walking times and distances, and NC symptoms assessed with the subscales from the Spinal Stenosis Questionnaires. METHODS: Motorized treadmill test used a level track, and SPWT was conducted in a rectangular hallway. Walking speeds were self-selected, and test end points were NC, fatigue, or completion of the 30-minute test protocol. Results from MTT and SPWT were compared with each other and self-reported measures. Internal responsiveness was assessed by comparing changes in the initial results with the posttreatment results and external responsiveness by comparing walking test results that improved with those that did not improve by self-reported criteria. RESULTS: Mean age of the participants was 68 years, and 58% were male. Neurogenic claudication included leg pain (88%) and buttock(s) pain (12%). Five participants could not safely perform MTT. Walking speeds were faster and distances were greater with SPWT, although the results from both tests correlated with each other and self-reported measures. Of the participants, 72% reported improvement after treatment, which was confirmed by significant mean differences in self-reported measures. Motorized treadmill test results did not demonstrate internal responsiveness to change in clinical status after treatment but SPWT results did, with increased mean walking times (6 minutes) and distances (387 m). When responsiveness was assessed against external criterion, both SPWT and MTT demonstrated substantial divergence with self-reported changes in clinical status and alternative outcome measures. CONCLUSIONS: Both MTT and SPWT can quantify walking abilities in NC. As outcome tools, SPWT demonstrated better internal responsiveness than MTT, but neither test demonstrated adequate external responsiveness. Neither test should be considered as a meaningful substitution for disease-specific measures of function.

Acute low back pain is marked by variability: An internet-based pilot study.

BACKGROUND: Pain variability in acute LBP has received limited study. The objectives of this pilot study were to characterize fluctuations in pain during acute LBP, to determine whether self-reported 'flares' of pain represent discrete periods of increased pain intensity, and to examine whether the frequency of flares was associated with back-related disability outcomes. METHODS: We conducted a cohort study of acute LBP patients utilizing frequent serial assessments and Internet-based data collection. Adults with acute LBP (lasting ≤3 months) completed questionnaires at the time of seeking care, and at both 3-day and 1-week intervals, for 6 weeks. Back pain was measured using a numerical pain rating scale (NPRS), and disability was measured using the Oswestry Disability Index (ODI). A pain flare was defined as 'a period of increased pain lasting at least 2 hours, when your pain intensity is distinctly worse than it has been recently'. We used mixed-effects linear regression to model longitudinal changes in pain intensity, and multivariate linear regression to model associations between flare frequency and disability outcomes. RESULTS: 42 of 47 participants (89%) reported pain flares, and the average number of discrete flare periods per patient was 3.5 over 6 weeks of follow-up. More than half of flares were less than 4 hours in duration, and about 75% of flares were less than one day in duration. A model with a quadratic trend for time best characterized improvements in pain. Pain decreased rapidly during the first 14 days after seeking care, and leveled off after about 28 days. Patients who reported a pain flare experienced an almost 3-point greater current NPRS than those not reporting a flare (mean difference [SD] 2.70 [0.11]; p < 0.0001). Higher flare frequency was independently associated with a higher final ODI score (ß [SE} 0.28 (0.08); p = 0.002). CONCLUSIONS: Acute LBP is characterized by variability. Patients with acute LBP report multiple distinct flares of pain, which correspond to discrete increases in pain intensity. A higher flare frequency is associated with worse disability outcomes.

Nonsurgical treatment of lumbar disk herniation: are outcomes different in older adults?

OBJECTIVES: To determine whether older adults (aged ≥ 60) experience less improvement in disability and pain with nonsurgical treatment of lumbar disk herniation (LDH) than younger adults (< 60). DESIGN: Prospective longitudinal comparative cohort study. SETTING: Outpatient specialty spine clinic. PARTICIPANTS: One hundred thirty-three consecutive patients with radicular pain and magnetic resonance-confirmed acute LDH (89 younger, 44 older). INTERVENTION: Nonsurgical treatment customized for the individual patient. MEASUREMENTS: Patient-reported disability on the Oswestry Disability Index (ODI), leg pain intensity, and back pain intensity were recorded at baseline and 1, 3, and 6 months. The primary outcome was the ODI change score at 6 months. Secondary longitudinal analyses examined rates of change over the follow-up period. RESULTS: Older adults demonstrated improvements in ODI (range 0-100) and pain intensity (range 0-10) with nonsurgical treatment that were not significantly different from those seen in younger adults at 6 month follow-up, with or without adjustment for potential confounders. Adjusted mean improvement in older and younger adults were 31 versus 33 (P = .63) for ODI, 4.5 versus 4.5 (P = .99) for leg pain, and 2.4 versus 2.7 for back pain (P = .69). A greater amount of the total improvement in leg pain and back pain in older adults was noted in the first month of follow-up than in younger adults. CONCLUSION: These preliminary findings suggest that the outcomes of LDH with nonsurgical treatment were not worse in older adults (≥ 60) than in younger adults (< 60). Future research is warranted to examine nonsurgical treatment for LDH in older adults.

The accuracy of the physical examination for the diagnosis of midlumbar and low lumbar nerve root impingement.

STUDY DESIGN: Cross-sectional study with prospective recruitment. OBJECTIVE.: To determine the accuracy of the physical examination for the diagnosis of midlumbar nerve root impingement (L2, L3, or L4), low lumbar nerve root impingement (L5 or S1) and level-specific lumbar nerve root impingement on magnetic resonance imaging, using individual tests and combinations of tests. SUMMARY OF BACKGROUND DATA: The sensitivity and specificity of the physical examination for the localization of nerve root impingement has not been previously studied. METHODS: Sensitivities, specificities, and likelihood ratios (LRs) were calculated for the ability of individual tests and test combinations to predict the presence or absence of nerve root impingement at midlumbar, low lumbar, and specific nerve root levels. RESULTS: LRs ≥5.0 indicate moderate to large changes from pre-test probability of nerve root impingement to post-test probability. For the diagnosis of midlumbar impingement, the femoral stretch test (FST), crossed FST, medial ankle pinprick sensation, and patellar reflex testing demonstrated LRs ≥5.0 (LR ∞). LRs ≥5.0 were observed with the combinations of FST and either patellar reflex testing (LR 7.0; 95% confidence interval [CI] 2.3-21) or the sit-to-stand test (LR ∞). For the diagnosis of low lumbar impingement, the Achilles reflex test demonstrated an LR ≥5.0 (LR 7.1; 95% CI 0.96-53); test combinations did not increase LRs. For the diagnosis of level-specific impingement, LRs ≥5.0 were observed for anterior thigh sensation at L2 (LR 13; 95% CI 1.8-87); FST at L3 (LR 5.7; 95% CI 2.3-4.4); patellar reflex testing (LR 7.7; 95% CI 1.7-35), medial ankle sensation (LR ∞), or crossed FST (LR 13; 95% CI 1.8-87) at L4; and hip abductor strength at L5 (LR 11; 95% CI 1.3-84). Test combinations increased LRs for level-specific root impingement at the L4 level only. CONCLUSION: Individual physical examination tests may provide clinical information that substantially alters the likelihood that midlumbar impingement, low lumbar impingement, or level-specific impingement is present. Test combinations improve diagnostic accuracy for midlum-bar impingement.

Inciting events associated with lumbar disc herniation.

BACKGROUND CONTEXT: No prior study has investigated the frequency of patient-identified inciting events in lumbar disc herniation (LDH) or their clinical significance. PURPOSE: To examine the clinical frequency of patient-identified inciting events in LDH, and to identify associations between the presence of inciting events and the severity of the clinical presentation. STUDY DESIGN/SETTING: Cross-sectional analysis of data from a cohort study with prospective recruitment, with retrospective data collection on inciting events. The setting was a hospital-based specialty spine clinic. PATIENT SAMPLE: One hundred fifty-four adults with lumbosacral radicular pain and LDH confirmed by magnetic resonance imaging. OUTCOME MEASURES: Self-report measures of disability measured by the Oswestry Disability Index (ODI), the visual analog scale (VAS) for leg pain, and the VAS for back pain. METHODS: Dependent variables included the presence of a patient-identified inciting event, which were categorized as spontaneous onset, nonlifting physical activity, heavy lifting (>35 lbs), light lifting (<35 lbs), nonexertional occurrence, or physical trauma. We examined the association of an inciting event, or a lifting-related event, with each outcome, first using univariate analyses, and second using multivariate modeling, accounting for important adjustment variables. RESULTS: Sixty-two percent of LDH did not have a specific patient-identified event associated with onset of symptoms. Nonlifting activities were the most common inciting event, comprising 26% of all LDH. Heavy lifting (6.5%), light lifting (2%), nonexertional occurrences (2%), and physical trauma (1.3%) accounted for relatively small proportions of all LDH. Patient-identified inciting events were not significantly associated with a more severe clinical presentation in crude analyses. Spontaneous LDH was significantly associated with higher baseline ODI scores in multivariate analysis, although the magnitude of this effect was small. There were no significant associations (p< or =.05) between the presence of a lifting-associated event and the outcomes of ODI, VAS leg pain, or VAS back pain. CONCLUSIONS: The majority of LDH occurred without specific inciting events. A history of an inciting event was not significantly associated with a more severe clinical presentation. There was no significant association between the occurrence of a lifting-related event and the severity of the clinical presentation. This information may be useful in the counseling of patients recovering from acute LDH.

Exercise as a treatment for chronic low back pain.

BACKGROUND CONTEXT: Exercise is a widely prescribed treatment for chronic low back pain, with demonstrated effectiveness for improving function and work. PURPOSE: The goal of this article is to review several key aspects about the safety and efficacy of exercise that may help clinicians understand its utility in treating chronic back pain. STUDY DESIGN/SETTING: A computerized literature search of MEDLINE was conducted using "exercise," "fitness," "back pain," "backache" and "rehabilitation" as search words. Identified abstracts were scanned, and useful articles were acquired for further review. Additional references were acquired through the personal collections of research papers possessed by the authors and by reviewing prior review articles on this subject. These final papers were scrutinized for data relevant to the key aspects about exercise covered in this article. RESULTS: For people with acute, subacute or chronic low back pain, there is no evidence that exercise increases the risk of additional back problems or work disability. To the contrary, current medical literature suggests that exercise has either a neutral effect or may slightly reduce risk of future back injuries. Exercise can be prescribed for patients with chronic low back pain with three distinct goals. The first and most obvious goal is to improve or eliminate impairments in back flexibility and strength, and improve performance of endurance activities. There is a large body of evidence confirming that this goal can be accomplished for a majority of patients with chronic low back pain. The second goal of exercise is to reduce the intensity of back pain. Most studies of exercise have noted overall reduction in back pain intensity that ranges from 10% to 50% after exercise treatment. The third goal of exercise is to reduce back pain-related disability through a process of desensitization of fears and concerns, altering pain attitudes and beliefs and improving affect. The mechanisms through which exercise can accomplish this goal have been the subject of substantial research. CONCLUSIONS: Exercise is safe for individuals with back pain, because it does not increase the risk of future back injuries or work absence. Substantial evidence exists supporting the use of exercise as a therapeutic tool to improve impairments in back flexibility and strength. Most studies have observed improvements in global pain ratings after exercise programs, and many have observed that exercise can lessen the behavioral, cognitive, affect and disability aspects of back pain syndromes.

Comparison of four tests of quadriceps strength in L3 or L4 radiculopathies.

STUDY DESIGN: This prospective cohort study evaluated four office tests of quadriceps strength in symptomatic adults with radiographic evidence of L3 or L4 nerve root compression. OBJECTIVE: The study observed the performance of each test for its ability to detect quadriceps weakness when compared to the asymptomatic side. To determine the potential influence of radicular pain on the performance of the four tests, a control group of patients over the age of 40 with clinical and radiographic L5 or S1 radiculopathies underwent identical testing of quadriceps strength. SUMMARY OF BACKGROUND DATA: The L3 and L4 nerve roots innervate the quadriceps; therefore, quadriceps weakness may be a consequence of L3 or L4 radiculopathies. There are no standardized or validated methods to evaluate quadriceps strength in the clinical office setting. This may lead to inconsistent detection by clinicians of quadriceps weakness in cases of L3 or L4 radiculopathy. METHODS: Thirty-three consecutive patients with L3 or L4 radiculopathies and 19 with L5 or S1 radiculopathies were studied. The four tests of quadriceps strength included: 1) single leg sit-to-stand test; 2) step-up test; 3) knee-flexed manual muscle testing; and 4) knee-extended manual muscle testing. Results from a second examiner repeating the four tests were used to calculate interrater reliability. RESULTS: In L3 and L4 radiculopathies, unilateral quadriceps weakness was detected by the single leg sit-to-stand test in 61%, by knee-flexed manual muscle testing in 42%, by step-up test in 27% and by knee-extended manual muscle testing in 9% of patients. The sit-to-stand test detected weakness in all but one case when weakness was detected by another test. All patients with L5 or S1 radiculopathies could perform the sit-to-stand test. Kappa coefficient was high for sit-to-stand test (0.85), step-up (0.83), and knee-flexed manual muscle testing (0.66), and low for knee-extended manual muscle testing (0.08). CONCLUSION: In L3 and L4 radiculopathies, unilateral quadriceps weakness was best detected by a single leg sit-to-stand test. Patients of similar age with radicular pain caused by L5 or S1 radiculopathies could perform this test. As the interrater reliability of the single leg sit-to-stand test is high, clinicians should consider utilizing this test for assessing quadriceps strength in cases of L3 and L4 radiculopathies.