Quantification of Walking Ability in Participants 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 functio

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

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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.</p> <p>Results</p> <p>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 (<it>ß </it>[SE} 0.28 (0.08); p = 0.002).</p> <p>Conclusions</p> <p>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.</p