Reliability of zygapophysial joint space measurements made from magnetic resonance imaging scans of acute low back pain subjects: comparison of 2 statistical methods.
ABSTRACT This purpose of this study was to assess the reliability of measurements made of the zygapophysial (Z) joint space from the magnetic resonance imaging scans of subjects with acute low back pain using new equipment and 2 different methods of statistical analysis. If found to be reliable, the methods of Z joint measurement can be applied to scans taken before and after spinal manipulation in a larger study of acute low back pain subjects.
Three observers measured the central anterior-to-posterior distance of the left and right L4/L5 and L5/S1 Z joint space from 5 subject scans (20 digitizer measurements, rounded to 0.1 mm) on 2 separate occasions separated by 4 weeks. Observers were blinded to each other and their previous work. Intra- and interobserver reliability was calculated by means of intraclass correlation coefficients and also by mean differences using the methods of Bland and Altman (1986). A mean difference of less than +/-0.4 mm was considered clinically acceptable.
Intraclass correlation coefficients showed intraobserver reliabilities of 0.95 (95% confidence interval, 0.87-0.98), 0.83 (0.62-0.92), and 0.92 (0.83-0.96) for each of the 3 observers and interobserver reliabilities of 0.90 (0.82-0.95), 0.79 (0.61-0.90), and 0.84 (0.75-0.90) for the first and second measurements and overall reliability, respectively. The mean difference between the first and second measurements was -0.04 mm (+/-1.96 SD = -0.37 to 0.29), 0.23 (-0.48 to 0.94), 0.25 (-0.24 to 0.75), and 0.15 (-0.44 to 0.74) for each of the 3 observers and the overall agreement, respectively.
Both statistical methods were found to be useful and complementary and showed the measurements to be highly reliable.
Full-textDOI: · Available from: Jerrilyn Cambron, May 05, 2014
SourceAvailable from: Jennifer Dexheimer[Show abstract] [Hide abstract]
ABSTRACT: OBJECTIVE: The purpose of this study was to quantify lumbar zygapophyseal (Z) joint space separation (gapping) in low back pain (LBP) subjects after spinal manipulative therapy (SMT) or side-posture positioning (SPP). METHODS: This was a controlled mechanisms trial with randomization and blinding. Acute LBP subjects (N = 112; four n = 28 magnetic resonance imaging [MRI] protocol groups) had 2 MRI appointments (initial enrollment and after 2 weeks of chiropractic treatment, receiving 2 MRI scans of the L4/L5 and L5/S1 Z joints at each MRI appointment. After the first MRI scan of each appointment, subjects were randomized (initial enrollment appointment) or assigned (after 2 weeks of chiropractic treatment appointment) into SPP (nonmanipulation), SMT (manipulation), or control MRI protocol groups. After SPP or SMT, a second MRI was taken. The central anterior-posterior joint space was measured. Difference between most painful side anterior-posterior measurements taken postintervention and preintervention was the Z joint "gapping difference." Gapping differences were compared (analysis of variance) among protocol groups. Secondary measures of pain (visual analog scale, verbal numeric pain rating scale) and function (Bournemouth questionnaire) were assessed. RESULTS: Gapping differences were significant at the first (adjusted, P = .009; SPP, 0.66 ± 0.48 mm; SMT, 0.23 ± 0.86; control, 0.18 ± 0.71) and second (adjusted, P = .0005; SPP, 0.65 ± 0.92 mm; SMT, 0.89 ± 0.71; control, 0.35 ± 0.32) MRI appointments. Verbal numeric pain rating scale differences were significant at first MRI appointment (P = .04) with SMT showing the greatest improvement. Visual analog scale and Bournemouth questionnaire improved after 2 weeks of care in all groups (both P < .0001). CONCLUSIONS: Side-posture positioning showed greatest gapping at baseline. After 2 weeks, SMT resulted in greatest gapping. Side-posture positioning appeared to have additive therapeutic benefit to SMT.Journal of manipulative and physiological therapeutics 05/2013; 36(4). DOI:10.1016/j.jmpt.2013.04.003 · 1.25 Impact Factor
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ABSTRACT: OBJECTIVES: The purpose of this study was to use previously validated methods to quantify and relate 2 phenomena associated with chiropractic spinal manipulative therapy (SMT): (1) cavitation and (2) the simultaneous gapping (separation) of the lumbar zygapophyseal (Z) joint spaces. METHODS: This was a randomized, controlled, mechanistic clinical trial with blinding. Forty healthy participants (18-30 years old) without a history of low-back pain participated. Seven accelerometers were affixed to the skin overlying the spinous processes of L1 to L5 and the S1 and S2 sacral tubercles. Two additional accelerometers were positioned 3 cm left and right lateral to the L4/L5 interspinous space. Participants were randomized into group 1, side-posture SMT (n = 30), or group 2, side-posture positioning (SPP, n = 10). Cavitations were determined by accelerometer recordings during SMT and SPP (left side = upside for both groups); gapping (gapping difference) was determined by the difference between pre- and postintervention magnetic resonance imaging scan joint space measurements. Results of mean gapping differences were compared. RESULTS: Upside SMT and SPP joints gapped more than downside joints (0.69 vs -0.17 mm, P < .0001). Spinal manipulative therapy upside joints gapped more than SPP upside joints (0.75 vs 0.52 mm, P = .03). Spinal manipulative therapy upside joints gapped more in men than in women (1.01 vs 0.49 mm, P < .002). Overall, joints that cavitated gapped more than those that did not (0.56 vs 0.22 mm, P = .01). No relationship was found between the occurrence of cavitation and gapping with upside joints alone (P = .43). CONCLUSIONS: Zygapophyseal joints receiving chiropractic SMT gapped more than those receiving SPP alone; Z joints of men gapped more than those of women, and cavitation indicated that a joint had gapped but not how much a joint had gapped.Journal of manipulative and physiological therapeutics 08/2012; DOI:10.1016/j.jmpt.2012.06.007 · 1.25 Impact Factor
Conference Paper: A new measure of EEG synchronization[Show abstract] [Hide abstract]
ABSTRACT: Reports a technique for studying synchronization. A general mathematical technique is developed for investigating synchronization among many subsystems of a system. The frequency-wavenumber spectrum is explored to derive an objective measure of the synchronization coefficient (SC). The problems concerning the correlation and coherence methods of quantifying synchronization are solved by this technique. The technique is validated by various simulation studies and is then applied to a biological system: the brain, for electroencephalogram (EEG) synchronization. The usefulness of the technique is demonstrated for eight channels of electrocorticogram (ECoG) data recorded from one row of a subdural grid. The technique has the potential of being an objective measure of synchronization in general and of brain synchronization in particular. The principle of the technique may be applied to any system for investigating synchronizationEngineering in Medicine and Biology Society, 1997. Proceedings of the 19th Annual International Conference of the IEEE; 01/1997