segmental extension following the intervention was defined as follows:(posttreatment end-range vertebral angle pretreatment resting vertebral angle) (pretreatment end-range vertebral angle pretreatment resting vertebral angle).
As calculated with this equation, a positive value indicated an increase in extension for a particular functional spinal unit, whereas a negative value indicated a decrease in extension.Total lumbar extension was quantified by summing the intervertebral motion at each of the 5 functional units of the lumbar spine. The investigator doing all image analysis was unaware of each subject’s treatment group assignment.
Measurement reliability. To establish the intratester reliability of the proposed measurements, dynamic MR images were obtained from 5 volunteers who were healthy on 2 separate occasions (1 week a part). Intraclass correlation coefficients were found to be excellent,ranging from .95 to .99 for all subjects. The standard error of measurement ranged from 0.40 to 0.66 degrees.
Determination of statistical power. Data from a previous publication indicated that the intersubject variability with respect to intersegmental motion in people who were healthy was moderate. However, it was anticipated that the variability in the tested population would be 50% greater. Therefore, all power calculations took this increased variability into consideration. Furthermore, all power calculations were based on an alpha level of .05 for a one-tailed test. Given 15 subjects per treatment group, the chances of detecting a 25% decrease in pain response and a 25% increase in lumbar segmental extension were 85% and 98%, respectively, for both interventions.
Data Analysis
Differences between the treatment groups in pain and total lumbar extension were compared over time by use of a 22 analysis of variance (ANOVA) (group time) with repeated measures. If significant interactions were observed, then the individual main effects were considered separately. Statistical analyses were performed with SPSS software, version 11.0. All significance levels were set at P
segmental extension following the intervention was defined as follows:(posttreatment end-range vertebral angle pretreatment resting vertebral angle) (pretreatment end-range vertebral angle pretreatment resting vertebral angle).As calculated with this equation, a positive value indicated an increase in extension for a particular functional spinal unit, whereas a negative value indicated a decrease in extension.Total lumbar extension was quantified by summing the intervertebral motion at each of the 5 functional units of the lumbar spine. The investigator doing all image analysis was unaware of each subject’s treatment group assignment.Measurement reliability. To establish the intratester reliability of the proposed measurements, dynamic MR images were obtained from 5 volunteers who were healthy on 2 separate occasions (1 week a part). Intraclass correlation coefficients were found to be excellent,ranging from .95 to .99 for all subjects. The standard error of measurement ranged from 0.40 to 0.66 degrees.Determination of statistical power. Data from a previous publication indicated that the intersubject variability with respect to intersegmental motion in people who were healthy was moderate. However, it was anticipated that the variability in the tested population would be 50% greater. Therefore, all power calculations took this increased variability into consideration. Furthermore, all power calculations were based on an alpha level of .05 for a one-tailed test. Given 15 subjects per treatment group, the chances of detecting a 25% decrease in pain response and a 25% increase in lumbar segmental extension were 85% and 98%, respectively, for both interventions.Data AnalysisDifferences between the treatment groups in pain and total lumbar extension were compared over time by use of a 22 analysis of variance (ANOVA) (group time) with repeated measures. If significant interactions were observed, then the individual main effects were considered separately. Statistical analyses were performed with SPSS software, version 11.0. All significance levels were set at P<.05.
การแปล กรุณารอสักครู่..