Inter-rater and test-retest reliabilities of lumbar stiffness measurement in the postero-anterior direction using a portable algometer and the Kinovea program.

Background: Back pain negatively impacts a person's quality of life and can cause major disability or even death. The measurement of spinal stiffness can be utilized as a promising tool to guide therapeutic decisions regarding physical therapy that result in effective back pain management. This study aimed to determine the reliability of instrumented postero-anterior (PA) stiffness assessment of the lumbar spine in asymptomatic participants by novice assessors using a portable algometer and the Kinovea program. Methods: Thirty asymptomatic participants aged 18-25 years were enrolled in this study. Two novice assessors examined the participants for lumbar spinal stiffness at L1-L5 for two consecutive days. The algometer was applied to measure the PA force that applied to each lumbar. The stiffness assessment of each lumbar region was recorded as a video. The 600 data sets of assessment videos were imported into the Kinovea program to perform displacement measurements of each lumbar level. Spinal displacement values at 15 N were defined by graph plotting between force and displacement. The spinal stiffness values were defined by slope calculation. Both variables were analyzed for inter-rater and test-retest reliabilities using intra-class correlation coefficients (ICCs) and standard error of measurement (SEM). Bland-Altman analysis was applied to assess the inter-rater and test-retest systematical bias and limits of agreement of measuring displacement and stiffness. Results: The inter-rater reliability of measuring the displacement and the stiffness of L1-L5 was moderate to good (displacement ICCs: 0.67-0.83, stiffness ICCs: 0.60-0.83). The test-retest reliability of measuring the displacement and stiffness of L1-L5 were moderate to good, ICCs: 0.57-0.86 and ICCs: 0.51-0.88, respectively. The inter-rater analysis's Bland-Altman plot showed that the systematic bias was 0.83 when measuring displacement and 0.20 when measuring stiffness and the bias of both parameters were in both directions. While the test-retest systematically biased measurements of displacement and stiffness were -0.26 mm and 0.22 N/mm, respectively, and the bias of both parameters were in both directions. Conclusions: The moderate-to-good inter-rater and test-retest reliabilities of the portable instrumented spinal stiffness assessment using a digital algometer and the Kinovea program by novice assessors were demonstrated in this study. Bland-Altman analysis showed that measuring stiffness was more stable and had less systematic bias than measuring displacement. To figure out how reliable the device is in general, more comprehensive studies should be comparatively conducted in the future on subgroups of patients with normal vertebra, hypomobile or hypermobile conditions.

A Screening Tool for Patients With Lumbar Instability: A Content Validity and Rater Reliability of Thai Version.

OBJECTIVE: Lumbar instability is a condition that has been extensively reported in its prevalence and its effect on patients. To date, however, a clinical screening tool for this condition has not been developed for use in Thailand. The objectives of this study were to translate and test the content validity and rater reliability of a screening tool for evaluating Thai patients with lumbar instability. METHODS: The investigators selected the lumbar instability questionnaire from an original English version. Elements of the tool comprised the dominant subjective findings reported by this clinical population. The screening tool was translated into the Thai language following a process of cross-cultural adaptation. The index of item-objective congruence (IOC) was checked for content validity by 5 independent experts. Seventy-five Thai patients with chronic nonspecific low back pain were asked to report their symptoms. The interview procedure using the tool was conducted by expert and novice physical therapists, which informed the intraclass correlation coefficient (ICC) for inter- and intrarater reliability. RESULTS: The IOC was 0.95. The interrater ICC between expert and novice physical therapists was 0.92 (95% CI = 0.88-0.95). The intrarater ICC of novice physical therapist was 0.91 (95% CI = 0.86-0.94). CONCLUSION: The Thai version of the screening tool for patients with lumbar instability achieved excellent content validity and interrater and intrarater reliability. This screening tool is recommended for use with Thai patients with low back pain to identify the subpopulation with lumbar instability.

Altered postural sway during quiet standing in women with clinical lumbar instability.

[Purpose] The current study aimed to investigate the center of pressure, as an indicator of postural sway, to determine any differences between women with clinical lumbar instability and asymptomatic low back pain. [Participants and Methods] Thirty healthy and fifteen clinical lumbar instability participants were measured for their postural sway in the anterior-posterior and medial-lateral directions. The women were tested for postural sway on a force plate in quiet standing and eyes closed. Center of pressure path length and mean velocity in the anterior-posterior and medial-lateral directions and total area of excursion were measured and analyzed for 30 seconds. [Results] Clinical lumbar instability participants showed a significantly increase when compared with healthy participants, in path length and mean velocity in both directions and total area of excursion. [Conclusion] The findings suggest that chronic low back pain patients with clinical lumbar instability have increased postural sway when vision is deprived. The clinical significance of this has not yet been determined but may provide an opportunity for therapy directed at improving balance control in this patient group.

Prevalence and individual risk factors associated with clinical lumbar instability in rice farmers with low back pain.

INTRODUCTION: Clinical lumbar instability (CLI) is one of the subgroups of chronic non-specific low back pain. Thai rice farmers often have poor sustained postures during a rice planting process and start their farming at an early age. However, individual associated factors of CLI are not known and have rarely been diagnosed in low back pain. This study aimed to determine the prevalence and individual associated factors of CLI in Thai rice farmers. METHODS: A cross-sectional survey was conducted among 323 Thai rice farmers in a rural area of Khon Kaen province, Thailand. Face-to-face interviews were conducted using the 13-item Delphi criteria questionnaire, after which an objective examination was performed using aberrant movement sign, painful catch sign, and prone instability test to obtain information. Individual factors such as sex, body mass index, waist-hip ratio, smoking, and number of years of farming experience, were recorded during the face-to-face interview. RESULTS: The prevalence of CLI in Thai rice farmers calculated by the method described in this study was 13% (age 44±10 years). Number of years of farming experience was found to be significantly correlated with the prevalence of CLI (adjusted odds ratio =2.02, 95% confidence interval =1.03-3.98, P<0.05). CONCLUSION: This study provides prevalence of CLI in Thai rice farmers. Those with long-term farming experience of at least 30 years have a greater risk of CLI.