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Biomedical subjects

M R Nourbakhsh

Publications and source records attributed to M R Nourbakhsh.

2 recordsLinked to original sources

Effects of lifestyle and work-related physical activity on the degree of lumbar lordosis and chronic low back pain in a Middle East population.

The relationship between the degree of lumbar lordosis and chronic low back pain (LBP) has long been speculated. It is postulated that prolonged sitting and sedentary lifestyle might change the degree of lumbar lordosis and cause LBP. The purpose of this study was to determine the effects of lifestyle, exercise, work setting, work intensity, and other demographic factors such as age, height, weight, and gender on the degree of lumbar lordosis and occurrence of LBP. Eight hundred forty subjects between ages 20 and 65 years were equally categorized into four groups: normal male, normal female, males with LBP, and females with LBP. A questionnaire was used to obtain information about the subject's lifestyle, work setting, level of exercise, and work-related physical activity. A flexible ruler was used to measure lumbar lordosis in all subjects. The average degree of lumbar lordosis for all subjects was 37 degrees +/- 13 degrees. Females had greater lumbar lordosis (42 degrees +/- 15 degrees ) than males did (32 degrees +/- 10 degrees ). There was no significant difference in the degree of lumbar lordosis in subjects with different lifestyle (p = 0.97), level of physical activity (p = 0.36), work setting (p = 0.5), and with or without LBP (p = 0.28). The degree of lumbar lordosis was positively related with the number of pregnancies (p = 0.04, r = 0.25), age (p = 0.02, r = 0.1) and height (p = 0.0001, r = 0.31) and negatively related with weight (p = 0.04, r = 0.06) of the subjects. The likelihood of developing LBP was significantly higher in the subjects who had high work-related physical activity (p = 0.03) and those who exercised less often (p = 0.008). We found no significant relationship between LBP occurrence and the degree of lumbar lordosis (p = 0.68), work setting (p = 0.15), height (p = 0.08), weight (p =0.06), and age (p = 0.67) of the subjects. The degree of lumbar lordosis was not different between normal subjects and those with LBP. Lumbar lordosis was not affected by lifestyle, level of physical activity, or type of work setting. Although these factors have not been found to affect the degree of lumbar lordosis, some affected the occurrence of LBP. This finding indicates that the effect of these factors on LBP involves mechanisms other than changing the degree of lumbar lordosis.

Adult↗

The statistical analysis of single-subject data: a comparative examination.

BACKGROUND AND PURPOSE: The purposes of this study were to examine whether the use of three different statistical methods for analyzing single-subject data led to similar results and to identify components of graphed data that influence agreement (or disagreement) among the statistical procedures. METHODS: Forty-two graphs containing single-subject data were examined. Twenty-one were AB charts of hypothetical data. The other 21 graphs appeared in Journal of Applied Behavioral Analysis, Physical Therapy, Journal of the Association for Persons With Severe Handicaps, and Journal of Behavior Therapy and Experimental Psychiatry. Three different statistical tests--the C statistic, the two-standard deviation band method, and the split-middle method of trend estimation--were used to analyze the 42 graphs. RESULTS: A relatively low degree of agreement (38%) was found among the three statistical tests. The highest rate of agreement for any two statistical procedures (71%) was found for the two-standard deviation band method and the C statistic. A logistic regression analysis revealed that overlap in single-subject graphed data was the best predictor of disagreement among the three statistical tests (beta = .49, P < .03). CONCLUSION AND DISCUSSION: The results indicate that interpretation of data from single-subject research designs is directly influenced by the method of data analysis selected. Variation exists across both visual and statistical methods of data reduction. The advantages and disadvantages of statistical and visual analysis are described.

Data Interpretation, Statistical↗