Cut-off point for diagnosing thoraco-lumbo-pelvic rotation range hypomobility through the leg lateral reach test in chronic low back pain: a cross-sectional study.

BACKGROUND

Studies have proposed using the leg lateral reach test (LLRT). However, they did not establish a cut-off point for testing.

OBJECTIVE

To establish a cut-off point for the thoraco-lumbo-pelvic rotation range using the LLRT in patients with chronic low back pain.

DESIGN AND

SETTING

Cross-sectional study conducted in Buriticupu, Maranhão, Brazil.

METHODS

In the chronic low back pain group (LBPG, n = 35), we included patients aged 18 to 59 years, of both sexes, with scores ≤ 4 on the Baecke Habitual Physical Activity Questionnaire, body mass indeces ≤ 26 kg/m2, disability levels ≥ 3 on the Roland-Morris Disability Questionnaire, and pain levels ≥ 3 on the Numeric Pain Rating Scale. In the healthy control group (HCG, n = 35), the patients had the same characteristics (except for pain and disability). We used receiver operating characteristic curves to check the rate of true versus false positives in different LLRT ranges of motion and found the best LLRT cut-off point using the following mathematical model: (1 - sensitivity)2 + (1 - specificity)2.

RESULTS

The sample was mainly composed of females (HCG = 65.71%; LBPG = 82.85%, P = 0.101), and 68.42% of the characteristics (13 of 19 comparisons between groups) showed a significant difference (P ≤ 0.05), with an effect size ranging from moderate to large (Cohen's d ≥ 0.5). The cut-off value for ideal sensitivity and specificity was ≤ 82.85 cm.

CONCLUSION

Patients with chronic low back pain and an LLRT range ≤ 82.85 cm have hypomobility regarding thoraco-lumbo-pelvic rotation range.