Correlation Analysis Between Pain Intensity, Functional Disability and Range of Motion Using Low-Level Laser Therapy in Patients With Discogenic Lumbar Radiculopathy: A Cross-sectional Study.

Low-level laser is a pain-free and non-invasive treatment modality. It is used in many acute and chronic painful conditions. This study aimed to determine the correlation between pain intensity, functional disability, and range of motion using low-level laser therapy (LLLT) in patients with discogenic lumbar radiculopathy. This cross-sectional study was conducted as a part of a randomized controlled trial of LLLT to treat patients with discogenic lumbar radiculopathy in physical therapy departments of three different hospitals in Islamabad, Pakistan, from August 2021 to September 2021. The study was conducted according to STROBE guidelines. Fifty-Five patients from the experimental group of the trial were invited to participate in this study. The outcomes of the treatment were recorded on a semi-structured questionnaire on the first day and last day of their treatment from each patient's pain intensity, functional disability, and Lumbar range of motion (L-ROM) (flexion and extension) by using the visual analogue scale (VAS) for pain intensity, Oswestry Disability Index (ODI) for functional disability, and dual inclinometer for L-ROM. The data were analyzed through SPSS version 26.0. The results of the correlation coefficient/Pearson's correlation of VAS, ODI, and dual inclinometer were varied. The strength of correlation between variables was weak to moderate (r=0.033 to 0.425) with statistically insignificant correlation coefficient ( > 0.05, 95% CI) except for lumbar flexion (<0.05, 95% CI). For acute (LBP) with discogenic lumbar radiculopathy, LLLT at a wavelength of 830-nm and a dose of 3J/point in conjunction with conventional physical therapy had no significant correlation, but rather weak to moderate values with pain intensity, functional disability, and L-ROM.