BACKGROUND Kendall’s approach is used to test the muscles strength and to determine the correct alignment of the muscle fibers. The major causes of back pain are work related problem, mechanical stress on muscles and faulty postures, which leads to core muscle weakness particularly rectus abdominis or may cause DRA. Thus the study aims to identify a causal relationship between low back pain and rectus abdominis muscle weakness using Kendall’s grading scale. STUDY DESIGN Cross Sectional Study SAMPLING TECHNIQUE Non-probability convenience sampling technique METHODOLOGY 142 (men 33.80% and women 66.20%) participants with low back pain were recruited in the study. The Kendall grading scale test the strength of muscles of the upper and lower rectus abdominis muscles among the participants while self-administered questionnaire was used to identify the nature of the back pain. RESULT Sperman’s rho coefficient of correlation was applied to find out the cause effective correlation between the two variables, result shows no significant cause effective correlation between the upper and lower back pain and lower rectus abdominis muscles weakness (P>0.05) with r= 0.065 and r=0.031respectively. CONCLUSION Although core muscle weaknesses are the source of back pain but no significant cause effective correlation exist between the two variables in this study.