“…Sample size was calculated using the formula for estimation of population prevalence (n = Z , where: n = the desired sample size (when population is greater than 10,000), z = the standard normal deviate, set at 1.96 corresponding to 95% confidence level, p = the proportion of persons with low back pain as reported from previous studies, q = 1.0-p, d = error tolerated, set at 0.05. [17][18][19][20][21] A minimum sample size of 288 was obtained based on the prevalence rate of 25.0% from a previous study among postpartum mothers, [22] a 0.5% degree of precision and 95% confidence interval. Among the nursing mothers attending the postnatal and paediatric clinics of the six selected private hospitals in Enugu Nigeria, 200 women volunteered to participate in the study.…”