Energy Consumption during Walking among Patients with Non-specific Chronic Low Back Pain, based on Physiological Cost Index

low back pain (LBP) is one of the most common and crucial health problems, which is difficult to treat and manage, causing an enormous economic burden on individuals, families, communities and governments. Walking as a usual and basic daily activity in order to have an independent life, is necessary. However, it seems that musculoskeletal sufferers like NCLBP patients spend more energy than normal individuals during walking. So, the purpose of this research is to evaluate energy consumption of patients with non-specific chronic low back pain during walking, compared with normal individuals this is a cross- sectional, case- control study, in which 2 groups of 16 (normal and patients) individuals participated in spring of 2013. Energy consumption was assessed during walking, based on the Physiological Cost Index (PCI), as a clinical tool. Difference between the mean values of walking speed and PCI was measured using two sample t-test amongst the participants. heart rate (HR) of normal individuals is significantly different from HR of those with NCLBP during resting and walking (P-value<0. 05). The mean value of walking speed of normal subjects was 76. 05 ± 5. 7 m/min compared to 69. 17 ± 7. 83 m/min in NCLBP patients (p-value = 0. 006). The PCI, measuring the difference between walking HR and resting HR in different walking speeds, was also significantly different between the two groups (0. 298 ± 0. 06 in normal individuals and 0. 388 ± 0. 098 in NCLBP patients). the results of this study showed that energy consumption of patients with NCLBP is more than that of the normal individuals due to insufficiency of heart muscular activity as a result of inactivity, or due to decrease in walking speed.