Aim: To investigate the influence of lumbar disc herniation on rheobase and chronaxie in patients with low back pain. Methods:The Strength duration curve, rheobase and Chronaxie in 10 LBP patients with radiculopathy due to lumbar disc herniation and 10 healthy controls were obtained following stimulation of tibialis anterior and peroneus muscles.Results: Tibialis anterior and peroneus muscles in both Low back patients with radiculopathy due to lumbar disc herniation and healthy control showed normal pattern of strength duration curve typical of an innervated muscle. The rheobase and chronaxie values for tibialis anterior were 11.8 ± 1.93 and 0.54 ± 0.014 respectively in LBP patients and 7.4 ± 0.84 and 0.24 ± 0.14 respectively in control subjects. The rheobase and chronaxie values for peroneus muscles were 12.8 ± 2.93 and 0.41 ± 0.07 respectively in LBP patients and 7.6 ± 1.71 and 0.16 ±0.01 respectively control subjects. Rheobase and chronaxie were significantly higher in low back pain patients with radiculopathy than apparently healthy control subjects (P<0.00). Conclusion:Findings from this study demonstrated higher rheobase and chronaxie in patients with LBP and lumbar disc herniation than the control subjects. The outcome of this study will be used to do power size calculation for a large randomised controlled trial.