Abstract: Objective To investigate the features of gait in patients with lumbar disc herniation suffering low back pain radiating to the unilateral lower limbs during walking, and estimate the test-retest reliability of the plantar pressure distribution. Methods 32 patients of lumbar disc herniation with low back pain radiating to the unilateral lower limb were tested with the Footscan plantar system during normal walking for 5 times. The gait phases, contacting time of every plantar region and maximum force were recorded in both the uneffected and the affected lower limbs in patients. The reliability was estimated with the intraclass correlation coefficient (ICC). Results There were significant differences between the uneffected and the affected lower limbs in the gait phase except for the Initial Contact Phase. The Forefoot Contact Phase and Foot Flat Phase of the affected lower limbs were obvious shorter than the uneffected ones (P<0.01), while the Forefoot Push Off Phase was longer (P<0.01). Except for the region of Metatarsal 5, the contacting time of every plantar region of the affected lower limbs were lower than the uneffected ones (P<0.05). The maximum force of regions of Metatarsal 4, Metatarsal 5 and Heel Lateral were lower in the affected limbs than the uneffected ones (P<0.05). ICCs of gait phase, the contacting time of every plantar region and maximum force were generally over 0.76. Conclusion Differences were found in gait phase, the contacting time of every plantar region and maximum force between the uneffected and the affected lower limbs in patients with lumbar disc herniation. All the variables are reliable for test-retest.

Key words: lumbar disc herniation, gait, plantar pressure, test-retest reliability