Effects of training frequency on lumbar extension strength in patients recovering from lumbar dyscectomy

Abstract

To determine the effects of lumbar extension exercise on strength, disability index, and pain scores in patients after lumbar discectomy surgery. Prospective comparative study. Forty patients experiencing a herniated disc at lumbar levels were divided into 4 subgroups for different training frequencies: twice/week (group 1), once/week (group 2), once/2 weeks (group 3), and no training (control). After completing the initial 12-week training, all subjects participated in a 12-week follow-up training. Groups 1 and 2 showed significant increases in lumbar extension strength (26 Nm and 7 Nm, respectively), while group 3 and the control group showed significant decreases in lumbar extension strength. Groups 1 and 2 showed significant decreases in disability index (1.4 and 0.8 Oswestry Disability Index points, respectively), and group 1 showed significant decreases in back and leg pain scores (both 0.5 units on a 10-cm visual analog scale). Lumbar extension strength and disability index improve with training frequencies of once and twice per week, while back and leg pain improve with a training frequency of twice per week. The clinical importance of these improvements is questionable, as the scores were already very low after the discectomy and the magnitude of absolute improvements were small.