Design: Forty-two (42) subjects suffering from chronic low-back pain were matched with the nature of their occupations and then randomly allocated into: (1) an electroacupuncture group (EA); (2) an electrical heat acupuncture (EH) group or; (3) a control group.
Interventions: Subjects in the EA group and the EH group received treatment for 20 minutes on a total of 6 acupuncture points. Treatment was delivered twice per week for 4 weeks (a total of 8 sessions). Back exercise was taught to all subjects including the control group as a home program.
Outcomes measures: A numerical rating scale of pain (NPRS), straight leg raise (SLR), and Roland Morris Disability Questionnaire (RMDQ) were recorded.
Results: There were significant reduction of NPRS within the EA (p = 0.000), EH (p = 0.000), and control (p = 0.013) groups across sessions. Significant between-group differences were shown in session 4 (p = 0.006), session 8 (p = 0.001), and 1-month follow-up sessions (p = 0.001). Posthoc tests showed that the NPRS of the EH group was significantly lower than that of the EA group and the control group by session 4 (p = 0.004). After session 8, the NPRS of both the EA group (p = 0.003) and the EH group (p = 0.001) were significantly lower than that of the control group. Such a difference was maintained at least up to the 1-month follow-up. Only the EA group had significant improvement in the measurement of SLR across sessions (p = 0.000). The between-group difference reached significance level in session 8 (p = 0.001) and at 1-month follow-up (p = 0.002). Posthoc tests showed that EA group had significantly greater gain than the EH group and the control group. For the RMDQ score, the improvement was statistically significant within each of the three groups over time (p = 0.000). However, the between-group difference did not reach statistical significance.
Conclusions: Our findings suggest that 4 sessions of EH treatment over 2 weeks produced significantly greater reduction in the NPRS than that of the EA or the control. However, EA produced greater improvement in SLR and reduction in RMDQ score than that of the EH and the control.