Purpose of study: To test the relative effectiveness of interferential therapy (IFT) and manipulative therapy (MT) when used as sole treatments and in combination for the management of acute low back pain (ALBP). Although IFT is the most widely used electrotherapeutic modality in Britain and Ireland for the physiotherapeutic management of patients with LBP, often in combination with MT, its evidence base is weak and limited.
Methods: In this assessor-blinded RCT, consenting subjects recruited from 4 NHS hospitals (n=240) were randomised to receive (1) MT (n=80), (2) IFT (n=80)1 or (3) combined MT and IFT (n=80), as well as a copy of the Back Book. Subjects completed the Roland Morris Disability Questionnaire (primary outcome), VAS, McGill Pain Questionnaire, EuroQol, SF-36 and a range of patient-related variables (secondary outcomes) at baseline, discharge (n=194, 83%), 6 months (n=166, 71%) and 12 months (n=158, 67%).
Results: There were significant improvements in all outcomes at discharge, which were not significantly different from the 6 month and 12 month values for the whole sample. Univariate analysis of covariance detected significant differences between groups in the mean adjusted change scores for SF-36 Physical Functioning (P = 0.03), Bodily Pain (P=0.04), and Mental Health (P = 0.03) scales at 12 months in favour of combined MT and IFT over MT. Although not statistically significant the trend of the change score data for the remaining pain outcomes suggested that subjects in the MT group deteriorated after discharge while those in the IFT and combined therapy groups displayed a more gradual improvement over the follow-up period, such that the MT group outcomes were poorer at 12 months.
Conclusions: The results provide some evidence for the continued use of IFT for short and long-term improvements in function and LBP particularly when used in combination with MT. However, MT alone was less effective for long-term improvements in pain.
