Interrater reliability of a movement impairment-based classification system for lumbar spine syndromes in patients with chronic low back pain

STUDY DESIGN: A prospective methodological study of interrater reliability. OBJECTIVES: To examine the interrater reliability of a movement impairment-based classification system for patients with chronic low back pain (LBP). BACKGROUND: Movement impairment-based classification for the lumbar spine categorizes LBP based on the findings derived from a patient history and standardized examination. Though many presume this classification to be useful for directing treatment of individuals with LBP, agreement between examiners for assigning a lumbar spine category to a patient has not been studied thoroughly. METHODS AND MEASURES: Two physical therapists independently examined 24 patients (8 men, 16 women) with chronic LBP (pain duration greater than 12 weeks). All patients enrolled in the study had been diagnosed with LBP that was believed to be due to mechanical causes, and the duration of their symptoms ranged from 20 to 1040 weeks. The examiners used a standardized examination to assess patients and classify them into 1 of 5 lumbar spine categories. Percent agreement and kappa coefficients were calculated between the examiners for the lumbar movement impairment-based classifications. RESULTS: Percent agreement between examiners was 75% and the kappa coefficient was 0.61. he most prevalent lumbar spine categories identified by both examiners were lumbar extension rotation syndrome (41.7% of patients by examiner 1, 37.5% of patients by examiner 2) and lumbar rotation syndrome (41.7% of patients by both examiners). CONCLUSIONS: Interrater reliability between 2 physical therapists classifying patients with chronic LBP into 1 of 5 lumbar spine movement impairment categories had substantial agreement.