Reliability of dual inclinometer for lumbar range of motion using two different Landmarking techniques

Objective: To measure the intra-rater and inter-rater reliability of active lumbar extension and flexion movements using dual inclinometer with two different landmarking techniques. Method: The reliability study was conducted at the Physical Therapy Department of the University Teaching Hospital, The University of Lahore, Pakistan, in January 2020, and comprised patients of either gender aged >18 years with mild or symptomatic lower back pain, and healthy subjects s controls. Repeated measurements with dual inclinometer were taken by two examiners and data was recorded by two separate observers. A set of three active lumbar extension and flexion movements were performed for an initial warm-up. The examiners repeated a palpation of bony landmarks prior to each trial. The two different landmarking techniques were applied on the lumbar spine to identify the start and end points. Both the examiners measured each participant thrice. For each examiner and each landmarking technique, the three data sets were acquired for active lumbar extension and flexion for a total of 120 sets per session per examiner per landmarking. Each set comprised three alternating active lumbar extension and flexion movements. Data was analysed using SPSS version 26. Results: Of the 40 subjects with mean age 27.8+11.0 years, 19(48%) were males and 21(52%) were females. There were 15(38%) cases; 6(40%) males and 9(60%) females. The remaining 25(62%) were controls. The two landmarking techniques with dual inclinometer produced a high to very high intra-rater reliability (intraclass correlation coefficient:0.73-0.91) for both lumbar extension and flexion movements with moderate to low standard error of measurement values (0.36-1.31), while a high inter-rater reliability (intraclass correlation coefficient: 0.72-0.76; standard error of measurement: 0.52-0.63) for extension measurements and only moderate inter-rater reliability (intraclass correlation coefficient: 0.59-0.65; standard error of measurement: 1.36-1.49) for flexion measurements. Conclusion: Dual inclinometer along with skilled examiners and accurate landmarking methodology provided clinically reliable measurements.