Measurement properties of a hand-held inclinometer during straight leg raise neurodynamic testing

ObjectivesThe most common lower quarter neurodynamic test is the straight leg raise (SLR) test. Quantification of limb motion during SLR testing should utilize reliable and valid measurement tools that are highly sensitive to change. The purpose of this study was to determine the psychometric properties of a hand-held inclinometer commonly utilized during SLR testing.DesignCross-sectional measurement, intra-rater reliability and validity study.SettingResearch laboratory.ParticipantsTwenty individuals without pain in their low back or extremities and no history of nerve injury participated in the study.Main outcome measuresTwo repetitions of the SLR were performed in each limb in two ankle positions (plantar flexion and dorsiflexion). A digital inclinometer and digital goniometer were utilized as the comparisons for range of motion measurements.ResultsIntra-rater reliability for the hand-held inclinometer during SLR testing was excellent (ICCs, 0.95 to 0.98). The standard error of measurement was between 0.54° and 1.22° and the minimal detectable change was between 1.50° and 3.41°. Construct validity revealed hand-held inclinometer measurements were highly correlated with both the digital inclinometer and digital goniometer measures. The mean difference scores between hand-held inclinometer and digital inclinometer (∼1.5°) and digital goniometer (∼10°) suggest that the hand-held inclinometer better matches the construct measured by the digital inclinometer (limb elevation angle) compared to the digital goniometer (hip flexion angle).ConclusionsThe hand-held inclinometer is a valid method for measuring limb elevation angle during the SLR neurodynamic test in a research setting. The hand-held inclinometer has high reliability and low minimal detectable change when used in healthy individuals.