Lumbar Protective Mechanism: Inter-rater and Intra-rater Reliability of a Clinical Test
Mark Paterson
The concept of “core strength” is well known in the orthopedic physical therapy community. It is widely agreed upon that appropriate core strength is a necessary component of low back health and musculoskeletal efficiency. The loss of core responsiveness after an episode of low back pain has also been well documented in the literature. In spite of this, there is no agreed upon definition of “core strength” and no gold standard for measuring it. The “Lumbar Protective Mechanism” (LPM) test is a test of core strength that has functional applicability because it is performed with the subject in a diagonal stance position. This allows for testing of the core in a position similar to what would be naturally assumed for most pushing and pulling activities. With the subject standing with either the right or left foot forward, the tester applies a pushing (flexion) and pulling (extension) force through the shoulder region. Trunk responsiveness and strength is measured on a 0-5 Likert scale with “0” meaning inappropriate response and 1-5 being similar to the manual muscle testing scale. Although this test has been used in the clinic, it has not been tested for reliability or validity. The purpose of this study is to test the intra-rater and inter-rater reliability of the lumbar protective mechanism test.