Relationship between Lumbar Clinical Instability and Muscle Onset Time during Prone Hip Extension in Individuals with Chronic Low Back Pain

Abstract

[Purpose] The aim of this study was to clarify the relationship between lumbar clinical instability and muscle onset time during prone hip extension in individuals with chronic low back pain. [Subjects] Twenty-five subjects with chronic low back pain were recruited. [Methods] Electromyography data of the back muscles were collected during prone hip extension. The prone instability test and aberrant movement patterns during lumbar flexion test were used as lumbar clinical instability tests. The relationships between lumbar clinical instability and onset timing of the muscles during prone hip extension were analyzed using correlation coefficients. [Results] Greater delays in the onset of the bilateral multifidus and contralateral erector spinae activities during prone hip extension correlated positively with the prone instability test findings. [Conclusion] Greater delays in the onset of the bilateral multifidus and contralateral erector spinae activities during prone hip extension correlated positively with the lumbar clinical instability test findings.