Changes in Lumbar Muscle Activity Because of Induced Muscle Pain Evaluated by Muscle Functional Magnetic Resonance Imaging

Abstract

These data demonstrate that unilateral muscle pain can cause hypoactivity of muscles during trunk extension at 40% of the repetition maximum. The changes were not limited to the side and level of pain. Moreover, the inhibition was not limited to the multifidus muscle; also the lumbar erector spinae and psoas muscles showed decreased activity during the pain condition. Further research has to assess possible compensation mechanisms for this reduced activity in other muscles.