As a muscle activity characteristic of patients with chronic low back pain, the "flexion relaxation phenomenon" in which the back muscles relax in the complete flexion position (bowing posture) when the trunk is flexed (bowed) in the standing position is attenuated or disappears. Has been reported.It has also been reported that the muscle activity of the back muscle group is enhanced or weakened when the trunk is extended from the fully flexed position (the body is raised from the bow).
On the other hand, the relationship between these characteristic muscle activities and pain-related factors in patients with chronic back pain has not been fully clarified.In particular, since it is unclear whether these factors change at the same time or whether one of them changes in advance, Hayato Shigeto and Shu Morioka of the doctoral program at Kio University Graduate School have decided. Muscle activity and pain-related factors in one case with chronic low back pain were evaluated over time and examined using cross-lag correlation analysis in a single case.
As a muscle activity index, the muscle activity of the erector spinae muscles during the standing body anteflexion task was evaluated over time using a surface electromyogram.As pain-related factors, four indexes of pain (pain), disability, physical paresthesia, and psychological factors were evaluated over time.
As a result of examining the correlation between the muscle activity index and the pain-related factors at the same time, a significant correlation was found between the flexion relaxation ratio calculated as an index of the flexion relaxation phenomenon and the physical paresthesia.In addition, a correlation was confirmed between muscle activity during trunk extension, pain, psychological factors, and disability.That is, improvement of the decrease in flexion relaxation phenomenon in standing body forward bending and improvement of physical paresthesia occur at the same time, improvement of muscle activity when extending the trunk and improvement of pain, psychological factors, and disability. It was shown to occur at the same time.
This result clarifies for the first time that improvement of muscle activity abnormality and improvement of pain-related factors occur at the same time in patients with chronic low back pain, and conversely, changes in pain-related factors over time become changes in muscle activity over time. It suggests that it will affect you.In the future, the researchers will consider approaches to muscle activity in patients with chronic low back pain that take pain-related factors into consideration.
