Abstract
Background
Previous work has identified differential kinematics and muscle activity between non-specific chronic low back pain (LBP) subgroups (flexion pattern (FP) and active extension pattern) and healthy controls. However, it is unclear if differences in muscle activity are maintained on resolution of pain and/or if they contribute to pain recurrence.
Purpose
To investigate differences in trunk muscle activity between individuals with a history of flexion-related LBP (who are currently pain-free) and no-LBP controls during three functional activities.
Methods
Fifteen individuals (10 male, 5 female) with a previous history of FP LBP (but who were currently pain-free) and 15 individuals with no history of low back pain (10 male, 5 female) were recruited. Surface electromyography of bilateral superficial lumbar multifidus, longissimus thoracis, transversus abdominus/internal oblique and external oblique muscle activity was recorded during three functional activities (sit-to-stand, step-up and bending to pick up a pen from the floor). Surface electromyography data was normalised (% maximum voluntary contraction) and compared between groups (Mann-Whitney U test).
Results
No significant differences were observed for any muscle in any activity (p>0.05) except for significantly increased right superficial lumbar multifidus during the bending task (p=0.04) in the FP group compared to the control group (36.55 vs. 19.97 respectively).
Conclusion
Individuals with resolved FP LBP have similar trunk muscle activation to those with no history of LBP. This suggests that muscle activity behaviours may ‘normalise’ in FP on resolution of pain. Further work should explore muscle activity during recurrent episodes to establish links with pain provocation.
No conflicts of interest
No funding obtained
