The Effects of Strengthening the Lumbar Multifidus and Transverse Abdominis in Healthy Individuals Using an Augmented Feedback System: A Randomized Control Trial

Purpose: A common musculoskeletal deficit is decreased core strength. Popular interventions to address this deficit include strengthening of core stabilization muscles, transverse abdominis (TrA) and lumbar multifidus (LM). The purpose of this study was to compare the effectiveness of using an augmented feedback (AF) device versus traditional core stabilization exercises at strengthening the TrA and LM.

Methods: Healthy university students were randomly allocated to two groups. The experimental group used an AF device, the control group performed traditional core stabilization exercises. Maximum voluntary isometric contraction (MVIC) of the TrA and LM at lumbar vertebrae levels L4 and L5 was tested using wireless electromyography (EMG). Both groups exercised 3 times a week for 20 minutes, returning after 8 weeks to retest MVIC.

Results: Paired-sample t-tests revealed significant improvements in MVIC from pre-test to post-test in the left and right L4 and L5 muscles for both groups, (p < .05, for all) after 8 weeks. To determine if improvements differed across exercise conditions, a series of analyses of covariance (ANCOVA) were used. Results of the analyses revealed no significant effect of exercise condition on change score left and right L4 and L5 muscles, (p > .05, for all).

Conclusion: This study demonstrated the AF device was equally effective at increasing EMG activity of the LM and TrA in healthy university students compared to traditional core stabilization exercises. An AF device could be used as an alternative to traditional core stabilization exercises to strengthen the TrA and LM.

Keywords:Stabilization; Biofeedback; Muscular Contraction

Abbreviations:TrA: Transverse abdominis; LM: lumbar multifidus; AF: augmented feedback; MVIC: maximum voluntary isometric contraction; PACES: Physical Activity Enjoyment Scale; EMG: electromyography