Is Abdominal Muscle Activity Different from Lumbar Muscle Activity during Four-Point Kneeling?

Background: Stabilization exercises can improve the performance of trunk and back muscles, which are effective in the prevention and treatment of low back pain. The four-point kneeling exercise is one of the most common types of stabilization exercises. This quasi-experimental study aimed to evaluate and compare the level of activation between abdominal and lumbar muscles in the different stages of the four-point kneeling exercise. Methods: The present study was conducted on 30 healthy women between 20 and 30 years old. Muscle activity was recorded bilaterally from transversus abdominis, internal oblique, and multifidus muscles with an electromyography (EMG) device during the different stages of the four-point kneeling exercise. All the collected EMG data were normalized to the percentage of maximum voluntary isometric contraction. The repeated measures ANOVA and paired t-test were used for the statistical analysis of the data. Results: A comparison between mean muscle activation in right arm extension and left leg extension showed that left internal oblique and left transverse abdominis muscles produced greater activation during left leg extension (P<0.05). The comparison of mean muscle activation between right arm extension and the bird-dog position showed that, except for the right internal oblique, all the muscles produced higher activation in the bird-dog stage (P<0.05). In comparison to the bird-dog stage, the left multifidus showed high activation during left leg extension (P<0.05). Conclusion: The results of this study showed that the activity of all the above-mentioned muscles during quadruped exercise can provide stability, coordination, and smoothness of movements.