The Effect of Ground Poles and Elastic Resistance Bands on Longissimus Dorsi and Rectus Abdominus Muscle Activity During Equine Walk and Trot

Abstract

Core strengthening and postural stability are desired outcomes of certain therapeutic exercises performed in horses. This study aimed to quantify changes in muscle activation at a walk and trot in horses traveling over eight consecutive ground poles evenly spaced (at 30 inches for walk and 48 inches for trot) in parallel fashion in a straight line, and with hindquarter and abdominal elastic resistance bands applied at 25% stretch. Surface electromyography (sEMG) data were collected for the longissimus dorsi and rectus abdominus muscles in six horses. A repeated measures ANOVA was performed for each muscle to test for significant differences in the means of the normalized average rectified and maximum amplitude signals. Within subject effects were reported, followed by post-hoc pairwise comparisons when significant main effects were seen, to evaluate differences between the conditions of with or without ground poles or elastic resistance bands. The use of ground poles at a walk resulted in a significant (p < 0.05) increase in the maximum EMG amplitude bilaterally in the longissimus dorsi and rectus abdominus muscles, with an increase in the average rectified EMG bilaterally in the rectus abdominus muscles and the right longissimus dorsi muscle. The use of ground poles at a trot resulted in a significant increase in the maximum EMG amplitude bilaterally in the rectus abdominus muscles. The hindquarter and abdominal elastic resistance bands resulted in a respective 27% and 27.2% increase in the mean average rectified value of the left and right RA muscles, however this only reached statistical significance in the left RA (p < 0.05). These findings provide support regarding changes in muscle activation when using ground poles to increase core and epaxial muscle engagement. While a significant effect on core muscle activation was identified with the elastic resistance bands at a trot, further research is needed in this area to further characterize their effect on muscle activation.