(59) THE EFFECTS OF ACUTE FOAM ROLLING ON MUSCLE FASCICLE LENGTH, PENNATION ANGLE, AND THICKNESS

Myofascial release is a common clinical practice used to reduce tension by releasing trigger points with the aim to increase tissue compliance. One common myofascial releaser technique is foam rolling. As foam rolling is now a popular practice in most training and clinical settings the underlying mechanism that may or may not lead to increase tissue compliance are still unknown.


Purpose: To determine the affect of acute foam rolling on pennation angle, fascicle length and thickness of the Vastus Lateralis.


Methods: Thirty participants (68.1 ± 3.9 cm, 72.1 ± 13.9 kg, Age 23.3 ± 8.46 years) participated in two days of testing. Three p<span style="color: black; border: none windowtext 1.0pt; mso-border-alt: none windowtext 0in; padding: 0in;">anoramic ultrasound images of the vastus lateralis were taken prior to and post intervention. The transducer was positioned in the center of the muscle belly just inferior to the largest circumference of the muscle, it was then moved superior until the full length of a fascicle was captured. On one of the days participants sat there for 7 minutes as this served as the control. On the other day, 5 minutes of foam rolling was performed in the prone position with a foam follower positioned between the thigh and floor. The participants moved themselves in a forward and back motion for5 sets of 60 second of rolling with 30 sec rest in-between.  Images were analyzed for pennation angle, fascicle length and muscle thickness. Values were then averaged across all three images (pre and post) and change scores from pre to post for each variable and condition were calculated and compared using paired t-tests.


Results: There was no significant difference for fascicle length (P=0.16) with the mean and standard deviation changes score for the control: 0.09±1.1 vs foam rolling 0.22± 1.3 cm. There was significant difference for pennation angle (p< 0.01) with the mean and standard deviation changes score for the control: 0.81±5.7 vs foam rolling -2.2± 3.3 degrees, indicating that pennation angle went down following foam rolling. There was significant difference for muscle thickness (p=0.01) with the mean and standard deviation changes score for the control: 0.0±0.2 vs foam rolling -0.1±0.28 cm, indicating that muscle thickness went down following foam rolling.


Conclusion:  After evaluating the effects of acute foam rolling on muscle fascicle length, pennation angle, and muscle thickness, there was no significant difference in fascicle length. However, a significant difference was found in pennation angle and muscle thickness. Pennation angle decreased from 18 to 16 degrees following foam rolling and subsequently muscle thickness decreased from 2.4 to 2.2 cm. This could be contributed to the pressure applied to the muscle during foam rolling having a compacting affect or the relaxing and elongation of the muscle do to myofascial release.  
PRACTICAL APPLICATIONS: The results of this study indicate that there is no measurable benefit to foam rolling prior to a performance. A decrease in the pennation angle can lead to a decrease in the amount of force the muscle can generate. If an athlete prefers to use a foam roller, it would be best to use it after a performance to reduce muscle soreness. 

Acknowledgements: None