Author(s): HIBIKI, T., NAKAMURA, M., SUGANO, J., YANASE, K., Institution: DOSHISHA UNIVERSITY, Country: JAPAN, Abstract-ID: 1956

INTRODUCTION:
Foam rollers are widely used in sports settings. Previous studies have reported the changes in mechanical muscle properties, such as range of motion (ROM), and maximal voluntary isometric contraction (MVC) torque, immediately after foam rolling (1). A recent study reported that contralateral joint ROM is increased immediately after foam rolling (2). However, it is unclear whether the foam rolling to one muscle (e.g. quadriceps muscle) affects the mechanical muscle property of the antagonist muscle (e.g. hamstrings muscle). The purpose of this study was to examine the changes in mechanical muscle properties in antagonist muscles following foam rolling intervention.
METHODS:
Sixteen male athletes belonging to the track and field club participated in this study (20.7 ± 0.7 years, 176.1 ± 6.1 cm, 75.0 ± 25.4 kg). All participants randomly conducted two interventions for 2 days (cross-over design). The foam roller group (FR group) performed foam roller to the right anterior thigh (anterior superior iliac spine to patella) for 60 seconds. The control group (CON group) rested in the prone position for 3 minutes. The following measurements were taken before and after each intervention for the right hamstrings, i.e., knee extension ROM, passive stiffness and knee flexion MVC using Biodex, and root mean square (RMS) of each hamstrings using electromyography system. The Visual Analog Scale (VAS) was also measured participant’s perceptive changes in hamstrings flexibility and muscle strength after foam rolling. Repeated measures analysis of variance (ANOVA) was performed for two factors: time and group. In addition, correlation analysis was used to examine the relationship between the amount of change of all values (ROM, stiffness, knee flexion MVC, and RMS) and the VAS (hamstrings flexibility and muscle strength) .
RESULTS:
The ANOVAs showed no significant interaction effects in all variables. Correlation analysis revealed a significant positive correlation between the amount of change in ROM and VAS of flexibility (r= 0.713, p<0.01), as well as a significant negative correlation between the amount of change in stiffness and the VAS of flexibility (r=0.575, p=0.03). On the other hand, there was no correlation between the muscle strengths (MVC and RMS) and the VAS of muscle strength.
CONCLUSION:
The results of this study suggest that mechanical properties (ROM, stiffness, MVC, and RMS) of antagonist muscles (hamstrings muscle) do not change immediately after foam rolling intervention for quadriceps muscle. However, those who feel that hamstrings flexibility (VAS) correlates with ROM and stiffness following foam rolling for quadriceps muscle.