The Effect Of Foam Rolling On Exercise-Induced Muscle Fatigue

Purpose: The objective of this study is to understanding the effectiveness of foam rolling(FR) on the rehabilitation of exercise-induced muscle fatigue by observing the variation of the muscle function, s EMG and subjective pain sensation. Besides that, the aim of this experimental study is also to explore the possible mechanism of foam rolling, thus providing the theoretical basis and guidance in practical exercise. Method: 42 male subjects from the department of Sports Medicine in Chengdu Sports University were randomly divided into the control(n=21) or FR(n=21) group. All the subjects followed the same protocol. The subjects participated pretest measurements, the exercise-induced muscle fatigue(EIMF) protocol, post-0.5h measurements, along with measurements at post-24 h,post-48 h. All measurements included: Peak Torque(PT), Peak Torque/Body Weight(PT/BW), the average Peak Torque(average PT) and total work measured by isokinetic test system; MPF Slope measured by s EMG; and Visual Analogue Scale(VAS). The only between-group difference was that the FR group performed a 6-min FR exercise protocol before each measurement(post-0.5h, post-24 h and post-48h).Result:(1) Torque index: PT of both isometric contraction and concentric contraction showed that there was a significant decrease in both groups after EIMF protocol at post-0.5h(P < 0.05), and no substantial difference between the control group and the FR group at post-0.5h(P>0.05); The FR group had a trend to surpass the control group at post-24 h, with no significant difference(P>0.05);Post-48 h witnessed that the FR group had substantially exceeded the control group(P<0.05)and approximately reached the level of pretest measurement(P >0.05). PT/BW of both isometric contraction and concentric contraction displayed that there was a significant decline in both groups after EIMF protocol at post-0.5h(P<0.05), and no substantial difference between the control group and the FR group at post-0.5h(P>0.05); The FR group had a trend to surpass the control group at post-24 h, with no significant difference(P>0.05);Post-48 h saw that the FR group had substantially exceeded the control group(P < 0.05) and approximately reached the level of pretest measurement(P>0.05). The average PT of both isometric contraction and concentric contraction showed that there was a significant descend in both groups after EIMF protocol at post-0.5h(P<0.05), and no substantial difference between the control group and the FR group at post-0.5h(P>0.05); The FR group had a trend to surpass the control group at post-24 h, with no significant difference(P > 0.05);Post-48 h witnessed that the FR group had substantially surpassed the control group(P < 0.05) and approximately reached the level of pretest measurement(P >0.05).(2)Total work index: 10 times total work of concentric contraction showed that there was a significant decrease in both groups after EIMF protocol at post-0.5h(P<0.05), and no substantial difference between the control group and the FR group at post-0.5h(P > 0.05); The FR group had a trend to surpass the control group at post-24 h, with no significant difference(P>0.05);Post-48 h witnessed that the FR group had substantially exceeded the control group(P<0.05) and approximately reached the level of pretest measurement(P>0.05).(3)s EMG index: MPF Slope in Vastus Medialis Muscle(VMM) : There was no significant difference in the control group among pretest, post-0.5h, post-24 h and post-48h(P > 0.05); Compared with pretest, the FR group had a substantial decrease at post-0.5h, post-24 h and post-48h(P < 0.05); Besides that, compared with the control group, the FR group had a substantial decrease at post-24 h and post-48h(P < 0.05). MPF Slope in Vastus Lateralis Muscle(VLM): There was no significant difference in the control group among pretest, post-0.5h, post-24 h and post-48h(P>0.05); Compared with pretest,the FR group had a substantial decrease at post-0.5h, post-24 h and post-48h(P<0.05); Besides that, compared with the control group, the FR group had a substantial decrease at post-48h(P<0.05). MPF Slope in Rectus Femoris(RF): There was no significant difference in the control group among pretest, post-0.5h, post-24 h and post-48h(P>0.05); Compared with pretest, the FR group had a substantial decrease at post-24 h and post-48h(P<0.05); Besides that, compared with the control group,the FR group had a substantial decrease at post-24 h and post-48h(P<0.05).(4)VAS:A substantial increase could be found in the control group at post-0.5h(P<0.05).Compared with post-0.5h, VAS in the control group had an another sharp rise at post-24 h and post-48h(P < 0.05). Compared with pretest, VAS in the FR group raised sharply at post-24 h and post-48h(P<0.05). Moreover, VAS in the FR group was significantly less than that in the control group at post-48h(P <0.05).Conclusion:(1) Foam rolling had an positive effect on fatigue eliminating, in the aspect of improving muscle strength, muscle performance and relieving subjective pain sensation.(2)The positive effect of foam rolling on fatigue eliminating started at post-24 h, and become significantly at post-48 h.(3)Foam rolling could decrease MPF, reduce excitability, thus relaxing muscle.(4)The possible mechanism of foam rolling may be the combination of the characteristics of massage and stretch, in the aspect of improving soft tissue structure and microenvironment,promoting blood circulation, enhancing energy resynthesis, eliminating metabolites and muscle inhibited relax.