PT - JOURNAL ARTICLE AU - LJ Macgregor AU - AM Hunter TI - FOAM ROLLING INCREASES SKELETAL MUSCULAR EFFICIENCY WITHOUT AFFECTING RANGE OF MOTION AID - 10.1136/bjsports-2016-096952.5 DP - 2016 Nov 01 TA - British Journal of Sports Medicine PG - e4--e4 VI - 50 IP - 22 4099 - http://bjsm.bmj.com/content/50/22/e4.29.short 4100 - http://bjsm.bmj.com/content/50/22/e4.29.full SO - Br J Sports Med2016 Nov 01; 50 AB - Foam rolling (FR) has been shown to alleviate some symptoms of exercise-induced muscle damage, and has been suggested to increase range of movement (ROM) without negatively impacting strength. However, the exact mechanisms of action are unclear. The aim of this study was to investigate mechanisms associated with a single acute bout of FR, as well as repeated bouts of FR, on healthy rested muscle. Muscle stiffness of vastus lateralis and rectus femoris of 16 healthy active male volunteers were measured using tensiomyography (TMG). Knee extension maximal voluntary contraction (MVC) and knee flexion ROM were also assessed, and surface electromyography (sEMG) was recorded during a submaximal isometric contraction (50% of MVC). Measures were performed before and after (0, 15 and 30 minutes) either a 2 minute rest period (control) or a 2 minute bout of FR, performed on quadriceps; each condition was repeated for 3 consecutive days, with 7 days between conditions. MVC was reduced in control compared to with FR (p<0.001), ROM was not altered (p=0.125). Dm of the VL (p=0.001) was elevated on the third day of FR. sEMG was reduced (p<0.01) 0, 15 and 30 minutes after FR compared to control. Following FR, MVC was elevated compared to control and sEMG was transiently reduced during a submaximal task. This suggests that the activation efficiency of the involved muscles has been increased by FR, which has spared the decline in MVC, observed in control, due to fatigue from repeated efforts.