Context: Several studies have reported that self-massage using a foam roller (FR) increased joint range of motion (ROM) immediately. However, the mechanism of increasing ROM by the FR intervention has not been elucidated. Objective: To clarify the mechanism by investigating properties and morphological changes of muscles targeted by the FR intervention. Design: An interventional study. Setting: An athletic training laboratory. Participants: Ten male college volunteers with no injuries in their lower limbs (mean [SD]: age 23.8 [3.2] y, height 173.2 [4.9] cm, weight 69.5 [8.6] kg). Intervention: The FR intervention on the right plantar flexors for 3 minutes. Main Outcome Measures: Maximum ankle ROM, muscle hardness, and fascicle length of the gastrocnemius muscle at the neutral (0°), maximum dorsiflexion, and maximum plantar flexion positions. All measurements were conducted before (PRE) and after (POST) the FR intervention. Results: Dorsiflexion ROM increased significantly at POST (PRE: 13.6° [8.0°], POST: 16.6° [8.4°]; P < .001), although plantar flexion ROM did not change significantly between PRE and POST (PRE: 40.0° [6.1°], POST: 41.1° [4.9°]). There was no significant difference in muscle hardness and fascicle length between PRE and POST in any of the angles. Conclusions: Dorsiflexion ROM increased significantly by the FR intervention in the present study; however, muscle hardness and fascicle length did not change. FR may affect not only the muscle but also the fascia, tendon, and muscle-tendon unit. The FR protocol of the present study can be applied in clinical situations, because it was found to be effective to increase ROM.
Akane Yoshimura, Robert Schleip and Norikazu Hirose
Jan Wilke, Philipp Niemeyer, Daniel Niederer, Robert Schleip and Winfried Banzer
Context: Foam rolling (FR) increases joint range of motion (RoM), but the optimal training parameters are unknown. Objective: To investigate the effect of FR velocity on RoM and tissue stiffness. Design: Randomized, controlled crossover trial. Setting: University. Participants: A total of 17 healthy, physically active adults (10 females; 25  y). Interventions: (1) Four 45-second high-velocity FR of the anterior thigh (FAST-FR), (2) four 45-second slow-velocity FR of the anterior thigh (SLOW-FR), and (3) inactive control. Outcome Measures: Maximal knee-flexion RoM (ultrasonic movement analysis) and anterior thigh tissue stiffness (semielectronic tissue compliance meter) assessed pre, immediately post (T0), as well as 5 (T5) and 10 (T10) minutes postintervention. Statistical analysis included Friedman tests with adjusted post hoc comparisons (Wilcoxon tests). Results: According to omnibus testing, RoM remained unchanged in all 3 conditions and at all time points (P > .05), while differences were found for tissue stiffness (P < .05). Post hoc tests revealed significant decreases following FAST-FR (T5: −17%, T10: −24%; P < .05) and SLOW-FR (T10: −15%; P < .05). The observed stiffness changes were significant in comparison with control (P < .01), but no difference was found between the 2 FR conditions (P > .05). Conclusions: FR of the anterior thigh decreases myofascial stiffness regardless of velocity. The lack of effects on RoM contrasts findings of recent literature and warrants further investigation.