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.
Jan Wilke, Philipp Niemeyer, Daniel Niederer, Robert Schleip and Winfried Banzer
Brian Klucinec, Craig Denegar and Rizwan Mahmood
During the administration of therapeutic ultrasound, the amount of pressure at the sound head-tissue interface may affect the physiological response to and the outcome of treatment. Speed of sonification; size of the treatment area; frequency, intensity, and type of wave; and coupling media are important parameters in providing the patient with an appropriate ultrasound treatment. Pressure variations affect ultrasound transmissivity, yet pressure differences have been virtually unexplored. The purpose of this study was to assess the effects of sound head pressure on acoustic transmissivity. Three trials were conducted whereby pig tissue was subjected to increased sound head pressures using manufactured weights. The weights were added in 100 g increments, starting with 200 g and finishing with 1,400 g. Increased pressure on the transmitting transducer did affect acoustic transmissivity; acoustic energy transmission was increased from 200 g (0.44 lb) up to and optimally at 600 g (1.32 lb). However, there was decreased transmissivity from 700 to 1, 400 g (1.54 to 3.00 lb).
Benjamin G. Serpell, Joshua Strahorn, Carmen Colomer, Andrew McKune, Christian Cook and Kate Pumpa
Objective: To examine the effect of a physical treatment (speed, power, and strength [SPS] training) and psychosocial treatment (group motivational presentation) on salivary testosterone (sal-T), salivary cortisol (sal-C), and sal-T-to-sal-C ratio (T:C) in professional rugby. Methods: Fourteen male rugby players (age = 25.9 [2.5] y, height = 186.1 [6.7] cm, and body mass = 104.1 [12.7] kg) participated in this study. Testing occurred across 2 d on 2 separate occasions (week 1 and week 2). On day 1 of both weeks, participants completed an SPS training session. On day 2 of both weeks, participants undertook a field-based rugby training session. In week 2, participants underwent an additional treatment in the form of a motivational presentation given by a respected former player before the rugby session. Saliva was collected before and after SPS training and before and after the rugby session and was assayed for testosterone and cortisol. Results: No differences were found between weeks for sal-T at any time point, but sal-C was higher in week 2 before and after SPS and before rugby on day 2 (P < .05). In both weeks, T:C increased following SPS (P < .02, ES > 0.91 [0.13, 1.69]). T:C increased when the motivational presentation accompanied rugby training (P = .07, ES = 1.06 [0.27, 1.85]). Sal-C, not sal-T, drove changes in T:C (P < .001). Conclusions: Physical or psychosocial treatments may affect sal-T, sal-C, and T:C, and individual variation in responses to treatments may exist.