Acute Effects of Foam Rolling on Viscoelastic Tissue Properties and Fascial Sliding: A Randomized, Controlled Crossover Trial

Treatment or training of fascial tissues has moved into the focus of medical research in the last decade. In this context, the use of foam rollers or roller massagers for self-myofascial-release (SMR) techniques has become increasingly popular in health and fitness professionals. The primary objective of these techniques is to mimic manual massage or myofascial-release therapy with a self-usable tool. Recent studies suggest that SMR improves, inter alia, range of motion (ROM) without a decrease in neuromuscular performance (Cheatham et al. 2015).

Concurrent effects on the muscle and especially the surrounding connective tissue network have been proposed as underlying mechanisms for these observed changes in ROM after SMR. Several authors assume a positive effect of SMR on sliding properties of different independent fascial layers. Also, changes in passive tissue stiffness is suggested. Passive stiffness is thereby characterized by passive resistance in the tissues' (muscles') functional direction, the passive resistive torque (PRT).

In conclusion, for many of the proclaimed effects of SMR, such as improvements of sliding of fascial layers or decreases of passive stiffness, there is a lack of evidence in the literature. Therefore, the aim of the study is to evaluate acute effects of SMR on the viscoelastic properties of the muscles on the anterior thigh and the corresponding fascia.

In a cross over design, 16 subjects receive all of the following interventions after a familiarization session: a) 2x60 seconds of SMR at the anterior thigh, b) 2x60 seconds of static stretching at the anterior thigh, c) no intervention in a balanced permutated randomization sequence. Before and directly after each intervention, outcome parameters are collected.

Passive Resistive Torque is evaluated using a computerized isokinetic dynamometer. In passive mode, the lower leg is moved from full knee extension (0°) to the point of maximal knee flexion with a velocity of 5°/s. Torque and angle are recorded at 100 Hertz (Hz). Sliding of fascial layers is quantified with a frame-by-frame cross correlation algorithm of high-resolution ultrasound images (Dilley et al. 2001).

First stretch sensation is quantified using the passive mode in the isokinetic dynamometer.

Maximal ROM is detected using a an ultrasonographic movement analysis system in a prone position.