Foam Rolling Acute Effects on Myofascial Tissue Stiffness and Muscle Strength: A Systematic Review and Meta-Analysis

Comparison of the Effects of a Roller Massager Intervention on the Rectus Femoris Between Lengthened and Slack Positions

ABSTRACT

Kasahara, K, Konrad, A, Murakami, Y, Thomas, E, and Nakamura, M. Comparison of the effects of a roller massager intervention on the rectus femoris between lengthened and slack positions. J Strength Cond Res XX(X): 000-000, 2024-A roller massager (RM) is a type of foam rolling device, which previous studies have shown to be effective for acutely decreasing tissue hardness and increasing range of motion (ROM). However, these effects may differ with the RM intervention position (i.e., knee flexion or knee extension). Therefore, this study aimed to compare the acute effects of an RM intervention on the rectus femoris (RF) in the knee flexed and extended positions. The subjects were 14 healthy male college students (age, 22.6 ± 0.8 years). The RF of the dominant leg was tested. Three conditions were compared: a control condition with no intervention (CON), an RM intervention in knee extension (i.e., RM_extension), and a RM intervention in knee flexion (i.e., RM_flexion). The measurements were tissue hardness in the proximal (TH_pro), middle (TH_mid), and distal (TH_dis) portions of the RF, knee flexion ROM, pain pressure threshold (PPT), maximal voluntary isometric contraction (MVC-ISO) torque, and maximal voluntary concentric contraction (MVC-CON) torque in the RF before and immediately after the intervention. There were significant interaction effects of TH_mid and knee flexion ROM. Both RM_extension and RM_flexion conditions showed a significant (p < 0.01) decrease in TH_mid and an increase in knee flexion ROM, but there were no significant differences between conditions. There was a main effect for TH_pro and PPT (p < 0.05) but no significant interaction effect or main effect for TH_dis, MVC-ISO torque, and MVC-CON torque. The results showed that the RM intervention can effectively decrease tissue hardness and increase ROM, regardless of limb position (i.e., knee extension or flexion).

Self-Massage Acute Effects on Pressure Pain Threshold, Muscular Electrical Activity, and Muscle Force Production: A Systematic Review and Meta-Analysis

ABSTRACT

Furlan, MR, Machado, E, Petter, GdN, Barbosa, IM, Geremia, JM, and Glänzel, MH. Self-massage acute effects on pressure pain threshold, muscular electrical activity, and muscle force production: a systematic review and meta-analysis. J Strength Cond Res 38(3): 620-635, 2024-Self-massage (SM) is often used in physiotherapy and sports training programs. However, the SM acute effects on pressure pain threshold (PPT), muscle electrical activity (MEA), and muscle force production remain unclear. A meta-analytical review was performed to verify the SM acute effects on neuromuscular responses in healthy adults or athletes. The review (CRD42021254656) was performed in the PubMed, Web of Science, and Embase databases. A synthesis of the included studies was performed, and both the risk of bias and the evidence certainty level were assessed through the PEDro scale and Grading of Recommendations Assessment, Development, and Evaluation approach, respectively. Nineteen studies were included, 5 evaluated the PPT, 7 the thigh muscles' MEA, and 15 the lower-limb strength. The SM application induces moderate increases in quadriceps' PPT (5 studies; standardized mean difference [SMD]: 0.487; 95% CI 0.251-0.723; p < 0.001; I2 = 0%). We found no SM effects on the hamstrings and plantar flexors' MEA. Also, we observed small increases in knee extensors' concentric torque (2 studies; SMD: 0.288; 95% CI 0.088-0.489; p = 0.005; I2 = 0%), without effects in isometric muscle strength, eccentric torque, and rate of force development. Grading of recommendations assessment, development, and evaluation analysis showed high and low certainty levels for the SM effects on quadriceps' PPT and muscle strength, respectively. Self-massage pressure-volume application seems to be a determining factor in inducing changes in these parameters, and it may vary among the treated muscles, where a higher pressure-volume application is required for increasing knee flexors and plantar flexors' PPT and strength. Thus, new studies with better methodological quality should be performed to strengthen this evidence.

Acute Effects of Different Foam Roller Intervention Techniques on Knee Extensors

The usefulness of Foam Roller (FR) even without a rolling stimulus (e.g., static compression with or without dynamic joint movements) has been recently demonstrated; however, the different effects of these methods remain unclear. Thus, this study aimed to compare and investigate the effects of such FR intervention methods on knee extensors. The dominant knee extensors of 20 male university students were investigated using the following four conditions: control (CON), FR with rolling (FR_rolling), FR with static compression (FR_SC), and FR with static compression + dynamic movement of the knee joint (FR_DM). FR_SC was intervened to compress the muscle belly of the knee extensors. FR_DM involved knee flexion and extension while maintaining the FR_SC condition. Knee flexion ROM, pain pressure threshold (PPT), tissue hardness, and countermovement jump (CMJ) height were outcome variables; they were compared before and immediately after the intervention. The results of this study showed that knee flexion ROM was significantly (p < 0.01) increased in FR_rolling (d = 0.38), FR_SC (d = 0.28), and FR_DM (d = 0.64). Tissue hardness was significantly (p < 0.01) decreased in FR_rolling (d = -0.55), FR_SC (d = -0.28), and FR_DM (d = -0.42). A main effect of time (p < 0.01) was observed in knee flexion ROM, PPT, and tissue hardness, but no change in CMJ was observed. The results of this study suggested that clinicians and athletes could choose any method they like as a warm-up routine.