Chronic Effects of Foam Rolling on Flexibility and Performance: A Systematic Review of Randomized Controlled Trials

Discussing Conflicting Explanatory Approaches in Flexibility Training Under Consideration of Physiology: A Narrative Review

The mechanisms underlying range of motion enhancements via flexibility training discussed in the literature show high heterogeneity in research methodology and study findings. In addition, scientific conclusions are mostly based on functional observations while studies considering the underlying physiology are less common. However, understanding the underlying mechanisms that contribute to an improved range of motion through stretching is crucial for conducting comparable studies with sound designs, optimising training routines and accurately interpreting resulting outcomes. While there seems to be no evidence to attribute acute range of motion increases as well as changes in muscle and tendon stiffness and pain perception specifically to stretching or foam rolling, the role of general warm-up effects is discussed in this paper. Additionally, the role of mechanical tension applied to greater muscle lengths for range of motion improvement will be discussed. Thus, it is suggested that physical training stressors can be seen as external stimuli that control gene expression via the targeted stimulation of transcription factors, leading to structural adaptations due to enhanced protein synthesis. Hence, the possible role of serial sarcomerogenesis in altering pain perception, reducing muscle stiffness and passive torque, or changes in the optimal joint angle for force development is considered as well as alternative interventions with a potential impact on anabolic pathways. As there are limited possibilities to directly measure serial sarcomere number, longitudinal muscle hypertrophy remains without direct evidence. The available literature does not demonstrate the necessity of only using specific flexibility training routines such as stretching to enhance acute or chronic range of motion.

Effects of foam roller on pain intensity in individuals with chronic and acute musculoskeletal pain: a systematic review of randomized trials

OBJECTIVE

To analyze the effects of using foam roller on pain intensity in individuals with chronic and acute musculoskeletal pain.

METHODS

This systematic review was registered in the National Institute for Health Research's prospective online registry of systematic reviews (PROSPERO) under CRD42023456841. The databases Pubmed, Medline (via Ovid), Embase, BVS, and PEDro (Physiotherapy Evidence Database) were consulted to carry out this systematic review. Notably, the records of clinical trials characterized as eligible were manually searched. The search terms were: (foam rolling OR foam rolling vibration) AND (acute musculoskeletal pain) AND (chronic musculoskeletal pain). The search was performed until August 22, 2023. For the analysis of the methodological quality, the PEDro scale was used for each of the manuscripts included in the systematic review. Due to the heterogeneity in the studies included in this systematic review, performing a meta-analysis of the analyzed variables was impossible.

RESULTS

Only six manuscripts were eligible for data analysis. The type of FR used was non-vibrational, being applied by a therapist in only one of the manuscripts. With an application time ranging from at least 45 s to 15 min, the non-vibrational FR was applied within a day up to six weeks. Using the PEDro scale, scores were assigned that varied between 4 and 8 points, with an average of 6 ± 1.29 points. Only two randomized clinical trials found a significant benefit in pain intensity of adding FR associated with a therapeutic exercise protocol in individuals with patellofemoral pain syndrome and chronic neck pain.

CONCLUSION

The results of this systematic review do not elucidate or reinforce the clinical use of FR in pain intensity in individuals with chronic and acute musculoskeletal pain.

Effects of Self-Myofascial Release on Athletes' Physical Performance: A Systematic Review

Therapists and strength and conditioning specialists use self-myofascial release (SMR) as an intervention tool through foam rollers or massage rollers for soft tissue massage, with the purpose of improving mobility in the muscular fascia. Moreover, the use of SMR by professional and amateur athletes during warm-ups, cool downs, and workouts can have significant effects on their physical performance attributes, such as range of motion (ROM) and strength. The purpose of this study was to analyse the literature pertaining to these types of interventions and their effects found in different physical performance attributes for athletes. A systematic search was carried out using the following databases: PUBMED, ISI Web of Science, ScienceDirect, and Cochrane, including articles up to September 2023. A total of 25 articles with 517 athletes were studied in depth. SMR seems to have acute positive effects on flexibility and range of motion, without affecting muscle performance during maximal strength and power actions, but favouring recovery perception and decreasing delayed-onset muscle soreness. Some positive effects on agility and very short-range high-speed actions were identified, as well. In conclusion, although there is little evidence of its method of application due to the heterogeneity in that regard, according to our findings, SMR could be used as an intervention to improve athletes' perceptual recovery parameters, in addition to flexibility and range of motion, without negatively affecting muscle performance.

The Effects of Foam Rolling Training on Performance Parameters: A Systematic Review and Meta-Analysis including Controlled and Randomized Controlled Trials

Foam rolling (FR) is a new and popular technique for increasing range of motion. While there are a few studies that demonstrate increased performance measures after an acute bout of FR, the overall evidence indicates trivial performance benefits. As there have been no meta-analyses on the effects of chronic FR on performance, the objective of this systematic meta-analytical review was to quantify the effects of FR training on performance. We searched PubMed, Scopus, the Cochrane library, and Web of Science for FR training studies with a duration greater than two weeks, and found eight relevant studies. We used a random effect meta-analysis that employed a mixed-effect model to identify subgroup analyses. GRADE analysis was used to gauge the quality of the evidence obtained from this meta-analysis. Egger's regression intercept test (intercept 1.79; p = 0.62) and an average PEDro score of 6.25 (±0.89) indicated no or low risk of reporting bias, respectively. GRADE analysis indicated that we can be moderately confident in the effect estimates. The meta-analysis found no significant difference between FR and control conditions (ES = -0.294; p = 0.281; I² = 73.68). Analyses of the moderating variables showed no significant differences between randomized control vs. controlled trials (Q = 0.183; p = 0.67) and no relationship between ages (R² = 0.10; p = 0.37), weeks of intervention (R² = 0.17; p = 0.35), and total load of FR (R² = 0.24; p = 0.11). In conclusion, there were no significant performance changes with FR training and no specific circumstances leading to performance changes following FR training exceeding two weeks.