Rehabilitative and Conditioning Exercises That Selectively Activate Individual Lower Extremity Muscles: A Systematic Review
TL;DR
There remains a paucity of literature exploring exercises that effectively isolate all muscle groups of the lower extremity, but there remains a paucity of literature exploring exercises that effectively isolate all muscle groups of the lower extremity.
Abstract
Context: Resistance training - the process of progressively overloading muscle fibers - is fundamental to muscle hypertrophy. People may benefit from intentional exercise prescription targeting selective muscle activation. There is a lack of synthesized literature on exercises targeting specific lower extremity muscles. Objective: To compile findings from studies that described exercises emphasizing selective recruitment of lower extremity muscles. Data Sources: A multi-database (MEDLINE via PubMed, Scopus, SportDiscus) search was performed. Study Selection: English-language primary research studies relating to selective lower extremity muscle activation in healthy active people were included. Studies based on healthy active people were included to establish normative activation patterns, providing a reference standard applicable to rehabilitation and injury prevention contexts. Study Design: Systematic review. Level of Evidence: Level 3. Data Extraction: Information on sample characteristics; muscle and muscle group; exercise and/or movement description; measurement modalities; and exercise intensity, and dosage, was extracted. Study quality appraisal was conducted using the Methodological Index for Non-Randomized Studies (MINORS) scale. Results: A total of 2561 studies were identified, of which 106 met the inclusion criteria, and 56 studies were considered high-quality evidence based on MINORS quality appraisal scores. A total of 29 lower-quarter muscles (including trunk musculature) were investigated in the included studies. Surface electromyography emerged as the most frequently used modality to measure selective muscle activation. Biceps femoris emerged as the most frequently investigated muscle for selective activation. Conclusion: Current literature reporting selective activation of individual lower extremity muscles exists, particularly for the biceps femoris, but there remains a paucity of literature exploring exercises that effectively isolate all muscle groups of the lower extremity. Further investigation is necessary to create a comprehensive resource that can be used to guide more personalized, precise, and effective approaches to addressing muscular deficits.