Author(s): HANSOULLE, T., VAN CANT, J.; MAHAUDENS, P.; NGUYEN, A.P., Institution: UCLOUVAIN, Country: BELGIUM, Abstract-ID: 1518

INTRODUCTION:
Developing or improving muscle function in running is frequently targeted in prevention programmes, rehabilitation, and performance. Yet “muscle function” remains poorly defined, and the constructs and variables used to operationalise it vary widely, impairing interpretation and comparison between studies. This mapping review aimed to characterise how muscle function is defined and operationalised in running research by (i) cataloguing constructs and variables assessed and (ii) examining differences across research domains.
METHODS:
This mapping review was registered on Open Science Framework and conducted according to the Arksey and O’Malley framework and PRISMA-ScR guidance. We searched Embase, MEDLINE, SPORTDiscus, Cochrane, and grey literature sources (HAL, BASE), without date restrictions. Eligible records explicitly assessed “muscle function” (or prespecified synonyms) in runners and reported at minimum an assessment method and corresponding metric.
RESULTS:
We identified 3,183 records; 227–228 studies met eligibility criteria. Only five studies provided an explicit definition of muscle function. The median number of constructs assessed per study was 2 (IQR 1; range 1–7). Nineteen constructs and 95 variables were identified. The most frequently assessed constructs were strength (~67%), power (~42%), muscle activation (~37%), stretch–shortening cycle (~8%), velocity (~8%), and endurance (~7%). MVIC dominated strength assessment, followed by isokinetic dynamometry and 1-RM tests. Sport research more often emphasised power, SSC and velocity, whereas rehabilitation more often included endurance and coordination-related outcomes.
CONCLUSION:
Muscle function is widely used in running research but inconsistently defined and assessed, with most studies capturing only one or two constructs, resulting in fragmented operationalisation. The observed heterogeneity supports the need for greater conceptual clarity and reporting transparency. Explicitly distinguishing ability-based constructs (intrinsic capacities such as strength/power/endurance) from role-based constructs (muscle contribution to task mechanics) may improve comparability across studies and facilitate development of more standardised, multidimensional assessment frameworks relevant to both rehabilitation and performance.