Exercise-induced muscle fatigue leads to changes in gait-related parameters among older adults: a systematic review and meta-analysis

Background: Exercise-induced fatigue is a common consequence of physical activities. Particularly in older adults, it can affect gait performance. Due to a wide variety in fatiguing protocols and gait parameters used in experimental settings, pooled effects are not yet clear. Furthermore, specific elements of fatiguing protocols (i.e., intensity, duration, and type of activity) might lead to different changes in gait parameters. We aimed to systematically quantify to what extent exercise-induced fatigue alters gait in community-dwelling older adults, and whether specific elements of fatiguing protocols could be identified.Methods: We conducted a systematic review and meta-analysis in accordance with the PRISMA guidelines. In September 2022 and April 2023, we searched through PubMed, Web of Science, Scopus, Cochrane and CINAHL databases. Two independent researchers screened and assessed articles using ASReview, Rayyan, and ROBINS-I. We extracted data related to spatiotemporal, stability, and variability gait parameters of healthy older adults (55+) before and after a fatiguing protocol or prolonged physical exercise. Random-effects meta-analyses were performed on both absolute and non-absolute effect sizes in RStudio. Moderator analyses were performed on six clusters of gait parameters (Dynamic Balance, Lower Limb Kinematics, Regularity, Spatio-temporal Parameters, Symmetry, Velocity). Results: We included 573 effect sizes on gait parameters from 31 studies. The included studies reflected a total population of 761 older adults (57% female), with a mean age of 71 (SD 3) years. Meta-analysis indicated that exercise-induced fatigue affected gait with a standardized mean change of 0.31 (p<.001). Moderator analyses showed no statistical differences between the different clusters. Within clusters, the effects were non-uniform, resulting in an overall effect that was indistinguishable from zero. The fatiguing protocols’ duration, intensity, or type of activity did not moderate effects.Discussion: Due to the (mainly) low GRADE certainty scores as a result of the heterogeneity between studies, and possible different strategies to cope with fatigue between participants, the only conclusion that can be drawn is that older adults, therapist, and researchers should be aware of the small to moderate changes in gait parameters as a result of exercise-induced fatigue. No changes in specific clusters, nor important elements of fatiguing protocols were identified.