Interlimb Asymmetries in Swimming and Their Impact on Performance: Evidence From a Scoping Review
Débora Aparecida Knihs, Chris Bishop, Haiko Bruno Zimmermann, Juliano Dal Pupo
Abstract
ABSTRACT The objectives of this review were to (a) map the studies analyzing bilateral asymmetries in specific (in-water tests) and nonspecific (dry-land tests) swimming contexts and (b) investigate the effects of interlimb asymmetries on swimming performance. Searches were systematically conducted on 4 databases. Of 768 studies examined, 60 were eligible for the final selection (https://osf.io/46gya). Twenty-eight studies analyzed asymmetries during in-water tests, with asymmetry values ranging from 2.7 to 60.0%, and most studies ( n = 18) reported significant between-limb differences ( p < 0.05). Asymmetries were also analyzed during dry-land tests in 24 studies, with asymmetry values ranging from 1.1 to 16.6%. Interestingly, most of these studies ( n = 12) did not verify any significant between-limb differences ( p > 0.05). Eight studies measured asymmetries in both contexts and reported asymmetry values from −24.1–17.4%, with 4 studies finding significant differences between body sides ( p < 0.05). Seven of the 60 studies selected investigated the relationship between asymmetries and swimming performance, with 5 reporting no meaningful associations. In conclusion, significant asymmetries in swimming are more evident during in-water than during dry-land tests. In addition, the few studies investigating asymmetries' influence on swimming performance reported that asymmetries rarely impact swimming performance.