Relationship between jumping abilities and skeletal muscle architecture of lower limbs in humans: Systematic review and meta-analysis.

The aim of this study was to examine the influence of skeletal muscle architecture (SMA) features measured by 2-D ultrasonography on jumping performance in humans. A systematic review and meta-analysis was conducted, registry number: CRD42016043602. The scientific literature was systematically searched in eight databases, last run on March 14th, 2017. Cross-sectional studies focused on the association between SMA features and vertical jumping performance were selected. A random-effects model was used to analyze the influence of lower-limb SMA and maximal jump height. A total of 11 studies were included in the qualitative synthesis and 6 studies were selected for meta-analysis. 250 correlations were reviewed across studies. The vast majority were either not statistically significant (185; 74%), weak or very weak (169; 68%) for different jump modalities; counter-movement jump (CMJ), squat jump (SJ), and drop jump. There was insufficient data to perform meta-analysis on muscles other than vastus lateralis for CMJ and SJ. The meta-analyses did not yield any significant association between vastus lateralis SMA and SJ height. Only a significant overall association was shown between vastus lateralis thickness and CMJ height (summary-r = 0.28; 95% confidence interval (CI) = -0.05 to 0.48; p = .059) for a 90% CI level. No differences were found between summary-r coefficients for SMA parameters and jump height during both jumps (CMJ: χ2 = 2.43; df   = 2; p = .30; SJ: χ2 = 0.45; df = 2; p = .80) with a low heterogeneity ratio. Current evidence does not suggest a great influence of lower-limb SMA on vertical jumping performance in humans.