The aim of this study was to explore the effects of simulated soccer match play on neuromuscular performance in adolescent players longitudinally over a two-year period. Eleven players completed all measurements in both years of the study (1st year: age 16.0 ± 0.4 y; stature 178.8 ± 6.4 cm; mass 67.5 ± 7.8 kg; maturity-offset 2.24 ± 0.71 y). There was a significant reduction in hamstring strength after simulated match by the soccer-specific aerobic field test (SAFT90), with four out of eight parameters compromised in U16s (4.7-7.8% decrease) and six in the U17s (3.1-15.4%). In the U17s all of the concentric quadriceps strength parameters were decreased (3.7-8.6%) as well as the vastus lateralis and semitendinosus firing frequency (26.9-35.4%). In both ages leg stiffness decreased (9.2-10.2%) and reactive strength increased pre to post simulated match (U16 8.0%; U17 2.5%). A comparison of changes between age groups did not show any differences. This study demonstrates a decrease in neuromuscular performance post simulated match play in both ages but observed changes were not age dependent.

• Keywords
• EMG, isokinetic, leg stiffness, reactive strength, simulated match-play,
• MeSH
• Lower Extremity * physiology   MeSH
• Soccer * MeSH
• Muscle, Skeletal * physiology   MeSH
• Humans MeSH
• Longitudinal Studies MeSH
• Adolescent MeSH
• Muscle Strength * physiology   MeSH
• Check Tag
• Humans MeSH
• Adolescent MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

The aim of the present study was to identify potential gender differences in leg stiffness and reactive strength during hopping tasks in 13 to16-year old team sports players. Reactive strength index (RSI) and leg stiffness were obtained in two consecutive seasons from 51 girls (U14: n = 31, U16: n = 20) and 65 boys (U14: n = 32, U16: n = 33). A significant main effect on absolute (U14: p = 0.022, η2= 0.084; U16: p < 0.001, η2= 0.224) and relative leg stiffness (U14 p<0.001; η2= 0.195; U16; p = 0.008, η2= 0.128) for gender was found in both groups with values higher in boys than in girls. For absolute and relative stiffness gender differences in the U14 group were significant in the 1st year only (p=0.027 and p=0.001), and for the U16s in the 2nd year only (p < 0.001 and p = 0.022). For RSI, a significant main effect for gender was observed in the U16 group only (p < 0.001 η2= 0.429) with values significantly higher in boys than in girls in both years of measurement (p = 0.001; p < 0.001). Results of this study support previous limited findings, mostly related to non-athletes, suggesting lower stretch-shortening cycle capability in adolescence female compared to male, however our data only partly supports the theory that quality of neuromuscular functions increases with age until post puberty.

• Keywords
• neuromuscular, reactive strength index, stretch-shortening cycle, youth,
• Publication type
• Journal Article MeSH