title: Comparison of Methods That Assess Lower-body Stretch-Shortening Cycle Utilization.
abstract: The purpose of this study was to compare 4 methods that assess the lower-body stretch-shortening cycle (SSC) utilization of athletes. Eighty-six National Collegiate Athletic Association Division I athletes from 6 different sports performed 2 squat jumps and 2 countermovement jumps on a force platform. Pre-stretch augmentation percentage (PSAP), eccentric utilization ratio (EUR), and reactive strength (RS) for jump height (JH) and peak power (PP) magnitudes, and reactive strength index-modified (RSImod) were calculated for each team. A series of one-way analyses of variance with a Holm-Bonferroni sequential adjustment were used to compare differences in PSAP, EUR, RS, and RSImod between teams. Statistical differences in RSImod (p < 0.001) existed between teams, whereas no statistical differences in PSAP-JH (p = 0.150), PSAP-PP (p = 0.200), EUR-JH (p = 0.150), EUR-PP (p = 0.200), RS-JH (p = 0.031), or RS-PP (p = 0.381) were present. The relationships between PSAP, EUR, and RS measures were all statistically significant and ranged from strong to nearly perfect (r = 0.569-1.000), while most of the relationships between PSAP, EUR, and RS measures and RSImod were trivial to small (r = 0.192-0.282). Pre-stretch augmentation percentage and EUR, RS, and RSImod values indicate that women's tennis, men's soccer, and men's soccer teams may use the SSC most effectively, respectively. Pre-stretch augmentation percentage, EUR, RS, and RSImod values may show vastly different results when comparing an individual's and a team's ability to use the SSC. Practitioners should consider using RSImod to monitor the SSC utilization of athletes due to its timing component.
authors.affiliation: 1Department of Exercise Science, East Stroudsburg University, East Stroudsburg, Pennsylvania; 2Department of Health, Exercise, and Sport Science, The Citadel, The Military College of South Carolina, Charleston, South Carolina; and 3Center of Excellence for Sport Science and Coach Education, Department of Exercise and Sport Science, East Tennessee State University, Johnson City, Tennessee.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Suchomel
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Sole
authors.forename: Michael H
authors.initials: MH
authors.lastname: Stone
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D052580:Muscle Stretching Exercises; D018482:Muscle, Skeletal / Q000502:physiology*; D013177:Sports / Q000502:physiology*; D055815:Young Adult