Common technique flaws identified by the tuck jump assessment in elite female soccer players

Although injury rates between elite female and male players are comparable, female players are more likely to sustain an anterior cruciate ligament (ACL) (Walden et al., 2011, Knee Surgery, Sports Traumatology, Arthroscopy, 19, 11–19). A common mechanism of ACL injury is non-contact trauma sustained when landing from a jump. The Tuck Jump Assessment (TJA) uses 10 criteria to identify technique flaws when jumping and landing (Myer et al., et al., 2008, Athletic Therapy Today, 13, 39–44) although interrater reliability has been challenged (Dudley et al., 2016, Journal of Strength and Conditioning Research, 30, 1510–1516). The aim of this study was to identify commonly occurring technique JOURNAL OF SPORTS SCIENCES s37 flaws during the TJA and to determine inter-rater agreement for each criterion and the composite score. Following institutional ethical approval, 60 female soccer players were recruited from one international squad (mean (SD): age = 20.27 ± 3.44 years; height = 168.02 ± 5.26 cm; mass = 62.54 ± 6.33 kg). Video recordings (sagittal and coronal plane) of each player undertaking the TJA on an artificial 4G playing surface were taken. Four raters (2 physiotherapists and 2 strength and conditioning coaches) independently assessed each TJA criterion post hoc (flaw present = 1 point, flaw absent = 0 points) and the composite score calculated for each player. There were 665 technique flaws. Criterion 2 “Thighs do not reach parallel” was most common (N = 147/665), followed by criterion 1 “Knee valgus on landing” (N = 80/665). Criterion 9 “Pause between jumps” was least common (N = 23/665).The most common fault category was “Knee and thigh motion” (N = 234/720, 32.5% composite of 3 criteria weighted for maximum possible faults). There were clinically acceptable levels of agreement between raters for “Lower extremity valgus at landing”, k = .83 (95% CI, .72–.93); “Thighs do not reach parallel (peak of jump)”, k = .84 (95% CI, .74–.94); “Thighs not equal side to side”, k = .86 (95% CI, .75–.96). The level of agreement for the composite score of all 10 criteria ranged from kw = .62 (95% CI, .48–.76) to kw = .80 (95% CI, .70–.90) suggesting a “fair-to-very good” level of inter-rater agreement. The “knee and thigh” motion category of the TJA may provide the most useful information for knee mechanics and potential risk factors for knee injury. We recommend its use for screening elite female soccer players.