EFFECTS OF A SOCCER-SPECIFIC VERTICAL JUMP ON LANDING MECHANICS

Anterior cruciate ligament (ACL) injury frequently occurs in female soccer athletes during deceleration movements such as landings. The drop vertical jump (DVJ) is often used a screening tool for ACL injury risk factors. Kinematic mechanisms have been linked to ACL injury risk including deficiencies in hip and knee flexion during landing. In soccer, landings mostly occur following jumping headers. Little research has been done to determine the mechanics that follow headers and how they compare to the standard DVJ. PURPOSE: This study analyzed the kinematic differences between landings in female soccer athletes to better assess the risk for ACL injury in soccer-specific vertical jumps (SSVJ). It was hypothesized that more biomechanical tendencies associated with ACL risk factors would emerge from the SSVJ compared to the DVJ across the first and second landings. METHODS: 8 female recreational soccer athletes (20.88 ± 1.17 years; 1.68 ± 0.06 m; 58.77 ± 7.65 kg) performed DVJs and SSVJs initiated from a 31 cm height. Motion capture was performed during landings. Data was analyzed using two-way ANOVA with repeated measures, collapsed across jump type (DVJ vs. SSVJ). RESULTS: SSVJs produced less peak hip flexion (67.50 ± 2.55° vs 78.62 ± 3.54°, p = 0.030), and less peak knee flexion (79.15 ± 3.59° vs 88.18 ± 3.95°, p = 0.002) compared to DVJs during landing. SSVJs demonstrated increased ankle plantarflexion at initial contact than DVJ across both landings (20.0 ± 15.66° vs 17.11 ± 17.21°, p = 0.005). CONCLUSIONS: SSVJs displayed a more erect landing posture than the DVJs at the hip and knee, a known ACL risk factor. Increased extension that occurred at the hip and knee in SSVJs compared to DVJs may be linked with the increased ankle plantarflexion at initial contact. The significant results between jump styles shows that the DVJ displays mechanics that are different from the SSVJ. The SSVJ may be a better sport-specific screening tool for ACL injury mechanisms than the DVJ in soccer athletes as it has more direct translation to the sport.Supported by BSU ASPiRE Grant 2020