What goes up must come down, part II: Consequences of jump strategy modification on dance leap landing biomechanics

Knee injuries are common in jumping athletes; modifying jump strategy may impact loads placed on the body and reduce injury risk. The purpose of this study was to determine if modifying strategy in a saut de chat leap to focus on height would decrease sagittal plane knee loading. Biomechanical data were collected while 28 dancers performed saut de chat leaps with instructions to jump far (FAR) or jump high (UP). In the UP condition, there was greater vertical GRF and less braking GRF. Also in UP, lower extremity contact angle was greater (71.3 ± 2.9º FAR; 75.8 ± 3.3º UP; p = 0.0178), peak knee extensor moment was greater (2.8 ± 0.7 Nm FAR; 3.2 ± 0.8 Nm UP; p = 0.01), and peak ankle plantar flexor moment was lower (3.19 ± 0.4 Nm FAR; 2.94 ± 0.4 Nm UP; p < 0.01). A more acute LECA was related to greater braking force and braking force was related to greater knee extensor moments. Despite these relationships, we observed greater knee extensor moments in UP. While the relationship among these whole-body variables and knee joint loading exists, it may not be the primary factor driving load distribution during dance leap landings.