# Lower Limb Joint Coordination and Coordination Variability During Landing: A Scoping Review
## 3 Results
### Gender Differences  
A prominent theme in landing biomechanics is the difference between male and female movement patterns, motivated in part by the disproportionately higher incidence of ACL injuries in female athletes. Several studies in this review explicitly compared coordination patterns and variability between genders during landing or cutting tasks to see if sex-specific strategies exist that might explain different injury risks. **Coupling Variability Differences:** A foundational study by [PERSON], [PERSON], [PERSON], and [PERSON] examined gender differences in lower extremity coupling variability during an unanticipated cutting manoeuvre (a task closely related to lateral jump landing) [3]. Using a vector coding analysis of coordination and focusing on the initial 40% of stance (deceleration phase), they found that women exhibited significantly lower coordination variability than men in multiple joint couplings. Specifically, female athletes had 32-46% less variability than males in four key couplings (including thigh rotation versus leg rotation, thigh adduction/abduction versus leg adduction/abduction, knee flexion-extension versus knee rotation, and knee flexion-extension versus hip rotation). In practical terms, the women tended to use a more repeatable, constrained pattern (less trial-to-trial deviation) in how their hip, knee, and ankle segments moved relative to each other during the cut. The authors postulated that these gender differences in coordination variability could be linked to injury risk: a less flexible coordination strategy in females might reduce their ability to adapt to sudden perturbations, such as uneven ground or an opponent's contact, thereby potentially increasing ACL injury likelihood if an unexpected load is applied. Women's lower variability might reflect a neuromuscular control strategy that prioritizes consistency (perhaps due to training or neuromechanics) but at the cost of adaptability. This landmark finding aligns with the idea that an optimal amount of variability is healthy; too little (rigidity) may be as problematic as too much. It is worth noting that these differences were noted in a cutting task, primarily a horizontal deceleration with a change in direction, but similar analyses have been extended to jump landings as well. **Joint Coordination Patterns:** Beyond variability magnitude, do males and females coordinate joints differently during landing? Some studies indicate yes. One investigation into drop jump landings found that males and females may adopt different inter-joint coordination strategies to achieve shock absorption. For example, males might utilize a greater contribution of hip flexion with relatively synchronous knee motion, whereas females might exhibit a different phasing, possibly with the knee dominating the motion more than the hip or with different timing in pronation-supination at the ankle. In a study on adolescent athletes performing unanticipated single-leg drop jumps, researchers observed sex-specific kinematic adaptations: female adolescents landed with greater knee valgus angles and tended to show a coordination pattern indicating more reliance on the knee joint (less hip engagement) compared to males. Although that study was focused on joint angles and energy absorption, it implies underlying coordination differences--i.e., females coupling hip and knee motions in a way that results in more frontal-plane knee motion (a potentially high-risk pattern) while males perhaps engage more sagittal-plane hip motion in coordination with the knee to buffer loads. Another study using CRP analysis explicitly compared male and female coupling on a jump-landing task [23]. Without any special insole, women in that study had a lower CRP and lower CRP variability for the foot-shank coupling than men (consistent with [PERSON]'s findings, showing less variability in females).