# Lower Limb Joint Coordination and Coordination Variability During Landing: A Scoping Review
## 4 Discussion
So, the integration of coordination training in late childhood and adolescence is key to bridging the gap in adult movement patterns. **Biomechanical Frameworks and Future Directions:** This review's findings can be framed in the context of the systems approach to biomechanics. Rather than viewing joints in isolation, it is clear that the coordination among joints is a critical determinant of outcome (injury or performance). Methods like vector coding and CRP have proven useful in quantifying these interactions. However, they also simplify complex 3D reality into planar couplings. Future research might expand into multi-planar or network analyses of coordination (treating the limb as a connected system rather than pairwise couplings only). Moreover, prospective studies are needed: while cross-sectional differences (i.e., between injured and healthy, or male vs. female) are shown here, we need to know if those differences cause injuries or are just correlated. Longitudinal studies could track coordination variability in athletes and see if certain patterns predict future injury. Early results in cutting manoeuvres suggest they might (i.e., women with very low coupling variability could be at higher ACL risk), but confirmation is needed in landing scenarios. Another area for future work is intervention efficacy: for example, does deliberately increasing landing coordination variability in a female soccer team lead to fewer ACL injuries? Or does balance training that normalizes coupling in CAI actually translate to fewer reinjuries? These practical links must be established. Finally, wearable technology (inertial sensors) and real-time biofeedback may soon allow coaches to monitor coordination patterns outside the lab [46; 47]. Imagine a system that detects if an athlete is getting too stiff in their landing coordination and prompts them or the coach to adjust training. The foundation laid by the studies in this review points toward such applications. Coordination and variability metrics provide a richer description of movement quality than single-angle measures, capturing the interaction between joints that is ultimately what defines a fluid, safe landing. **Limitations:** This scoping review has several potential limitations. First, as a scoping review, it does not include a meta-analysis or quantitative synthesis, limiting the ability to draw conclusions about effect sizes or intervention efficacy. Additionally, the included studies are highly heterogeneous in terms of participant populations, tasks performed (i.e., drop jumps, sidestep cutting, single-leg landings), coordination measures used (i.e., CRP, vector coding, Lyapunov exponent), and experimental conditions such as fatigue or taping protocols. This variability presents challenges in directly comparing results. Furthermore, many studies emphasized functional outcomes without addressing underlying neuromuscular, anatomical, or hormonal mechanisms that may influence coordination. The review may also be affected by language and publication bias, as only English-language, peer-reviewed articles were included. Age and sex influences were not consistently reported across studies, despite being relevant factors in motor coordination. The predominance of cross-sectional studies also limits the understanding of longitudinal changes. Lastly, variability in motion capture technology, signal processing, and normalization techniques across studies may introduce inconsistencies in coordination metrics. To mitigate these limitations, a comprehensive and systematic search strategy was employed across multiple databases, detailed data extraction was performed using a structured template, and findings were synthesized thematically to highlight patterns and gaps without overinterpreting heterogeneous data. The decision to clearly distinguish time-series from non-time-series studies further allowed a more nuanced interpretation of coordination variability outcomes.