Comparative kinematic analysis of forelimb and hindlimb cushioning strategies in German Shepherd dogs: implications for injury prevention.

Objectives: While German Shepherds are widely utilized in agility and working roles, the limb-specific kinematic strategies they employ to attenuate impact during locomotion, and how these strategies relate to clinical injury susceptibilities, remain insufficiently understood. Methods: In this preliminary study, we used a three-dimensional motion capture system to quantify the forelimb and hindlimb kinematics of four clinically healthy German Shepherd dogs during walking, trotting, and controlled drop-landing. Results: Joint angle profiles revealed significant functional differentiation: forelimbs exhibited inverted pendulum-like kinematics prioritizing initial contact stability, whereas hindlimbs demonstrated spring-like kinematics specialized for propulsion. Crucially, we identified distinct limb-specific cushioning mechanisms during initial ground contact: forelimbs passively absorb impact via rapid carpal hyperextension (dorsiflexion), while hindlimb tarsal flexion geometrically implies active eccentric muscular control. Conclusion and relevance: These findings provide essential preliminary kinematic baseline data for healthy German Shepherds. The passive forelimb strategy is biomechanically consistent with the high clinical incidence of carpal ligamentous injuries, whereas the active hindlimb strategy may predispose the stifle to fatigue-related cranial cruciate ligament insufficiency. These insights deepen our understanding of functional limb differentiation and establish a critical normative reference for evaluating pathological gait deviations, informing targeted conditioning programs in veterinary sports medicine and orthopedic rehabilitation.