Mechanical Analysis of Diving-Evasion and Seated-Block Defensive Skills in Kho-Kho

Abstract: Two further skills complete the mechanical picture of kho-kho: the runner's diving evasion, a low-trajectory dive used to gain distance from a chaser or escape a tap attempt, and the seated blockers' defensive posture, in which players seated along the central lane must react and extend to obstruct or intercept play. Despite their frequent occurrence, neither skill has been examined using projectile-motion or postural-stability frameworks. This paper analyses diving evasion through the principles of projectile motion and impulse-momentum landing mechanics, and analyses the seated- block posture through principles of static and reactive stability, including base of support and centre-of-pressure control. Sixteen state-level kho-kho players (runners and seated defenders) were filmed using high-speed video and a landing- zone force platform while executing match-simulated diving evasions and reactive blocking actions. Dive take-off angle, horizontal displacement, flight time, and landing ground reaction force (GRF) were extracted for the diving skill; base of support width, centre-of-pressure displacement, and reactive extension time were extracted for the seated-block skill. Results showed that successful diving evasions -- defined as gaining sufficient horizontal distance to avoid an immediate tap -- were associated with a low take-off angle (mean 16.8° from horizontal) that maximised horizontal range relative to flight time, and with a progressive, sequential flexion of the wrist, elbow, and shoulder on landing that reduced peak vertical GRF compared with a stiff-armed landing strategy. Among seated blockers, players who maintained a wider base of support and pre-flexed knee and hip angles demonstrated significantly faster reactive extension toward an approaching ball or runner than those in a more upright, narrow-based posture. These findings characterise diving evasion as a low- angle projectile skill constrained by a landing-safety trade-off, and characterise seated blocking as a stability-for-speed postural skill, with direct implications for technique coaching and injury prevention in both.