Fig. 3
From: Key transition technology of ski jumping based on inertial motion unit, kinematics and dynamics
Graph a shows the placement position of the IMUs (Xsens, Nos. 1–16), total of 18 IMUs (with 2 others on the ski). Detecting area division of the fore (0–6) and rear (7–12) foot parts in a wireless pressure insole. Graph b presents the key angle parameters of an athlete’s body posture during early flight. α, the angle of attack, is the angle between the longitudinal axis of the body and the horizontal plane of the centre of gravity. β is the angle between the longitudinal axis of the body and the ski. γ is the angle between the upper part of the body. Points ski-1–4 constitute the whole ski