Figure 2. Experimental 3D kinematic set up. SB, starting block. CF, calibration frame. Sc, surface camera - 0.8 m height: 1, 2, 3 and 4 (5.5 and 7 m away from swimmers’ plane of movement, aligned or 5 m away from SB). Sc-5, 3 m height, 8 m away from swimmers’ plane of movement and 15 m away from SB. UWc, underwater camera - 1.4 m deep: 1, 2, 3 and 4 (4.5 and 6.5 m away from the swimmers’ plane of movement, 0.5, 1.0 and 5 m away from SB).