Example 1: Reliability study focusing on the Achilles tendon. The first (a) and second (b) score vectors are plotted together with the average angle measured by the isokinetic dynamometer for the two movements. Both the plantar and the dorsal flexions are clearly captured by both score vectors. The dorsal flexion is divided into three phases: Phase 1 is the end of the plantar flexion, Phase 2 is the transition from plantar to dorsal flexion and Phase 3 is the beginning of the dorsal flexion. The phases are marked in both Figure (a) and (b); in the case of Figure (b), the different phases are indicated by the numbers 1, 2 and 3. The corresponding speckle tracking vector field plots are shown in (c) and (d) for Phase 1, (e) and (f) for Phase 2 and (g) and (h) for Phase 3. The directions of the vectors indicate the direction of motion of the corresponding tissues.