Start by drawing the ‘contact’ pose. This is when the heel of the leading leg is just striking the ground, and the toes of the trailing leg are bearing most of the body’s weight. Note that the torso twists so that one shoulder is further forward than the other
Next draw the ‘pass’ pose. This is when the arms and legs are passing each other as they move. The arms are close to the body; one leg is straightened, bearing all the weight, while the other leg is bent and moving forward. The torso should not be twisted at this point.
The final pose of the sequence is the ‘contact’ pose, where the arm and leg positions are the opposite of those of the first frame.
Now draw the first of the in-between poses. The ‘plant’ pose comes between the first ‘contact’ pose and the ‘pass’. This is when the leading leg takes the full weight of the body, and the foot is planted flat on the floor. This is the lowest point of the head movement arc.
Finally, the ‘striding’ pose comes between the ‘pass’ and the final ‘contact’, and has the trailing leg stretched upwards, and the leading leg moving forward, with the knee raised. This pose is the highest point of the head movement arc.