Pelvis Motion
The pelvis should be able to do four movements with each step that you take, these are:
Tilt Forwards (anterior tilt) and Tilt Backwards (posterior tilt).
Hike & Drop - Lateral tilt motion
Shift - Lateral Shift
Rotation - Left to Right
Tilt Forwards (anterior tilt) and Tilt Backwards (posterior tilt).
As the foot makes contact on the ground the pelvis tilts forward (anterior tilt) over the hip joint to absorb the load of the foot hitting the ground. This is an important action so that your spine received less force. So if the pelvis tilts forward it then most perform the opposite action so that the all the muscles surrounding the pelvis and spine can load and then unload. The opposite action is a tilt backwards (posterior tilt). Your pelvis must be able to perform both movement equally for the pelvis, hips and spine to function properly.
Hike & Drop - Lateral tilt motion
This action occurs at the same time as the forward tilt and is again used by the body to dissipate the load at the hip joint. The pelvis should tilt up equally on both sides as your walk with every step. If one pelvis is always higher than the other then this may impact the spine and hip joint as it probably won’t have time to do the opposite action. So if one side of your pelvis is hiked (higher than the other) then the other side must drop (be resting lower). Again we are after the left and right pelvis to work equally.
Shift - Lateral Shift
As the foot strikes the ground the pelvis is laterally shifting towards it. This action is preparing the body to hike and drop in preparation to absorb the load. This motion side flexed the spine and again is needed for motion in the spine and hip joints.
Rotation - Left to Right
With each step that you take the pelvis is also rotating equally left to right so that if the left foot is forward the pelvis is rotating right and vice versa. If you pelvis is already rotated in one direction, it become difficult to rotate in the opposite direction. This eventually affects the entire spine as the spine acts like a staircase and is governed by the ability of the pelvis to rotate equally in both directions.