Part of these sets

This exercise rarely works alone. It appears in the following routines, where it is sequenced alongside the others that support it.

What it works

Primary muscles

Lower abdominals, rolling the pelvis backwards
Lumbar erectors, arching it forwards

Also involved

Gluteals, lightly assisting the backward roll
Pelvic floor, moving with the pelvis

Equipment: None. A mat, or a firm bed during a flare.

How to do it

1
Lie on your back with knees bent, feet flat and hip width apart, arms resting by your sides.
2
Breathe out and gently roll the pelvis backwards, so the lower back flattens softly into the floor and the lower abdomen draws in slightly.
3
Breathe in and roll the pelvis the other way, letting a small arch appear under the lower back.
4
Keep rocking slowly between the two, staying inside a range that is completely comfortable. Effort around a two out of ten.
5
Leave everything above the waist out of it: ribs heavy, shoulders relaxed, jaw loose.

How much to do

10 to 15 slow rocks

2 to 3 times a day during an episode

Two weeks of gentle, consistent mobility beats one heroic session. A minute of rocking every few hours does more for an irritable back than one long stretch a day.

Stop and get assessed if

Stop and get assessed if this small movement sends pain, pins and needles or numbness into a leg, or if even the tiniest range stays sharply painful. A gentle pelvic tilt should be one of the most comfortable things a sore back can do.

Common mistakes

Bracing hard to force the back flat: This is mobility, not a strength test. Heavy bracing rehearses the guarding that keeps a back sore; the movement should feel almost lazy.
Lifting the hips off the floor: The pelvis rolls, it does not lift. If your bottom leaves the floor you have started a bridge, which is a different exercise for a later stage.
Holding the breath: Pair the movement with breathing: out as you flatten, in as you arch. The rhythm keeps the effort low and stops the trunk from bracing.
Pushing into a sharp catch to loosen it: Stay inside the comfortable range. A dull, familiar ache that settles within a few minutes is fine to work with; sharp or shooting pain means make the movement smaller.

Making it harder

Let the range grow gradually over days as the back relaxes.
Practise it seated: rolling the pelvis forward and back on a chair is one of the most useful thirty-second breaks in a desk day.
Progress to cat cow on hands and knees, which is the same movement working against gravity.

Pelvic Tilt