core·mobility

Birth-ball pelvic tilts

Sit on a stability/birth ball, feet flat, knees at 90°. Roll the ball forward and back via the pelvis (NOT the whole body), then in circles. 5 minutes total. Late-pregnancy mobility for the SI joint + opens the pelvic outlet — same drill midwives recommend for early labor.

Secondary muscles

glutes
hip flexors

Form cues

1Pelvis leads the motion — torso stays relatively still
2Feet stay flat on the floor as anchors
3Small circles both directions for full SI release

Common mistakes

Rolling with the whole body (defeats the SI focus)
Ball that's too small or too inflated — sit so knees are at 90°

Contraindications

Skip or modify this move if you have:

placenta previa (low-lying placenta — strict activity restriction)
incompetent cervix or cervical cerclage
preterm labor risk or history
preterm premature rupture of membranes
physician-ordered bed rest or activity restriction