Right after jackknife is shoulder bridge, which is a nice restorative exercise after the jackknife.
So, the knees will be bent, the feet are open inner hip distance apart, and the knees are open inner hip distance apart. And your arms will press down into the mat.
Take an inhale to prepare. Then exhale, curl your tailbone. Lift up your hips to a bridge position. And hold it here. So in this position, the knees are in the same plane as the hips and the collarbones. It's not an arched rib cage that may find in other modalities like Yoga, but in Pilates, the ribs are always softening and pulling together.
From here, bend your right knee in toward your chest and extend the right leg toward the ceiling. Flex your heel. Lower your leg down knee-to-knee. Point and lift. Flex, inhale as you lower the leg. Exhale, point to lift. One more. Inhale to lower. Exhale to lift. Now, bend your knee, bringing your foot to the mat and switch legs.
Stretch you leg to the ceiling. Flex your heel. Inhale, lower the leg knee-to-knee. And exhale, point. Do two more, Madeleine. So as you're working, you keep the hips very steady and balanced. It's extremely hard, but just try to keep them balanced. Bend you knee. Lower your foot to the mat. Breathe in. Then breathe out, and articulate through the spine: upper back, middle back, lower back and tail bone. So this is a graduated version of the pelvic tilt. You go right through the spine.
Let's see it one more time. Inhale. Exhale, bridge your hips up off the mat. Bend your right knee toward your chest. Extend the leg to the ceiling and flex your heel. Inhale, lower the leg down knee-to-knee. Exhale, point to lift. And again. And lift. As you lower the leg, keep lifting the hip toward the ceiling. There you go! Bend the knee. Lower the foot. And switch legs.
Extend your leg. Flex the heel. Lower on an inhale. Then exhale, lift. And two. One more time here. Bend your knee. Lower your foot. Inhale again. Balance your pelvis. Scoop your abs. Then exhale, start to roll down through the spine, one vertibra at a time.
So that's shoulder bridge, which leads right into the sidekick series in the beginner system.