Mobility
Strengthening
Stretching
Lumbar spine
Mobility
Lie on your back with your legs bent at the knee and alternate between raising the small of your back and lowering it back down onto the mat.

Strengthening
Lie on your stomach with your head slightly raised and then lift one outstretched leg, holding the position for a few seconds. Repeat with the other leg.

Stretching
Lie on your back and bend your lower legs at the knee inwards toward your stomach until you feel tension in the small of your back.