I herniated a disc in my back and had sciatica 20 years ago so I've been stretching my back for years. After my stroke I was worried my back pain would come back. It did. A recent bout of back spasms taught me stretching my back every morning is not enough. Freezing in place when a back spasm hits and hoping I can walk slowly to sit down without dropping my cane is scary.
I was shocked to learn I repeatedly arch my back because the abdominal muscles on my paralyzed side are weak. This weakness lets my pelvis tilt forward (bottom half of red line on left). To stop myself from falling while I am standing I lean back (top half of red line). It gets worse. My back arches every time I lift my leg to walk. Leg muscles (arrow on right) need a stable base to pull on. Stomach and back muscles (triangles on right) are suppose to hold the pelvis and spine still when the leg moves.
It gets worse. My PT discovered I arch my back when I lean down to pick up an object, like when I reach down to get a pot from a bottom cabinet, get milk from the bottom shelf of the refrigerator, or pick up something from the floor. I arch my back when I rinse a dish and brush my teeth because I am leaning my stomach on the edge of the counter for support.
Thank goodness I figured a way to add abdominal exercises to my morning routine. I was shocked to discover that stronger abdominals also improve my hand function.