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.
My PT showed me I arch my back because my abdominal muscles on my paralyzed side are weak (bottom half of red line on left). To stop myself from falling forwards while standing I lean back (top half of red line). I also arch my back every time I lift my leg to walk. Leg muscles (small arrow pointing upwards) need a stable base to pull on. Abdominal muscles (arrows pointing downwards) are suppose to hold the pelvis and spine still when my leg moves.
It gets worse. I 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 wash a dish because I am leaning my stomach on the edge of the counter for support.
my NDT certification course did not teach that hand function comes from my gut.
Bottom Line: It takes both stretching my tight back and strengthening my weak abdominals to keep back spasms away.