Stretching the legs first can make a significant difference for the tension in the low back. The suggestion is to stretch leg muscles first, then go to the low back stretch. Stretching after physical activity and anytime you have tension or pain is recommended. No need to force the stretch. Stretch gently with correct form and hold with relaxed breathing. You will notice after 30-60 seconds that the stretch is more relaxed with greater flexibility. Mission accomplished! Move to the next stretch.
