Middle back pain exercises are designed to address the most common causes of this condition. Namely stiffness through the thorax and ribcage as well as poor muscular strength and endurance through the middle back and shoulder girdles. Perform stretches/ mobility exercises for 5x30 seconds twice daily. Perform strength exercises with 3-4 sets x15 repetitions once daily or every other day. Find a difficulty level that is challenging without causing excessive pain.