Tackle poor posture, spine mobilty and improved overhead positioning with exercises such as shoulder presses with my favourite spinal mobilty drill...
What you need
Two massage balls in a sock or 2 lacrosse balls duct taped together will work just fine.
How to do it
Elevate your feet with your knees bent at 90 degrees and keep your spine in a neutral position. Hug your arms round your body to move the scapular out of the way. Place the 2 balls on the thoracic spine (around chest level). Slowly extend over the balls, but keep your core engaged to prevent any hyperextension of the spine.The great thing about working with the two balls is you can localise the target area and work on 2 segments of the spine at a time. Feel free to move the balls up or down to work on another 2 segments of the T spine. Spend at least 120 seconds on the mobilisation to see and feel some change.