Here is another prehab hack to address those forward shoulders. The latissimus dorsi and the teres major (Lat's little helper) can contribute to forward shoulder alignment. This is a contract-relax stretch targeting these muscles, along with other shoulder extensors + internal rotators + scapulae depressors.
Start with your palms up and your shoulders flexed resting on the swissball. Next, extend those shoulders down and internally rotate them (palms will turn in towards the ground). Be sure not to just pronate your forearms, but to actually internally rotate the shoulder to activate the muscles we want to stretch!
After the muscle contraction, move into the stretch by bringing your torso down to be parallel with the ground. Simultaneously reach your arms forward rolling on the ball and externally rotate your shoulders with a palm up end position. MOST IMPORTANT, in order to lengthen these muscles when you move into stretch you have to breathe! The exhalation of this breathing technique is passive, which helps the nervous system to relax and the muscles to release tension. Staying in lumbar and lower thoracic flexion/neutral as you stretch is very important, as this will further lengthen the lats. After a few active contractions and passive stretches you should be able to move into a further passive stretch.