The pectoral muscles (consisting of pec major and minor) are found at the front of the chest, and are frequently tight in people who spend a lot of their day at a computer (which is most of the population!) Being seated in this position for hours on end causes the shoulders to roll forward and the pec muscles to shorten, leading to excessive tightness in these areas.
Ongoing tension in the pecs can contribute to imbalance in the shoulder girdle and potential shoulder instability, which may lead to eventual rotator cuff injury.
Using the spiky ball as shown in the video above can help to give relief of pec tightness, and may help to keep painful symptoms at bay until a longer term solution can be found if necessary.