Thanks to the opposable thumb, courtesy of evolution and our fine motor skills, we're able to grasp and hold things, be it a tool or surgical instrument, the steering wheel, a pen or the computer mouse. That has been a boon for the development of humankind but has not been without its downside, namely tension and contractions especially in the flexor muscles of the hand and forearm. Overloading and one-sided use of the muscles, not necessarily a particular sport, can cause a so-called tennis arm or golfer's elbow, or painfully irritated tendons. Avoiding such situations is, of course, the best prophylaxis, but stretch exercises and concentric and eccentric training units also help, for instance in the neck and shoulder area. The haptic ball can also help here, which (the name gives a hint) in addition to training simply feels good to hold, which is why people like to move it back and forth in their hand, staying in motion themselves.