When a muscle lengthens under load during training it is called the eccentric phase of the movement. The controlled lowering phase of training is not only important for muscular growth, but has other training benefits.
Following years of systematic reviews of the scientific literature, it has been determined that the act of stretching has "limited effectiveness in preventing injury or reducing the risk of injury." What is becoming apparent is that eccentric training is an effective way of changing range of motion, as well as, reducing injury. This is accomplished through strengthening the tissue and changing the compliant end of the tendon. Injuries are reduced when you have a healthy myotendinous junction, that is, the connection between the muscle and the tendon. Maintaining the health of this region requires adding movements of low velocity to your athletic program. Get Strong and stay injury free by emphasizing the lowering phase of training.