This is an excerpt from Optimal Muscle Training-Paper by Ken Kinakin.
Risk-Benefit Ratio of Specific Weight-Training Exercise Techniques
Each weight-training exercise can be performed in various ways. Some techniques are beneficial for the development of strength, while other techniques are more suited for muscular hypertrophy. The benefit and inherent risk of each exercise modification such as grip width, foot position, arm position, range of motion, head position, and trunk motion will alter dependent on the person's experience, body type, and outcomes desired. The exercise modifications should always be done to increase the stress on the muscles and not the joints, ligaments, or capsules. The following photos review variations in technique for each weight-training exercise to offer guidelines for the optimal implementation in an individual training program. Remember that high risk does not automatically mean that the person will be injured. It means that the potential for injury may be higher due to specific techniques needed for increased strength and development.
This is an excerpt from Optimal Muscle Training.