The decision whether or not to restrain a potentially violent person must be carefully and quickly thought out. When involved in a posible restraint situation there are several steps to be considered. The safety of the "target" person, others in the area as well as the the respondent must be considered. In my experience, several steps allowed the process to be effective.
The first step I took was supportive. In other words, try to verbally de escalate the crisis. As long as the "target" person is responding, that effort must continue. However, the supportive time frame might be very short as violence may increase. When this happens step #2 will be implemented. That is when I would take charge of the situation and call for assistance. Anything to avoid handling the situation alone is good. First you have an additional set of eyes, and the second responder can step in to mediate if necessary. If a conflict occurred between me and the "target", I would steps back and my partner would take over. Often this will deescalate the situation. If not, there is more than one person to become forceful.
My partner was of utmost importance when it came to stage 3, the restraint. Restraint should only be used when absolutely necessary like breaking up a fight, a physically aggresive person, and only when every other option has been tried. If possible, we would avoid restraining someone alone. It is not safe. We knew there were ways to control someone physically with out hurting them or us. And never, ever would we put hands on or even near the throat, the head, the back or the chest. Not only is it dangerous, it is not necessary.
We only restraint a person to the ground in extreme cases. BE AWARE THAT A COMMON MISTAKE IS TO ASSUME THAT A LOUD, ARGUMENTITIVE PERSON IS VIOLENT. THEY ARE NOT! When I did this I used the following steps: 1. My partner and I stood on each side of the "target". 2. We both placed one hand on the shoulder of the 'target" while placing the other hand on the wrist stretching out the arm. 3. Then we used our inside legs to trip the target while gently controlling their descent to the ground. Because of the position we were in, the fall was fully controlled.
Once someone was on the ground they would be held with 2, 3 or 4 people, one hand on the shoulder another on their outstretched arm for those near the front. Near the feet, each person would hold one foot. Never ever would we put any weight on their chest, neck, head or back. First there would be dead silence, and then one person would quietly ask if the target person is ready to cooperate. Patience is the issue here. We would wait until there was full compliance or when police arrived.