Although support takes place quite naturally and effortlessly under the right conditions, it is because we interfere with this expansive support of the trunk that we must compensate for this elastic support by tightening the abdomen, elevating the ribs, or supporting the diaphragm, which is where the idea of supporting the breath comes from in the first place. Many singers insist that such tension is the key to breath support, often based on superficial observation rather than a real understanding of how vocalization takes place. But they are in fact compensating for the harmful conditions that force them to resort to this kind of specific control. If the overall support system is working well, no specific effort or control is required to support the voice; support will occur automatically as a result of the coordinated action of the entire muscular system. In this sense, support isn’t about breathing at all but about bodily coordination. In fact, when vocalization takes place efficiently, there is no sensation of having to take breath in, of having to support the breath, or of having to use the breath to vibrate the vocal folds, which seem to produce sound of their own accord; the total expansive and antagonistic action of the trunk and ribs is coordinated with closure of the larynx to produce a completely effortless, powerful sound. And this efficient action of the entire system, which constitutes true vocal support, occurs as a totally natural reflex activity when the muscular system is properly coordinated.
Such a process, however, is not without strength. Even if true support comes not from using effort to control the air flow but by naturally controlling the exhalation, there is a palpable sense, when the system is well coordinated, of athletic power and energy in the trunk. Many singing approaches speak about forcefully and energetically supporting the voice. Properly understood, however, support should be derived not from muscular effort but from the antagonistic action of the muscles of the back and trunk, which engage during the vocal act into a powerful, elastic whole. Supporting the breath from the abdomen is a fallacy; true motive power or support comes not from the increased tension or breath pressure but from the antagonistic action of the muscular system in expansively supporting the breathing apparatus and larynx in a controlled exhalation.
Dimon, Theodore. Your Body, Your Voice: The Key to Natural Singing and Speaking. North Atlantic Books, 2011.