ऊर्ध्वोत्क्षेपैरुरो यत्र निरन्तरकृतैः कृतम् । प्रकम्पितं तु विज्ञेयमुरो नाट्यप्रयोक्तृभिः ॥ २३०॥
The breast is known as Prakampita (shaking) when it is repeatedly heaved upwards with continuous upward movements. This is recognized by practitioners of drama and dance.
english translation