'Prone' refers to the perceived likelihood of being affected by something. For example, a person who's 'accident prone' is thought more likely to be involved in an accident. Someone who is 'prone to laziness' is thought to be more likely to be lazy, whilst a person 'prone to telling lies' persistently embroiders the truth, as if these traits or behaviours are actually the result of external influence.
From the most basic idea of being 'prone to attack' (exposed or defenceless,) comes the other definition of the word...
'Prone' also refers to the face down position of the (human) body.
In first aid, medical, or police forensic work, for example, it is important to differentiate between prone and supine (face up.)
The 'three-quarter prone' position in paramedics is otherwise known as the 'recovery' position. An unconscious person may be put in this position, where they lie mostly face down, but with one arm and leg bent to right angles, and the head turned towards that side. This makes it difficult for them to accidentally roll into a supine position, where saliva, phlegm, or vomit could block the airway. The position of the head in three-quarter prone position enables these liquids to drain out of the mouth.
A few Olympic sports are done in the prone position, such as rifle shooting and luge.
The experience brings to mind the philosophical underpinnings of the novels of French postmodernist Alain Robbe-Grillet, whose repetitions and splintered ``objective" descriptions show that it's the viewer who imposes meaning on scenes and events; the pieces and players don't hold significance in themselves.
In one crystalline example of Jasperse's theme, all three dancers lie prone on the ground with their arms bent at the elbows, their hands now slapping down, now bobbing or half-waving in the air.
``Prone" may be about ideas, but in the end it's the humanism at its core -- our vulnerability as participants, how the performers' bodies shape those concepts in blood, sweat, and tears -- that lingers when the lights come up.