"Arrears" put invisible obstacles in his path.

But upon reaching the lowlands, the wind seemed to strike invisible obstacles and form many conflicting streams of air.

And the conclusion found everyone slogging forward, as if hacking away at invisible obstacles in the air.

He flinched as his hands touched an invisible obstacle.

Stamping across the stage, he could have been defying invisible obstacles.

In all three works, the performers could have been contending with invisible obstacles.

His face would jerk to a stop as though it had smacked into an invisible obstacle.

But still the boy ran ahead, bounding circuitously around invisible obstacles.

Occasionally the dancers contend with invisible obstacles around them.

The dancers brushed at the air with their hands, as if clearing away invisible obstacles.