Albert Barnes Commentary Job 18:7

"The steps of his strength shall be straitened, And his own counsel shall cast him down." — Job 18:7 (ASV)

The steps of his strength - Meaning, strong steps. “Steps of strength” is a Hebraism, denoting firm or vigorous steps.

Will be restricted - This means the steps will be compressed, encumbered, or hindered. Instead of walking freely and widely, he will be compressed and limited in his movements.

“Large steps,” “free movement,” and similar phrases are proverbial expressions among the Arabs, denoting freedom, prosperity, and so on, as noted by Rosenmüller. Schultens quotes the following illustrations from Arabic poets. From Ibn Doreid, “He who does not confine himself within human limits, his vast strides shall be straitened.” And from Taurizius, “After the battle of Bedrense, the steps were straitened.”

The meaning here is that he will be greatly impeded in his movements, instead of moving about freely and with full vigor as he had done previously.

And his own counsel - His own plans will be the means of his fall.