"supporting leg" is a correct and usable phrase in written English.
You could use it when referring to a physical support, such as a leg of a desk, table, or chair, for example: "The desk has four supporting legs."
The dancer brushes the working leg, as in an assemblé, to the side and into the air while simultaneously pushing off from the supporting leg, and then beats in front or in back of the supporting leg.
She raises a leg, fully sculptured in its volume and then jumps on the supporting leg.
Keeping one leg stretched straight in front of you, just how deep can you bend your supporting leg?
Her supporting leg, bended at the knee, leans forward, forming another arc that likewise leads to the upturned head.
We choose the inter-link angles for the four powered articulations as polynomials depending on non-powered ankle angle of the supporting leg.
To this end, we have developed a new method of extracting the gait feature (step length and speed), based on a maximum likelihood estimation of supporting leg positions in accumulated range data.
At this performance, however, I noticed in particular an opposite virtue: the smoothness and fullness of tone with which these dancers often, while holding one leg extended, lower the heel and bend the knee of the supporting leg.
The dancer raises the thigh to the side with the knee bent while bringing the toe of the working leg along the calf to the back of the knee of the supporting leg.
The biggest black triangle region represents the supporting leg polygon, except for the groping leg.
Both actions keep the center of mass in the upper body balanced above the supporting leg, but men, with their buttocks slightly behind the supporting foot, move their trunk so as to use the upper and lower torso as a counter weight above the supporting leg.
