Comparing performance on single-leg exercises to double-leg exercises can reveal balance control issues and instability.

“How does someone do on the double leg versus single leg? Gives us a really nice window to okay, where is the lack? Great example, two leg, really strong, they're solid. We put them on single leg and they're abnormally less functional and weak and don't have the range. So, I'm immediately thinking, okay, there's a balance control issue here. Cuz on two legs, I'm really stable, but on one leg, I'm significantly less stable and it's much more complex for the body.”