Walking Session w Alex

Bending the landing leg, you will use eccentric contractions. This allows the pushing back leg to relax as it swings, allowing delegated team work. Eccentric contractions are stronger and cause the muscle to strengthen quicker.
The floor work I suggested is not targeting specific muscles as you saw, but working for cross connection strength from hip to opposite shoulder.
I suggest 8 to ten repetitions of these spinal strengthening movements in two sets with a few seconds in between sets per day.