People want to feel physically capable. There are certain exercises that translate into feeling more capable during daily living than others. Because of its positional usefulness, the ability to perform a proper lunge will give any person the ability to feel more physically able and strong than just about any other exercise.
The lunge is basically a deep stride. Striding is the action necessary to run longer, walk straighter, climb higher, sprint faster, bound farther, and even jump higher.
Lunging gives us the ability to go up and down stairs, or safely pick something up off the floor.
A lunge is, however, somewhat limited in that it only moves in one direction whereas the human body lives in a three-dimensional space. We can therefore alter the lunge to make it more applicable to a varying environment.
By asking someone to lunge with different postures or foot positions, we instigate altered muscle recruitment which creates a more dynamic environment more applicable to a three-dimensional space.
The standard lunge requires a person to keep an upright spinal posture, the forward knee extends to above the forward foot but not usually beyond the toe and the rear knee descends to the ground directly beneath the hip.
Primary Movers: Front leg quad, glute
Primary Stabilizers: Front leg hamstring, rear leg quad