Ski Muscle of the Week #4: The Rectus Femoris.

This is the fourth muscle of the Quadriceps group.  It’s separated out from the Vastus group of Week #3 because it performs an extra action that the Vastus do not.  As with the Vastus muscles, the femoris helps us make our leg long and strong.  But in addition to extending the leg at the knee and hip, the femoris also acts as a lever to flex the leg at the hip.  Here’s why this is important:

1.  Skiers need a long outside leg to carve their skis.  The Vastus and Rectus muscles accomplish this by helping us use our outside thigh like a strong pole.  That strong pole (with a bit of bend at the knee) flattens the outside ski so that the inside edge of that ski slices and carves the turn.
2. While our outside leg is long and providing the power for the turn, the inside leg is short and helping us maintain our balance as well as our movement down the hill.  The Femoris, then, when it's the inside leg, helps us shorten that leg by helping us lift our leg from our hip and toward our chest. 

 Here’s some pictures to explain:


Here my left or outside leg is long; my right leg or inside is short; both are doing a good job of supporting me in the turn—I’m carving, not skidding.  My zipper matches the vertical of the shrubs in the background, and my right ski pole is above the snow.

When I don’t lift my inside leg enough, I get ski and balance confusion:

If I did a better job of lifting my inside thigh toward my chest I would lose the confusion and both skis would do a better job of tracking in sync.  And my stance would be ready for the next turn.

In my opinion, this muscle action of the inside leg also helps answer a long-standing question that skiers ask ski instructors:  how much weight is on your outside leg and how much is on your inside leg?

From the point of view of the Rectus femoris, the amount of weight you put on the inside leg is related to how high you need to lift the leg to keep your skis headed in the same direction.

Exercises for this muscle:

Supine leg raise.

Jump squat.

Leg extension machine.

Knee extension machine.

Walking lunge.

Leg press machine.

     Deadlift.  Please don’t use too much weight—the best way to hurt your knees is too overdo this exercise.