Review of a Slash and Overlap Method to Alter Patterns for Knock Knees

One of the cool features of VStitcher is being able to move the avatar into different positions. One of the positions I thought would be helpful to understand fit is a subtle knock-knees stance.

Knee Alignment

I’m going to ignore bowlegs since that issue is less frequent. However, the approach can be applied similarly if needed. For regular anatomical alignment, the center of the ankle, the center of the knee, and the center of the hip can all be aligned along the same vertical line. However, with knock knees, when the ankle and hip are aligned, the center of the knee will deflect toward the midline.

I choose only a 3% knee deflection on my avatar to explore fit changes. The avatar knock-knees are the same across patterns.

Slash and Overlap

To make an alteration for knock-knees, I used a slash and overlap method at the knee level. Cutting along the horizontal knee level, overlap along the side seam the amount needed leaving the inseam untouched. How to determine the amount to overlap? You may be able to pinch out the excess on a muslin. The goal is to get the hem parallel with the ground if it’s a wider leg or to get the center grainline centered with your ankle if the leg is more narrow.

Knock-knee adjustments should be made after adjusting the center grainline at the hip. Why? Adjusting the center grainline at the hip impacts the fit from the hip down. Knock-knees only impact fit from the knee down. You want to fit pants starting at the top and working down because alterations at the top will cascade down and change the fit. Let’s look at three patterns to see how the alteration is made and the impact on fit.

May Jeans from Make by TFS

Knock-Knees Alteration

Using the slash and overlap method, I only had to overlap 0.375 inches at the side seam. The key point to getting this alignment was to focus on the hem. I wanted the hem parallel to the floor, and I wanted the hem to not be touching along the inseam. Notice that the center grainline is still in the middle of the ankle and knee level! The center grainline will NOT be perpendicular to the floor from the ankle to the knee. The center grainline is only perpendicular from the knee upward.