The symptom for a small bicep can be horizontal draglines, or it may simply feel too tight. This correction is also great for making the sleeve cap wider if that area was also too tight.

Bicep Adjustment Process

1. Open the underarm seam and allow it to relax. You may need to also open up the side seam as well to allow the bicep to open enough. Measure the amount that you want your bicep to increase.
2. Mark your pattern as shown in the video and cut along those lines. You will stop cutting once you get close to the edges of your pattern piece.
3. Spread the bicep area by pulling out your pattern pieces as shown. You want to achieve the same measurement at the bicep location as you opened your sample in step 1.
4. You can see that the cap width has increased. The cap height has decreased.
5. If you’re not pleased with how wide the cap width has become, you can always play with the angle of your slashed diagonal line or add a few additional diagonal slashes to even out the cap distribution better.

In the end, the sleeve must fit back into the armhole of the body.

This information and more can be found in The Fitting Book. Order your book today through the link below.