Forward Shoulder Adjustment in Knitted Sweaters

Question

I'm an experienced seamstress who recently started knitting. After countless hours of fitting woven garments, it's a bit of an understatement to say that fitting a knitted sweater is giving me a lot of anxiety. The reason for this is that I have very forward set shoulders. This causes the shoulder seam to run towards the back. In extreme cases, the shoulder back not quite wide enough and there is too much fabric across the front.

Here is a threadbare RTW T-shirt. You can see the diagonal creases along the back caused by my shoulder pulling it forward. I have identical T-shirts that I wear less often that don't fit this well.

In flat patterns, the simple adjustment is to redraw the shoulder seam by removing a piece from the front and giving it to the back. The front shoulder ends up with a steeper slope, while the front has a flatter slope. The sleeve cap is also shifted to the front. This usually makes it impossible for vertical repeats to match at the shoulder seams.

via Melly Sews

Here's a woven shirt I made with a forward shoulder adjustment. The shoulder seam runs along the top of my shoulders. Sadly, those vertical stripes don't match.

When it comes to RTW, the shoulder seam often fits worse on knitted garments than it does with woven garments. Here is a Croft & Barrow sweater that fits all kinds of wrong in the shoulder area. It doesn't help that the shoulder seam sits too far back even at the base of the neck.

I've looked at quite a lot of information regarding fitting knitted sweaters, but I can't find anyone discussing this type of adjustment. Would I go about this the same way I would with a woven fabric? Are there any sort of issues I should be aware of?

Answer 1

As far as I'm aware (I don't knit sweaters), you should treat your knitted fabric like a woven one. That means, if you already have a bodice block that fits your shoulders well, try fitting the swater into this block as you knit. That can mean increaseing or decreasing rows along the shoulder in a different pattern than given in the original pattern.

If you knit with a thick yarn or very loosely, it could lead to uneven edges or stretched stitches along the seam, since the lose knit has more opportunity to move and stretch. This problem shouldn't arise in a tight pattern with thin yarn.

An alternative is to completey change the way the sleeves are attached to the bodice.

A Reglan Sleeve doesn't have any shoulder seam at all:

(image source)

A Saddle Shoulder has a wide strip of fabric where the shoulder seam would be. That makes it more forgiving.

(image source and instructions)

A yoked sweater is knit in the round and has no shoulder seam at all:

(image source)

(I'm not affiliated with any of the linked products or shops)

Answer 2

Fitting techniques in knitting don't seem to be on the same level that they are for sewing. What fitting information I can find mainly focus on the bust/waist/hip area.

Making a forward shoulder adjustment requires a bit of geometry (ie. math). Besides your gauge, you need to know 3 things:

• width of the shoulder area (ie. the value you would use to determine how many stitches across it is)
• shoulder drop length (I have a normal 1.5" drop from the base of the neck to the end of my shoulders)
• amount to adjust the shoulder by (I need to remove 0.5" from the front and add 0.5" to the back).

I'm going to use stitches/rows here because that's what my shaping calculator uses internally, so it's easier for me to grab those numbers.

In my imaginary sweater pattern, I have a gauge of 4.25 st/in and 6 row/in.

• 21 stitches for the shoulder area that I would decrease over for the shoulder seam
• 9 rows for a shoulder drop without a shoulder adjustment

To make the forward shoulder adjustment, I need to either change by 2 stitches (for sleevecap adjustments) or 3 rows (shoulder seam adjustments). Since we working with the shoulder seam (the sleevecap adjustments are too complicated to cover here), our adjusted rows for the shoulder drop look like this:

• 12 rows for the front (steeper slope)
• 6 rows for the back (shallower slope)

But you also need to make adjustments to the number of stitches wide the shoulder area is. For that, we need to dig up the good old Pythagorean theorm: a squared + b squared = c squared.

Calculate the length of the slope:

sqrt(pow(rows / rows_per_inch, 2) + pow(stitches / stitches_per_inch, 2));

The length of my slope for 9 rows and 21 stitches is 5.1638". Now I need to back solve the number of stitches based on this slope (hypotenuse) and the number of rows I have for both the front and the back. If you don't do this, one piece will be much longer slope than the other and you have to do a bit of easing to get them to fit.

sqrt(pow(hypotenuse, 2) - pow(stitches / stitches_per_inch, 2)) * rows_per_inch;

• 20 stitches for the front (rounded down from 20.233)
• 22 stitches for the back (rounded up from 21.53)

From there, you evenly distribute the number of bind offs you need to do for each row on both the front and back.

I knitted 3 samples of shoulder slopes (top to bottom): back (22 stitches x 6 rows), front (20 stitches x 12 rows), normal (21 stitches x 9 rows). I've marked stitch 10 from the left with a hot pink stitch marker (I did a column there of purls, but they don't show up very well on the right side). The shaping is done with short rows to make the slope very distinct.

Now of course, if you have vertical stitch patterns, they're not going to match at the shoulder seams if you just knit according to your pattern. However, depending on the stitch pattern, this might be something you could fudge by moving things over by a stitch. In my sample, shifting the purl column by 1 stitch on both the front and back would have made them match, but that might not be the case for every point on the slope.

Answer 3

I suggest:

• only buy patterns that give you an outline of each of the pieces that will be sewn together, with measurements

• compare these with a knit garment that fits you well, and adjust as needed

• use your gauge (determined from a good-sized swatch) to knit to the dimensions (See Zimmerman's Knitting Without Tears).

• alternatively, use the commercial patter for inspiration, but draw your own outlines, using a garment which fits you well as the basis -- the "garment that fits you well" could be knitted from yarn, or it could be made from a stretchy knit fabric

I think you could improve the fit of the Croft and Barrow sweater (with cables and ribs) as follows:

• undo the top part of the seam that sets the sleeve in

• reduce the width of the sleeve in the cap (in the area where we see the bulge in the front)

• in other words, make the sleeve cap narrower

• also, make the sleeve cap taller

• then re-do the part of the seam you took apart -- if the edges don't match perfectly, you may introduce a bit of gathering in the sleeve as necessary -- if there is not much gathering, it won't be visible when you're wearing the sweater

I don't think you would need large adjustments to solve the basic problem -- the changes needed are fairly subtle. Also, I don't think you will need to do anything with the shoulder shaping to make this sweater fit you better. Knitted three-dimensional creations are so much more forgiving than sewn garments made from woven material. The slight wave in the shoulder seam doesn't really matter, and I would not bother redoing the shoulder shaping.