I am continuing my quest for clothes that are easy to put on and take off. Our son has muscular dystrophy and contractures in his elbows -- which keeps his arms at roughly 90 degrees. It makes putting on and taking off jackets difficult. So, my idea was to essentially make the arm hole a whole lot bigger.
Step 1: Make Pattern
The idea is to open up the sleeves so there is more room to bend an arm into them. Lay out the jacket and make sure to lift the arm. The higher the arm is raised -- the higher the wearer will be able to lift his arm. Put a piece of paper under the sleeve and cut out a triangle that goes from the bottom of the jacket to somewhere further down on the sleeve. I chose to go from right at the hem of the jacket -- and I made the sides of the triangle equal -- so to wherever that landed on the sleeve.
Then, use your pattern to cut out four triangles. (Two for each arm)
Step 2: Cut Open the Jacket
I turned the jacket inside out and cut the stitching out where the triangle pieces will be sewn in. The pictures illustrate this pretty well.
Step 3: Sew in the Triangles
You want to maintain the hole in the sleeve that you just cut out. So, first start with one triangle. Separate the jacket halves at the point of the seam that was just cut. Sew from the jacket hem up to the sleeve and then from the armpit of the sleeve down to the wrist along one jacket half. Do not sew the jacket halves together. Do the same with the second triangle on the other half of the jacket half. Then sew together the hypotenuse of the triangle.
Step 4: Stitch a Second Time Around
This step isn't necessary. I turned the jacket rightside out and sewed a second stitch around the entire cutout.
Step 5: Repeat for the Other Arm and DONE
This modification has helped a lot. I made a mistake in the jacket I bought, though. The fabric isn't very stretchy -- I should have started with a stretchier jacket. On the other hand, without this modification, I doubt there would be any chance we could have been able to put it on.