Split skeleton in a binary and measure its length

I want to split the skeleton of a binarized image like what is stated here

Splitting a skeleton in a binary object to equal lengths! - (mathworks.com).

I tried the solutions suggested such as interpar() but the result is not what I wanted. And when I tried the bwtraceboundaries() and based on the code presented here https://www.mathworks.com/matlabcentral/answers/1593279-splitting-a-skeleton-in-a-binary-object-to-equal-lengths#comment_1849284 , I receive errors such as:

Index in position 1 exceeds array bounds (must not exceed 3).

y = trace(1:skel_L,1);

This is the code I recently tried. I was looking to measure the entire length per line connected by points created along the skeleton but I can't seem to understand how to make it work. Hoping for any help and suggestions. Thank you.

im = imread('crack-image.png'); %crack is the object
I = rgb2gray(im);
I = im2bw(I);
skel = bwskel(I);
skel_L = length(find(skel));
[endpointsX, endpointsY] = find(bwmorph(skel == 1, 'endpoints') );
trace = bwtraceboundary(skel, [endpointsX(1), endpointsY(1)],'N');
y = trace(1:skel_L,1);
x = trace(1:skel_L,2);
imshow(skel);