Daniel's character wasn't actually a hutchback--he had been misdiagnosed as a hunchback. He actually had a large cyst and Frankenstein (McAvoy) grabbed him in order to jam a large needle into his shoulder to drain the cyst. He then slammed him against a pillar to fix his posture in what appears to be a rather crude form of chiropracy. He explains what he's doing as he's doing it. I don't know if any of that is medically accurate for the early 19 century...they were trying to make it look cutting edge--although Frankenstein was only a medical student, he was supposed to be well ahead of his peers and professors, hence being able to figure out how to create life. Here's a low-quality clip of the scene.