Medizin und Massage kennen durchaus "Knoten"; so dürfte es auch in den folgenden Beispeilen aus Oxforddict. sein:
‘I squeeze her muscles once more, surprised at how the knot has completely vanished.’
‘The masseuses are friendly and seem to be able to find every little knot.’
‘From a seated position, curl one dumbbell up, feeling the muscles in your arm bunch up in a strong, searing knot as you reach the top and pause.’
‘He was sitting up with his back to her for now, one hand rubbing the newly formed knot on his head and the other holding the knife he had used to cut the tape earlier.’
‘The sobs coming from the girl started to get louder, and Jon looked up at her and saw she had a pretty big knot on her head.’
‘I smacked my arm into a doorknob really hard, and there's a knot in the muscle of the forearm now.’
"a knot could form" - würde man das übersetzen mit "ein Krampf könnte sich bilden/formen"?