Unfortunately, you will hardly find code examples that you can use out-of-the-box. What I suggested was that you probably could take a pretrained object detection model, which is suited for transfer learning, and tune it to detect specialised equipment like wheelchairs and crutches.
Then you can take an image and get two predictions from two models: pose detection model will give you exact coordinates of the key points of a person, and fine-tuned object detection model will say if the image also contains the equipment and where it is located. And you’ll be able to identify positions of a person and equipment relative to each other.
Here is a list of object detection models that could be tuned: TensorFlow Hub 7
Hope that helps.