No, EasyAR basically can't detect body parts. You can use OpenCV and detect any body parts. In theory, you need get frames from camera and send to OpenCV for detecting and tracking body parts. First, you need to learn Computer Vision and practice knowledge many times.
Books:
https://opencv.org/opencv-computer-vision-with-python/
Some examples OpenCV:
https://www.youtube.com/watch?v=nUjGLjOmF7o
https://www.youtube.com/watch?v=gPeeFCvJOWA