How come there are 22 keypoints in the Hand Pose output

[rabum]

Models used are:
rtmdet_nano_8xb32-300e_hand-267f9c8f.onnx
rtmpose-m_simcc-hand5_pt-aic-coco_210e-256x256-74fb594_20230320.onnx

hand = Hand(to_openpose=openpose_skeleton,
            backend=backend,
            device=device)
frame = cv2.imread(image_path)
keypoints, scores = hand(frame)
print("keypoints.shape",keypoints.shape)

The output is keypoints.shape=(1, 22, 2)
It caused draw_skeleton return NotImplementedError