Palpation of knee joint can be done in various positions based on the comfort of the patient and therapist. If the patient is sitting, high sitting is a good position to start. If not, supine is an alternative position where the patient is most relaxed; as shown by Hutchinson in the BJSM video.
Practice is the key to master the examination. The students should be aware of the location of the structures in such a way that you should be able to see through the skin and locate the structures underneath. Practice by marking the skin for various structures under the skin.