Answer:
The strength of the muscles around the joint and the quality of the cartilage of the bones of the joint.
Step-by-step explanation:
The joints are formed by the meeting of two bones within the organism, they can be mobile or not and are present in all vertebrate organisms.
The joints are lined with cartilage, which allows them to stay in place and slide whenever necessary to make a movement, in addition, they are protected by the muscles that sit around them.
The strength of these muscles and the quality of the cartilage are very important factors to justify the ease in popping the particular joint.