Final answer:
The described gait abnormality, where the right side of the pelvis drops when the right leg is lifted, is known as the right gluteus medius gait. This condition is associated with right gluteus medius muscle weakness.
Step-by-step explanation:
If a patient's right side of the pelvis drops every time their right leg leaves the ground while walking, this indicates a gait abnormality known as the right gluteus medius gait. This condition is also referred to as Trendelenburg gait and is caused by weakness or dysfunction in the right gluteus medius muscle. When this muscle is unable to properly stabilize the pelvis, it results in the dropping or dipping of the pelvis on the side of the lifted leg during the walking cycle.