Basics of polymyalgia rheumatica. Polymyalgia rheumatica (PMR) is a disorder that causes stiffness and aching that begins in the neck, shoulder and hip areas. It is not known whether it is a disease of the joints muscles or arteries.However it is thought that inflammation in these areas leads to pain and stiffness.Incidence.olymyalgia rheumatica (PMR) is a disorder that causes stiffness and aching that begins in the neck, shoulder and hip areas. It is not known whether it is a disease of the joints muscles or arteries. However it is thought that inflammation in these areas leads to pain and stiffness. Incidence.
There are two main types of volcanic eruptions: Explosive and Nonexplosive eruptions.he types of volcanic eruptions are magmatic, phreatomagmatic, and phreatic. For a description of each type and different styles of each, refer to the link below.
Here are some of the most common types of eruptions: In a Hawaiian eruption, fluid basaltic lava is thrown into the air in jets from a vent or line of vents (a fissure) at the summit or on the flank of a volcano.The jets can last for hours or even days, a phenomenon known as fire fountaining.ere are some of the most common types of eruptions: In a Hawaiian eruption, fluid basaltic lava is thrown into the air in jets from a vent or line of vents (a fissure) at the summit or on the flank of a volcano. The jets can last for hours or even days, a phenomenon known as fire fountaining.