AR-Power Patient Powered Research Network (GHLF)

Participants will be derived from the population of people who indicate that they have been diagnosed by a physician as having musculoskeletal conditions including RA, SpA and other chronic musculoskeletal conditions. These will come from two sources:

1. CreakyJoints website, an online rheumatic-disease patient support community (www.CreakyJoints.org), composed of patients with arthritis and arthritis-related disease, CreakyJoints members with self-reported musculoskeletal conditions will be invited to join the ArthritisPower research registry and download the ArthritisPower App.
2. CreakyJoints Facebook and Twitter social network platforms. CreakyJoints "fans" or "followers" will be told about the ArthritisPower registry and app on the CreakyJoints Facebook page (www.Facebook.com/CreakyJoints) and/or Twitter account (https://twitter.com/creakyjoints).

Inclusion Criteria:

1. Age 19 and above. We will only allow Puerto Rican residents to join if they are 21 or older. We will add conditional logic in the registration to ensure that Puerto Ricans under the age of 21 cannot complete the registration and participate in ArthritisPower.
2. Self-report that a physician has given a diagnosis of RA, SpA, or other musculoskeletal condition.
3. The Registry is only intended at this time for residents of the United States and United States territories who are nineteen (19) years or older (for Puerto Rico residents, you must be 21 years or older to participate).

Exclusion Criteria:

a) Age < 19 years b) No self-reported physician diagnosis of musculoskeletal condition.