Which two features suggest inflammatory back pain rather than mechanical back pain?

Which two features suggest inflammatory back pain rather than mechanical back pain?

• A. Morning stiffness less than 5 minutes and onset after age 60.
• B. Morning stiffness >30 minutes that improves with activity and onset before age 40.
• C. Alternating buttock pain.
• D. Pain that worsens with activity.

Answer: (B)

Long morning stiffness lasting more than 30 minutes and an onset before age 40 are classic clues for inflammatory back pain. Inflammation in the spine and sacroiliac joints tends to cause stiffness that is worse after rest and improves with movement and activity, and inflammatory conditions often appear earlier in life. Mechanical back pain, by contrast, usually features stiffness that is brief in the morning and begins later, along with pain that worsens with activity. So the combination of morning stiffness >30 minutes and onset before 40 best signals an inflammatory process rather than a mechanical one.