AI scores your pattern — mechanical wear or inflammatory signals — and explains what it means in plain language. A physician attests the direction: orthopedic surgeon, rheumatologist, or the preventive habits that protect the joints you have. Not a diagnosis. A direction.
10 questions. About 2 minutes. Everything runs locally — no data is collected or stored.
Ten validated risk signals drawn from published clinical evidence. Each one maps directly to a question in the assessment above.
Your answers plot you on two independent axes — structural load and inflammatory signal. Where you land decides which of four routes fits.
Mechanical pathway
Orthopedic surgery
High BMI, prior joint injury, age, activity pattern. Structural wear that eases with rest. Route: orthopedic evaluation and outcome tracking.
Inflammatory pathway
Rheumatology
Morning stiffness over 30 minutes, multi-joint involvement, recurrent swelling. Immune-mediated. Route: rheumatology evaluation.
Mixed pathway
Multidisciplinary
Both axes elevated — common and easy to mismanage. Route: a coordinated work-up so neither component is left to progress.
Low signal
Prevention + education
Neither pattern strongly expressed. Route: weight, movement, anti-inflammatory nutrition, and monitoring if symptoms shift.
Mechanical and inflammatory arthritis are treated by different specialists using different drugs. The distinction between them is the most important diagnostic question in joint pain. Morning stiffness duration is the single fastest clinical signal.
| Feature | Mechanical (OA) | Inflammatory (RA) |
|---|---|---|
| When is pain worst? | After activity, end of day | At rest and in the morning |
| Does movement help? | Initially, but worsens with overuse | Yes — stiffness loosens with movement |
| Morning stiffness duration | Under 30 minutes — usually under 15 | Over 60 minutes, often 1–4 hours |
| Which joints? | Weight-bearing: knees, hips, spine | Symmetric small joints: hands, wrists, feet |
| Joint distribution | Asymmetric, single or few joints | Symmetric, multiple joints simultaneously |
| Systemic symptoms | Rare — localized problem | Fatigue, low-grade fever, weight loss |
| Blood tests | Normal RF, ESR, CRP | Elevated RF, anti-CCP (70–80% of RA), CRP |
| X-ray findings | Osteophytes, joint space narrowing | Joint erosions, periarticular osteoporosis |
| Who develops it? | Over 45, higher BMI, prior injury | Women 2–3× more; any age; autoimmune triggers |
Sources: ACR 2021 RA Classification Criteria (Aletaha et al.); ACR OA Guideline 2022; EULAR OA Recommendations 2019; StatPearls NBK430728.
This comparison is for education only and does not constitute a diagnosis. Many patients present with overlapping or atypical features. A physician evaluation — including blood tests and imaging — is required to distinguish these conditions definitively.
Osteoarthritis — Mechanical Wear
OA affects over 528 million people worldwide and is the most common joint disease. It is NOT simply "wear and tear" — it is progressive cartilage failure driven by mechanical overload, metabolic factors, and aging. Most people over 60 have radiographic OA in at least one joint, yet only half have symptoms. Knees bear 4× body weight with each step; hips bear 3–5× body weight on stairs. (GBD 2019; ACR OA Guideline 2022)
Rheumatoid Arthritis — Autoimmune Attack
RA affects approximately 1% of adults globally — roughly 1.5 million Americans. It is an autoimmune disease in which the immune system attacks the synovial joint lining. Untreated, RA can cause joint erosions that may develop within the first months of onset, and established joint damage is often permanent. This is why the "window of opportunity" matters — starting treatment within roughly the first 12 weeks substantially reduces long-term joint damage. Anti-CCP antibody is 70–80% sensitive and 95% specific for RA. (ACR RA Guideline 2021; Aletaha et al. 2010)
Morning Stiffness — The Fastest Clinical Signal
Morning stiffness duration distinguishes mechanical from inflammatory arthritis more reliably than any single imaging finding. Under 30 minutes (usually under 15) points to osteoarthritis — cartilage "gelling" after rest. Over 60 minutes, often 1–4 hours, that improves with movement points to inflammatory arthritis such as RA. Tracking your morning stiffness duration is the most useful thing you can do before seeing a specialist. (ACR RA Classification Criteria 2010; EULAR OA Recommendations 2019)
Risk Factors — What the Evidence Shows
OA: age over 45, BMI over 30, prior joint injury, female sex for knee OA, repetitive occupational loading (construction, nursing). Genetic factors account for 40–65% of OA risk. RA: female sex (2–3× higher risk), family history, smoking (the strongest modifiable environmental risk factor for RA), and age 30–60 at peak onset. Every pound of body weight adds approximately 4 pounds of force to the knee — losing 10 lbs reduces knee OA progression significantly. (ACR; Arthritis Foundation; Felson DT et al.)
Physical Therapy — What Actually Works
For OA: strengthening the quadriceps reduces knee pain by approximately 2–3% for every 1% increase in muscle strength. Aquatic exercise and cycling preserve joint health with minimal load. Walking is beneficial — not harmful — for knee OA and is associated with a 40% reduction in new frequent knee pain over 4 years. For RA: land-based exercise is safe during stable disease and improves physical function without increasing disease activity. A physical therapist should guide the specific program. (Lo GH et al., Arthritis Care Res 2019; Cochrane OA Exercise Reviews 2017–2023; ACR OA Guideline 2022)
When Surgery Helps — and When It Doesn't
Total knee replacement (TKA) and total hip replacement (THA) are among the highest-value procedures in medicine for end-stage OA — 90%+ of patients report significant pain relief, and implant survival exceeds 15–20 years in most registries. Surgery helps when conservative care (exercise, weight management, PT, injections) has been genuinely exhausted. Surgery does NOT reverse RA — that requires DMARDs and biologic agents. A rheumatologist should lead RA management; an orthopedic surgeon addresses structural joint failure when reconstruction is appropriate. (NJR 2023; ACR; AAOS OA Guideline 2022)
See a healthcare provider if you experience any of these.
Pain type is the fastest diagnostic signal. Two main patterns, two different specialists. This tool does not replace a physician evaluation — it tells you which door to walk through.
Mechanical — worse with activity
Orthopedic evaluation
Inflammatory — worse in the morning
Rheumatology evaluation