Your sore joint deserves a clear answer

Wear, muscles, or tendons can make a joint sore

A joint is where two bones meet and move. Cartilage is the smooth, firm cover over each bone end, much like a slick cap. It keeps the bones from rubbing as you move. That cover doesn't always stay thick over time. As it thins, the joint may feel stiff, swollen, or sore. Your doctor may call this arthritis.

Muscles can ache after extra work, while tendons are tough cords joining muscle to bone. A tendon may hurt after a sudden reach or repeated motion. This soreness may sit near the joint even when the bones aren't causing it.

Where it hurts and which movement starts it help find the cause.

Gentle movement usually helps more than long rest

A short rest can calm a spell of worse soreness. Long rest often brings more stiffness, though. Try an easy walk or slow joint movement instead. Stop before the ache climbs and allow time for it to ease. Sharp pain means you shouldn't keep going.

Cold may ease swelling after activity. Mild warmth can loosen stiffness before you move. A brace or cane may take some load off the sore joint. Ask your doctor before changing medicine. Heart, kidney, stomach, or bleeding problems can change what is safe.

Steady, gentle movement is often kinder to a sore joint.

Sleep trouble or lasting soreness calls for an exam

Arrange a visit when soreness keeps disturbing sleep or daily tasks. The doctor checks tender spots, swelling, strength, and movement. An X-ray can show an old injury or wear inside the joint. It can also show a narrower gap between the bones. Less space can mean the cartilage cover has worn thinner.

Fever plus a joint that feels hot and looks swollen needs quick care. Sudden weakness, a major injury, or a bent-looking joint also needs prompt help. New numbness or weakness shouldn't wait. If back pain comes with loss of bladder or bowel control, get emergency help.

The exam helps separate bone wear from a muscle or tendon problem.

Sources

1. In a 480-patient, four-arm, multicenter randomized phase 2/3 trial, none of three orthobiologic cell injections - autologous bone marrow aspirate concentrate, autologous adipose stromal vascular fraction, or allogeneic umbilical cord tissue-derived mesenchymal stromal cells - was superior to any other, or to a corticosteroid injection control, on pain at 12 months.

   Mautner K, et al. — Cell-based versus corticosteroid injections for knee pain in osteoarthritis: a randomized phase 3 trial. Nat Med, 2023. DOI: 10.1038/s41591-023-02632-w.

2. The International Society for Cell & Gene Therapy position statement holds that the acronym MSC should mean mesenchymal STROMAL cells and should only be called stem cells where rigorous in vitro and in vivo evidence of stemness exists for that specific preparation.

   Viswanathan S, et al. — Mesenchymal stem versus stromal cells: International Society for Cell & Gene Therapy (ISCT®) Mesenchymal Stromal Cell committee position statement on nomenclature. Cytotherapy, 2019. DOI: 10.1016/j.jcyt.2019.08.002.

3. The 2018 AAOS/NIH consensus work group recommended that minimally manipulated mixed cell preparations be called CELL THERAPY rather than stem cell therapy, and that their untested and uncharacterised nature be clearly communicated to patients and the public, because stem cells have properties these preparations do not meet.

   Chu CR, et al. — Optimizing Clinical Use of Biologics in Orthopaedic Surgery: Consensus Recommendations From the 2018 AAOS/NIH U-13 Conference. J Am Acad Orthop Surg, 2019. DOI: 10.5435/JAAOS-D-18-00305.

4. A 2025 meta-analysis of 73 double-blind placebo-controlled injection trials in 5,895 knee osteoarthritis patients found placebo responder rates above 50 percent at 1, 3 and 6 months, declining by 12 months - which is why any uncontrolled 'our patients improved' claim from a clinic is uninterpretable.

   Previtali D, et al. — Placebo response to intra-articular injections in knee osteoarthritis: magnitude, evolution over time, and influencing factors. A systematic review and meta-analysis with meta-regression. EFORT Open Rev, 2025. DOI: 10.1530/EOR-2025-0022.

5. A meta-analysis of 14 placebo cohorts across 13 Level I trials in 1,076 knee osteoarthritis patients found that intra-articular saline - the placebo - produced pain and function improvements exceeding the minimal clinically important difference at 3 and 6 months.

   Saltzman BM, et al. — The Therapeutic Effect of Intra-articular Normal Saline Injections for Knee Osteoarthritis: A Meta-analysis of Evidence Level 1 Studies. Am J Sports Med, 2017. DOI: 10.1177/0363546516680607.

6. FDA states in its consumer alert that the only FDA-approved stem cell products in the United States are blood-forming stem cells derived from umbilical cord blood, approved for disorders of the blood-forming system, and that NONE of these products - stem cells, stromal vascular fraction, umbilical cord blood, Wharton's jelly or amniotic fluid - has been approved for the treatment of any orthopedic condition, including osteoarthritis, tendonitis, disc disease, tennis elbow, back pain, hip pain, knee pain, neck pain or shoulder pain.

   US Food and Drug Administration, Center for Biologics Evaluation and Research — Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. , 2020.

7. The OARSI non-surgical management guideline evaluated 60 interventions with GRADE methodology and built its recommendations around core treatments - structured exercise, weight management and self-management education - for every patient with knee osteoarthritis, regardless of what else is added.

   Bannuru RR, et al. — OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis. Osteoarthritis Cartilage, 2019. DOI: 10.1016/j.joca.2019.06.011.