Myth: recreational running causes knee osteoarthritis

Running is often perceived as bad for your knees.

In particular, concern exists regarding the development and progression of knee osteoarthritis due to long-term exposure to running.

Despite these fears, recreational running does not have negative consequences on knee joint articular cartilage in runners without symptomatic knee osteoarthritis and may actually be beneficial for long-term joint health

Only 3.5% of recreational (amateur) runners have osteoarthritis (knee or hip) compared with 10.2% of sedentary individuals.

However, a dose–response relationship may be present; 13.3% of elite or ex-elite runners (competitive professional athletes of an international level) had osteoarthritis, a higher rate than seen in recreational runners.

While knee cartilage may undergo acute changes during a run (eg, reduction in cartilage volume and thickness, oligomeric matrix protein increase), these changes are likely to be temporary in runners without knee osteoarthritis.

Evidence relating to the influence of repeated exposure to running on cartilage morphology and composition remains limited.

WHAT IF A RUNNER ALREADY HAS KNEE OSTEOARTHRITIS?

Fear of causing pain or further osteoarthritis progression likely leads many runners to reduce or cease running following a?diagnosis of knee osteoarthritis.

To date, little evidence exists to guide such decisions. A single studyreported that running does not appear to accelerate the?progression of knee osteoarthritis in runners aged ≥50 years, and runners with knee osteoarthritis reported more improvement in knee pain compared with non-runners with osteoarthritis over a 4-year period.

These findings support earlier prospective research which reported that long-distance running among healthy older individuals was?not associated with accelerated radiographic knee osteoarthritis.

A small study (n=20) of runners suggested that knee cartilage in runners with knee osteoarthritis does not recover as quickly after a 30 min run as the cartilage in runners without knee osteoarthritis.

These findings suggest that runners with symptomatic knee osteoarthritis may benefit from running less frequently to allow for sufficient cartilage recovery time between running bouts. Overall, more research is needed to provide definitive guidelines for runners with knee osteoarthritis on the optimal run frequency ,intensity and volume.

SO, WHAT SHOULD CLINICIANS TELL RUNNERS?

Further high-quality prospective research is needed to improve our ability to educate runners about the risks or benefits of running to osteoarthritis development. However, current evidence suggests that running may have a protective effect against the development of knee osteoarthritis, provided sustained elite-level training is avoided.

However, ideal running training load (ie, intensity, volume, frequency) to optimise knee joint health for runners with and without knee osteoarthritis remains unclear.

Other factors, such as older age, excessive body mass, heavy?occupational workload and previous traumatic knee injury may be more relevant risk factors for knee osteoarthritis than running alone.

However the confounding influence of these risk factors in runners is yet to be determined.

Runners with knee osteoarthritis should feel safe continuing to run, since running does not appear to accelerate the progression of

existing knee osteoarthritis.

Given the overwhelming health benefits associated with running, it is currently not sound advice to tell a runner with knee osteoarthritis who is managing their symptoms to cease or reduce running participation.

REFERENCES

1 Esculier J-F, Krowchuk NM, Li LC, et al. What are the perceptions about running and knee joint health among the public and healthcare practitioners in Canada? PLoS One 2018;13:e0204872–e.

2 Dong X, Li C, Liu J, et al. The effect of running on knee joint cartilage: a systematic review and meta-analysis. Phys Ther Sport 2021;47:147–55.

3 Heckelman LN, Riofrio AD, Vinson EN, et al. Dose and recovery response of Patellofemoral cartilage deformations to running. Orthop J Sports Med 2020;8:232596712096751.

4 Alentorn-Geli E, Samuelsson K, Musahl V, et al. The association of recreational and competitive running with hip and knee osteoarthritis: a systematic review and meta-analysis. J Orthop Sports Phys Ther 2017;47:373–90.

5 Khan MCM, O’Donovan J, Charlton JM, et al. The influence of running on lower limb cartilage: a systematic review and meta-analysis. Sports Med 2021. doi:10.1007/s40279-021-01533-7. [Epub ahead of print: 03 Sep 2021].

6 Lo GH, Musa SM, Driban JB, et al. Running does not increase symptoms or structural progression in people with knee osteoarthritis: data from the osteoarthritis initiative. Clin Rheumatol 2018;37:2497–504.

7 Chakravarty EF, Hubert HB, Lingala VB. And knee osteoarthritis: a prospective study. American Journal of Preventive Medicine 2008;35:133–8.

8 Esculier J-F, Jarrett M, Krowchuk NM, et al. Cartilage recovery in runners with and without knee osteoarthritis: a pilot study. Knee 2019;26:1049–57.