Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


The impact of physical activity on weight-bearing knee joint

Exercise for cardiovascular health keeps knee cartilage healthy, too, suggests long-term, community-based study

The world’s most common joint disease, osteoarthritis (OA) is a major cause of disability among adults over the age of 50. Whether physical activity is beneficial or detrimental to weight-bearing joints, knees in particular, has been open to debate.

Some studies implicate physical activity in provoking knee OA, while others suggest that physical activity may actually protect the knee joint from the disease. Confounding the matter is the fact that knee injury is a known risk factor for knee OA. Then, there’s the unclear role of osteophytes in knee OA progression, compounded by the limitations of radiographs for monitoring small yet significant changes in joint structure.

For a clearer picture of the impact of physical activity on the knee joint, a team of researchers in Australia turned to magnetic resonance imaging (MRI). This highly accurate high-tech tool makes it possible to directly visualize joint structures, detect early and pre-disease states of OA, and assess the influence of potential risk factors. Taking advantage of this novel methodology, the researchers studied the effect of physical activity, in various degrees of intensity, frequency, and duration, on knee structures in a total of 257 healthy adults between the ages of 50 and 79, with no history of knee injury or OA. Their findings, presented in the October 2007 issue of Arthritis Care & Research (, suggest that exercise that is good for the heart is also good for the knee.

Recruited from an established community-based research population, the Melbourne Collaborative Cohort Study, subjects all underwent MRI exams on the tibia bone and tibiofemoral joint of their dominant knee—the one on the leg they first step forward when walking. MRI was used to assess cartilage defects and bone marrow lesions, as well as measure cartilage volume, an indicator of cartilage health and strength. Loss of knee cartilage is linked to worsening knee symptoms in OA sufferers. Subjects also answered specific questions regarding their exercise and walking habits, as well as routine activity at home and at work, to determine their level of physical activity in both the 6 months and 7 days prior to the study. To create a baseline for each subject, past information on weight, height, body mass index, and physical activity, from questionnaires completed between 1990 and 1994, was obtained. Then, the team performed a series of analyses and comparisons.

Among the notable findings, both baseline and current vigorous physical activity— exercise that gets the heart pumping and the body sweating—were associated with an increase in tibial cartilage volume, free from cartilage defects. What’s more, tibial cartilage volume increased with frequency and duration of vigorous activity. Recent weight-bearing exercise was also linked to increased tibial cartilage volume and reduced cartilage defects. Finally, moderate physical activity, including regular walking, was associated with a lower incidence of bone marrow lesions.

“This is the first study to demonstrate a potentially beneficial effect of walking on the reduction in the risk of bone marrow lesions in the knee,” notes the study’s leading author, Dr. Flavia M. Cicuttini. “Bone marrow lesions have been associated with pain and radiograph-defined progression of osteoarthritis, type II collagen degradation, and loss of cartilage volume.”

Demonstrating a protective effect of past and current vigorous physical activity on knee cartilage in healthy adults, this study strongly supports the benefits of exercise for older individuals at risk for OA. Though both the intensity and duration of physical activity had a significant positive impact on cartilage, the ideal amount of physical activity for joint health remains unclear. “Our data suggest that at least 20 minutes once per week of activity sufficient to result in sweating or some shortness of breath might be adequate. This is similar to, if not somewhat less than, the recommendations for cardiovascular health,” Dr. Cicuttini observes.

Amy Molnar | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University

nachricht New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>