Exercise for bone and cartilage in postmenopausal women with mild knee osteoarthritis

Osteoarthritis patients will benefit from bone favorable exercise 

The postmenopausal women, who may be at risk of osteoporosis (bone loss) as well as at risk of osteoarthritis, can do safely progressive high-impact training to maintain and improve their bone strength and physical function. This was discovered in Juhani Multanen’s doctoral thesis, in which the effects of high-impact exercise program were examined on bones, cartilages, osteoarthritis symptoms and physical function in postmenopausal women with mild knee osteoarthritis.

Jumping exercise and versatile rapid movements for strong bones

The most efficient exercise modality to improve bone strength is shown to be high-impact loading (jumping type of exercise) including rapid change of movement directions. Previously, this type of exercise has been thought to be harmful for the integrity of articular cartilage, although the issue has never been proven scientifically.

This study showed that training increased femoral neck bone mineral mass and strength, and also improved physical function, such as muscle strength and balance, which both are important in terms of fall prevention. The most important finding was that high-impact jumping exercise did not have harmful effects on the biochemical composition of cartilage as investigated by MRI in subjects with mild knee osteoarthritis. In addition, the 12-month training was very well tolerated; it did not induce knee pain or stiffness, and the general training compliance was high. The clinical significance of this study is, postmenopausal women in mind, that despite of mild knee osteoarthritis, a person is allowed, and even encouraged to progressively implement high-impact loading exercises to maintain and improve her bone strength and functional ability.

Cartilage has ability to withstand high loading forces

Eighty eligible postmenopausal women from 50 to 65 -years of age and having knee pain on most days of the month, were enrolled into the study and randomly assigned into either a training group or a control group. The mild knee osteoarthritis of all participants was confirmed prior the randomization and intervention by radiographs. Training group exercised according a supervised progressive high-impact exercise program three times a week for 12 months, while the control group continued their normal physical activity. The effects of exercise on femoral neck bone structure and competence was measured by DXA, and the effects of exercise on knee cartilage biochemical composition was measured by dGEMRIC and T2 relaxation time – MRI methods specifically designed to assess biochemical composition of cartilage.

-   The loss of proteoglycans and breakdown of collagen fibers in the articular cartilage are considered to represent the onset of the degenerative process of osteoarthritis. Our study showed that high-impact loading exercise program had no effect on knee cartilage biochemical composition. This means that even rather intensive exercise, if progressively implemented, is safe for cartilage health in mild knee osteoarthritis, says Multanen.

The study was carried out in the Department of Health Sciences at University of Jyväskylä in cooperation with the Central Finland Central Hospital and the Department of Medical Technology, Institute of Biomedicine in University of Oulu in Finland.

The research was funded by the Academy of Finland, the Finnish Ministry of Education and Culture, the Finnish Cultural Foundation, the Juho Vainio Foundation, the Yrjö Jahnsson Foundation, the Emil Aaltonen Foundation, the Central Finland Health Care District and the Finnish Doctoral Programme of Musculoskeletal Disorders and Biomaterials (TBDP).

For more information, please contact: juhani.multanen@ksshp

The dissertation is available on web address:

https://jyx.jyu.fi/dspace/bitstream/handle/123456789/48974/978-951-39-6564-8_vaitos_20160311.pdf?sequence=1