Sport can be both a risk and a protective factor with regard to the development and progression of osteoarthritis. Whether sport has a positive or negative effect depends on the type and intensity of the load.
Average life expectancy in industrialized countries has almost doubled since the beginning of the 20th century thanks to better nutrition, hygiene and healthcare. The flip side of the coin is that this means the human body has to function at its best for twice as long, with this primarily affecting the muscles and joints, as the main mechanical elements of movement processes. That this cannot be taken for granted is shown by the high prevalence of osteoarthritis, a disease pattern that is undergoing rapid change. What for a long time was interpreted as a mere wear and tear of the articular structures (especially the cartilage), is now increasingly understood as a complex inflammatory disease affecting the entire joint including adjacent structures (and may even have a systemic component).
The type and intensity of the load is crucial
The etiologic processes leading to osteoarthritis are multifactorial. Genetic factors play a role, but so do lifestyle factors. While genetic predisposition cannot be influenced, lifestyle factors can be shaped to a certain extent. Physical activity is a modifiable lifestyle factor that is important for osteoarthritis as a preventive measure and as a protective factor, but also as a potential risk factor. In this context, the intensity and type of stress are the main factors determining whether the effects tend to be positive or negative.
The extent of the load on the body varies depending on the type and intensity of the movement. While during walking the rearfoot load is 1.2 times the body weight, during leisurely jogging it is 2.4 times the body weight. For a person with a body weight of 70 kg, this means a load of 2.52 tons per 8000-10,000 steps (lower limit for a health-beneficial effect) and, extrapolated to a year, a load of 858 480 tons. With such loads, it is not surprising that various structures of the musculoskeletal system begin to strike! So are sports activities door openers for the development of osteoarthritis?
Surprisingly, the data on sport and osteoarthritis are relatively good, and a number of publications have appeared on this subject, all of which come to the same conclusion on the whole [1]: Sport is on the one hand a risk factor and on the other hand a protective factor with regard to osteoarthritis. The risks include, above all, acute injuries, which are clearly a favoring factor for the development of osteoarthritis. Thus, the likelihood of developing gonarthrosis increases exponentially after a meniscectomy or after surgery due to rupture of the anterior cruciate ligament.
In contrast, there is no evidence of an increase in the risk of osteoarthritis in individuals who exercise at a “normal” intensity compared with individuals who do not exercise. Thus, the risk of developing osteoarthritis seems to be higher only in people who perform a very intensive sports program. It is understandable that a weekly running workload of 100 km on an asphalt track does not only have positive effects on the joint structures. So when assessing an individual’s potential risk of osteoarthritis, it’s important to know the type of sport, the intensity of training, and the extent of joint stress.
“Use it or loose it”
In contrast to secondary osteoarthritis, which can usually be treated causally, a broad spectrum of measures is available for the treatment of primary osteoarthritis: Analgesics e.g. NSAIDs, opioids, SYSADOA (“Symptomatic Slow Acting Drugs in Osteo-Arthritis”)/DMOAD (“Disease Modifying Osteo-Arthritis Drugs”), topical medications, new substances (strontium ranelate, anti-NGF, cathepsin inhibitor, etc.) intraarticular applications (glucocorticoids, viscosupplementation, PRP (“platelet-rich plasma”), “chondroprotectives” (chondroitins, glucosamines), taping, biomechanical shoes for load distribution, orthoses to reduce biomechanical joint stress, physical measures (cold, heat, electrotherapy), patient information, weight reduction, physiotherapy, physical activity etc.
In the following, the latter two options (physiotherapy, physical activity) will be considered in more detail. Physical activity has an important place in the treatment of osteoarthritis. As is true for all structures of the musculoskeletal system, the joint elements affected in osteoarthritis (bone, cartilage, synovial membrane, menisci, and even ligaments and nearby tendons) “Use it or lose it”: What is not challenged atrophies. It is important for people with osteoarthritis-related pain or limited mobility to be physically active as well. It is scientifically proven that an exercise program to improve cardiovascular health also has positive effects on arthritis-related and psychosocial factors, as well as contributing to weight loss. Weight control is an aspect that is particularly important with regard to gonarthrosis (knee osteoarthritis); this seems to be less relevant for coxarthrosis [2]. According to recent evidence, there is also evidence of a link between obesity and inflammatory processes mediated by interleukins (IL6) [3].
In conclusion, sport and osteoarthritis are not mutually exclusive, but it depends on the choice of the appropriate activity. Sports with harmonious (versus brusque) movements are particularly well suited. If arthritis is present in the upper extremities, striking and throwing movements should be avoided. If, on the other hand, the lower extremity is affected, impact loads and the effects of strong rotational forces should be avoided. Table 1 contains a list of sports activities according to the criterion of the extent of the load on the joint.
Literature:
- Tran G, et al: Does sports participation (including level of performance and previous injury) increase risk of osteoarthritis? A systematic review and meta-analysis. Br J Sports Med 2016; 0: 1-9. doi:10.1136/bjsports-2016-096142.
- Reijman M, et al: Body mass index associated with onset and progression of osteoarthritis of the knee but not of the hip: the Rotterdam Study. Ann Rheum Dis 2007; 66: 158-162.
- Kaur J: A comprehensive review on metabolic syndrome. Cardiol Res Pract 2014; 2014: 943162. doi: 10.1155/2014/943162.
HAUSARZT PRAXIS 2018; 13(11): 5-6
