Q: Why do you keep stressing the need to move around so often?
Why Movement is Important to Keep your Joints Healthy
Movement is important — or as might be better understood, a lack of movement is potentially harmful. This is the foundation for concepts like “Sitting is the new smoking”, “Motion is Lotion“, and the “Move More Challenge“. A lack of movement, commonly termed “sedentary behaviours”, have recently been repeatedly linked to poor health in general (Biswas et al, Ford et al, Martin et al, Santos et al).
But there is one specific part of the body for which movement may be extremely important:
Joints are covered in cartilage (“articular” cartilage), which provides a smooth, lubricated surface with very little friction, making movements smooth and easy while transmitting the forces of activity (Fox et al). Loss, alteration, or eventual damage to the cartilage changes the ease with which the joints are able to move and function as we would like — think of riding a bike on a freshly paved road (normal joint) and compare that to riding in a gravel parking lot (damaged joint). When we account for other body components that are involved in movements (bones, ligaments, muscles, etc), we begin to understand the important role that cartilage plays in human movement.
However, cartilage is very different from other tissues in our body. Unlike our muscles, tendons, ligaments, and bones, articular cartilage does not receive blood vessels, nerve endings, or lymphatic tissue (Fox et al). Instead, it is primarily made of water, collagen (dense proteins), and proteoglycans (more proteins) — a selected mix that allows your cartilage to promote water retention*. What this means is that your cartilage acts somewhat like a sponge — water flows in and out as pressure changes, and nutritional components move with it. For example, if you load the joint, water squeezes out — and when you unload the joint, new water and nutrients are drawn in.
* To be clear though, considering this fluid “water” is an oversimplification. We would be more accurate to discuss the role of Synovial Fluid, but in the interest of understanding this concept through metaphor, the fluid around your joints is considered ‘water’ for this post.
This is important, because where other body tissues would receive their nutrition from the circulation of blood, monitoring of the nerves, and drainage from the lymphatics, cartilage receives its nutrition from movement. As mentioned above, with water flowing in and out as joints are unloaded and/or loaded, this also delivers nutrition to the cartilage. Without the consistent change in our joints — back and forth, loaded and unloaded — there can be no transfer of water, and therefore poor nutritional delivery to the joints.
How does this impact most of us? Consider sitting. The joints of the back and hips are loaded when we sit, meaning we slowly squeeze water out from the cartilage in these areas. If we do not get up and move around frequently, this also means there is no opportunity for nutrients to re-enter those joints! This is why movement throughout the day, periodic breaks, and frequently changing positions are so important — it helps to maintain good cartilage health, and prevent future damage.
With no actual blood flow to the cartilage of your joints, movement must be its substitute! The cyclic change between loaded and unloaded states are important for our joints to stay healthy into the future. This is a key reason why staying active and promoting movement (avoiding inactivity!) is such an important part of a healthy lifestyle.
Dr. Jim Gilliard is a chiropractor in Burlington, ON at Endorphins Health and Wellness Centre — located in the Burlington Professional Centre at 3155 Harvester Road, Suite 406. If you have questions, comments, or wish to book an appointment, please feel free to contact him at your convenience.
- Biswas A, Oh PI, Faulkner GE, Bajaj RR, Silver MA, Mitchell MS, et al. Sedentary Time and Its Association With Risk for Disease Incidence, Mortality, and Hospitalization in Adults. Ann Intern Med. 2015;162(2):123.
- Ford ES, Caspersen CJ. Sedentary behaviour and cardiovascular disease: A review of prospective studies. Int J Epidemiol. 2012;41(5):1338–53.
- Martin A, Fitzsimons C, Jepson R, Saunders DH, van der Ploeg HP, Teixeira PJ, et al. Interventions with potential to reduce sedentary time in adults: systematic review and meta-analysis. Br J Sports Med. 2015;49:1056–63.
- Santos R, Mota J, Okely AD, Pratt M, Moreira C, Coelho-E-Silva MJ, et al. The independent associations of sedentary behaviour and physical activity on cardiorespiratory fitness. Br J Sports Med. 2014;48:1508–12.
- Fox AJS, Bedi A, Rodeo SA. The basic science of articular cartilage: structure, composition, and function. Sports Health. 2009;1(6):461–8.