Joints and Exercise

Editor's Note: When you see these three dots surrounded by a gray rectangle — 1 — you can click on it to get further information about the topic. Click a second time, and the message goes away.

This article was edited and updated on March 23, 2018.

What is a joint?

Joints occur wherever two or more bones meet. They are, unfortunately, the weakest part of the skeleton, but we’d be in real trouble without them: they hold our bones together and they permit us to move in various ways.

How do joints stay together?

Joints are held together by three types of connective tissue:

Classification of Joints

The structure of a joint can be one of three types:

The bones of the skull are fibrous.

Intervertebral joints of the spine and cartilage which joins ribs to the sternum are both cartilagenous joints.

The knee joint is a synovial joint.

The function of a joint will be:

Movement Patterns of Joints

Joints can move in various ways. Some of the most common types are:

The knee is a hinge joint.

The C1 and C2 vertebrae of the spine when the head is rotated are pivot joints.

The wrist is a condyloidal joint.

When you twiddle your thumbs, you are using the saddle joint at the base of the thumb.

The shoulder and hip joints are both ball-and-socket joints.

Here are drawings of some of the different types of joints. 2

Can exercise hurt your joints?

Exercise is widely promoted in the media and in fitness journals as having many benefits, including weight control, prevention of cardiovascular disease and diabetes, as well as improving psychological well-being.

In contrast, unfortunately, the community perception tends to be that exercise is potentially harmful to one's joints.

Which viewpoint is right? Here are two:

Canadian Online Fitness Education (a Fitness Theory course for fitness instructors) says this: “Articular cartilage does not have its own blood supply and must rely upon repetitive weight bearing movements to bring in nutrition and remove waste. When the joint is compressed, nutrition is forced into the cartilage and when weight is removed the metabolic wastes flow out and can be removed by the surrounding blood vessels. When synovial fluid is warmed up during exercise, it becomes thinner and absorbed more easily by the cartilage. This increased absorption leads to swelling of the articular cartilage and increased cushioning ability.” 3

Two men — Dr. David J. Hunter (from New England Baptist Hospital in Boston, Boston University School of Medicine) and Felix Eckstein (from The Institute of Anatomy and Musculoskeletal Research Medical Lab) — combined research data to determine if exercise could assist the joints. Hunter and Eckstein particularly focused on those who suffered from osteoarthritis but exercised, and they published their results in October 2008. The conclusion of the researchers was: “Despite the common misconception that exercise is deleterious to one's joints, in the absence of joint injury there is no evidence to support this notion. Rather it would appear that exercise has positive benefits for joint tissues in addition to its other health benefits.”

And my own view: Moderation in all things! We know that marathoners have trouble with their knees. If you want to exercise for general health and fitness, there are easier ways to do it than running 26 miles.

See Also:

I am a BCRPA-certified fitness instructor in Vancouver, BC. I teach four classes at the West End Community Centre in Vancouver, BC, mostly designed for the older adult. The Inevitable Disclaimer: Everything published here expresses only my opinion, based on my training and research. What you do with the information is entirely your own responsibility. I am not liable for any injury you suffer that seems to be related to anything you read here. Always consult your doctor before beginning an exercise program. For other articles, return to the table of contents.

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  1. These three dots behave exactly like a footnote. Click on them and you will get more information about the topic. 

  2. Thanks to Columbia University Medical Centre for the image, although their page can no longer be found. 

  3. Page 83.