In fact, according to the National Institutes of Health’s National Institute of Arthritis and Musculoskeletal and Skin Diseases, in any given three-month period, about one–fourth of U.S. adults experience at least one day of back pain. So I asked several experts to respond to my questions about how weight affects your body, and here’s what they said:
How, specifically, does being overweight affect your back and joints?
Eric Robertson, P.T., D.P.T., Assistant Professor, Physical Therapy, Texas State University, San Marcos, Texas, a spokesperson for the American Physical Therapy Association
There are two basic ways that extra pounds can cause an increase in back pain. First, extra weight shifts the body’s center of gravity, which may alter posture and mechanically create more strain on the load–bearing joints in the spine, such as the facet joints and disks. Also, some studies have also reported that a stiff thoracic spine is a feature commonly seen in obese people, and this may have something to do with predisposing people to experience chronic low–back pain.
The second theory is that changes in systemic inflammation associated with obesity may make people more likely to experience pain. Obesity is linked to low levels of systemic inflammation, (as compared to normal-weight individuals who do not have this sustained inflammation) and this is thought to be one reason for the increased prevalence of osteoarthritis, periodontal disease and cardiovascular diseases associated with obesity. Obesity and inflammation are thought to be linked through the ability of fat cells to release cellular cytokines, a type of chemical messenger that may increase the body’s inflammatory response. These cytokines (in those who are overweight or obese) can also trigger the release of chemicals involved in the transmission of pain, such as Substance P (a neurotransmitter related to pain).
Therefore, people who are overweight may not only have increased stress on their joints but may also be more likely to feel pain.
Nathaniel Tindel, M.D., New York City back surgeon and author of I’ve Got Your Back (NAL Trade, 2007)
Whether we are talking about the back or any of the joints in the body, what we are really referring to is the cartilage and the synovial lining of these joints. Cartilage makes for a smooth, frictionless surface that allows us to move with ease. If the cartilage is damaged (due to added stress from extra pounds) the joint surface is no longer smooth and frictionless, and this results in pain. The unfortunate fact is that once cartilage is damaged it cannot grow back.
What scientific research has been done regarding back pain, joint pain and inflammation in relation to being overweight?
Eric Robertson, P.T., D.P.T
The link between back pain and obesity is a logical connection, but one that isn’t strongly supported by research. Over the years, countless studies have been done to establish the clear link between obesity and back pain, but currently there is only a weak association. Research has been able to show that people who are overweight have increased systemic inflammation, altered postures and reduced activity and available motion at their joints. However, since the exact cause of most low–back pain is hard to determine (85 percent of low–back pain is non–specific in nature) and many researchers often use varied definitions of low–back pain, research studies have not yet been able to tease out the nature of the relationship.
Given the variable findings, some researchers have hypothesized that the relationship between back pain and obesity may be indirect, mediated by factors such as lifestyle and activity level, rather than a direct causal relationship.
Robert Sterling, M.D., orthopedic surgeon and a spokesperson for the American Academy of Orthopaedic Surgeons (AAOS)
Weight clearly has an effect on the development of arthritis. Research has shown that the incidence of knee arthritis is increased in individuals with a body mass index over 30 (“obese”). Radiologic studies have also shown increased spinal arthritis in obese individuals. While typically thought of as a “wear and tear” phenomenon, recent studies suggest that this explanation greatly oversimplifies the problem. There is likely a complex interaction of genetics, anatomy (alignment of the joints) and biology that leads to the development of arthritis.
If you lose weight will it improve your quality of life and reduce pain?
Nathaniel Tindel, M.D.
While we know that significant improvement in quality of life is achieved with reduction in body weight, there are no hard numbers to quote to our patients. What we do know is that patient self–satisfaction improves significantly and continues to do so with further weight reduction. This is a situation where a little is good and a lot is better.
Robert Sterling, M.D.
In one recent report of a weight–loss program for obese individuals with symptomatic osteoarthritis of the knee, weight-loss patients (average loss 8.7 percent) had better six–minute walking distance, faster stair climbing and an improved score on the Western Ontario and McMaster Universities Osteoarthritis Index (a validated measure of pain and function in individuals with lower–extremity arthritis). The Framingham osteoarthritis study also found an increase in the incidence of knee osteoarthritis of 1.4 times for every 10–pound weight gain over time.
Eric Robertson, P.T., D.P.T.
You can gain some knowledge from research assessing the effects of bariatric surgery for weight loss. In one trial, the group of subjects reduced their BMI from 49 to around 32. During this time, their reports of pain and functional scores related to low–back pain reduced about 75 percent. Other studies have demonstrated similar results and, anecdotally, many patients whom I’ve observed to lose significant amounts of weight have reported dramatic reductions in back pain. One caveat is that you may need to lose enough weight to significantly affect posture before you realize meaningful reductions in back pain.
What are some common myths regarding exercise and body pain?
Eric Robertson, P.T., D.P.T.
One persistent myth regarding back and joint pain is that the joints and back require rest to reduce the pain. In fact, the opposite is true, and research supports the fact that the best thing you can do is to keep moving and keep exercising. Study after study show that bed rest is not indicated for back pain and that joint pain reduces with exercise and regular activity. Since motion can assist in weight loss, there is a strong rationale for remaining active despite experiencing this pain. Of course, pain that is severe or unrelenting may require the oversight of a health professional.
Robert Sterling, M.D.
The most common myth is that exercise is going to make arthritis worse. Certainly, exercises that are painful should be avoided, and high–impact exercises place more mechanical stress on the joints, but most individuals with arthritis have improvement in their function with an exercise program.
Nathaniel Tindel, M.D. .
The one myth that has really been disproven over the years is that if your back hurts, bed rest is the best answer. While an acute back–pain flare–up may require one to two days of bed rest, getting out of bed and mobilizing as soon as possible has been shown to be one of the most important variables in speeding recovery. The other myth is “take two aspirin and call me in the morning.” Aspirin may be a fair pain reliever, but it is also a blood thinner, and doctors no longer recommend aspirin for pain.
Are there exercises you should avoid when you have back pain?
Eric Robertson, P.T., D.P.T.
Exercises that increase pain should be avoided or done in moderation. Sit–ups may stress the back unnecessarily. Try crunches instead. High–impact activities such as jumping, or beginning a running program if you’re not already accustomed to one, are best avoided.
The great thing about exercise is that it doesn’t need to be fancy to be helpful. The key to avoiding back and joint pain and inflammation is that the exercise needs to occur regularly. It could be anything from simply walking to swimming to regular stretching.
Julia Valentour, M.S., an exercise physiologist and program coordinator at the American Council on Exercise
You should avoid:
What are some key exercises and stretches available to reduce lower-back pain?
Julia Valentour, M.S.