Obesity and Your Musculoskeletal System

It’s no secret that being overweight or obese is a significant risk factor for a wide variety of health conditions.  By one estimate, the treatment of obesity and the medical problems associated with it costs $168 billion each year in the US alone.  And while many of these diseases have familiar names—Type 2 diabetes, heart disease, cancer, high blood pressure, high cholesterol and metabolic syndrome, to name a few—being overweight or obese can also take a significant toll on the body’s musculoskeletal system.

Based on the body of research available today, it’s useful to talk about three different ways that being overweight or obese may also contribute to chronic musculoskeletal Pain (CMP).

A Simple Matter of Wear and Tear

At one level, the problem involves a simple combination of gravity and biomechanics.  Additional weight causes additional wear and tear on the body’s muscles and joints.  And wear and tear is cumulative over time.  This is particularly true of the knees, hips and back.  For instance:

  • Osteoarthritis has grown increasingly common as the rate of obesity has increased. The American Obesity Association warns that individuals with a body mass index (BMI) higher than 25 are at greater risk of osteoarthritis.  Obese women are nine times more likely to suffer from osteoarthritis of the knee, often leading to the need for a total joint replacement.  However, researchers have found that losing as little as 11 pounds can reduce the risk of knee osteoarthritis by half.
  • Excess weight, particularly around the stomach, pulls the pelvis forward and causes an excess curvature in the vertebrae of the lower back, causing pain and stress on the muscles and supporting structures of the back.
  • Being overweight or obese may lead to bulging or herniated discs, which may in turn contribute to the development of nerve compression, sciatica or piriformis syndrome.

The Downward Spiral of Inactivity

It’s pretty clear that inactivity can contribute to someone becoming overweight or obese.  But it’s more complicated than that because physical Inactivity is both a cause and effect when it comes to obesity.  Carrying all that extra weight places a great deal of extra strain on the musculoskeletal system as well as the circulatory and respiratory systems.  For those who are overweight, even short periods of exercise often cause pain, fatigue, lightheadedness and shortness of breath.  They also face a higher likelihood of injury.  It’s hardly surprising that these factors would discourage overweight and obese people from being physically active.

This downward spiral may help explain some dismal statistics produced by the University of Alabama’s Nutrition Obesity Research Center and published in the December 2013 Mayo Clinic Proceedings.  The average obese man in the US gets just 3.6 hours of vigorous exercise per year, while the average obese woman gets the equivalent of only 1 hour.

Physical inactivity can indirectly lead to CMP, especially in the back, where inactivity is often a major contributing factor and a lack of exercise leaves core muscles stiff, weak and out of condition.

Increased Pain Sensitivity

A link between obesity and pain sensitivity has not been conclusively proven, but researchers have noticed some clues that suggest a relationship.  In one recent study, overweight participants—those with BMIs between 25 and 29—reported about 20% more pain than normal-weight participants.  At the same time, participants with BMIs between 30 and 34 had about 68% more pain. Participants with BMIs between 35 and 39 had 136% more pain and those with BMIs over 40 reported having 254% more pain.

However, the data are noisy, and it is difficult to control for the fact that excess weight contributes to other health problems that may actually be the cause of participants’ pain.  When researchers accounted for the influences of these other health problems and pain-causing conditions, being overweight was no longer associated with being in pain.  But participants who were obese still reported more pain than those with normal BMIs.

All this said, fat cells are known to produce chemicals that increase inflammation, which is very closely linked to pain perception.  This means that there could very well be a physiological mechanism that translates additional body weight into additional pain sensitivity.

The Good News

So the bad news is that—for a growing number of people—more weight seems to equal more pain.  The good news, though, is that the opposite also seems to be true.  Losing weight appears to have an immediate effect on pain.  If you suffer from back pain and are more than 10 pounds above your ideal weight, losing that weight may significantly reduce the amount of pain you are experiencing.  According to Dr. Andre Panagos, co-director of The Spine Center at New York’s Presbyterian Hospital, “Although research on weight loss and back pain is minimal, in my clinic, every single person who loses a significant amount of weight finds their pain to be significantly improved.”

What is a “Bone Bruise”?

Although the term “bone bruise” seems to indicate a relatively mild injury, in actuality it is no less severe than a broken bone. Also referred to as a bone contusion or bone swelling, bone bruises result from an acute trauma or a repetitive stress injury, and should be treated professionally.

A bone bruise occurs when the inner structure of your bones becomes fractured. Bone is made up of two different types of tissue: compact “cortical” bone on the outside and “cancellous” or “spongy” bone on the inside. Cortical bone is strong and solid, whereas spongy bone, as its name suggests, is a more delicate meshwork of bone tissue that can more easily suffer many small fractures, resulting in a bone bruise.

An acute trauma or stress to a bone may not be sufficient to fracture the outer bone, but there may be enough force to cause the spongy inner bone to fracture, leading to bleeding in the injured area. Sports injuries may be one of the most common causes of bone bruises, when an athlete falls or bumps into another person with considerable force. Auto accidents, falls and twists, particularly to the knees and ankles, also frequently result in a bone bruise. Other areas likely to sustain a bone bruise are the wrist, foot and hip.

Symptoms of a bone bruise (which include pain, stiffness and swelling) can sometimes be mistaken for tendon or ligament damage, or even a muscle bruise. Intense pain that lasts more than a couple of days (and often for weeks or months) may be a sign of a bone bruise. Stiffness may occur if the bone bruise is located near a joint or is in part of the joint. However, swelling is the leading symptom of a bone bruise, and there will usually be no sign of bruising on the skin, as the bleeding occurs within the bone itself. If you think you may have a bone bruise, an MRI can determine whether it’s that or something else. X-rays and CT scans can only indicate a fracture of the outer bone.

A bone bruise usually takes several months to heal because the inner spongy bone takes longer to repair than the outer layer. Treatments typically involve rest to take any pressure off the bone, elevating the affected area to help reduce swelling, taking an anti-inflammatory pain reliever and using ice packs to relieve pain soon after the injury. A brace can be worn to provide support to the injured area and reduce healing time. Experts also recommend that people quit smoking if they want the bone to heal more quickly, since smoking constricts blood vessels, reducing the circulation necessary to bring healing.

Are We Sitting Ourselves to Death?

Whether we like to admit it or not, the technology in our lives—and the fact that we use much of it while sitting down—is contributing to a growing list of health problems in our society. Those who sit at a desk all day or sit behind the wheel of a car or truck with little or no exercise are at increased risk for a number of chronic health problems. According to the Mayo Clinic, those who have such a sedentary lifestyle are in danger of things like “obesity and metabolic syndrome — a cluster of conditions that includes increased blood pressure, high blood sugar, excess body fat around the waist and abnormal cholesterol levels.”

One study showed that those who spend a large amount of time in front of a television or other forms of screen entertainment had a roughly 50% greater risk of death from any source. It’s not really difficult to imagine why this might be the case. Greater body weight combined with lower strength and stamina and reduced balance and flexibility means less agility and durability. This in turn raises the likelihood of more accidents or injuries. The same study showed a 125% greater risk of problems from cardiovascular disease. Care was taken to separate the risk of sitting from that of high blood pressure. Those who had the same high blood pressure, but who sat less, had fewer incidents of health problems.

WebMD has added cancer to the list of ailments for which excessive sitting may be a risk factor. One Australian study of 63,000 older adult men showed that men who sat for more than 4 hours a day were more likely to have a serious, chronic illness than those who sat for less than 4 hours per day. Above 6 hours per day, men were at significantly greater risk of diabetes. Those who regularly sat more than 8 hours a day had the highest level of health risk.

Yet another study showed that back pain strikes 80% of all adults at some time in their life. A significant number of these people suffer because they sit too much. Their core muscles lose conditioning and their waistline becomes a burden that causes the back muscles to do more work to make up for soft abdominals. Weak muscles put the body at risk even during simple tasks. With a more sedentary lifestyle, it becomes easier and easier to overdo the reaching, the lifting or other simple physical work that occurs during any typical day.

There’s another reason that movement is particularly important when it comes to maintaining good spinal health. If the spine is kept motionless, circulation is reduced and it cannot get the nutrients it needs to stay healthy or to heal itself.

If you already have back pain, seeing a chiropractor is a big step in the right direction. A chiropractor can help to realign your vertebrae and, in many cases, an adjustment can provide immediate relief. However, even world-class chiropractic care is no substitute for a healthy lifestyle that includes a good diet and lots of exercise. The doctor can’t do all the work for you.

So what can you do? The Mayo Clinic recommends finding more excuses to move around throughout the day, instead of saving it up for a trip to the gym. Waiting until the end of the day to push your body at the gym for 30 minutes is a bit like saving your meals to the end of the month and eating 90 platefuls all at once. You need to spread your movement throughout the day so your body can stay in top condition.