Weight Gain and Back Pain: The Link Explained
If you’re overweight, you’re probably already aware that those extra kilos can have an impact on your health and wellbeing. Excess weight increases the risk of many chronic health conditions such as type 2 diabetes, heart disease and some cancers. Many types of joint pain are also related to weight.
Your joints
Joints are the parts of your body where two or more bones meet.
Fixed joints, like those in your skull, don’t move at all. The joints in your spine move a little, allowing you to bend and twist your torso. Other joints are more mobile. These include:
- Ball-and-socket joints like your shoulder, which allow backward, forward and sideways movements and rotations
- Hinge joints that only allow bending and straightening, like your fingers, knees, elbows and toes
- Pivot joints that allow limited rotating movements, such as in your neck
- Ellipsoidal joints like your wrists, which allow many different types of movement.
Your joints consist of more than bone, though. Those bones are held in place by many different types of soft tissues including:
- Cartilage and meniscus, which covers the bone surfaces
- Synovial membranes and fluid, which protect and lubricate the joint
- Bursas, fluid-filled sacs that cushion the friction
- Strong connective tissues including:
- Ligaments, that surround and support the joint and limit its movements
- Tendons on the side of each joint that connect bones to muscles.
What’s the link between weight gain and sore joints?
Excess weight has two key effects on your joints:
- It puts more stress on weight-bearing joints like your hips, knees and ankles
- It causes chronic inflammation which can lead to pain in other joints.
Let’s look at each of those in turn.
Weight creates an excessive load on your joints
When you walk, your knees experience a force equal to 1.5 times your body weight. Let’s say you’re a 168 cm tall, 60-year-old woman who weighs 66 kg. Your BMI is 23.4, meaning you’re a healthy weight for your height. When you walk, your knees experience 99 kg of pressure.
Now, let’s imagine, you’re the same height but now weigh 90 kg. Your BMI is 31.9, which places you in the obese category. When you walk, your knees experience 135 kg of pressure. That’s a big increase.
What about weight and back pain? Well, it’s a similar story. Your spine supports your body’s weight and distributes the loads you encounter during rest and movement. When you’re overweight or obese, your spine has to bear the extra burden, which often results in lower back pain. Added to which, excess belly fat and weak core muscles deprive your spine of the support it needs. Weight contributes to a number of spinal conditions including spinal stenosis, degenerative disc disease and osteoarthritis.
Weight causes chronic inflammation
As for inflammation, this is an emerging area of research and clinical practice. We know there’s an association between increased weight gain and increased inflammation though we’re still learning exactly how obesity triggers inflammation. It seems to be linked to your immune response.
Your immune system is responsible for fighting off infections, often with a defensive inflammatory response at the infection site which resolves when the infection clears. However, inflammation caused by obesity does not resolve. Instead it becomes a chronic problem.
Your fat cells keep releasing proteins that travel around your body and cause inflammation. That’s why you’re twice as likely to develop osteoarthritis (OA) of the hand if you’re overweight rather than lean. If you’re obese and have OA in one knee, you’re 5 times more likely to get it in the other knee than someone who is a healthy weight. Furthermore, OA progresses more quickly and more severely in overweight or obese people who are more likely to need a hip or knee replacement.
Sagittal imbalance may exist as a primary condition or may be a consequence of other spinal conditions such as:
- Ankylosing spondylitis, a type of arthritis
- Kyphosis, excessive forward curvature in the spine
- Degenerative disc disease
- Traumatic injury
- A congenital defect present at birth
- Osteoporosis
- Neuromuscular conditions such as cerebral palsy, spina bifida, or muscular dystrophy
- A previous spinal fusion surgery that disrupts sagittal balance.
What can you do?
If you’re carrying extra kilos and experiencing joint pain then, yes, unfortunately those two things are probably linked.
Losing weight is the best thing you can do. We know that’s not easy. There are complex reasons why people gain weight and it’s not always easy to shift. We suggest you follow the general guidelines for losing weight and talk to your GP if you need more help and support.
Every little bit helps, though. A 2005 study found that every 1 lb of weight lost resulted in a 4-fold reduction in the load exerted on the knees. To put that in Aussie measurements, every half a kilo you lose takes 2 kg of pressure off your knees.
The more you lose, the better it gets. If you manage to shift 10-20% of your bodyweight, you may be able to significantly improve your pain levels, function and quality of life.
How can the Victorian Orthopaedic Spine Service help?
Orthopaedic surgeons specialise in diagnosing and treating conditions that affect your bones and joints. We’re here to provide you with the advice and support you need to improve your joint pain. That may involve a hip or knee replacement, or it may involve more conservative treatments including medication or injections.
If you’d like help, please contact us today.
Disclaimer
All information is general in nature. Patients should consider their own personal circumstances and seek a second opinion. Any surgical or invasive procedure carries risks.
About Dr David Edis
Dr David Edis is an Orthopaedic and Spine Surgeon. David’s areas of special interest include the management of adult spinal conditions as well as hip and knee replacements. He has extensive experience in all facets of spine surgery from simple to complex, covering cervical to lumbo-pelvic conditions. He is an active researcher and medical educator and believes in lifelong learning. He is constantly updating his skills and helping other surgeons.
