Your Joint Health – It’s Important!
Keeping a healthy weight is a major factor in maintaining joint health. This is especially true for weight bearing joints, such as hips and knees. The force placed on your joints with everyday movement varies with the surface you walk on: on level ground, the force on your knees is approximately 1.5 times your body weight with each step. This changes with an incline, depending upon the slope. The force across your knees can be up to 3 times your body weight going up and down stairs, and up to five times with squatting.
Carrying extra kilos increases the mechanical stresses already placed on these joints: one kilo can add nearly four kilograms of stress to a knee joint, and up to six to a hip. So, a extra two kilos results in eight kilograms of stress on the knees with each step. Imagine carrying an extra 8 kilos in each hand all day, and you can understand why your knees or hips start to complain. That they last so long is remarkable.
With time, this increase in strain breaks down the cartilage in joints. When the cushioning effect of the cartilage is lost, the bone can no longer move smoothly. Once an injury occurs and impairs mobility, it can be hard to shed the extra weight; doing so before any damage arises also decreases the risk of developing osteoarthritis in that joint, or slow its progression if it is already present. (Decreasing the force put on the joint will also help to control pain).
Being overweight not only places an increased load on the joints. There is increasing research evidence on how fat tissues produce cytokines, a type of protein which can promote inflammation throughout the body. Chronic inflammation alters both the structure and function of cartilage cells. This explains why those who are significantly overweight have an increased risk of arthritis in non-weight bearing joints, such as their hands. Evidence also supports that every kilo lost aides in reducing joint inflammation and stress.
Bursitis is also associated with being overweight. Essentially a sack filled with lubricating fluid, a bursa keeps nearby tissues from rubbing against a bone. When irritated, it can swell and become inflamed, resulting in pain. This can be a result of overuse, but also can be caused by extra weight.
Diabetes may also be a risk factor for osteoarthrits, as high blood glucose levels accelerate the formation of certain protein molecules which result in stiffer cartilage. This in turn leaves a joint more sensitive to mechanical stress. Diabetes is also associated with higher levels of systemic inflammation, which will accelerate cartilage damage and loss. (In 2014, of the nearly 30 million Americans with Type 2 diabetes, over half had arthritis). Diabetes is associated with many other body disorders, and those with late-onset, or Type II diabetes are often overweight; these factors compound to both accelerate confounding and worsen arthritis.
Maintaining a health muscle mass is important – weak muscles can not hold a joint stable, especially when it is placed under unexpected strain. Core strength is important for stability of both your spine and pelvis, whereas gluteus maximus strength is important for pelvis and hip stability, exercising these muscles can benefit your joints greatly. Those with a largely sedentary lifestyle will often have weak glutes, leading to unrecognised instability, and even the need for hip replacement.
Bone strength is also affected by overall health. Weight bearing exercise helps maintain bone density, as does an adequate diet along with sufficient vitamin D. Hormones play a role: bone density decrease in woman after menopause, and more women than men develop arthritis after the age of 50.
Sleep, diet, exercise, smoking, alcohol consumption, even stress; all come to bear on overall joint health. So, with so many factors involved in joint health, there are many ways of protecting your joints against injury and problems as you (and your joints) grow older.
Here’s some more information in case you missed my last blog about joint preservation.