Fat Pads: What You Need to Know
All of us have fat pads (technically, “plantar fat pads”) on the bottoms of our feet. These fat pads protect the feet’s bones, tendons, ligaments, blood vessels and nerves. They provide this protection by absorbing the impact, shear forces and pressures that are involved in nearly every type of activity—e.g., walking, running, playing sports and even simply standing still.
The plantar fat pads are composed of many microchambers that contain fatty tissue. These chambers are formed by walls of elastin (mainly collagen) that are flexible and pliable. They stretch and rebound to help absorb and dissipate the forces and pressures— especially shock and vibration—that occur during activity. However, this fat pad protection tends to diminish with age and everyday activities.
Age, Activity, Trauma
By age 50, a normally active person will have walked or run about 75,000 miles, and will have lost as much as half of the fat pad protection on his or her feet. If we all walked barefooted on natural surfaces such as sand and grass, the damage would not be nearly as severe. But most of us spend the bulk of our time moving around on man-made surfaces (pavement, hard floors and other “non-yielding” surfaces). This takes a toll on the fat pads, making the feet more vulnerable to pain and injury. (For more on how hard surfaces affect the feet’s fat pads, see the IPFH white paper “New Treatment Modalities for the Human Foot”). Thinning fat pads also leave the outer skin and underlying areas more vulnerable to shear stress, which can cause lesions, wounds, and eventually ulceration of the skin.
In addition, trauma caused by landing heel-first on a hard surface (after a fall or jump, for example), or from spending long periods of time standing and walking on hard surfaces in poorly designed and/or poorly fitted footwear, can lead to fat-pad displacement. When this happens, the fat pads do not fully protect the bones and other structures beneath the pads.
Diabetes, Obesity
People with diabetes who have insensate (no feeling) feet are particularly at risk for foot conditions—especially ulceration that may lead to amputation. This usually is due to neuropathy, or loss of nerve sensation that keeps them from feeling pain when trauma (stepping on a nail, for example) occurs. But diabetes affects the fat pads as well. Several studies have shown that the fat pads in people with diabetes are less pliable, stiffer and less able to regain their shape and position after absorbing impact. The combination of damaged fat pads and neuropathy is dangerous and can lead to significant damage if the feet are not properly protected.
Overweight or obese people also are more vulnerable to fat-pad loss and possible displacement, especially if they are not careful to select footwear that is well designed, protective, and properly fitted. The increased pressure on the fat pads can cause them to displace to one side or another, especially in the heel area. Also, the increased physical load from excess body weight can cause the pads to lose their protective resiliency.
Preventive Strategies
The best way to help protect against fat pad degradation and loss is by taking good care of your feet and choosing the right footwear. IPFH suggests wearing properly selected and fitted, as part of an integrated approach, padded socks with shoes with non-slip outsoles and any inserts or orthotics prescribed or recommended by a doctor or foot health professional. Peer-reviewed, published studies have shown that wearing clinically- tested padded socks can help protect against injuries to the skin/soft tissue of the foot due to impact, pressure and shear forces.
If you have diabetes, you should be especially vigilant. Inspect your feet daily and follow good foot hygiene. Your feet should be examined and assessed regularly by your doctor. Make sure your feet are measured and you are properly sized and fitted, as outlined in the integrated approach, every time you buy a new pair of shoes to avoid cuts, abrasions, blisters and other foot conditions that may lead to ulceration. According to IPFH’s National Foot Health Assessment 2012, only 46% of people with diabetes reported having regular foot screenings by their doctor; only 20% were told that they are at risk for foot-related complications; and only 11% reported being properly sized and fitted each time they purchased shoes. Take care of your feet and help turn these statistics around.
Armed with the knowledge of how the fat pads protect your feet, and the awareness that they lose much of their protective ability over time, you can take better care of your feet and help avoid foot pain and injuries.