Understanding the problem
The human body has two factors that limit the effectiveness of its circulatory system:
- the placement of the heart
As shown in the accompanying figure, many animals have 70% of their blood volume at or above the level of their hearts. Humans, on the other hand, have 70% of their blood volume below their hearts. And the pressure needed to move that blood back up to the heart to counteract the effects of gravity increases significantly as you reach the ankles and feet.
If a healthy person sits quietly for 30 minutes, about 15% of their total blood volume will pool into the veins in their legs and another 15% will pool into the surrounding tissues. This results in an effective 30% decrease in blood volume, and a corresponding 30% decrease in cardiac output. As we are not normally doing heavy physical exercise while seated, this decrease in cardiac output is not usually a problem, although this reduction will impact the ability to deliver necessary oxygen and nutrients to the rest of the body (including the brain).
An additional problem is that your skin is also very flexible and can stretch. When blood pools in the legs, as the skin stretches so do the veins, thus weakening them. This allows even more blood to pool. Continuing this process over time will result in heath issues in the legs, such as the formation of varicose veins.
Skeletal muscles in the foot and legs provide the pumping normally needed to prevent excessive fluid pooling when in an upright posture. Three skeletal muscle pumps exist: the foot pump, the calf muscle pumps (soleus muscles) and the thigh pump. The foot pump serves to “prime” the calf muscle pump which provides about 75% of the fluid returning to the heart, while the thigh pump provides the remaining 25%.
When a person is walking, the superficial calf muscle (the gastrocnemius) provides skeletal muscle pumping by compressing the soleus muscles driving fluids back to the heart. However, when sitting or standing quietly, the soleus muscles alone are the primary pumps for returning pooled fluids. The importance of the soleus muscles in returning blood and interstitial fluid (lymphatic fluid) back to the heart has resulted in these muscles commonly being called the “secondary hearts".
In the absence of adequate calf muscle pumping, there will be insufficient fluid returning to the heart and it will be unable to maintain normal blood pressure or sufficient output to sustain the tissues of the body. The result will not only be swollen feet, ankles and lower legs, but also varicose veins, achy muscles and joints due to excess fluid build-up. In addition, the reduced output to the brain can lead to fatigue, migraine headaches, dizziness, blurry vision and cognitive dysfunction.
There are interventions available which will assist in reducing many of these symptoms. For example, one can raise their feet above the heart when sitting so as to drain out the veins and lymphatic vessels. Compression stockings or, in severe cases, pneumatic compression devices are available which can help prevent fluid pooling and push the fluid out of the legs. There are also electrical muscle stimulation devices available which serve to force contractions of the foot or calf muscles to help pump out fluid from the legs.
The preferred solution is to train up the soleus muscles so that they can naturally sustain contracting activity whenever you are sitting or standing quietly. These muscles respond best to long duration, low level exercise. A typical soleus exercise is to sit with your feet flat on the floor, and then raise your heels as high as possible with your toes still on the floor. This should be repeated every few seconds for an hour or more each day.
Given the impracticality of actively training up the soleus muscles due to most people's busy work and personal schedules, a passive approach is preferred. And that has been made possible by the research done for over fifteen years by Dr. Ken McLeod, who received his Ph.D. in Electrical Engineering, Bioengineering from the Massachusetts Institute of Technology.
Discovering a better solution
Dr. McLeod discovered that vibrations at a specific frequency applied to the bottom of the foot could help stimulate and train the soleus muscles. Just in front of the instep are a group of sensory nerve endings called Meissner’s Corpuscles. When these particular Meissner’s Corpuscles are activated or stimulated, the soleus muscles contract as a result of a nervous system reflex. Since Meissner’s Corpuscles can be activated by a specific mechanical signal, all that is necessary is for the individual to place their feet on a device which provides the optimal mechanical stimulus for their activation. That research led to the development of the HeartPartner.
The user only needs to place the front part of their feet on the HeartPartner in order to begin training and strengthening their soleus muscles. There is no need to remove your shoes, socks or stockings, as the vibrations will pass through them to activate the Meissner’s Corpuscles.
Because this is essentially a muscle exercise, you may want to start the “exercise” regimen slowly, using the device for half an hour a day. Over time, the length of “exercise” duration can be extended. One to two hours per day of usage has been found to be sufficient to train the soleus muscle back to normal behavior in a period of six to eight weeks.
The human soleus muscles are capable of undergoing periodic contractions for more than 12-18 hours in the course of a day, so there is no concern about “over-training” the muscle. There is also never a situation where there is supposed to be fluid pooled into the lower limbs, and so the pumping out of this fluid should not cause any complications. However, if you have any concerns about whether the HeartPartner is the right approach for addressing your specific health concerns, you should discuss this option with your personal physician.