Why your foot health matters

You probably know that the health of your feet can affect the rest of your body. Reflexology is so popular these days that many of us could probably point to the spot on the foot that corresponds to the colon. On an even more obvious level, it’s common knowledge that a “dropped arch” can lead to knee pain and many other leg and back problems.

An explanation of simple biomechanics easily explains the effect foot posture has on knee, hip or lower back pain. Yet this is all just the tip of the iceberg in how your foot impacts on your overall wellbeing. Disordered mechanics of the foot can cause common problems such as period pain or headaches. If this seems a long bow to draw, a quick look at the anatomy and function of the foot will show it’s not so far-fetched after all.

Picture a 35-year-old businesswoman who presents with pain in her left foot and knee after spraining her ankle 12 months ago. Like many people, she believed her ankle would regain its former movement after the swelling subsided. She had no other medical history of note and was otherwise healthy. However, when examined she had a “plantar flexed left ankle” (toes pointed), dropped medial arch, rotation of the leg, a twist through her pelvis on the same side and compensatory changes in the spine from bottom to top.

On further questioning of her general health it emerged that since her injury she had developed markedly painful periods and regular headaches. If this sounds like a bizarre case, it’s not. This is actually quite a common situation. Damage to the foot and the structures around it can have far-reaching effects in the body.

The basis of health

The importance of good posture to general health has long been accepted. The mechanics of the foot are in a literal sense the basis of your posture. Podiatrist Andrew Scown describes the effects of altered foot mechanics as wide and varied, from foot, knee and hip pain to headaches, fatigue and even increased appetite. So how could the foot have such significant effects on parts of the body so far removed from it?

“The options really are quite endless as to the effect foot problems can have on the person as a whole,” says Scown. “After correcting the biomechanical function of someone’s foot and ankle complex, I am often told they no longer suffer headaches or their energy levels have increased, with one woman recently reporting a marked reduction in appetite!”

To understand this, it helps to consider for a moment the nature of your body. The structure of the human body is intimately related to its function. Since the body is a unit, every aspect of it affects every other aspect. The body’s mechanical movement therefore, or lack of it, provides a complex interplay with your physiology.

In anatomical terms, the body is made up of a number of elements. There are “fascial lines”, which are continuous connective tissue pathways from the toes to the skull. There is also a system of tubes transmitting fluids from one chamber of your body to the next. The flow of these fluids (blood and lymph) is controlled by pressure differentials.

In addition to this pressure, control is also derived from electrical circuitry (nerves) found in the central nervous system (CNS — brain and spinal cord), peripheral nervous system (spinal nerves) and the autonomic nervous system (ANS — sympathetic and parasympathetic).

The interaction of all these systems determines how efficiently we function as a whole. So let’s start with how the foot feeds into this complex network.

What’s in a foot?

There is more than just 12 inches in a foot (for all you empirically minded folk). There is a mass of interconnected bones, ligaments and tendons. To understand the effect foot biomechanics has on the body, it helps to understand this anatomy. The foot comprises 26 bones that can be divided into hind foot, mid foot and forefoot. This, together with ligaments and tendons, forms a structure that affords stability and shock absorption while acting as a lever for energy transmission and propulsion during walking or running.

The skeleton of the foot begins with the talus, which articulates with the tibia and fibula of the leg to form the ankle joint, allowing the foot to move up and down. The talus sits on top of the calcaneus (heel bone) and together they form the subtalar joint that allows the foot to move side to side. There are five tarsal bones that fit closely together, forming the mid foot. The forefoot comprises five metatarsal bones and 14 phalanges of the toes.

Bones of the foot

Hindfoot — talus and calcaneus

Midfoot — five tarsal bones

Forefoot — five metatarsal bones and 14 phalanges (toes)

Ligaments, muscles and tendons are integral to the function of the foot and together with the bony anatomy they form three arches: medial, lateral and transverse. These arches are critical for the shock-absorptive function of the foot and its adaptation to the varying terrains that you move on when walking or running.

Do the locomotion

Locomotion is the technical term given to human movement. While the term has spawned a series of questionable pop songs, it’s also a simplified way of expressing a complex process. When you walk (or engage in locomotion), your heel strikes the ground first, followed by the outside of the foot up to the ball and fifth toe then across to the big toe, to push the foot off the ground, bringing the leg forward again, ready to take another next step.

During this motion the foot absorbs shock through the arches, contours itself to the changing terrain, transmits energy upwards and acts as a lever to propel the body forward. The linkage design of the joints and supporting structures of muscles, tendons and ligaments is what affords the foot/ankle complex such functional capacity. It is therefore reasonable to assume that if the integrity of this structure is altered, so too is its function.

In a common “rolling” ankle sprain the ligaments on the outside of the joint are disrupted. The body’s response is swelling, bruising, pain and stiffness that can extend down into the foot and up to just below the knee. The subtalar joint is central to the foot’s function and is forced into inversion, or turning inward. What results from this is a common pattern of compensation in the body that extends far beyond the foot, as illustrated in the box below.

Common pattern resulting from a sprained ankle

There is a downward drop of the joint between the two bones that join the ankle to the rest of the foot (the navicular bone and the cuboid bone). This causes the ankle joint to extend forward away from the body (plantarflexion). As a result, the tibia (shin bone) rotates outward.

The fibula (outside leg bone) is pulled downward. This pulls on the biceps femoris (hamstring) muscle and iliotibial band (ITB) that are both attached to the pelvis at the ischial tuberosity (“sit” bone) and the iliac crest (waist bone) respectively.

This then results in an inward twisting of the femur (thigh) affecting the sacroiliac joint on that side, placing a strain (twist) through the pelvis. The organs that reside within the pelvis have direct connections, via ligaments and fascia, to the surrounding bones and to varying degrees can be affected by this strain.

So an unbalanced foot can have effects throughout the body. To illustrate this, it helps to look at two conditions that are remote from the feet but intimately connected to the foot: period pain and headaches.

The foot and period pain

Period pain is a common complaint from women during their menstrual cycle. There are many causative factors including hormonal imbalance, nutritional deficiencies and gynaecological disorders such as endometriosis. However, direct mechanical influences can also be a cause.

The uterus sits in the pelvis between the rectum and the bladder and has a direct mechanical link to the sacrum via the uterosacral ligaments. The wall of the uterus has a rich blood supply and these blood vessels are controlled by nerves from the autonomic nervous system (ANS). As mentioned earlier, the ANS has two parts, the sympathetic and the parasympathetic, and nerve control from the ANS is a kind of balancing act, much like a see saw, where both parts of the system contribute to optimal function simultaneously. These nerves emerge from the spine and go to the organs they control.

If the areas of the spine where these nerves emerge are restricted, the balance of nerve supply can be disrupted. This results in a drop in blood supply and less effective drainage of the uterine wall, leading to congestion and pain. In addition, a mechanical imbalance through the pelvis and torso impedes fluid flow to and from the uterus, much as standing on a garden hose slows the flow of water (rather than stopping it altogether), worsening this congestion.

Additionally, period pain can also be referred pain arising from musculoskeletal structures that share the same pelvic nerve pathways. This type of pain can be very similar to gynecological pain as it can also present cyclically from hormonal fluctuations.

Hormonal fluctuations cause ligaments to be become lax, particularly in the pelvis, placing greater strain on other supporting structures, such as joints and muscles. Podiatrist Amy Daly has a special interest in the menstrual cycle and its relationship to the lower limb.

“As a practitioner, I have often found an improvement in premenstrual cramps from structural treatment of the foot/ankle complex. My theory is that optimal biomechanical function of the foot improves muscle efficiency and core stability, allowing muscles to work better when ligamentous laxity occurs during the menstrual cycle, thus avoiding excessive strain on other structures in this region”.

Head to toe

The pelvis sits at the base of the spine and forms the foundation for all structures above. Likening the spine to a flagpole, a small “tilt” at the bottom of the pole is often reflected more significantly at the top. Ultimately, our brains want our eyes level and looking forward so, to achieve this, our body is adjusted accordingly. An imbalance in the pelvis is reflected with compensatory positional changes in the thoracic spine and rib cage, creating further change in the neck and head so our eyes point forward and are level.

In achieving this “balance”, potentially significant strains or twists in the body can occur, particularly at the top of the neck (cervical spine). It’s quite common for the upper neck to be restricted in its range of movement as part of an overall postural compensation following an ankle sprain. This affects surrounding muscles, nerves and blood vessels. Neck and jaw pain as well as headaches are quite common symptoms of restrictions in this area.

There are many types of headaches, each with different causes. A “cervicogenic” headache occurs when restrictions in the upper neck refer pain into parts of the head that share the same nerve pathways, via what is called the “trigeminocervical nucleus”. This is one of the most common headaches seen in manual therapy clinics and often is part of a compensatory pattern in the body whereby the underlying cause is actually not within the neck.

Headaches can also be caused by constriction of the arteries supplying the head and neck, the nervous control of which is derived from the upper part of the back (thoracic spine). Restrictions in these joints can therefore also be the cause of a headache, which can again be observed as distant effects of changes in the leg that can, in turn, come back to problems with the foot.

The foot and energy

Strains in the foot/ankle complex reduce its efficiency in absorbing shock, transmitting energy and the ease in which it propels us forward during movement. This makes simple functions such as walking or running more demanding on the body as a whole, requiring more energy than should otherwise be necessary.

It follows then that an increased consumption of energy encourages fatigue and/or increased appetite. Could better foot mechanics be the next diet? Obviously, there is so much more to this picture, but the fact is the foot and ankle have an important role to play in how well we function, both mechanically and physiologically.

Maintaining healthy, well-balanced feet is the basis of wellbeing in many ways. If you have foot problems or experience injury, it’s wise to seek professional assessment and help to correct changes in the foot and ankle. Especially following an injury such as an ankle sprain, the earlier the intervention the better, as compensatory changes in the body are then much easier to reverse and also less likely to occur.

It can also accelerate the healing process by reducing strain from other areas and positioning the injured area in the best state possible for blood supply and drainage. A good manual therapist with a holistic approach can help improve mechanical efficiency of the foot and ankle complex, potentially influencing a multitude of other systems in the body.

Your body’s compensatory response to an unresolved mechanical strain pattern through the lower limb, pelvis and spine, following something as simple as an ankle sprain, has the potential to cause many problems. Compensation patterns in the musculoskeletal system can place strain on fascial connections to the organs, restrict flow of fluid and disrupt the nervous supply to these areas. Dysmenorrhoea, headaches and fatigue are only three examples of potential ailments.

There is no doubt that there are many causative factors underlying these problems, but consideration of the influence of the foot and ankle might just be a step in the right direction.