Foot orthoses have become a multi-billion dollar industry in the U.S. The most common reason is the diagnosis of "over" or "excessive" pronation. As Prime for Life (the book) points out, all feet normally pronate, which is very roughly a rolling in of the arch. Almost all studies examining the ability of ped-orthists, physical therapists and podiatrists to assess the foot's motion and position either standing or in motion have consistently shown very poor inter-rater reliability. This means that although in some studies individual examiners are fairly consistent in their own findings about individual feet, there is almost no agreement between clinicians on what they find! They can't even reliably agree whether the foot is abnormally pronating! And this was found in experienced podiatrists! (see Van Gheluwe et al, 2002 on Evidence page in Foot chapter on Prime for LIfe website)
     Even the idea of "over pronating" has not been quantified or explained well in the medical literature. The typical method for making custom orthoses, which typically cost $300 to $1000 a pair, is the "subtalar neutral" method. This method was developed by a Podiatrist in 1966 based on a prior study, which measured foot motion in two subjects. The podiatrist, Merton L. Root, DPM, was ahead of his time and provided a conceptual way to improve foot function with orthoses. However, he misinterpreted the original study (see Wright, 1964 under "Evidence" page in foot literature on Prime for Life website), presuming that when one is walking with the body right over the foot that the foot on the floor is neither pronating nor supinating. He called this "subtalar neutral" and devised methods of placing the foot in this position for casting orthoses.  All subsequent larger, better quality studies have shown, however, that the foot is to some degree pronating in normal feet the entire time it is on the ground. The foot never, in normal feet, attains the subtalar neutral position on the ground. Rather, they have consistently shown that it is always pronated on the ground. So orthotics, which are designed to place your foot in this neutral position, essentially attempt to place your foot in a position that is only attained after the foot leaves the ground swinging in space.
    The good news is that other studies have shown that orthoses don't significantly alter pronation and supination anyway (See all studies by BM Nigg on Evidence page on Prime for Life website under Foot and Ankle chapter). We do not really understand why they do help people. It may alter proprioception or sensation and /or muscle activation patterns. Or it may simply disperse forces over a larger surface area decreasing pressures. Nigg has shown that comfort may be the most important factor dictating success of orthoses - not some mythical ideal foot position that is never attained. Some research has shown that inexpensive over-the-counter orthoses and arch supports may be as helpful as custom ones that cost a fortune. Try the ones recommended in Prime for Life.
    If you have unusually shaped feet, such as very wide feet or deformities from arthritis, then custom ones can really help improve comfort. Be wary of shoe salesmen who purport to be able to accurately diagnose foot types. If podiatrists don't have good inter-rater reliability assessing feet, don't expect someone with very little training to be good at it. However, that said, some shoe stores are getting better at fitting shoes to feet. While no one can reliably tell what a foot is doing inside the shoe, rough "gestimations" may help. Wear shoes inside for at least 20 minutes (on a treadmill or in a mall) to see if they are comfortable.  That tells the most.  When your feet are happy, so are you.   For significant foot problems see a physical therapist who specializes in feet or a podiatrist.
    

     For many years the prevailing belief about low back pain was that it was caused by  "stuck" joints or restricted connective tissues. It spawned an industry of modalities to address the problem. Consequently, the "fix" was often manipulation, mobilization (a gentler form of manipulation) or stretching. Other practices such as "trigger point" release techniques (e.g. myofascial release, craniosacral therapy, ischemic pressure, strain/counterstrain, dry needling, etc.) also gained popularity - despite anecdotal evidence only. There is certainly evidence that manipulation and mobilization provide relief for new onset back pain. Unfortunately, an examination of the literature regarding whether different examiners reliably agree on which segment needs "fixed" has shown they don't. A study at Washington University in St. Louis found that unless positions of tissues varied by at least 1/2 inch, examiners did not agree reliably on findings. Spinal joints, imbedded deep under erector spinae muscles, are not believed to move more than a few millimeters. Other studies have shown that manipulative techniques are not specific to the intended segments in any reliable way! Nor can it be proven that a measureable change in  joint position is accomplished.
     This is not to say that patients don't find relief with these methods. Is it caused by a placebo effect? This is a possibility and not one to take lightly. Placebo pills in pain studies typically have a 20% success rate at decreasing symptoms and, as mentioned in Prime for Life, have been shown to increase endogenous opiates such as endorphins.  Another speculated reason for success with manipulation may be that it effects the nervous system - altering perception and motor control in subtle ways. We just don't know how or why it helps some people. Generally a good rule of thumb is that if a treatment doesn't last more than a few weeks, it is not affecting the cause of the problem.
      The Washington University in St. Louis "Movement System Impairments (MSI)" method of diagnosing and treating patients, though, has a different perspective. By having a patient perform systematic movements and watching for compensatory patterns and listening to patient reports of symptoms, clear and reliable patterns tend to emerge. Studies have shown that patients consistently report pain patterns, regardless of the examiner. As a practitioner who uses this system of diagnosing and treating patients, I am constantly struck by the almost universal pattern of excessive motion in the spine and consistent, accompanying complaints. The patient will add extra low back rotation or flexion or extension and complain of pain. When they are taught to restrict the extra motion, they report a decrease or elimination of pain. Upon questioning, they usually admit to some repetitive movement in their day-to-day life that repeats the offending motion. Sleeping on the belly with low back arching correlates to the examination and a realization that they wake up with pain. Or a twisting of the upper body to face the computer correlates to the report of pain with rotation or sidebending. Or doing early morning stretches of knee to chest and forward bends in yoga (when disc pressure is at its highest) is the link to pain with bending over. Changing movement patterns tends to permenently address the problem. I shows that the most common cause of musculoskeletal pain is faulty movement patterns, which stems from the brain - not the body. The problem is upstairs not downstairs in the spine.
     The passive "fixes" may decrease pain. In my experience usually only temporarily. If you keep bending your index finger back as far as you can, the knuckle becomes painful and swollen. Only by stopping the offending action can the knuckle stop hurting. It doesn't need stretched to the extreme opposite direction, or massaged, or manipulated - just treated respectfully. Extreme end-range stretches or manipulations are stressful to the body. Figuring out how you are offending your body's innate wisdom is the first step in staying in your prime. Avoiding pain or discomfort is the first step towards that goal.

     One of the reasons that flexibility may not be as important as we once thought, is that tendons that are adequately stiff are more energy efficient than overly flexible ones. When you are walking and plant your right foot on the ground, your body continues to advance over and past it. As it does, the Achilles tendon becomes increasingly taut. Like a wound up rubber band propeller in a toy airplane, it is storing energy - "kinetic energy."  When stretched to a certain length of tension at push off, the Achilles tendon literally snaps into contraction helping push your foot into plantarflexion (i.e. your foot pushes off the ground). A study by  Maganaris and Paul (2002, see Evidence page on PrimeforLife.net under "Achilles Tendinopathy") determined that in walking this "catapult action" of the Achilles tendon  provided about 6% of the energy in walking in 6 men! Hopping on one foot in a study by Lichtwark and Wilson (2005), provided in elastic recoil 16% of the total work!
     The degree of elasticity, or ability of the tendon to spring back to its original length is not perfect, though. The inability to return immediately to the original length/tension results in lost kinetic energy - a phenomenon known as hysteresis. The lost kinetic energy is, instead, heat energy. If excessive, this heat production may be injurious to the tendon and contribute to Achilles tendon degeneration. Animal studies have shown that the heat produced may exceed 108 degrees F. - more than enough to cause tendon damage.  More flexible tendons tend to not spring back as well as adequately stiff ones, which means they produce more heat then stiffer tendons. Indeed, the Lichtwark/Wilson study found a variable amount of hysteresis (or lost energy) of 17 to 30%. More flexible individuals tended to be more inefficient at using the elastic recoil. Several other studies showed that individuals with stiffer lower extremities ran and walked with significantly more energy efficiency than more flexible people. It makes sense. A flexible person with long, less stiff Achilles tendons, never even feels a stretch of the tendon as they advance past the planted foot. There is no or little kinetic energy to provide recoil and help push off. So this, looser person, must compensate by adding an additional 6% of energy to maintain the same pace as the stiffer person. In most sports the elite athletes are not the gumbies. They are stiff, coiled springs.
     Stretch appropriately, but don't do so with the goal of being super flexible. Doing so may increase the odds of tendon problems. Read the Flexibility chapter in Prime for Life to assess whether you need to stretch and which areas need added range.

    

Welcome to my blog. I will try to post weekly small articles about staying in your prime with exercise. You can subscribe and receive it as an e-mail if you enter your e-mail address and click on "subscribe." As a Physical Therapist, my passion is preventing osteoarthritis. The time to begin thinking about this major cause of immobility is NOW. The younger you are in maintaining healthy joints, the longer you'll be active and healthy. So stay tuned...