foot inserts Tag

Orthotics

With the onset of so many infomercials on television about shoe inserts and orthotics, we’ve had a rash of confusion among our patients about when to use orthotics and if it’s appropriate for them.

To understand orthotics, it’s important our patients have a good understanding of normal foot mechanics because that’s what orthotics do — change foot mechanics.

In a normal foot, the arch is both taunt and rigid while also being flat and flexible. When our heel hits the ground, the foot needs to accommodate the surface — flex like a shock absorber to dissipate the force of impact and provide a stable wide platform to accept the body weight (think about walking barefoot on an uneven lawn).  Our foot will naturally pronate to allow all the midfoot joints to become loose and accomplish these goals.

   

To walk on uneven ground, our feet need to be flexible

To walk on uneven ground, our feet need to be flexible

Once our body weight is completely loaded on top of our foot, the arch must tighten to provide a rigid lever so our muscles can propel us forward for the next step.

In normal mechanics, the foot needs to be both flexible and rigid for effective propulsion.  However, when we suffer from an injury in the body (lower back, hip, knee, ankle) the normal mechanics are disrupted.  We walk with a limp or we put abnormal forces across our limbs to hide a limp or guard ourselves from pain.  Now the foot and arch can no longer function normally.

The purpose of an orthotic is to intervene in these injured states and try to restore normal mechanics.

Many times, when we hold the heel of the foot straight up and down, the front portion of the foot is not aligned.    Looking straight on, the inner border of the foot can be rotated upward or downward.  The purpose of orthotics is to compensate for this rotation by building up the “floor” to meet the foot.

 

In some orthotics, the floor is built up to meet the foot

In some orthotics, the floor is built up to meet the foot

Another way of accomplishing this same goal is to have a person walk across a computer force plate.  By analyzing areas of high pressure, an orthotic can be precisely made to dissipate and transfer pressure from one area to another.

 

Computer force plates help with other types of orthotics

Computer force plates help with other types of orthotics

Since the foot is the very foundation that we walk on and because all the joints above the foot are affected by the forces of weight bearing, orthotics can be critical for anyone who suffers from an injury.

Malalignment at the foot can cascade upwards

Malalignment at the foot can cascade upwards

In older patients with arthritis, orthotics are effective in relieving foot fatigue.  In athletic individuals, sports activities result in a great deal of movement and pressure on the foot.  Slight imbalances in the foot that aren’t harmful or even detectable under usual circumstances may make one more vulnerable to injury with the extra stress of sports.  By eliminating the need for one’s muscles to compensate for imperceptible imbalances, orthotics can reduce fatigue and promote efficient muscle function to enhance performance.  With enough functional correction, the foot structure can be aligned to give more propulsion and make walking, running and cycling more mechanically efficient.

In plantar fasciitis, orthotics support the arch so it’s less likely to collapse.  In addition, the support along the inner border of the foot helps control pronation of the foot. These two effects take pressure off the plantar fascia and the Achilles tendon to give relief.

In bunions and hammertoes, orthotics will help support the balls of the feet so the tendons across the toes are better balanced.  Hammertoes and bunions occur when the natural balance of the tendons across the toes, which act like the reins of a horse, is lost and one rein starts to over pull compared to the other.

For anyone who has had braces on their teeth, you know how important the retainer is after correction.  The same is true of surgical correction of the feet.  To insure maintenance of the correction and relieve pressure from the surgical site, orthotics are used to protect the time and effort invested in the surgery.

And, like eyeglasses, orthotics are an effective tool in attempting to restore normal function.  The best ones seem to make little immediate difference and only with prolonged use and persistence do we realize many of our previous complaints have lessened or even disappeared.  Like eyeglasses, orthotics are sometimes not covered by insurance and require an initial investment.

The bottom line is this: orthotics can make a difference to people who have been injured.  Orthotics are effective in changing abnormal mechanics.  Normal mechanics of the foot are essential to having normal mechanics of the entire limb.