Replacement insoles come in many forms and serve different functions to different people: some use them because they feel good and some for added support. Others use them to relieve pain in their feet, knees, hips or back or because a friend, doctor or physical therapist recommended them. All are good reasons and most people probably should have more support and cushion in their shoes.

The human foot is an amazing structure, composed of some 27 bones that make up 33 joints and controlled by 20 some muscles and tendons. During each step it performs a seemingly simple movement through a series of intricate motions as it changes from a flexible structure that conforms to the surface upon which it is walking or running, to a rigid weight bearing structure that allows the body to be propelled efficiently forward.

When in contact with the ground the foot rolls inward along the arch (pronation) then reverses course and rolls outward (supination). This cycle of pronation and supination is normal and needs to occur in order for the foot (and leg) to function most efficiently. Pronation is necessary for accommodation and shock absorption and supination for leverage to propel the body forward. And as the first point of contact with the ground, the foot serves as the foundation of movement for the knee, pelvis and even the back.

Too much or too little pronation or supination can lead to a chain reaction of dysfunctional movements including, but not limited to, excessive internal rotation of the shin bone and thigh which may ultimately increase the stress on the foot, knee, pelvis and spine and the muscles that control these movements. Excessive movement can lead to excessive stress on the involved tissues of the foot and lower extremity and may ultimately result in injury. Repetitive stress has been associated with and linked to various pain syndromes including, plantar fasciitis, posterior tibialis tendonitis, Achilles tendonitis, “shin splints”, patellofemoral pain, and iliotibial band friction syndrome.

A good pair of shoes is the first line of defense not only for comfort but also in reducing unwanted stress and promoting normal foot function. But the shoe alone is often not enough and this is where a replacement insole comes into play. The insole is the foot’s point of contact with the shoe and what your foot actually sits on and feels. Standard factory footbeds may be comfortable at first, but they are typically flat, unsupportive and quickly wear out, no matter the quality of the shoe. It’s like driving a high-end sports car with great suspension and tires, but the seat is a towel laid on top of a hard park bench. Not very comfortable for the driver! Similar to the way a bucket seat conforms to your thighs, hips and low back, a quality replacement insole will conform to the contours of your foot while providing support and shock absorbing comfort and improving the fit of the shoe. 

Support

Proper support helps control excessive and undue stress in the tissues of the foot and lower extremity. Proper support promotes more efficient movement patterns and helps keep the repetitive stress within an ‘optimal’ (injury free) zone. Proper support mitigates the amount of force on the bottom of the foot, improves pressure distribution, and enhances proprioceptive response and balance.

Unfortunately, support is often associated with ‘hard’ and ‘uncomfortable’ – but nobody wants to wear something that’s uncomfortable! It doesn’t matter if it’s good for you or not, you’re not going to use it if it hurts. A quality replacement insole should provide firm but comfortable support under the arch of the foot as it sits inside the shoe. Even those that prefer “minimalist” shoes can benefit from a good insole without compromising weight or the feeling of the minimalist experience – most feet still need some measure of enhanced support to function most efficiently, no matter the shoe type. 

Comfort

Comfort is a subjective term, but when it comes to footwear, insoles or orthotics, comfort is typically enhanced with shock absorption. Shock absorption is important for any activity whether during athletics or just standing. According to the American Academy of Orthopedic Surgeons, your feet can experience up to 1 million pounds of pressure in a day when walking and up to 5 times body weight with each step when running. Shock absorption works with support to reduce stress on the feet, knees, hips, and back and similar to support helps keep this stress within that optimal, healthy, injury-free zone. Shock absorption ultimately and typically equates to greater comfort.

Remember, the insole of a shoe is the part of the shoe your foot actually contacts and feels. Comfort is important and the function of cushioning material is to improve shock absorption and force distribution to help reduce the impact associated with weight bearing. Keep in mind, too much cushion and the support is lost, too little and it’s uncomfortable. A quality replacement insole should strike a balance between the two.

Improved Performance - Really?

Can a shoe insole improve performance? Performance involves more than just foot comfort and support. An insole, by itself, will not improve performance just like shoes with a rocker bottom, by themselves, will not produce ‘buns of steel’. There is no such thing as a “magic pill” or a passive path to improved performance. Performance in ANY skill requires proper training and dedication.

However, in any sport or activity that requires you to be on your feet, activity-specific footwear and fit are critical and the insole can go a long way in supplementing any given shoe with appropriate support, comfort, and fit. Just as your shoe is your connection with the ground, the insole is the connection between your foot and the shoe and both assist in providing the leverage and energy transfer needed for efficient movement of the rest of your body. Combined with an appropriate training program, a properly fitted shoe will improve performance.

Proper fit also improves the sensory input through the foot, enhancing the proprioceptive response of the lower extremity. This allows for more coordinated movement and balance. Proper shoe fit also reduces excessive movement within the shoe, which will help reduce friction and blisters. Talk to any athlete who performs on their feet and they will tell you that proper shoe fit, support, and comfort plays a big role in their performance.

Injury Prevention - Really?

Combine support with shock absorbing comfort and the result is less stress in the entire lower extremity and back. A quality insole used in conjunction with an appropriate conditioning program that avoids overuse and includes adequate recovery can help reduce the chance of injury. A quality insole or custom orthotic will not necessarily prevent injury by themselves but can make a significant difference in comfort and mechanics and help reduce many of the pain syndromes associated with faulty foot mechanics and high impact activities.

Other variables that influence faulty movement patterns and lead to injury include level of fitness, training schedule, technique, and equipment, among others. These variables should be addressed by a qualified professional before and certainly after an inflammatory or painful condition presents itself so that an appropriate plan of action can be made.

Cost

The cost of a quality replacement insole can start at $35 and a custom orthotic $150 to $400 or more. Research has demonstrated that replacement insoles offer similar benefits as custom orthotics for the relief of common foot and lower extremity pain syndromes, such as plantar fasciitis, for significant savings. This is not to say that custom orthotics are not sometimes necessary. Chronic pain, leg length discrepancies, foot deformities, circulatory problems, and other medical conditions may require custom orthotics and need to be addressed by a qualified medical professional.

 Not all Replacement Insoles are Created Equal

Whatever the reason for purchasing an insole, whether for comfort, support, better fit or pain relief, it is important to know that not all replacement insoles are created equal and expense varies as much as the variety. Quality, durability, and type of material vary widely. Many claim to offer “max support” but in reality offer no support at all. Others are comfortable but the material compresses and loses its cushioning after just a few weeks.

Not to get too technical, but for cushioning, closed cell polyurethane retains its cushioning properties much longer than EVA (ethylene vinyl acetate) or open cell polyurethane. As for support, look for an insole that utilizes a hard shell such as nylon or polypropylene. A simple test before putting it in your shoe: put the insole on the ground and push down on the arch with your finger and feel how easy or difficult it is to compresses towards the ground.

How do you know which brand is right for you? Talk to your friends and family, see what they are using and why. Talk to a doctor, physical therapist or another qualified healthcare professional, have your feet and gait evaluated and see what they recommend. Then go to a reputable shoe store and try them on and see how they feel to you.

If comfort is what you’re looking for are they actually comfortable? Do they feel good under the heel and ball of the foot? If support is what you’re looking for do you actually feel support and if so where? Is it under the arch, the middle of the arch, the edge of the arch, too much towards the heel, the toe? Try on different sizes of the same brand and try different brands. Keep in mind that if it is a support insole you’re looking for it may take a few hours or a few days to accommodate. But even a “supportive” insole can and should ultimately be comfortable.

Who Will Benefit?

Anyone who spends time on their feet or participates in sports, from runners, hikers, walkers, and golfers to busy executives or service personnel can benefit from a good replacement insole. Shoes are the first line of defense for comfort and support, but the insole is what your foot contacts and feels. A quality insole will provide lasting comfort and support and can help alleviate and protect against some of the more common pain syndromes associated with repetitive impact activities and excessive pronation including, but not limited to, plantar fasciitis, Achilles tendonitis, “shin splints”, patellofemoral pain, and iliotibial band friction syndrome.

 

Partial list of references

 

Christensen, K Clinical Chiropractic Biomechanics. Dubuque: Foot Levelers College Division, 1986.

Howard J. Dananberg, DPM, Michelle Guilano, DPM “Chronic Low-Back Pain and Its Response to Custom-Made Foot Orthoses”

Kirby, Kevin, DPM http://www.kirbypodiatry.com/document_disorders.cfm?ID=148

Kevin A. Kirby, Simon K. Spooner, Paul R. Scherer and John M. Schuberth Foot Ankle Spec 2012 5: 334 originally published online 10 September 2012 Foot Orthoses DOI: 10.1177/1938640012458900 http://fas.sagepub.com/content/5/5/334

Kirby, Kevin DPM Chapter 2: Evolution of Orthoses in Sports from Athletic Footwear and Orthoses in Sports Medicine Werd, MB; Knight, E.L. (Eds) 2010

McPoil TG, Hunt GC. Evaluation and management of foot and ankle disorders: Present problems and future directions. J Orthop Sports Phys Ther. 1995; 21(6):381-388.

Payne, Craig Do Foot Orthotics Really Work? runningresearchjunkie.com, February 13, 2013

Pfeffer GB, “The Conservative Management of Plantar Fasciitis” University of California, San Francisco, CA.

Renstrom P, Kannus P (1993) Injuries to the foot and ankle. In: DeLee JC, Drez D (eds) Orthopedic Sports Medicine, vol.2, pp 1705-67. Philadelphia: WB Saunders

Renstrom, Pers, Peterson, Lars (2001) Foot. In: Sports Injuries their prevention and treatment 3rd ed. Pp393-427. Human Kinetics, United States

Sobel E, Levity S T,Caselli MA Division of Orthopedic Sciences, New York College of Podiatric Medicine The Journal of American Podiatric Medicine May 1999, Vol. 94 Number 6 542-549 2004

Sobel E, Levity S T, Caselli MA Division of Orthopedic Sciences, New York College of Podiatric Medicine The Journal of American Podiatric Medicine May 1999, Vol. 94 Number 6 542-549 2004

Stude, DE, Brink, DK, Effects of nine holes of simulated golf and orthotic intervention on balance and proprioception in experienced golfers. J Manipulative Physiol. Ther. 1997 Nov-Dec; 20(9): 590-601.