Part of the Assurance Series - Orthotics, Insoles or Arch Supports
Your Doctor has recommended custom-made orthotics as part of your treatment plan. Custom-made orthotics are a functional biomechanical device for specific foot conditions and long-term wear. They require a prescription and a healthcare evaluation.
Prescription orthotics ARE NOT ARCH SUPPORTS or OVER THE COUNTER INSOLES. Over-the-counter (OTC) insoles or inserts lack the customization of a prescription orthotic. They only address structural and functional foot abnormalities in a very general sense and are available off the shelf in many retail sites, pharmacies, sports and fitness stores. Minor problems, foot fatigue, cushioning bony prominences and areas of pressure may be improved by OTC insoles/inserts whereas more significant issues need to be addressed with a prescription orthotic. All the above symptoms can relate to an underlying problem that will persist and often benefits from a custom orthotic. Prescription orthotics may be combined with other treatment modalities or surgical interventions and are customized according to age and diagnostic need.
To get a better understanding of OTC inserts or insoles vs the benefits of a custom-made prescription orthotic consult with your podiatric physician who can advise you where to begin and work with a qualified retailer if an OTC device is a good starting point for you.
Care vs Confusion
Mass market commercialization is blurring the lines between over-the-counter inserts/arch supports and custom-made orthoses. All orthotics are not created equal and outcomes vary. It's important to know whether an OTC or custom-made orthotic will successfully improve your symptoms. Many people begin with a trial OTC and then seek professional care if it doesn't work. When choosing a device based on incorrect information, an incorrect diagnosis or improper orthotic fabrication the outcome is problematic.
With the right prescription and instruction on how to use them, custom foot orthotics have been a proven treatment option to control structural abnormalities, relieve pain, prevent the progression of disease and the need for surgery. Prescription orthotics are no different than prescribed medication. Prescribing the wrong medication or in this case, the wrong orthotic complicates treatment and compromises patient care.
As a board certified foot and ankle surgeon with 46 years experience practicing podiatric and lower extremity sports medicine, I know the value of prescription orthotics when used properly. I know they are a significant non-invasive treatment modality that have helped countless numbers of patients in my practice and improved the quality of foot and ankle care around the globe.
The Process
Virtual doctor evaluations, in-store pressure measurement systems with “foot mapping technology" and foam molds for fabrication of “orthotics" seem to offer a quick fix to your foot problems but there is an inherent limitation in the process if there is not a definitive diagnosis or identification of the root cause of the problem. The structural and functional anatomy of the foot, ankle, lower extremity and human body and the biomechanical implications of pathological abnormalities and systemic diseases that the patient presents are significant to achieving a successful treatment outcome. Gait and body alignment need to be evaluated so as not to compromise weight bearing and asymmetries of muscle tension and strength and range of motion affecting soft tissues, joints, and organ systems throughout the body. This involves a hands-on approach to establish the patient's range of motion, neutral foot position, specific patient biomechanics, rotational forces, existing foot pathology and injury history. Patients with diabetes and plantar ulceration are at risk for complications associated with these conditions. In these cases physician directed treatment and specialized orthotics as opposed to generic off-the-shelf OTC inserts/insoles are advised.
The Biomechanical Exam
Biomechanics is the study of the mechanical properties of the human body. A podiatric biomechanical exam is an assessment related to the movement, structure and mechanics of the human body with attention to the lower extremities, foot and ankle. Postural assessment, limb length equality, muscle testing, gait and range of motion are evaluated. Clinical measurements of the lower extremity are made using specialized instruments and your practitioner's expertise to confirm findings and recognize abnormal structural conditions which effect the way you walk.
A biomechanical exam is useful in the evaluation of foot and ankle misalignment and pathology as well as optimal foot health and posture and pain in the ankles, legs, knees, hips or feet. It includes
Patient history and physical exam.
Gait and posture analysis.
Diagnostic x-rays and related imaging.
Measurements and findings.
Foot Impressions -Plaster, Foam or CAD/CAM
Obtaining an accurate foot impression used to make a custom orthotic is crucial to the orthotic’s ultimate success and treatment outcomes. Achieving that impression can be done using a computer scan, a foam block impression or casting to obtain a positive plaster mold of the foot. The gold standard has always been plaster casts and they continue to remain the preference because a plaster cast provides an impression of the patient’s foot taken with the subtalar joint in a neutral position, non-weight bearing, so that the appropriate prescribed correction can be made.
The reliability of plaster casting depends on a skill set that is not typically available at the retail level. Proper training and experience in the medical diagnosis and treatment of the foot and ankle with academic credentialing should be considered when casting for orthotics.
For CAD/CAM the recognized specifics for computerized digital technology in the fabrication of a custom foot orthosis is that the laser or scanning system must create a three-dimensional foot image from points directly from the foot itself or from a direct model of the foot. The scanning technology must not use computer algorithms, extrapolations or interpretations to calculate shapes and contours from two-dimensional pressure readings (1). Depending on the system the level of "customization" is generated based on an existing orthotic in a digital library that closely matches the patient's foot. Improvements in image processing algorithms have enabled more accurate model reconstruction. However experts in the field advise that reliance on these 3D technologies requires more research within clinical settings to validate it as a prime method for orthotic impressions (2).
A foam box impression requires the foot to be placed on a foam surface in the middle of a foam block while the patient is standing or a technician slowly guides and presses the foot into the foam. The foot must be properly placed in the molding media. On-line retailers will often send an impression kit with video instructions on how to create a biomechanical impression of your feet.
Orthotic Fabrication
The making of a prescription orthotics is a 23 step process fabricated by specialized technicians according to your Doctor's prescription. Typically the process of making your orthotics takes approximately 2 weeks. Orthotics are made from a variety of materials depending on their prescribed need.
Functional orthotics are designed to prevent abnormal movement or position of the foot. Because they provide foot control, they are made from hard orthotic materials like polypropylene (a type of plastic) and carbon graphite. Functional orthotics are useful to treat foot pain caused by abnormal motion.
Accommodative orthotics provide protection and relieve pressure by cushioning and padding a painful or injured area. They are made from softer and less rigid materials such as EVAs (Ethylene Vinyl Acetates), neoprene (a type of rubber), and plastazote (a type of foam). Common indications include diabetic foot ulcerations, painful calluses and peripheral neuropathy.
Collaboration with Shoe Stores - A Circle of Care
Clinicians who prescribe orthotics will need to assess the patient’s current shoes and recommend the style of shoe best adapted to orthotic wear. The patient’s choice of shoe needs to be adaptable to a foot orthotic device. Here is where a relationship between physicians and professionally trained retail store sales staff can enhance patient outcomes by guiding customers towards the appropriate footwear in the correct size, with expert fittings in styles patients feel comfortable in. With a fashionable fit patients are more likely to wear their orthotics on a regular basis with positive outcomes. Healthcare professionals and retailers can work together to help find the best fit.
Foot capture/Casting /Scanning-Pedorthic Association of Canada 2018
Silva R, Silva B, Fernandes C, Morouço P, Alves N, Veloso A. A Review on 3D Scanners Studies for Producing Customized Orthoses. Sensors (Basel). 2024 Feb 20;24(5):1373. doi: 10.3390/s24051373. PMID: 38474907; PMCID: PMC10935386.