Custom orthotics can contain a multitude of features and modifications to facilitate effective treatment. With this in mind, this author reviews pertinent decision-making pathways for the optimal orthotic to help address conditions of the rearfoot.
Custom foot orthoses are a common and often preferred treatment method in the management of rearfoot pathology. Successful management of these conditions requires a complete understanding of multifactorial etiologies and patient manifestations.
With the exception of trauma and systemic disease with manifestation in the rearfoot, pathomechanics are likely the cause of the patient’s presenting symptoms. We must focus on the movement pattern of the foot, ankle, leg, core and superstructure in order to effectively manage these concerns. Indeed, one must have a full understanding of the patient’s mechanics and movement patterns in order to identify the specific etiology or etiologies. This enables us to provide effective treatment that reduces or eliminates symptoms and allows the patient full and better function.
Keep in mind that if you load a dysfunction, the dysfunction will worsen. Human biomechanics and pathomechanics are as unique to each individual as a fingerprint. For example, no two patients with heel pain will exhibit the same function, range of motion, flexibility and movement patterns. Repetitive loading of a weak structure will further weaken the structure. Continued load to an unstable segment or joint will increase instability.
As we fabricate custom foot orthoses for our patients, we must keep in mind our goal: to facilitate optimal functional and mechanical capabilities. Ideally, we would like the foot and body to function within the individual’s unique stable and optimal alignment. We are looking to minimize instability and pathologic movement patterns. In turn, we also aim to eliminate pathological changes in directional movement.
Essential Insights For The Physical Examination
In the patient examination, we obviously need to go beyond the chief complaint. Obtain a thorough patient history, including all previous or current orthopedic issues and injuries. The examination and workup must be thorough enough to determine where problematic movement is coming from and why this is occurring. Look at the results of the static and active biomechanical examination and gait analysis. Note how they relate and what you are seeing about the patient’s range of motion, flexibility and movement. How does this correlate with the presenting symptomatology?
I initially perform an off-weightbearing examination to evaluate range of motion and flexibility of the lower extremity and superstructure. This portion of my overall examination is fairly succinct. I think we all must develop our own version of the biomechanical examination that best gives us the information that we need. Of note, the joints with the expected greatest range of motion are the talonavicular and calcaneocuboid joints.
However, I conduct the majority of the physical examination with the patient weightbearing. I examine the patient both in stance and under stress. I also assess the patient in all planes in order to see how the structure responds when I place it under physiological stress. This allows one to evaluate stance and movement, viewing the patient from anterior, posterior and side views. I induce these stresses by having the patient perform various exercises such as single leg stance, single leg balance, squats, lunges and medial/lateral movement. The use of video on smartphones, particularly in slow motion, greatly enhances our ability to evaluate patients. If I have a patient who is athletic, I will also take him or her outside of my office, and have the patient run so I can film this as well.
One of my treatment goals is to make my patient as symmetrical in his or her function as I possibly can. Contributing factors for asymmetry may include anatomical, functional, timing-related causes or a combination of causes. The torque and stress generated by asymmetrically functioning limbs is often exhibited within the symptom complex.
For example, an anatomical or functional limb length difference can be a major factor in heel pain. Given that many of our patients have unilateral complaints, there must be some level of asymmetry that exists or their concerns would more likely be bilateral. One should examine for limb length discrepancy and compensate in the orthotic for even small limb length differences if they seem contributory to the issue that the patient is experiencing. Remember, loading a dysfunction will make the problem worse.
I also use an in-office treadmill and the office hallway for evaluation of gait. We film slow-motion video in all three planes. Smartphones and smart devices equipped with this type of video capability makes this easy to accomplish and allows for thorough review of the footage. If the video is to be incorporated into the patient chart, HIPAA compliance is necessary.
Detailed gait analysis will yield tremendous information. Hypermobility, rigidity, excessive or limited range of motion and flexibility will be apparent. If you notice issues with mobility or strength, refer the patient to a good physical therapist for intervention. Evaluate the patient in all planes and evaluate the ankle, knee and hip for their respective ranges of motion and relationships to each other as well as trunk position and function. For athletic patients, it is essential to view them in their sport. Running form can be dramatically different than that of walking. If you are unable to view the patient in sport, ask him or her to have a friend or parent film his or her sport activity.
Analyzing The Data And Obtaining An Accurate Foot Impression
Another important aspect of successful orthotic therapy is capturing a proper impression of the feet. Capturing the foot accurately is essential to reaching our treatment goals. Off-weightbearing neutral position impressions remains the standard for obtaining a precise model of the foot. This technique is also my personal preference, and I usually will obtain these impressions with the patient prone. Dorsiflexing the hallux while taking the impression will plantarflex the first metatarsal.
After completing a biomechanical exam, performing gait analysis and obtaining appropriate X-rays of the patient’s feet, one can determine if there is a logical path from those findings to the patient’s symptoms. If I cannot immediately see the correlation or connection, I go back to the beginning and re-evaluate what I may have missed. Make certain you understand how the unique mechanics and movement pattern of this particular patient are creating the symptomatology he or she is experiencing. For instance, first MPJ pathomechanics are often implicated in rearfoot pain.
What You Need To Know About Choosing The Best Orthotic Features
Orthotic materials. This should be based on the patient’s weight and the type of control you feel is necessary for the patient. The more firm and thick the material is, the more rigid the device. I tend to favor the semi-flexible to semi-rigid range for my patients. For patients over the age of 30, I am increasingly using a semi-flexible device. Elimination of pronation with an orthotic is not possible and in my experience, there is no evidence that pronation is a cause of injury. Semi-flexible devices can work to enhance motion and have a better comfort level for the patient. For these instances, I am partial to the new lightweight nylon composite devices. Comfort contributes to adherence and patient adherence is necessary to eliminate pain.
Orthotic width. The next step is determining the width of the device. The wider the device, the more contact it has with the foot. This results in a greater ability to direct the foot into a better functional movement pattern and slow down pathological movement patterns. Optimally, I like to have a full-width device. A full-width device will fit primarily in sneakers, wider boots and multiple styles of men’s casual shoes. The greater the width of the device, the more contact with the foot and the greater the ability of the device to influence foot movement. As the patient’s shoe gear moves in a more fashionable direction, it will likely be necessary to narrow the width of the device. A wide device will not fit in a narrow shoe. In my opinion, the most successful device is one that can be worn 80 percent of a patient’s weightbearing time. As shoes and devices become narrower, one must explain to the patient that there is a resulting loss of correction with the device.
Heel cups. The depth of the heel cup will also dictate the amount of control of the device. Deeper heel cups require shoes with a deeper heel counter but do allow for greater control of the rearfoot. A deep heel seat also allows for incorporation of a heel skive or heel pads. For severely symptomatic patients with flat foot types, a deep or extra-deep heel cup is extremely beneficial in controlling excessive subtalar joint motion.
Flanges and arch platforms. The use of flanges can also help with more severe rearfoot pathology. Flanges can be medial or lateral. Medial flanges can be low, medium or high height, and are directly related to the amount of influence we are looking to introduce to the foot. Arch platforms or mini-arch platforms can also provide additional medial support for the foot. To create an arch platform, one can widen the medial aspect of the device in the arch area to provide more medial foot contact. If shoe gear does not allow for a full arch platform, a mini-arch platform (a shorter, less aggressive version of the arch platform) can also be very helpful in providing extra influence into the foot without the irritation-related problems that flanges can sometimes cause.
Skives and posts. The use of a medial heel skive places additional correction inside the medial aspect of the heel cup of the device to influence the calcaneus. A Kirby skive involves incorporating this additional correction into the shell of the device. With regard to posting, I only utilize an intrinsic forefoot post. Intrinsic forefoot posting will guide the metatarsals from their origin and allow the metatarsals to more properly contact the ground. Extrinsic forefoot posts exert an abrupt force against the forefoot just prior to metatarsal head ground contact. I have found it is much better to use an intrinsic post to guide the metatarsals to the ground along their entire movement pattern, allowing them to achieve optimal positioning.
Wedges and first metatarsal cutouts. Kinetic wedges and first metatarsal cutouts are designed to allow the first metatarsal head to purchase the ground at the correct time in the gait cycle. One can alternately achieve this goal by dorsiflexing the hallux while taking impressions of the feet, This subsequently plantarflexes the first metatarsal head. It is essential to get the first metatarsal head on the ground and in a stable configuration at the correct point in the gait cycle. If the first metatarsal is dorsiflexed, the body will continue to move medially in order to get the first metatarsal head onto the ground. This prolonged and increased pronation is particularly problematic, leading to a multitude of symptoms. I advise everyone to try different sizes of first metatarsal cutouts and kinetic wedges to determine what works best in his or her hands. The first metatarsal head must be able to maintain a stable position against the ground to allow the transition into push-off. Adequate range of motion at the joint is also essential to propulsion. Deficiencies in either of these functions can contribute to rearfoot pathology.
Arch reinforcement. Arch reinforcement can be a useful tool for several reasons. First, it adds more medial stability and control to the device. This can be very helpful when using a semi-flexible shell. Arch reinforcement is also beneficial for patients in jumping and high-impact sports as it allows him or her to land on a shell that has some ability to flex underneath the foot. This allows for a softer landing while the arch reinforcement gives the necessary element of support.
Heel, metatarsal, scaphoid and other pads. Clinicians may utilize heel pads to offload a particularly painful area and supplement any loss of the plantar rearfoot fat pad. We can employ metatarsal pads for a multitude of reasons, whether it is addressing metatarsalgia, neuromas and/or aiding in relative plantarflexion of the first metatarsal head. These modifications are particularly useful in a dress-style device, which may prohibit the space required for a reverse Morton’s extension.
Scaphoid pads can be very beneficial for a patient with a cavus foot type. Many patients with a rigid cavus foot will not tolerate an orthotic with minimal arch fill. As we drop the arch fill down, the use of a soft scaphoid pad can provide support without causing irritation. With the exception of patients with cavus foot, I always utilize a minimal arch fill in my devices, creating a tighter fit of the orthosis to the foot. Minimal arch fill provides greater contact between the foot the device, thus promoting a greater ability of the device to influence foot movement.
Other useful additions to orthotics include cuboid pads that one would place in the cuboid groove in an effort to get the peroneus longus muscle to fire sooner, hopefully bringing the first metatarsal head down onto the ground and stabilizing it.
Heel lifts. Heel lifts are another essential element in successful orthotic treatment. I will use a heel lift to address a limb length discrepancy. Additionally, I will use heel lifts to address limitations in ankle dorsiflexion or hamstring flexibility. When both issues are present, I will use bilateral heel lifts of different heights with the higher lift on the short limb and the lesser lift on the longer limb. I will also use combination heel lifts of PPT and cork with limited ankle dorsiflexion. The PPT aspect allows for a lightly longer heel contact time and the cork will act as a traditional heel lift. The influence of equinus and lack of adequate ground contact time in gait can be factors in a multitude of rearfoot pathology.
Offloading cutouts and Morton’s extensions. Cutouts in areas of porokeratoma or ulceration can also be very useful. In those cases, I will generally use a full-length 1/8 inch or 3/16 inch padding on the device and cut out in the area necessary, filling in the void with 1/16 inch of a soft material. I will also fill in kinetic wedges and first metatarsal cutouts with a similar thinner padding. I also frequently utilize reverse Morton’s extensions in an effort to get the first metatarsal head onto the ground and stable at the proper point in the gait cycle.
Top covers. Top cover choice is based on the personal preference of the patient and is also dependent upon the activities for which the patient will use the device and what conditions to which the device will be subjected. I personally like softer top covers but the patient has to be aware that they will have a relatively short lifespan.
Although this article focuses on orthotic pearls in the management of rearfoot pathology, one can and should apply the same principles to any condition for which we are fabricating custom foot orthoses. A thorough history, detailed biomechanical evaluation, gait analysis, precise impressions of the foot, a quality lab and a solid rehabilitation protocol are the essential pieces of a successful treatment plan, including fabrication of a successful orthotic device. There are no cookie-cutter prescriptions for rearfoot pathology, or any foot and ankle pathology. In my experience, it is only in addressing the unique comprehensive biomechanics of each patient that successful treatment occurs.
Dr. Langone is a Diplomate of the American Board of Podiatric Medicine and a Distinguished Fellow of the National Board of Practitioners. She is a Fellow and Past President of the American Academy of Podiatric Sports Medicine, Lead Clinical Director of the New York State Fit Feet program for Special Olympics International and a Co-Vice President of the American Association For Women Podiatrists. Dr. Langone is in private practice in Southampton, NY.