Orthotics or Sensory inserts: Support vs. Sense
One of the main treatment tenets that we rest our program on is our ability and desire to restore and maximize normal upright orientation and “alignment” so the need for compensatory movement patterns is limited. One of the big pieces of our PRIME program is ensuring that upright appropriate foot and ankle position and sense is achieved.
In general your brain utilizes the input coming from the sensory receptors on the bottom of the foot (primarily just when standing still) as well as the position sense receptors of the ankle joint and ligaments (both with static stance and with movement) to help figure out where the body is in relation to the ground and foot. This is necessary to maintain balance and is constantly challenged as we move, walk, and explore different surfaces. How we stay balanced on uneven ground is quite an amazing and complex activity. If you research robotics one of the hardest issues they face is figuring out how to keep 2 legged robots balanced when they “walk” on uneven surfaces. The feedback loops required for this are intricate and complex. When we function in an asymmetrical state for long periods of time or have injuries to the ankle or foot that feedback loop can get stuck or biased in a non-normal pattern. This can make it challenging for us to stay “balanced” or learn new movement patterns when we get upright on our feet if not addressed. Restoring appropriate and correct sense and mechanics of the foot and ankle therefore is a main issue in order to progress with upright activity.
Examples of some “Good” shoes that we like to use with our patients.
Lately with our PRIME patients we have been exploring new ways to help fine-tune and maximize this input from the floor up. An appropriate shoe such as the New Balance 1080 V7 or Asics Foundation has great qualities to help sense heel and arch support, as well as cushion and guidance for walking and each has their benefit for certain patients. However, everyone’s foot is slightly different in what they sense, don’t sense, or need to sense. Just putting a shoe on, while important, is not a very individualized treatment option. We have a wonderful podiatrist in Dr. Paul Coffin who makes some wonderful orthotics. He understands and appreciates postural patterns, asymmetry, and the influence foot and ankle biomechanics has on the entire body. His “PRI orthotics” are essential in a lot of cases, especially when structural or physiological limitations of the foot and/or ankle exist. The way his orthotics are manufactured allows them to be easily modified to achieve different biomechanical goals and sensory inputs. Unfortunately, however it takes him some time to manufacture his orthotic so they are not available the first week we see someone in PRIME. What this means is that we are not able to objectively ensure they do what we want them to do. For some patients this is very important. What we want to be able to do is tell Dr. Coffin what each particular patient needs to sense and feel and what happens objectively to the rest of their body *before* they see him for impressions.
“Any different sense will immediately have an impact on movement patterns and gait whether its on the foot, between the teeth, or in front of the eyes. ”
We like to ensure that what we think each patient needs is actually what they need by testing and retesting objective measures of mobility and functional performance which is reinforced by what the patient is subjectively telling us. Any different sense will immediately have an impact on movement patterns and gait whether its on the foot, between the teeth, or in front of the eyes. In the case of feet what we have started using is thin pieces of cushioned poron (a foam-like substance that comes in sheets or pads), that we call sensory inserts, placed strategically underneath the liner of each shoe to direct sensory awareness of that foot and ankle at specific points throughout the gait cycle depending on the needs of each patient and each foot separately.
Some examples of how this could be used are: The ability to sense pronation of the subtalar joint through arch contact is necessary at mid-stance for glute activation. The ability to sense toe off of the first ray at late stance (while same side fingers are moving forward) is necessary for rotation of the upper trunk to the opposite direction. The ability to sense ankle eversion and “wobble” in mid-stance is necessary for proper stability at the hip joint.
Example of PRI orthotic from Dr Coffin.
Example of potential sensory insert set up for a patient directly placed on shoe liner.
By assessing what each patient needs, whether support or sense, and maximizing the appropriate input they receive from the ground up, we have a valuable tool to assist each patient in integrating upright activity. Utilizing sensory inserts in shoes allows us to observe and test the needs of each patient and how they respond and fine tune it to each patient. This information, if needed, can be relayed to Dr. Coffin to be built into a custom orthotic or in some cases as they integrate these new movement patterns will not need to be addressed and just appropriate footwear or a traditional PRI orthotic will be enough. This is just one way we are trying to improve and maximize what our interventions can do to assist each and every patient as an individual.
If you have specific questions on how our program may benefit you please do not hesitate to contact us at firstname.lastname@example.org or at 402-975-8533.