Biomechanical orthotic insoles Introduction

Before customizing orthotics, we need to fully understand our patients and know their physical conditions objectively and subjectively. Therefore, in addition to talking with the patient and listening to her complaints, we will also perform plantar pressure analysis, posture analysis, and gait analysis on her to let the patient understand the characteristics of her body mechanics when standing and walking, as well as the causes of pain or abnormal posture. When we reach an agreement with the patient, we will proceed to the next step of the orthotic insole customization process. Only by treating the patient as our partner from the beginning can she truly benefit from our orthotic insoles. The same applies to other treatment methods.

Now we will carry out targeted fine measurement according to the results of the examination just now. To better make corrective insoles,We need to measure the following several data： The first are the angle of inversion or eversion of the forefoot and tibial torsion angle. Next we're going to stand up and test the ankle later. Let's start measuring forefoot inversion or eversion data. And then we're going to measure the patient's tibial torsion angle...

Now let's measure the resting position of the calcaneus and the neutral position of the calcaneus. In the patient's foot pressure report ,We can observe that the pressure on her heel is biased towards the medial side.We can infer that she has calcaneal valgus. Now let's measure the angle of her calcaneus valgus to guide us in making the insoles. The calcaneus resting position of the left foot is -9 degrees Because her calcaneus is valgus.So if the calcaneus is varus,We have to write a positive number. Next we're going to measure the neutral position of the calcaneus. When measuring the neutral position of the calcaneus, it is necessary to have patient's cooperation.We observed from the posterior side that after the two line segments basically became a straight line .We measure the angle of the calcaneus at this point. The neutral position of the calcaneus of the left foot is -4 degrees. We must ensure that when we read the data the patient's arch is supporting. We observe that the line segments are in almost a straight line. Otherwise, it may cause certain deviations.

These angles are basically consistent with the report of our gait analysis. Due to the collapse of the transverse arch,Excessive pressure is on the forefoot. When pushing off during walking, the big toe did not land well. Similarly, in the gait report, it was observed that the patient's foot pressure curve had a pressure shift at the very end. Then in this interval between landing and pushing off,The flexibility of the patient's foot arch is also relatively poor. That is to say, when landing and pushing off, the pressure on the ankle joint will also be a bit high. And the pressure distribution is uneven. Then we will refer to the patient's gait analysis, foot pressure analysis report and the angles we measured just now to make the orthotic insoles.

We will first make the angular patch of the forefoot according to the angle just measured. Based on the angle of the patient's forefoot we just measured,we make a support for the lateral side of her forefoot.But in consideration of patient's comfort and adaptability,We start by taking one-half of the degree we measured. For the right foot, we hope to make a degree of 3. But our thicker inclined patch is 4 degrees. Therefore, we can cut off one fourth lengthwise. We divide the entire inclining process into four equal parts. We remove the outermost part. It is equivalent to a 3mm inclined patch which is also 3 degrees. Now, one is 3 degrees and the other is 2 degrees. Right foot and left foot. Just now, we measured that when the calcaneus was in the neutral position, it was -4 degrees on the left and -3 degrees on the right. We can add 1 degree on the left or just leave it alone. Because our semi-made insoles themselves have an inherent varus angle of 4 degrees. That means if her angle doesn't exceed 4 degrees,We can choose not to add any angle. Meanwhile, at the calcaneal resting position, the degree on the left is greater. Therefore, we consider making an arch support on the left. Now the patch that we want to add has been cut out. Next, we will carry out the pasting of the patches.

We will use double-sided tape to stick the patches that were just cut onto the insoles. Check the data again before pasting.Left forefoot we paste the 2-degree patch.Right forefoot We apply a three-degree patch.When pasting for the first time, Don't stick it too tightly so that we can make an adjustment later. If the patient has obvious uncomfortable areas during the preliminary fitting. We can make adjustments to the position of the patch or the degree according to the discomfort of hers. Then fit again.If the patient feels OK,We move on to the next step. Next, polish the sharp parts of the sole and the patches. So that they can better fit the patient's shoes later.

You need two kinds of angle rulers to measure thoes angles. And the small grinding machine we use during the grinding process,to smooth out some of the sharp corners so that the insoles can better fit the patient's shoes. After grinding,We need to use a hot air gun to do a thermoplastic shaping. The purpose of thermoplastic shaping is to make the entire shape of the insole fit better into the patient's shoes. And the insole can fit the patient's foot better, especially the calcaneus and the forefoot.

After the insoles are ground, they can be put into the patients' shoes for further fitting. There are two ways of cutting the size. The first way is to take out the patient's original insoles, compare them with our corrective insoles and make cuts along the outer contour. The second method is that if the patient has no insoles or the insoles cannot be taken out, we ask the patient to step on the corrective insoles barefoot again. After stepping on it, we make marks on the outermost side of the patient's toes. We make an arc-shaped cut according to the marking line just now. It's best to have her original insoles to compare. After cutting, we will grind it a little bit.Smooth the frizzy edges . We'll put them in shoes after cutting. Pay attention to cutting bit by bit . We would rather cutting less than cutting too much. Now we will do the last process: thermal reshaping. When we do the heating reshape . We do this in order to make the orthotic insoles fit the patients' shoes better. We soften the bottom of the insoles by using a hot air gun. After becoming soft, the insoles can be reshaped. Then we put them in and ask the patient to step on them. At the same time we put our feet on a neutral position So the patient can adapt to the angle added to the insoles just now. When doing the thermo reshape process, we blow hot air in circles at the bottom of the insoles. The time of our hot air blowing is 15-20 seconds. Until you observe the text on the sole becomes foamed and soft.

Through the initial foot pressure, posture and gait testing We know that the foot pressure of the patient is biased towards the hindfoot. Then the transverse arch of the foot collapses. Both feet land on the lateral side. The hallux valgus of both feet is severe. In combination with her posture, Her entire pelvis is anterior and with lateral tilt, under this risk she could also have scoliosis. So let's go back to the gait report: As we mentioned just now, When her feet land and push off, her ability to extend the forefoot forward is relatively weak. That is to say, her forefoot is in a stiff and varus state. Then both calcaneus are valgus. When she walks, the state of her feet is not stable. And she has poor feet control. At the same time, Her feet are asymmetrical. The right foot is in a toe-out and the left foot is toe-in. This is related to the patient's usual habits of crossing legs and sitting crookedly. After that, we conducted precise measurements of the angles of her feet. We got the varus angel of her foreoot. Angles of calcaneus resting position and neutral position. Our treatment method is adding angles on the lateral side of forefoot. The purpose of doing this is to enable her toes to touch the ground more fully when standing. The second purpose is that the forefoot can exert a greater push-off ability. For the hindfoot, we increased the varus angle by one degree on the left. Because our semi-made insoles themselves have a 4-degree calcaneal varus angle. Therefore, for this patient, only one degree needs to be added on the left. It's also okay not to add. But since the patient is fitting the insole for the first time. It's very likely that she won't adapt to the orthotic insoles at the beginning. We can wait until the patient has worn the current insoles for 3 to 4 weeks. We'll ask her to come back and do a new assessment. Then we'll see if it's necessary to add a supporting attachment to her anterior arch at that time.