Insoles

Workflow

In this section, I describe the process I followed to create the support for my feet. Troy mentioned that it was crucial to analyze my footprint at different times of the day, as changes in posture and weight distribution can affect ergonomics. He also emphasized the importance of a detailed analysis to prevent worsening the issue instead of solving it. Because of this, I decided to approach the problem in multiple stages.

Scanning

First, I scanned my footprint while standing with my full body weight, following these steps:

• Created a mold of my foot using foam, applying my weight for 5 minutes.

• Coated the cavity with white glue (Resistol) to prevent the plaster from seeping through when poured, let the pieces dry for 24 hours.

• I prepared the plaster mixture with a 100% plaster to 80% water ratio, poured it into the cavities, and let it dry for 48 hours.

• Scanned the molds using the CR-Scan Ferret 3D Scanner and cleaned up the point cloud in the software provided by the same manufacturer.

Analizing

Using the 3D design of my foot soles, captured while applying pressure with my own body, I conducted a foot pressure test with the Gensoles project. This test allowed me to observe the difference in pressure between my left and right foot. While I had some initial assumptions, I decided that the best course of action was to consult the orthopedic specialist who had previously treated me. His analysis would help assess my current condition, my progress or setbacks, and his perspective on my workflow for this project.

With the help of a more professional diagnosis, my doctor informed me that the test I had previously undergone was a full-body densitometry. I repeated this study, and the results showed that my spine had improved. However, he recommended that I exercise more due to the long hours I spend sitting at the computer. My hip still had some residual issues that could be improved with physical therapy and anti-inflammatory medication.

Regarding the insole, he specified the key adjustments needed to correct my gait:

• 12 mm longitudinal arch to improve arch support.

• 2 mm external wedge to correct joint alignment (my heel has a slight curvature because I put more weight on the outer part of my foot). In my foot pressure test, it is evident that the red marking on my right foot is less evenly distributed compared to my left foot. This is due to the pressure imbalance I mentioned earlier.

• 5 mm heel lift for my right foot—for which I am grateful I consulted a specialist, as an up-to-date diagnosis is crucial. This adjustment is particularly important because, without this assessment, I might have mistakenly increased my right foot lift to 1 cm instead of the 5 mm it actually needs, potentially worsening the issue.

• In contrast, my left foot distributes pressure more evenly.

I was also informed that my insole can be considered an orthotic that helps with my sacral condition. The imbalance I have directly affects this bone, which is a triangular structure at the base of the spine that connects the spine to the pelvis.

When a person has one leg shorter than the other, the sacrum and pelvis can tilt or rotate, leading to postural imbalance, joint wear, and lower back or sacroiliac pain. Because of this, professional supervision is essential. Therefore, I will be closely monitoring the insole I created to ensure its effectiveness.

Generic insoles

With the intention of further analyzing my foot mechanics, I continued examining common shoes and insoles. These often alter the natural position of the feet—in general, our feet adapt to the shape of the shoe when, ideally, it should be the other way around.

In this image, the following points can be observed:

• A. Wear marks in the toe area because the insole is larger than it should be in this region.
• B. Wear in the metatarsal ligament area.
• C.1 My toe extends beyond the insole.
• C.2 The ligament area also extends beyond the insole.
• C.3 My foot is noticeably larger than the generic insole.
• F. The arch support follows a standard shape, which does not fully adapt to my foot. Wear marks on the right side of the insole indicate that I exert more pressure in that area.

Nowadays, orthopedic insoles are designed to adapt to both feet and shoes. However, the fact that they conform to the shoe reveals another issue: shoes are designed generically, forcing the foot to adapt to them. This adaptation reduces the foot’s natural base area, leading to greater instability and potentially exacerbating other problems.

Additionally, because most shoes are not tailored to different foot shapes, they can cause misalignments and conditions such as ingrown toenails, bunions, and ankle wounds, among others.

In the image below, you can see these foot modifications caused by footwear. On the right side of the image, there is an insole made with Gensole software, where the customization has certain limitations. This custom insole needs to extend beyond specific areas to properly fit my foot, as I have a wide forefoot in the metatarsal area and toes that form a downward curve from the first toe.

This is why I will design my insoles based on a fully customized shoe, incorporating lifts and supportive elements to prevent wear and tear on my hip.

Design

Grasshopper ¹ Meshes ²

For the design of my shoes, I will start with the right contact base, ensuring proper support for the plantar surface of my foot while considering the following key elements:

• 5mm heel lift.
• 12mm arch support.
• Supination support with an external wedge.

These adjustments will address my leg length asymmetry, helping to improve the alignment of my sacral bone in the hip area. Since this imbalance causes rotation, it can lead to pain and spinal misalignment, which I aim to correct through this design.

The insole features a parametrically perforated design, with larger openings in the toe and metatarsal ligament areas, as these zones tend to produce more perspiration. The perforated pattern allows ventilation across the entire plantar surface of the foot.

On the left foot, there will be no heel lift — the heel and toes will remain at the same level to ensure balanced weight distribution. However, this insole will include arch support. Although I have a supinated foot type, it does not significantly affect the weight distribution on this foot.

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1. File: insoles Grasshopper ↩

2. File: Rhino Meshes ↩