What orthotic modifications can reduce pressure on the apex of the hallux (big toe)?

From the Guidelines

To reduce pressure on the apex of the hallux, orthotic modifications such as toe silicone or (semi-)rigid orthotic devices can be considered. According to the guidelines on the prevention of foot ulcers in persons with diabetes (IWGDF 2023 update) 1, these modifications can help reduce excess callus on the toe. The use of toe silicone or (semi-)rigid orthotic devices is a conditional recommendation with low certainty of evidence, but it may be a valuable option for people with diabetes at risk of foot ulceration (IWGDF risk 1–3) with a non-rigid hammertoe and nail changes, excess callus, or a pre-ulcerative lesion on the apex or distal part of the toe.

Some key considerations for orthotic modifications include:

• Using toe silicone or (semi-)rigid orthotic devices to reduce excess callus on the toe 1
• Providing information on proper use of the orthosis to avoid wrong placement that may aggravate the situation 1
• Considering the use of felted foam in addition to therapeutic footwear to reduce excess callus and associated increased foot pressure 1

It is essential to note that preventative surgery, such as digital flexor tendon tenotomy, may also be considered for people with diabetes who have pre-ulcerative lesions that fail to respond to non-surgical treatment 1. However, orthotic modifications can be a valuable non-surgical option for reducing pressure on the apex of the hallux.

The goal of these orthotic modifications is to redistribute plantar pressures, control abnormal foot mechanics, and provide cushioning to vulnerable areas, ultimately reducing focal pressure on the hallux apex during standing and walking activities. By considering these modifications, healthcare professionals can help prevent foot ulcers and improve the quality of life for people with diabetes at risk of foot ulceration.

From the Research

Orthotic Modifications to Reduce Pressure on the Apex of the Hallux

To reduce pressure on the apex of the hallux (big toe), several orthotic modifications can be considered:

• Custom-made molded silicone toe props can be effective in distributing apical and metatarsophalangeal joint peak plantar pressures and force-time integral in toe deformities, including hammertoes and claw toes 2.
• A metatarsal pad placed proximal to the second metatarsal head can diminish peak pressures, and a thicker insole can further reduce peak metatarsal head pressures 3.
• Custom and semi-custom foot orthotics can decrease bone strain of the second metatarsal, with custom orthotics having a greater effect 4.
• Customized insoles can be more effective in plantar pressure reduction than toe separators for hallux valgus deformity 5.
• Gel toe props can be effective in reducing peak pressure and pressure-time integral on the apex of the second digit in patients with claw or hammer toe deformity 6.

Specific Modifications

Some specific modifications that can be made to orthotics to take the pressure off the apex of the big toe include:

• Using a molded silicone toe prop to reduce peak pressure and pressure-time integral at the apex of the hallux.
• Placing a metatarsal pad proximal to the first metatarsal head to diminish peak pressures.
• Using a customized insole to reduce plantar pressure distribution in the forefoot region.
• Incorporating a gel or silicone material into the orthotic to reduce peak pressure and pressure-time integral on the apex of the hallux.

Considerations

When considering orthotic modifications to reduce pressure on the apex of the hallux, it is essential to:

• Individualize treatment approaches and consider patient education as a central aspect of therapy 3.
• Avoid narrowed shoes that can limit the impaction of the distal phalanx and toenail into the ground 3.
• Monitor patient comfort and adjust the orthotic modifications as needed 6.