Midori Anzen Obtains Patent for Slide-type Instep Protector

Midori Anzen Co., Ltd. (Headquarters: Shibuya-ku, Tokyo; Representative Director and President: Kansaku Matsumura), a supplier of safety shoes and workwear, has obtained a patent for a new structure for safety shoes that protects the instep while ensuring the protector follows the foot's natural flexion during movement (Patent No. 7855540, dated April 28, 2026).

Traditionally, safety shoes with instep protectors were fixed at the top, which caused the protector to interfere with the shoe's upper, making it difficult for workers to crouch or walk. This new technology features a structure where shoelaces are threaded through loops on the underside of the instep protector, allowing the top part to slide and enhancing ease of movement during work.

The 'PRM212 Kopro M2' series using this technology was launched in June 2023 and has been widely adopted in workplaces handling heavy objects, including manufacturing, construction, and transportation. Since then, the 'RT912 Kopro M2' series, which applies this technology to Rubbertech safety shoes, has been added to the lineup.

Background of the Patent: Risks of Falling Heavy Objects and Challenges with Protective Gear In industries such as manufacturing and construction, occupational accidents caused by falling objects remain a concern, and the instep of the foot is a particularly vulnerable area. While safety shoes with instep protectors offer excellent defense, they have historically been criticized for being difficult to move in and stiff, which has been a barrier to widespread adoption in workplaces.

An instep protector is a protective piece attached to the top of safety shoes. According to JIS T8101 additional performance M, it is required to maintain a clearance of at least 25mm beneath the protector when subjected to an impact energy of 100J (equivalent to a 20kg object dropped from a height of 51cm). However, because conventional protectors were fixed, they restricted movement, hindering workers.

Development Story Responding to customer feedback regarding discomfort and difficulty in bending, Midori Anzen initiated development with the goal of maintaining protective performance without restricting the worker's movement. Initial efforts to improve flexibility by changing the protector shape were insufficient. The breakthrough came from addressing the fixed top structure. By replacing the single-point fixed structure with a loop structure that spans the underside of the protector, the protector now slides in response to foot movement.

Overview of the Patented Technology: New Slide-type Instep Protector Structure The patented technology uses a new structure where the protector slides in tandem with foot movement. By threading shoelaces through loops on the back of the protector, it follows the foot's flexion.

This structure enhances operability during walking and bending while maintaining protection against falling objects. Products adopting this technology comply with JIS T8101 additional performance M, achieving a balance of safety and functionality.

This technology has already been adopted in the 'PRM212 Kopro M2' series (released June 2023) and the 'RT912 Kopro M2' series (released December 2025).