US-based private equity firm Berkshire Partners LLC has invested in Masai Group International, the distributor of shoes under the Masai Barefoot Technology (MBT) brand, to help accelerate and support the next phase of the company’s growth. Current shareholders Klaus Heidegger, a former world-class skier and past owner of Kiehl’s, and Hermann Oberschneider, an Austrian sports and tourism entrepreneur, have retained a majority stake in the company.

Initially developed for orthopaedic applications by Swiss engineer Karl Muller, MBT’s shape and structure, with the elliptical section or ‘Masai Sensor’ underneath the heel, creates a natural instability underfoot that stimulates and exercises the body’s supporting muscle system. Benefits are said to include reduced impact on joints, better posture, increased caloric burn and muscle toning due to increased buttock, thigh and abdominal muscle activity, as well as a significant decrease of stress and pressure on the hip and knee joints.