A novel 3D printed personalised insole for improvement of flat foot arch compression and recoil – preliminary study

Abstract

Conventional corrective insoles for flatfoot individuals traditionally utilise solid arch support to prevent the collapse of medial longitudinal arch. Such design restricts the foot arch compression and recoil in stance phase and increases the expanded energy during gait. In this study, a novel customised design insole was designed and manufactured using person's 3D foot scans. A novel elastic mesh pad was implemented in the mid-insole to replace the conventional solid arch support. The new insoles were tested in standard straight gait laboratory trials. The kinematic analysis showed that the novel insoles improved foot arch compression and recoil in stance phase with flatfooted individuals. Finally, the new insoles were provided to the participants to be habitually worn during a prolonged period of daily usage. The obtained gait analysis results and user feedback indicate strongly that the novel insoles provide improved comfort, static and dynamic balance, and arch support in stance phase. In summary, the new insoles show substantive potential in addressing the shortcomings of the widely used passive support ones while providing less restrictive and effective dynamic support.

3D Printing of Individual Running Insoles – A Case Study

“…5 Previous studies mainly focus on insoles composed from different materials and components; 3,8,15,28 only a few are made from one material. 10,19,20 This was one of the main points of our research.…”

“…8 Precise positioning of 3D foot model for the CAD coordinate system. 8,10,19 Alignment primitives to the coordinate system according to CAD software for Insole design. We removed unnecessary parts of the foot.…”

“…Smoothing of the model and removing the most noise. 10 Alignment of Pternion 10 to second distal phalange (X-axis). Identification of morphologically significant points 8 (close to support points) on sole and creation of horizontal XY-plane.…”

“…1,[3][4][5]7,15,21,27,28 It follows from the above that a fundamental assumption for the successful designing CMIs is to understand the correlation of the foot to posture 29 and other aspects of the musculoskeletal system, 1,[3][4][5][6][7][8][9] to perceive relationships to associated diseases and cognition of the biomechanics, 1,4,5,12 weight-bearing activities 1,3,[5][6][7]9 of humans, and pathological forces 1,3,[5][6][7]13 which affect the foot. In general, the main principle in the design of CMI is the correction of deformities, 1,3,[7][8][9] reductions of painful symptoms, [3][4][5][6][7][8][9][10] and adequate load distribution. 1,…”

“…1,3,6,8,12 Pain in the lower limbs and muscle fatigue are characteristic symptoms of flat feet. [1][2][3][4][5][6][7][8][9][10] These severe accompanying phenomena make ordinary life miserable and are why a person seeks professional help. 3 An insole must bear the oftenextreme loads 3,8,9 in athletes.…”