Comparison between traditional plaster-molded and 3D printed orthoses in excessive foot pronation control in female runners

Abstract

Rationale/ Objectives: Foot orthoses are commonly prescribed to prevent injury in runners with excessive foot pronation. Traditional plaster-molded method is currently the mainstream approach in clinical practice, while 3D printing technology may be a novel alternative for foot orthoses fabrication. However, the effectiveness difference between traditionally plaster-molded (TPM) and 3D printed (3DP) orthoses on the foot pronation control remains largely unknown. Methods: 14 asymptomatic female runners with excessive foot pronation were recruited from local running clubs. They ran on a self-paced treadmill in three conditions: 1) TPM orthoses; 2) 3DP orthoses; and 3) without orthoses (Ctrl) in a randomized sequence. Rearfoot angle and perceived comfort in each condition were measured and compared. Results: Runners with TPM (p=0.001, Cohen’s d=0.38) or 3DP orthoses (p=0.002, Cohen’s d=0.24) exhibited lower rearfoot angle than Ctrl. When comparing between the two types of orthoses, the rearfoot angle was slightly higher in the 3DP orthoses (p=0.043, Cohen’s d=0.15). The kinematics was matched with the perception. Runners experienced better ‘medial-lateral control’ with TPM orthoses (p<0.001) Cohen’s d=1.74) and 3DP orthoses (p=0.003, Cohen’s d=1.34) when compared with Ctrl. Conclusions: Both TPM and 3DP orthoses are able to control foot pronation and enhance subjective perception of ‘medial-lateral control’ in female runners with excessive foot pronation