Effects of shoe sole construction on skeletal motion during running

Purpose: The purpose of this study was to quantify effects of shoe sole mod ification on skeletal kinematics of the calcaneus and tibia during the stan ce phase of running. Methods: Intracortical bone pins with reflective marke r triads were inserted under standard local anesthetic into the calcaneus a nd tibia of five healthy male subjects. The three-dimensional tibiocalcanea l rotations were determined using a joint coordinate system approach. Three shoe sole modifications were tested with different sole geometry: a latera l heel flare of 25 degrees (flared), no flare 0 degrees (straight), and a r ounded sole. Results: The results showed mat these shoe sole modifications did not change tibiocalcaneal rotations substantially. The shoe sole effect s at the bone level were small and unsystematic (mean effects being less th an 1 degrees) compared with the differences between the subjects (up to 7 d egrees). Shoe eversion measured simultaneously with shoe markers showed no systematic shoe sole effects. A comparison of shoe and bone results showed the total shoe eversion and maximum shoe eversion velocity to be approximat ely twice as large as the respective measurements based on bone markers (co rrelations being r = 0.79 for maximum eversion velocity; r = 0.88 fur total eversion), indicating that there may be a relationship or coupling effect between the shoes and the bone. Conclusions: II is concluded that the tibio calcaneal kinematics of running may be individually unique and that shoe so le modifications may not be able to change them substantially.