Relationship between neutral subtalar joint position and pattern of rearfoot motion during walking.

The purpose of this study was to determine the relationship between the angle formed by the rearfoot when the subtalar joint is positioned in neutral and the pattern of rearfoot motion during walking. Each lower extremity for 50 healthy young adult subjects (mean age 25.5 years) was videotaped and the pattern of rearfoot motion was assessed using two-dimensional analysis. The results indicate that the rearfoot is slightly inverted before heel strike and that the average time to maximum pronation occurs at approximately 37.9% of the stance phase duration. Contrary to a previously published theory, the "neutral" position of the rearfoot for the typical pattern of rearfoot motion during the walking cycle was found to be resting standing foot posture rather than subtalar joint neutral position.