The long-term use of foot orthoses affects walking kinematics and kinetics of children with flexible flat feet: A randomized controlled trial

Abstract

Background: Due to inconclusive evidence on the effects of foot orthoses treatment on lower limb kinematics and kinetics in children, studies are needed that particularly evaluate the long-term use of foot orthoses on lower limb alignment during walking. Thus, the main objective of this study was to evaluate the effects of long-term treatment with arch support foot orthoses versus a sham condition on lower extremity kinematics and kinetics during walking in children with flexible flat feet.

Methods: Thirty boys aged 8-12 years with flexible flat feet participated in this study. While the experimental group (n = 15) used medial arch support foot orthoses during everyday activities over a period of four months, the control group (n = 15) received flat 2-mm-thick insoles (i.e., sham condition) for the same time period. Before and after the intervention period, walking kinematics and ground reaction forces were collected.

Results: Significant group by time interactions were observed during walking at preferred gait speed for maximum ankle eversion, maximum ankle internal rotation angle, minimum knee abduction angle, maximum knee abduction angle, maximum knee external rotation angle, maximum knee internal rotation angle, maximum hip extension angle, and maximum hip external rotation angle in favor of the foot orthoses group. In addition, statistically significant group by time interactions were detected for maximum posterior, and vertical ground reaction forces in favor of the foot orthoses group.

Conclusions: The long-term use of arch support foot orthoses proved to be feasible and effective in boys with flexible flat feet to improve lower limb alignment during walking.

Fig 1. Flow diagram of the randomized controlled trial.

Fig 2

Fig (A) illustrates an arch support foot orthoses that was applied in the experimental group. Fig (B) shows a flat, 2-mm-thick insole that was used in the control group as sham condition.

Fig 3. Maximum frontal angle (degree) of the ankle for each subject during the push-off phase of walking (A5).

Positive values are related to inversion and negative values to eversion movements. Group-specific mean values are indicated by grey bars.

Fig 4. Ensemble average kinematics for all 15 subjects of the experimental group.

The black and red curves represent the values for the pre- post-test condition, respectively. Grey shading illustrates the 95% confidence interval for the pre-test condition. For clarity, errors are not shown for the post-test condition.

Fig 5. Ensemble average of three-dimensional GRF values for all 15 subjects of the experimental group.

The black and red curves represent the values for the pre- post-test condition, respectively. Grey shading illustrates 95% confidence interval for the pre-test condition. For clarity, errors are not shown for the post-test condition.