Influence and benefits of foot orthoses on kinematics, kinetics and muscle activation during step descent task

Abstract

Medial wedged foot orthoses are frequently prescribed to reduce retropatellar stress in patients with patellofemoral pain (PFP) by controlling calcaneal eversion and internal rotation of the tibia. During activities of daily living, the highest patella loads occur during stair descent, but the effect of foot orthoses during stair descent remains unclear. The purpose of this study was to compare the kinematics, kinetics and muscle activation during a step descent task in healthy volunteers using three designs of foot orthoses (insoles). Sixteen healthy subjects with a mean age of 25.7 years, BMI of 23.3, and +5 Foot Posture Index were recruited. Subjects performed a step down task from 20 cm using a 5 o rearfoot medial wedge (R), a 5 o rearfoot and forefoot medial wedge (R/F), and a control flat insole (C). Significant improvements in control were seen in the R and R/F insoles over the C insole in the foot and at the ankle and hip kinematics. The R and R/F insoles increased the knee adduction moments, but decreased the knee internal rotation moment compared to the C insole. Adductor hallucis (AH) activity was reduced with both insoles, whereas tibialis anterior (TA) activity was reduced with the R insole only. Foot orthoses can change joint mechanics in the foot and lower limbs providing greater stability and less work done by AH and TA muscles. This data supports the use of foot orthoses to provide functional benefits during step descent, which may benefit patients with PFP.

The immediate effects of sensorimotor foot orthoses on foot kinematics in healthy adults

“…Recently, Laštovička et al [8] reported a sensorimotor orthosis with a medial heel bar and retrocapital bar with lateral elevation, decreased peak foot eversion, increased peak dorsiflexion and increased peak foot abduction. These findings suggest that the medial heel bar decreases whole foot eversion in a similar fashion to a medial heel wedge which has been reported to reduce rearfoot/ankle eversion [9][10][11][12][13]. Whilst changes to ankle kinematics were reported, this study did not use a multi-segment foot model and as a result was unable to identify subtle foot segment kinematic changes between orthotic conditions [14].…”

Shoes and Insoles: The Influence on Motor Tasks Related to Walking Gait Variability and Stability

“…With NeuroSky, we showed that the greatest beta wave activity in the studied cortical areas was recorded in the WTS condition as a response to the greater perturbations coming from the motor sense system [41]. The lowest activity was shown by the WSI condition: we think that the insoles provide more "passive" comfort, and the foot turns off the motor sensor system; indeed, it is well documented that the use of insoles reduces muscular activity [42]. and the foot turns off the motor sensor system; indeed, it is well documented that the use of insoles reduces muscular activity [42].…”

“…The lowest activity was shown by the WSI condition: we think that the insoles provide more "passive" comfort, and the foot turns off the motor sensor system; indeed, it is well documented that the use of insoles reduces muscular activity [42]. and the foot turns off the motor sensor system; indeed, it is well documented that the use of insoles reduces muscular activity [42]. The plots of the experimental time-series for the duration of stride cycles revealed some qualitative differences among the subjects.…”

“…There were extremely regular behaviors (Figure 4a), in which any time range was basically undistinguishable from the others; therefore, they were characterized by a relatively low global variability of the dataset. On the contrary, some subjects exhibited a walking behavior characterized by "sudden" jumps from a range of gait cycle duration values to another, as in Figure 4b (it is worth noting that in such a case, a simple SD analysis would not be able to differentiate such a behavior from another one with the same values, but homogeneously distributed along the duration and the foot turns off the motor sensor system; indeed, it is well documented that the use of insoles reduces muscular activity [42]. The plots of the experimental time-series for the duration of stride cycles revealed some qualitative differences among the subjects.…”

Surface electromyography of the foot: A protocol for sensor placement

“…Such guidelines currently make sEMG sensor placement recommendations for a selection of commonly investigated muscles, but there lacks evidence-based protocol on sEMG sensor placement for many muscles, including the muscles of the feet Intrinsic foot muscles are small and thus pose difficulties in isolating anatomically and physiologically correct placement of sEMG sensors. The Abductor Hallucis is a superficial muscle located on the medial border of the foot and sEMG of this muscle has been examined during various movements, including standing from a seated position [3], performing Hallux exercises [4], performing arch exercises [5] and with the use of foot orthoses [6]. There is little explanation in these studies to define the location of the sEMG electrodes to gather data from abductor hallucis, making repeating these protocols difficult to reproduce.…”