The Design and Simulation of a 16-Sensors Plantar Pressure Insole Layout for Different Applications: From Sports to Clinics, a Pilot Study

The quantification of plantar pressure distribution is widely done in the diagnosis of lower limbs deformities, gait analysis, footwear design, and sport applications. To date, a number of pressure insole layouts have been proposed, with different configurations according to their applications. The goal of this study is to assess the validity of a 16-sensors (1.5 × 1.5 cm) pressure insole to detect plantar pressure distribution during different tasks in the clinic and sport domains. The data of 39 healthy adults, acquired with a Pedar-X® system (Novel GmbH, Munich, Germany) during walking, weight lifting, and drop landing, were used to simulate the insole. The sensors were distributed by considering the location of the peak pressure on all trials: 4 on the hindfoot, 3 on the midfoot, and 9 on the forefoot. The following variables were computed with both systems and compared by estimating the Root Mean Square Error (RMSE): Peak/Mean Pressure, Ground Reaction Force (GRF), Center of Pressure (COP), the distance between COP and the origin, the Contact Area. The lowest (0.61%) and highest (82.4%) RMSE values were detected during gait on the medial-lateral COP and the GRF, respectively. This approach could be used for testing different layouts on various applications prior to production.

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Biomechanical Evaluation of the Efficacy of External Stabilizers in the Conservative Treatment of Acquired Flatfoot Deformity

Foot & Ankle International ◽

10.1177/107110070202300809 ◽

2002 ◽

Vol 23 (8) ◽

pp. 727-737 ◽

Cited By ~ 38

Author(s):

Carl W. Imhauser ◽

Nicholas A. Abidi ◽

David Z. Frankel ◽

Kenneth Gavin ◽

Sorin Siegler

Keyword(s):

Pressure Distribution ◽

Plantar Pressure ◽

Center Of Pressure ◽

Lower Limbs ◽

Quiet Standing ◽

Medial Longitudinal Arch ◽

Longitudinal Arch ◽

Plantar Pressure Distribution ◽

Flexible Flatfoot ◽

Fresh Frozen

This study quantified and compared the efficacy of in-shoe orthoses and ankle braces in stabilizing the hindfoot and medial longitudinal arch in a cadaveric model of acquired flexible flatfoot deformity. This was addressed by combining measurement of hindfoot and arch kinematics with plantar pressure distribution, produced in response to axial loads simulating quiet standing. Experiments were conducted on six fresh-frozen cadaveric lower limbs. Three conditions were tested: intact-unbraced; flatfoot-unbraced; and flatfoot-braced. Flatfoot deformity was created by sectioning the main support structures of the medial longitudinal arch. Six different braces were tested including two in-shoe orthoses, three ankle braces and one molded ankle-foot orthosis. Our model of flexible flatfoot deformity caused the calcaneus to evert, the talus to plantarflex and the height of the talus and medial cuneiform to decrease. Flexible flatfoot deformity caused a pattern of medial shift in plantar pressure distribution, but minimal change in the location of the center of pressure. Furthermore, in-shoe orthoses stabilized both the hindfoot and the medial longitudinal arch, while ankle braces did not. Semi-rigid foot and ankle orthoses acted to stabilize the medial longitudinal arch. Based on these results, it was concluded that treatment of flatfoot deformity should at least include use of in-shoe orthoses to partially restore the arch and stabilize the hindfoot.

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Assessing Plantar Pressure Distribution in Children with Flatfoot Arch

Journal of the American Podiatric Medical Association ◽

10.7547/8750-7315-104.6.622 ◽

2014 ◽

Vol 104 (6) ◽

pp. 622-632 ◽

Cited By ~ 9

Author(s):

Jolanta Pauk ◽

Mikhail Ihnatouski ◽

Bijan Najafi

Keyword(s):

Mathematical Model ◽

Pressure Distribution ◽

Body Mass ◽

Plantar Pressure ◽

Reaction Force ◽

Retest Reliability ◽

Plantar Pressure Distribution ◽

Foot Posture ◽

Test Retest Reliability ◽

Pressure Magnitude

Background Flatfoot, or pes planus, is one of the most common foot posture problems in children that may lead to lower-extremity pain owing to a potential increase in plantar pressure. First, we compared plantar pressure distribution between children with and without flatfoot. Second, we examined the reliability and accuracy of a simple metric for characterization of foot posture: the Clarke angle. Third, we proposed a mathematical model to predict plantar pressure magnitude under the medial arch using body mass and the Clarke angle. Methods Sixty children with flatfoot and 33 aged-matched controls were recruited. Measurements included in-shoe plantar pressure distribution, ground reaction force, Clarke angle, and radiography assessment. The measured Clarke angle was compared with radiographic measurements, and its test-retest reliability was determined. A mathematical model was fitted to predict plantar pressure distribution under the medial arch using easy-to-measure variables (body mass and the Clarke angle). Results A high correlation was observed between the Clarke angle and radiography measurements (r > 0.9; P < 10−6). Excellent between- and within-day test-retest reliability for Clarke angle measurement (intraclass correlation coefficient, >0.9) was observed. Results also suggest that pressure magnitude under the medial arch can be estimated using the Clarke angle and body mass (R2 = 0.95; error, <0.04 N/cm2 [2%]). Conclusions This study suggests that the Clarke angle is a practical, reliable, and sensitive metric for quantification of medial arch height in children and could be recommended for research and clinical applications. It can also be used to estimate plantar pressure under the medial arch, which, in turn, may assist in the timely intervention and prognosis of prospective problems associated with flatfoot posture.

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High-Intensity Running and Plantar-Flexor Fatigability and Plantar-Pressure Distribution in Adolescent Runners

Journal of Athletic Training ◽

10.4085/1062-6050-49.3.90 ◽

2015 ◽

Vol 50 (2) ◽

pp. 117-125 ◽

Cited By ~ 18

Author(s):

François Fourchet ◽

Luke Kelly ◽

Cosmin Horobeanu ◽

Heiko Loepelt ◽

Redha Taiar ◽

...

Keyword(s):

Pressure Distribution ◽

Plantar Pressure ◽

High Intensity ◽

Contact Time ◽

Plantar Flexor ◽

Distance Runners ◽

Fatigue Index ◽

Plantar Pressure Distribution ◽

Before And After ◽

Mean Pressure

Context: Fatigue-induced alterations in foot mechanics may lead to structural overload and injury. Objectives: To investigate how a high-intensity running exercise to exhaustion modifies ankle plantar-flexor and dorsiflexor strength and fatigability, as well as plantar-pressure distribution in adolescent runners. Design: Controlled laboratory study. Setting: Academy research laboratory. Patients or Other Participants: Eleven male adolescent distance runners (age = 16.9 ± 2.0 years, height = 170.6 ± 10.9 cm, mass = 54.6 ± 8.6 kg) were tested. Intervention(s): All participants performed an exhausting run on a treadmill. An isokinetic plantar-flexor and dorsiflexor maximal-strength test and a fatigue test were performed before and after the exhausting run. Plantar-pressure distribution was assessed at the beginning and end of the exhausting run. Main Outcome Measure(s): We recorded plantar-flexor and dorsiflexor peak torques and calculated the fatigue index. Plantar-pressure measurements were recorded 1 minute after the start of the run and before exhaustion. Plantar variables (ie, mean area, contact time, mean pressure, relative load) were determined for 9 selected regions. Results: Isokinetic peak torques were similar before and after the run in both muscle groups, whereas the fatigue index increased in plantar flexion (28.1%; P = .01) but not in dorsiflexion. For the whole foot, mean pressure decreased from 1 minute to the end (−3.4%; P = .003); however, mean area (9.5%; P = .005) and relative load (7.2%; P = .009) increased under the medial midfoot, and contact time increased under the central forefoot (8.3%; P = .01) and the lesser toes (8.9%; P = .008). Conclusions: Fatigue resistance in the plantar flexors declined after a high-intensity running bout performed by adolescent male distance runners. This phenomenon was associated with increased loading under the medial arch in the fatigued state but without any excessive pronation.

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