Effect of Extrinsic Rearfoot Post Design on the Lateral-to-Medial Position and Velocity of the Center of Pressure

2006 ◽  
Vol 96 (5) ◽  
pp. 383-392 ◽  
Author(s):  
Joanne S. Paton ◽  
Simon K. Spooner
Keyword(s):  
Center Of Pressure ◽  
Foot Orthoses ◽  
Experimental Conditions ◽  
Period Data ◽  
Fourth Pair ◽  
Center Of Pressure Velocity

Findings from investigations of the effects of external forefoot and rearfoot posts added to foot orthoses have been inconclusive. This study was undertaken to examine the effects of rearfoot post design on the lateral-to-medial position and velocity of the center-of-pressure path. Four identical pairs of neutral-cast polypropylene orthotic shells were constructed; three pairs had a rearfoot post of specified design added. The fourth pair, the control, did not have a post added. Stance period data were broken down into four functional phases, and the statistically significant differences between the experimental conditions were calculated and analyzed. The addition of a rearfoot post to an orthotic shell affects center-of-pressure lateral-to-medial position and velocity. Although the effect of the post designs seemed to provide reasonably predictable changes in center-of-pressure position, the effect on center-of-pressure velocity was variable and inconsistent. The effect of the orthotic post was dependent on design and phase of gait. The addition of a rearfoot post and, specifically, the design of the post can probably be used to alter the center-of-pressure position and velocity. (J Am Podiatr Med Assoc 96(5): 383–392, 2006)

The effect of custom carbon ankle-foot orthosis alignment on roll-over shape and center of pressure velocity

2020 ◽  
pp. 030936462097140
Author(s):  
Elizabeth Russell Esposito ◽  
Mitchell D Ruble ◽  
Andrea J Ikeda ◽  
Jason M Wilken
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Center Of Pressure ◽  
Heel Strike ◽  
Control Group ◽  
Foot Orthoses ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis ◽  
Center Of Pressure Velocity

Background: Maintaining an optimal rolling of the foot over the ground is thought to increase the stability and efficiency of pathologic gait. Ankle-foot orthoses are often prescribed to improve gait mechanics in individuals with lower extremity injuries; however, their design may compromise how the foot rolls over the ground. Objectives: The aim of this study was to investigate the effects of the sagittal plane ankle-foot orthosis alignment on roll-over shape and center of pressure velocity in individuals with lower limb reconstructions. Study design: Randomized cross-over study with a control group comparison. Methods: In total, 12 individuals with lower limb reconstruction who used a custom carbon ankle-foot orthosis and 12 uninjured controls underwent gait analysis. Ankle-foot orthosis users were tested in their clinically-provided ankle-foot orthosis alignment, with an alignment that was 3° more plantarflexed, and with an alignment that was 3° more dorsiflexed. Components of roll-over shape and center of pressure velocity were calculated from heel strike on the ankle-foot orthosis limb to contralateral heel strike. Results: Roll-over shape radius was not affected by 3° changes to alignment and was not significantly different from controls. Aligning the ankle-foot orthosis in more dorsiflexion than clinically provided resulted in a smaller peak center of pressure velocity that occurred later in stance. Conclusion: Individuals using custom carbon ankle-foot orthoses can accommodate 3° alterations in the dorsiflexion or plantarflexion alignment.

scholarly journals Effects of additional load at different heights on gait initiation: A statistical parametric mapping of center of pressure and center of mass behavior

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0242892
Author(s):  
Marcus Fraga Vieira ◽  
Fábio Barbosa Rodrigues ◽  
Alfredo de Oliveira Assis ◽  
Eduardo de Mendonça Mesquita ◽  
Thiago Santana Lemes ◽  
...  
Keyword(s):  
Time Series ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Statistical Parametric Mapping ◽  
Gait Initiation ◽  
Experimental Conditions ◽  
Distributed Load ◽  
Uniformly Distributed Load ◽  
Reaction Forces ◽  
Controlled Object

The purpose of this study was to investigate the effects of different vertical positions of an asymmetrical load on the anticipatory postural adjustments phase of gait initiation. Sixty-eight college students (32 males, 36 females; age: 23.65 ± 3.21 years old; weight: 69.98 ± 8.15 kg; height: 1.74 ± 0.08 m) were enrolled in the study. Ground reaction forces and moments were collected using two force platforms. The participants completed three trials under each of the following random conditions: no-load (NL), waist uniformly distributed load (WUD), shoulder uniformly distributed load (SUD), waist stance foot load (WST), shoulder stance foot load (SST), waist swing foot load (WSW), and shoulder swing foot load (SSW). The paired Hotelling’s T-square test was used to compare the experimental conditions. The center of pressure (COP) time series were significantly different for the SUD vs. NL, SST vs. NL, WST vs. NL, and WSW vs. NL comparisons. Significant differences in COP time series were observed for all comparisons between waist vs. shoulder conditions. Overall, these differences were greater when the load was positioned at the shoulders. For the center of mass (COM) time series, significant differences were found for the WUD vs. NL and WSW vs. NL conditions. However, no differences were observed with the load positioned at the shoulders. In conclusion, only asymmetrical loading at the waist produced significant differences, and the higher the extra load, the greater the effects on COP behavior. By contrast, only minor changes were observed in COM behavior, suggesting that the changes in COP (the controller) behavior are adjustments to maintain the COM (controlled object) unaltered.

Effect of 4 Weeks of Foot Orthosis Intervention on Ambulatory Capacities and Posture in Normal-Weight and Obese Patients

2020 ◽  
Vol 110 (1) ◽  
Author(s):  
Patricia Griffon ◽  
Bruno Vie ◽  
Jean Paul Weber ◽  
Yves Jammes
Keyword(s):  
Postural Sway ◽  
Center Of Pressure ◽  
Effective Means ◽  
Normal Weight ◽  
Foot Orthoses ◽  
Obese Patients ◽  
Healthy Individuals ◽  
Foot Arch ◽  
Foot Orthosis ◽  
Study Inclusion

Background: Several works have shown the benefits of foot orthosis intervention on postural stability in healthy individuals and patients with foot malalignment. However, the effects of foot orthoses on the daily ambulatory activities explored by the Six-Minute Walk Test (6MWT) were never examined. We hypothesized that foot orthoses could increase the gait distance and attenuate the post-6MWT posture alterations already reported in healthy individuals. Methods: In ten normal-weight (NW) and ten obese patients with foot malalignment and/or abnormal foot arch, we examined the benefits of 4 weeks of custom-molded orthosis intervention (D30) on 6MWT gait distance, fatigue sensation scores, ankle plantarflexion force, and post-6MWT sway of the center of pressure (COP) measured by a pedobarographic platform. Data were compared with those measured in two control-matched groups of ten NW and ten obese individuals, explored at study inclusion and at D30. Results: At study inclusion, the post-6MWT changes in COP surface and the medial and lateral COP deviations were significantly higher in obese participants who needed to wear the foot orthoses compared with obese control subjects. The foot orthosis intervention significantly improved the ambulatory performances of NW and obese individuals during the 6MWT, attenuated the bodily fatigue sensation after the 6MWT, and reduced the post-6MWT COP deviations, with the benefits of insoles being significantly accentuated in obese participants. Conclusions: Four weeks of foot orthosis intervention significantly increases gait distance and is an effective means to reduce postural sway after walking.

Changes in Plantar Foot Pressure with In-Shoe Varus or Valgus Wedging

2004 ◽  
Vol 94 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Bart Van Gheluwe ◽  
Howard J. Dananberg
Keyword(s):  
Pressure Distribution ◽  
Loading Rate ◽  
Peak Pressure ◽  
Center Of Pressure ◽  
Scientific Evidence ◽  
Peak Load ◽  
Foot Orthoses ◽  
Foot Pressure ◽  
Custom Made

Varus and valgus wedging are commonly used by podiatric physicians in therapy with custom-made foot orthoses. This study aimed to provide scientific evidence of the effects on plantar foot pressure of applying in-shoe forefoot or rearfoot wedging. The plantar foot pressure distribution of 23 subjects walking on a treadmill was recorded using a pressure insole system for seven different wedging conditions, ranging from 3° valgus to 6° varus for the forefoot and from 4° valgus to 8° varus for the rearfoot. The results demonstrate that increasing varus wedging magnifies peak pressure and maximal loading rate at the medial forefoot and rearfoot, whereas increasing valgus wedging magnifies peak pressure and maximal loading rate at the lateral forefoot and rearfoot. As expected, the location of the center of pressure shifts medially with varus wedging and laterally with valgus wedging. However, these shifts are less significant than those in peak load and maximal loading rate. Timing variables such as interval from initial impact to peak load do not seem to be affected by forefoot or rearfoot wedging. Finally, rearfoot wedging does not significantly influence pressure variables of the forefoot; similarly, rearfoot pressure remains unaffected by forefoot wedging. (J Am Podiatr Med Assoc 94(1): 1-11, 2004)

scholarly journals Higher Dependency on Visual Inputs During Posture Control: Another Long-Term Effect of mTBIs

2021 ◽  
Author(s):  
Alessander Danna-dos-Santos ◽  
Adriana Menezes Degani
Keyword(s):  
Center Of Pressure ◽  
Vertical Posture ◽  
Military Operations ◽  
Long Term Effects ◽  
Experimental Conditions ◽  
Fast Reactions ◽  
Visual Inputs ◽  
Long Term Effect ◽  
Behavioral Markers

Abstract This study investigated the hypothesis that individuals living with long-term effects of mild traumatic brain injury (mTBI) develop increased dependency on their visual inputs to control their vertical posture. To test this hypothesis we quantified visuo-postural dependency indices (VPDIs) calculated independently for multiple postural behavioral markers extracted from the body’s center of pressure coordinates signals recorded during the execution of a quiet bipedal stance. One hundred and twenty-nine volunteers participated in this study. An mTBI (n = 50) and a neurotypical Control group were formed (n = 79). VPDIs were calculated as the normalized pair-wise subtraction of recordings obtained under Vision and No-Vision experimental conditions. Consistent with our hypothesis the results of this study show that balance behavior of mTBI participants deteriorate more abruptly in the absence of visual inputs when compared to neurotypical controls. These impairments may increase the likelihood of recurrent traumas when fast reactions are needed in daily activities, sports practice, or military operations. Additionally, the methodology used in this study showed to be potentially useful to aid future investigations of neural circuitry impaired by mTBI and provide indices of recovery in future clinical trials testing mTBI-related clinical interventions.

scholarly journals Biomechanical effects of foot orthoses with and without a lateral bar in individuals with cavus feet during comfortable and fast walking

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248658
Author(s):  
Gabriel Moisan ◽  
Martin Descarreaux ◽  
Vincent Cantin
Keyword(s):  
Vastus Lateralis ◽  
Statistical Parametric Mapping ◽  
Knee Kinematics ◽  
Gluteus Medius ◽  
Knee Extension ◽  
Ankle Dorsiflexion ◽  
Foot Orthoses ◽  
Experimental Conditions ◽  
Peroneus Longus ◽  
Fast Speed

Background/purpose The biomechanical effects of foot orthoses (FOs) with and without a lateral bar compared to a control condition during walking at different speeds are still unknown. The objective of this study was to compare the biomechanical effects of functional FOs with and without a lateral bar to a control condition during comfortable walking in individuals with cavus feet and determine if their effects change at a fast speed. Methods Fifteen individuals with cavus feet (age: 25.3 ± 5.8 yrs) walked under two experimental conditions (FOs with and without a lateral bar) and a control condition (shoes only) at comfortable (CW) and fast (FW) speeds. The outcome measures were ankle and knee angles and gluteus medius, vastus lateralis, gastrocnemius lateralis, gastrocnemius medialis, peroneus longus and tibialis anterior electromyography (EMG) amplitudes during the stance phase of walking and were compared between the FOs and a control condition using one-dimensional statistical parametric mapping. Results During CW, both FOs decreased ankle dorsiflexion and increased knee extension angles compared to no FOs. FOs with a lateral bar also decreased peroneus longus EMG amplitudes. During FW, FOs with and without a lateral bar decreased ankle dorsiflexion angles compared to no FOs. Conclusion Both types of FOs had different effects on the biomechanics of the lower limb compared to a control condition. The decreased peroneus longus EMG amplitudes during CW in individuals with cavus feet could have important clinical implications in other populations, such as individuals with painful cavus feet. The orthoses only affected the ankle dorsiflexion angles at a fast speed and no EMG amplitude or knee kinematics effects were observed. Further studies assessing the ankle kinematics and kinetics effects of these orthoses are needed to improve our understanding of their mechanism of action and inform future efficacy trials.

scholarly journals Effects of the degree of freedom and assistance characteristics of powered ankle-foot orthoses on gait stability

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242000
Author(s):  
Ho Seon Choi ◽  
Yoon Su Baek
Keyword(s):  
Subtalar Joint ◽  
Center Of Pressure ◽  
Pearson Correlation ◽  
Critical Role ◽  
Angular Acceleration ◽  
Degree Of Freedom ◽  
Measurement Unit ◽  
Foot Orthoses ◽  
Gait Stability ◽  
Ankle Foot Orthoses

We studied the use of powered ankle-foot orthoses (PAFOs) and walking stability of the wearers, focusing on the ankle joint, which is known to play a critical role in gait stability. Recognizing that the subtalar joint is an important modulator of walking stability, we conducted the walking experiment on a treadmill by applying varying assistance techniques to the 2-degree-of-freedom (DOF) PAFO, which has the subtalar joint as the rotating axis, and the commonly used 1-DOF PAFO. The participants were 8 healthy men (mean±SD: height, 174.8±7.1 cm; weight, 69.8±6.5 kg; and age, 29.1±4.8 years) with no history of gait abnormality. Center of pressure (COP) was measured with an in-shoe pressure sensor, and stability was estimated on the basis of the angular acceleration measured with the inertial measurement unit attached to the trunk. The experimental results of the 2-DOF PAFO, with or without assistance, showed a significantly higher stability than those of the 1-DOF PAFO (up to 23.78%, p<0.0326). With the 1-DOF PAFO, the stability deteriorated with the increase in the degree of assistance provided. With the 2-DOF PAFO, this tendency was not observed. Thus, the importance of the subtalar joint was proven using PAFOs. The mean position analysis of the COP during the stance phase confirmed that the COP highly correlated with stability (Pearson correlation coefficient: −0.6607). Thus, we conclude that only the 2-DOF PAFO can maintain walking stability, regardless of the assistance characteristics, by preserving the COP in the medial position through eversion. Awareness regarding the role of the subtalar joint is necessary during the manufacture or use of PAFOs, as lack of awareness could lead to the degradation of the wearer’s gait stability, regardless of effective assistance, and deteriorate the fundamental functionality of PAFO.

Effect of Visual Condition on Performance of Balance-Related Tasks in Elite Dance Students

Motor Control ◽  
2020 ◽  
Vol 24 (3) ◽  
pp. 397-407
Author(s):  
Elizabeth Coker ◽  
Terry Kaminski
Keyword(s):  
Center Of Pressure ◽  
Balance Control ◽  
Plantar Flexion ◽  
Knee Extension ◽  
Light Conditions ◽  
Visual Condition ◽  
Low Light ◽  
Technical Requirements ◽  
Dance Movements ◽  
Center Of Pressure Velocity

The purpose of this study was to investigate the effects of visual condition (low light, full light, and full light with mirror) on balance control and technical form during two technical dance movements in a group of elite collegiate dance students. Dancers demonstrated higher center of pressure velocity indicating lower control while performing a static dance task (parallel relevé retiré) and a dynamic dance task (fondu relevé en croix) under low light conditions than either lighted condition. Measures of Western ballet technique (pelvic obliquity, knee extension, and ankle plantar flexion) showed no decrement under low light conditions. No effect of concurrent mirror feedback was found on either center of pressure velocity or technical requirements of the dance tasks.

scholarly journals Muscle-Activation Onset Times With Shoes and Foot Orthoses in Participants With Chronic Ankle Instability

2015 ◽  
Vol 50 (7) ◽  
pp. 688-696 ◽  
Author(s):  
Bart Dingenen ◽  
Louis Peeraer ◽  
Kevin Deschamps ◽  
Steffen Fieuws ◽  
Luc Janssens ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Linear Model ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Ankle Instability ◽  
Chronic Ankle Instability ◽  
Foot Orthoses ◽  
Experimental Conditions ◽  
Peroneus Longus ◽  
Hip Muscles

Context Participants with chronic ankle instability (CAI) use an altered neuromuscular strategy to shift weight from double-legged to single-legged stance. Shoes and foot orthoses may influence these muscle-activation patterns. Objective To evaluate the influence of shoes and foot orthoses on onset times of lower extremity muscle activity in participants with CAI during the transition from double-legged to single-legged stance. Design Cross-sectional study. Setting Musculoskeletal laboratory. Patients or Other Participants A total of 15 people (9 men, 6 women; age = 21.8 ± 3.0 years, height = 177.7 ± 9.6 cm, mass = 72.0 ± 14.6 kg) who had CAI and wore foot orthoses were recruited. Intervention(s) A transition task from double-legged to single-legged stance was performed with eyes open and with eyes closed. Both limbs were tested in 4 experimental conditions: (1) barefoot (BF), (2) shoes only, (3) shoes with standard foot orthoses, and (4) shoes with custom foot orthoses (SCFO). Main Outcome Measure(s) The onset of activity of 9 lower extremity muscles was recorded using surface electromyography and a single force plate. Results Based on a full-factorial (condition, region, limb, vision) linear model for repeated measures, we found a condition effect (F3,91.8 = 9.39, P &lt; .001). Differences among experimental conditions did not depend on limb or vision condition. Based on a 2-way (condition, muscle) linear model within each region (ankle, knee, hip), earlier muscle-activation onset times were observed in the SCFO than in the BF condition for the peroneus longus (P &lt; .001), tibialis anterior (P = .003), vastus medialis obliquus (P = .04), and vastus lateralis (P = .005). Furthermore, the peroneus longus was activated earlier in the shoes-only (P = .02) and shoes-with-standard-foot-orthoses (P = .03) conditions than in the BF condition. No differences were observed for the hip muscles. Conclusions Earlier onset of muscle activity was most apparent in the SCFO condition for ankle and knee muscles but not for hip muscles during the transition from double-legged to single-legged stance. These findings might help clinicians understand how shoes and foot orthoses can influence neuromuscular control in participants with CAI.

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