Effect of 1.5 mm biter-width meniscectomy on cadaveric knee pressure, peak pressure, force, and contact area

Introdução: as úlceras por pressão são complicações frequentes em pacientes com lesão medular. Almofadas de ar são apontadas como as mais indicadas para aliviar a pressão de interface e prevenir úlceras. Objetivo: Analisar, em um caso de tetraplegia por lesão medular, o efeito da distribuição da pressão de interface nádega/almofada em posturas estáticas e dinâmicas e verificar se o uso de uma almofada nova interfere na distribuição da pressão. Método: A análise da pressão de interface foi realizada durante duas situações distintas: com o participante sentado em postura estática; e mais uma etapa utilizando a cadeira de rodas para a locomoção. Para a avaliação da pressão de interface foram utilizadas duas almofadas Roho® Quadtro Select High Profileâ„¢: uma em uso pela participante e outra fornecida pelos pesquisadores. Resultados: Foram analisados: pressão média, pico de pressão e área de contato na interface nádega/almofada nas duas etapas de coletas de dados. A almofada fornecida pelo estudo apresentou índices melhores para pressão média, pico de pressão e área de contato. Conclusão: O estudo traz evidências da importância de manter a calibração de almofadas para sujeitos lesados medulares para prevenção de úlceras de pressão. Abstract Introduction: pressure ulcers are frequent complications in patients with spinal cord injury. Air cushions are appointed as the most appropriate to relieve the interface pressure and prevent pressure ulcers. Objective: To analyze the effect of the distribution of the buttock / cushion interface pressure under static and dynamic posture and check the use of a new cushion interferes with the pressure distribution in a case of tetraplegia after spinal cord injury. Method: Analysis of interface pressure was performed for two different situations, with the participant sitting in static and one more step using the wheelchair for locomotion. For the evaluation of interface pressure were used two Roho® Quadtro Select High Profile â„¢ cushions: one used by the participant and another provided by the researchers. Resulted: Was analyzed the mean pressure, peak pressure and the contact area in buttock/cushion in both data collect. The cushion provided by the study presented better indices for mean pressure, peak pressure and contact area. Conclusion: The study provides evidence of the importance of maintaining cushion calibration for spinal cord injured individuals to prevent pressure ulcers.Keywords: Cushion; Spinal Cord Injury; Assistive Technology.

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Effects of Minimalist Footwear and Foot Strike Pattern on Plantar Pressure during a Prolonged Running

Applied Sciences ◽

10.3390/app12010506 ◽

2022 ◽

Vol 12 (1) ◽

pp. 506

Author(s):

Marta Izquierdo-Renau ◽

Roberto Sanchis-Sanchis ◽

Jose I. Priego-Quesada ◽

Alberto Encarnación-Martínez ◽

Ana Queralt ◽

...

Keyword(s):

Contact Area ◽

Plantar Pressure ◽

Contact Time ◽

Peak Pressure ◽

Maximal Aerobic Speed ◽

Mean Pressure ◽

Pressure Peak ◽

Foot Strike ◽

Running Mechanics ◽

Lower Contact

The use of minimalist shoes (MS) in running involves changes in running mechanics compared to conventional shoes (CS), but there is still little research analysing the effects of this footwear on plantar pressure, which could help to understand some risk injury factors. Moreover, there are no studies examining the effects of a prolonged running and foot strike patterns on baropodometric variables in MS. Therefore, the aim of this study was to analyse the changes produced using MS on plantar pressure during a prolonged running, as well as its interaction with the time and foot strike pattern. Twenty-one experienced minimalist runners (age 38 ± 10 years, MS running experience 2 ± 1 years) ran with MS and CS for 30 min at 80% of their maximal aerobic speed, and mean pressure, peak pressure, contact time, centre of pressure velocity, relative force and contact area were analysed using a pressure platform. Foot strike pattern and time were also considered as factors. The multivariable linear regression mixed models showed that the use of MS induced, at the end of a prolonged running, higher peak pressure (p = 0.008), lower contact time (p = 0.004) and lower contact area (p < 0.001) than using CS. Also, runners with forefoot strike pattern using MS, compared to midfoot and rearfoot patterns, showed higher mean and peak pressure (p < 0.001) and lower contact time and area (p < 0.05). These results should be considered when planning training for runners using MS, as higher peak pressure values when using this type of footwear could be a risk factor for the development of some foot injuries.

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Pressure Distribution in the Ankle and Subtalar Joint With Routine and Oversized Foot Orthoses

Foot & Ankle International ◽

10.1177/1071100718770659 ◽

2018 ◽

Vol 39 (8) ◽

pp. 994-1000 ◽

Cited By ~ 3

Author(s):

Patrick Williamson ◽

Aron Lechtig ◽

Philip Hanna ◽

Stephen Okajima ◽

Peter Biggane ◽

...

Keyword(s):

Contact Area ◽

Lower Limb ◽

Subtalar Joint ◽

Peak Pressure ◽

Weight Bearing ◽

Force Distribution ◽

Foot Orthoses ◽

Pressure Mapping ◽

Mean Pressure ◽

Pressure Peak

Background: Foot orthoses are used to treat many disorders that affect the lower limb. These assistive devices have the potential to alter the forces, load distribution, and orientation within various joints in the foot and ankle. This study attempts to quantify the effects of orthoses on the intra-articular force distribution of the ankle and subtalar joint using a cadaveric testing jig to simulate weight bearing. Methods: Five lower-limb cadaveric specimens were placed on a custom jig, where a 334-N (75-lb) load was applied at the femoral head, and the foot was supported against a plate to simulate double-leg stance. Pressure-mapping sensors were inserted into the ankle and subtalar joint. Mean pressure, peak pressure, contact area, and center of force were measured in both the ankle and subtalar joints for barefoot and 2 medial foot orthosis conditions. The 2 orthosis conditions were performed using (1) a 1.5-cm-height wedge to simulate normal orthoses and (2) a 3-cm-height wedge to simulate oversized orthoses. Results: The contact area experienced in the subtalar joint significantly decreased during 3-cm orthotic posting of the medial arch, but neither orthosis had a significant effect on the spatial mean pressure or peak pressure experienced in either joint. Conclusion: The use of an oversized orthosis could lead to a decrease in the contact area and alterations in the distribution of pressure within the subtalar joint. Clinical Relevance: The use of inappropriate orthoses could negatively impact the force distribution in the lower limb.

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Effect of Distal Tibial Varus and Valgus Deformity on Tibiotalar Joint Contact

Foot & Ankle Orthopaedics ◽

10.1177/2473011420s00253 ◽

2020 ◽

Vol 5 (4) ◽

pp. 2473011420S0025

Author(s):

Zhao Hong-Mou

Keyword(s):

Contact Pressure ◽

Ankle Joint ◽

Contact Area ◽

Peak Pressure ◽

Tibiotalar Joint ◽

Force Center ◽

Fibular Osteotomy ◽

Group I ◽

Joint Contact ◽

Group A

Category: Ankle; Basic Sciences/Biologics Introduction/Purpose: To study the effect of different degrees of distal tibial varus and valgus deformities on the tibiotalar joint contact, and to understand the role of fibular osteotomy. Methods: Eight cadaveric lower legs were used for biomechanical study. Nine conditions were included: normal ankle joint (group A), 10° varus (group B), 5° varus (group C), 5° valgus (group D), 10° valgus (group E) with fibular preserved, and 10° varus (group F), 5° varus (group G), 5° valgus (group H), and 10° valgus (group I) after fibular osteotomy. The joint contact area, contact pressure, and peak pressure were tested; and the translation of contact force center was observed. Results: The joint contact area, contact pressure, and peak pressure had no significant difference between group A and groups B to E (P>0.05). After fibular osteotomy, the contact area decreased significantly in groups F and I when compared with group A (P<0.05); the contact pressure increased significantly in groups F, H, and I when compared with group A (P<0.05); the peak pressure increased significantly in groups F and I when compared with group A (P<0.05). There were two main anterior-lateral and anterior-medial contact centers in normal tibiotalar joint, respectively; and the force center was in anterior-lateral part, just near the center of tibiotalar joint. While the fibula was preserved, the force center transferred laterally with increased varus angles; and the force center transferred medially with increased valgus angles. However, the force center transferred oppositely to the medial part with increased varus angles, and laterally with increased valgus angles after fibular osteotomy. Conclusion: Fibular osteotomy facilitates the tibiotalar contact pressure translation, and is helpful for ankle joint realignment in suitable cases.

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The influence of the flexibility of the chair seat on pressure peak and distribution of the contact area in individuals with cerebral palsy during the execution of a task

Disability and Rehabilitation Assistive Technology ◽

10.3109/17483107.2010.529632 ◽

2010 ◽

Vol 6 (4) ◽

pp. 331-337 ◽

Cited By ~ 2

Author(s):

Lígia Maria Presumido Braccialli ◽

Andréia Naomi Sankako ◽

Ana Carla Braccialli ◽

Franciane Teixeira Oliveira ◽

Paulo Roberto Garcia Lucareli

Keyword(s):

Cerebral Palsy ◽

Contact Area ◽

Pressure Peak

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Plantar support adaptations in healthy subjects after eight weeks of barefoot running training

PeerJ ◽

10.7717/peerj.8862 ◽

2020 ◽

Vol 8 ◽

pp. e8862

Author(s):

Celso Sánchez-Ramírez ◽

Luis M. Alegre

Keyword(s):

Peak Pressure ◽

Time Factor ◽

Flat Foot ◽

Barefoot Running ◽

Running Training ◽

Significant Difference ◽

Increasing Trend ◽

Pressure Peak ◽

Reaction Forces ◽

The Moment

Background Although the studies of barefoot running have intensified, it is still missing longitudinal work analyzing the effects of barefoot running on the phases of plantar support. The objective of this research was to analyze the modifications undergone by the Total Foot Contact (TFC) phase and its Flat Foot Phase (FFP) in subjects beginning the practice of barefoot running, in its acute and chronic effects. Methods A total of 28 subjects were divided into the Barefoot Group (BFGr) (n = 16) and the Shod Group (SHGr) (n = 12), evaluated before (Baseline) and after running for 20 min at 3.05 m·s−1 (Post 20 min Running), and at the end of a running training protocol with an 8-week long progressive volume (Post-8-week Training). The dynamic plantar support was measured with a baropodoscope. The duration of TFC (ms), the moment at which the FFP occurred, the maximum surface of TFC (MSTFC) (cm2), the FFP surface (SFFP) (cm2), the peak pressure of TFC (PP°TFC) (kg·cm−2), and the peak pressure of FFP (PP°FFP) (kg·cm−2) were recorded. The 3 × 2 ANOVA analysis was made to determine the effects and interactions that the condition produced (Shod/Barefoot), and the time factor (Baseline/Post 20 min Running/Post-8-week Training). Results The condition factor caused more significant effects than the time factor in all the variables. Duration of TFC in BFGr showed significant differences between the Baseline and Post-8-week Training (p = 0.000) and between Post-20-min Running and Post-8-week Training (p = 0.000), with an increasing trend. In the moment at which the FFP occurred a significant increase (p = 0.029) increase was found in Post-20 min Running (48.5%) compared to the Baseline (42.9%). In MSTFC, BFGr showed in Post-8-week Training values significantly higher than the Baseline (p = 0.000) and than Post-20-min Running (p = 0.000). SHGr presented a significant difference between the Baseline and Post-8-week Training (p = 0.040). SFFP in BFGr modified its values with an increasing trend (p = 0.000). PP°TFC in BFGr showed a significant decrease (p = 0.003) in Post-8-week Training (1.9 kg·cm−2) compared to the Baseline (2.4 kg·cm−2). In PP°FFP significant decreases were recorded in BFGr and between Post-8-week Training and Baseline (p = 0.000), and Post-8-week Training and Post 20 min Running (p = 0.035). Conclusions The adaptation took place after the 8-week training. The adaptations to running barefoot were characterized by causing an increase of the foot’s plantar support in TFC and in FFP, as well as a decrease of the plantar pressure peak in both phases. Also, there is an increased duration of the TFC and FFP, which may be related to an acquired strategy to attenuate the impacts of the ground’s reaction forces.

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Ankle Joint Pressure in Supination-External Rotation Injuries: A Dynamic Biomechanic Cadaveric Study

Foot & Ankle Orthopaedics ◽

10.1177/2473011420s00306 ◽

2020 ◽

Vol 5 (4) ◽

pp. 2473011420S0030

Author(s):

Fabian Krause ◽

Ivan Zderic ◽

Angela Seidel ◽

Boyko Gueorguiev ◽

Marc C. Attinger ◽

...

Keyword(s):

Operative Treatment ◽

Contact Area ◽

Peak Pressure ◽

External Rotation ◽

Clinical Results ◽

Deltoid Ligament ◽

Type Ii ◽

Type Iv ◽

Joint Contact ◽

Supination External Rotation

Category: Ankle; Basic Sciences/Biologics; Trauma Introduction/Purpose: In isolated lateral malleolar fractures of the supination-external rotation (SER) type and competent medial stabilizers (type II and III), non-operative treatment has yielded excellent outcome. With complete rupture of the deltoid ligament (SER type IV) fracture instability increases substantially. The rationale for operative treatment of SER type IV fractures is based upon good clinical results and previous biomechanical studies. A significant reduction of the ankle contact area that however is caused by an artificially forced lateralization of the talus in the ankle mortise has been demonstrated. Presumed resultant elevated joint contact stresses are thought to lead to ankle arthritis in the longterm. Methods: In 12 lower leg specimen SER type injuries were simulated by gradual bony and ligamentous destabilization of the ankle from lateral to medial according to the mechanism of injury as described by Lauge and Hansen. High-resolution pressure sensors placed in the ankle joint recorded tibio-talar pressure changes at physiologic weightbearing (700N) in three positions (plantigrade, 10° dorsiflexion and 20° plantarflexion). Results: With increasing instability changes of the ankle kinematics were seen in SER II and III fractures with the same trend also in SER IV lesions. In the plantigrade position, the medial clear space (MCS) increased significantly from an average of 2.5+-0.4mm (no fracture) to 3.9+-1.1mm (SER type IV fracture). However, the corresponding peak pressure increased only slightly from 2.6+- 0.5 mPa to 3.0+-1.4 mPa on average, and the contact area decreased slightly from 810+-42 mm2 to 735+-27mm2 on average representing a non-significant reduction of only 9% of the contact area (p=0.08) after the deep deltoid ligament was completely dissected.The comparison of the results in plantigrade and plantarflexed position revealed substantial differences for MCS, contact area and center of force. Conclusion: Under physiologic load SER type IV isolated lateral malleolar fracture with completely disrupted deep deltoid ligament led to a significant increase of the MCS, but neither to a significant decrease of the of the joint contact area nor significant increase of peak pressure. Clinical Relevance: The findings of this biomechanical study support the recently reported good clinical results of non-operative treatment of SER type II to IV fractures.

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The effect of medial arch support over the plantar pressure and triceps surae muscle strength after prolonged standing

Medical Journal of Indonesia ◽

10.13181/mji.v24i3.1198 ◽

2015 ◽

Vol 24 (3) ◽

pp. 146-9 ◽

Cited By ~ 1

Author(s):

Hindun Saadah ◽

Deswaty Furqonita ◽

Angela Tulaar

Keyword(s):

Muscle Strength ◽

Contact Area ◽

Plantar Pressure ◽

Peak Pressure ◽

Standing Position ◽

Triceps Surae ◽

Prolonged Standing ◽

Triceps Surae Muscle ◽

Before And After ◽

Arch Support

Background: The activity with prolonged standing position is one of the causes of abnormalities in the lower leg and foot. The aim of this study is to discover the effect of medial arch support over the distribution of plantar pressure when standing and walking.Methods: This was an experimental study with pre- and post-design the strength of triceps surae muscle after prolonged standing, was also evaluated in an experimental study with pre- and post-design. Variables of plantar pressure measurement are the contact area and pressure peak were measured by using the Mat-scan tool. The measurement of the triceps surae muscle strength was done with a hand-held dynamometer, before and after using the medial arch support. Measurement was performed before and after working with prolonged standing position which took place about seven hours using the medial arch support inserted in the shoes. Data was analyzed using paired T-test.Results: There was a significant difference of peak pressure between standing (p = 0.041) and walking (p = 0.001). Whereas the contact area showed a significant decrease in the width of the contact area when standing (104.12 ± 12.42 vs 99.08 ± 10.21 p = 0.023). Whereas, the triceps surae muscle strength pre- and post-standing prolonged did not indicate a significant difference.Conclusion: There was decrease in peak pressure when standing and walking and decrease in contact area when standing on plantar after used of the medial arch support after prolonged standing.

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Development of Pant-Type Harness with Fabric Air-Pocket for Pain Relief

Applied Sciences ◽

10.3390/app9091921 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1921

Author(s):

Dongwoo Nam ◽

Miyeon Kwon ◽

Juhea Kim ◽

Bummo Ahn

Keyword(s):

Contact Area ◽

Peak Pressure ◽

Applied Pressure ◽

The Body ◽

Area Measurement ◽

Medical Applications ◽

Air Pocket ◽

Long Time ◽

Developed Pressure ◽

Air Pockets

Harnesses can be used in various applications, such as entertainment, rescue operations, and medical applications. Because users are supported on the harness for a long time, they should feel comfortable wearing the harnesses. However, existing commercial harnesses are uncomfortable to wear and cause continuous serious pain. Therefore, in this study, a new pant-type harness with a fabric air pocket to reduce the applied pressure on the body, especially in the groin, is proposed. Keeping this in mind, we have designed and developed the pant-type harness. In addition, we performed pressure and contact area measurement experiments using the harness developed, pressure sensor, and a human mannequin. Peak and mean pressures and contact areas near the groin and waist were measured in the experiments. From the results, when air is injected in the air pockets, the peak pressure and contact area near the waist increased, and the peak pressure near the groin decreased. This means that the pressure applied on the human mannequin near the groin reduces because of the increased contact area near the waist, which is achieved by multi-layered air pockets. In this study, we proposed the optimal design of a novel pant-type harness that can address the limitations of existing harnesses. The proposed harness can be used for a prolonged time in applications, such as virtual reality entertainment, rescue operations, and rehabilitation.

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CLEAR Cleat: A Proof-of-Concept Trial of an Aerobic Activity Facilitator to Reduce Plantar Forefoot Pressures and Their Potential in Those with Foot Ulcers

Journal of the American Podiatric Medical Association ◽

10.7547/0980261 ◽

2008 ◽

Vol 98 (4) ◽

pp. 261-267 ◽

Cited By ~ 2

Author(s):

Erin E. Klein ◽

Ryan T. Crews ◽

Stephanie C. Wu ◽

James S. Wrobel ◽

David G. Armstrong

Keyword(s):

Contact Area ◽

Peak Pressure ◽

Proof Of Concept ◽

Aerobic Activity ◽

Time Integral ◽

Plantar Aspect ◽

Pressure Time ◽

The Right ◽

Recumbent Bicycle ◽

Healthy Participants

Background: Exercise has not been studied extensively in persons with active neuropathic diabetic foot wounds, primarily because a device does not exist that allows patients to exercise while sufficiently off-loading pressure at the ulcer site. The purpose of this project was to demonstrate a device that reduces cycling plantar forefoot pressure. Methods: Ten healthy participants rode a recumbent bicycle under three cycling conditions. While the left foot interaction remained constant with a standard gym shoe and pedal, the right foot was exposed to a control condition with standard gym shoe and pedal, gym shoe and specialized cleat, and gym shoe with an off-loading insole and specialized cleat. Pressure and contact area of the plantar aspect of the feet were recorded for a 10-sec interval once during each minute of each condition’s 7-min trial. Results: The off-loading insole and specialized cleat condition yielded significantly lower (P < .01) peak pressure, contact area, and pressure–time integral values in the forefoot than the specialized cleat condition with gym shoe, which yielded significantly lower values (P < .01) than the standard gym shoe and pedal. Conclusion: Modifications to footwear may alter plantar forefoot pressures, contact area, and pressure–time integrals while cycling. The CLEAR Cleat could play a significant role in the facilitation of fitness in patients with (or at high risk for) neuropathic wounds. (J Am Podiatr Med Assoc 98(4): 261–267, 2008)

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