Effects of a contoured foot orthosis and flat insole on plantar pressure and tibial acceleration while walking in defence boots

Associations between static foot posture, dynamic in-shoe plantar foot forces and knee pain in people with medial knee osteoarthritis: A cross-sectional exploratory study

OBJECTIVE

To investigate relationships between static foot posture, dynamic plantar foot forces and knee pain in people with medial knee osteoarthritis (OA).

DESIGN

Data from 164 participants with symptomatic, moderate to severe radiographic medial knee OA were analysed. Knee pain was self-reported using a numerical rating scale (NRS; scores 0-10; higher scores worse) and the Knee Injury and Osteoarthritis Outcome Score pain subscale (KOOS; scores 0-100; lower scores worse). Static foot posture was assessed using clinical tests (foot posture index, foot mobility magnitude, navicular drop). Dynamic plantar foot forces (lateral, medial, whole foot, medial-lateral ratio, arch index) were measured using an in-shoe plantar pressure system while walking. Relationships between foot posture and plantar forces (independent variables) and pain (dependent variables) were evaluated using linear regression models, unadjusted and adjusted for sex, walking speed, Kellgren & Lawrence grade, shoe category, and body mass (for dynamic plantar foot forces).

RESULTS

No measure of static foot posture was associated with any knee pain measure. Higher medial-lateral foot force ratio at midstance, and a higher arch index during overall stance, were weakly associated with higher knee pain on the NRS (regression coefficient = 0.69, 95% confidence interval (CI) 0.09 to 1.28) and KOOS (coefficient=3.03, 95% CI 0.71 to 5.35) pain scales, respectively.

CONCLUSION

Dynamic plantar foot forces, but not static foot posture, were associated with knee pain in people with medial knee OA. However, the amount of pain explained by increases in plantar foot force was small; thus, these associations are unlikely to be clinically meaningful.

Effects of a range of 6 prefabricated orthotic insole designs on plantar pressure in a healthy population: A randomized, open-label crossover investigation

BACKGROUND

Prefabricated orthotic insoles are widely commercially available for self-selection to treat foot and lower-body musculoskeletal pain, without requiring advice from health care professionals. Although they are generally designed to mimic traditional design features of custom-made orthotics used in clinical practice, the effects of prefabricated insoles on plantar pressure distribution are poorly understood.

OBJECTIVE

This investigation aimed to evaluate and directly compare the effects of a range of 6 different commercially available prefabricated orthotic insole designs on plantar pressure in healthy individuals.

METHODS

This was a single-center, randomized, open-label, crossover investigation. In-shoe dynamic pressure (F-scan) was investigated in 24 healthy subjects with normal foot posture, wearing standard shoes alone and in combination with 6 different orthotic insoles, consecutively, measured on a single day. The biomechanical impact of each insole was determined by the statistical significance of changes from baseline measurements (standard shoe alone).

RESULTS

Insoles with heel cups and medial arch geometries consistently increased contact area at medial arch and whole-foot regions and reduced both plantar peak pressure (PP) and pressure time integral at medial arch and heel regions.

CONCLUSIONS

This investigation has aided in further understanding the mode of action of prefabricated insoles in a healthy population. The insoles in this study redistributed plantar pressure at key regions of the foot, based on design features common to prefabricated insoles. Prefabricated orthotic insoles represent an easily accessible means of reducing lower-body musculoskeletal stress for those who spend prolonged periods of time on their feet.

What's the Impact of Safety Footwear on Workers Concerning Foot-Related Problems? A Systematic Review

BACKGROUND

This study aims to assess the impact of safety footwear (SF) on workers concerning foot-related problems, especially regarding discomfort, foot pain, and skin lesions.

METHODS

A literature search of PubMed, Embase, Scopus, and Cochrane databases was performed according to PRISMA guidelines. Studies reporting foot-related problems in workers wearing SF were included. Exclusion criteria included non-English papers, reviews, laboratory and animal studies, expert opinions, letters to the editor, and grey literature. The quality assessment was performed using the Newcastle-Ottawa Scale. Descriptive statistic was used to present data.

RESULT

The initial search results yielded 483 articles; 7 articles were included in the review process. Despite the extensive variety of SF, all studies consistently reported symptomatic discomfort and pain. The discomfort factors included heat, sweating, heaviness, and footwear flexibility, with primary issues in the toes, toecaps, or metatarsal-toe crease region. The pain prevalence ranged from 42.3% to 60.8% in various anatomical regions. Irritant Contact Dermatitis was the most common (97.9%) foot dermatosis, but other foot lesions were reported: dry skin (30.2%), calluses (30%), hard nails (28%), corns (27%), and blisters.

CONCLUSIONS

Current SFs are designed to comply with safety regulations but are influenced by the frequent occurrence of discomfort and foot problems. The literature review identified weaknesses in certain design features. Recommendations have been proposed to improve SF development. These include addressing issues such as the selection of specific types and designs of SF based on task performance and the working environment, footwear weight, and breathable materials for moisture permeation. Considerations should also encompass distinct sizing for an optimal fit, insole application, especially for prolonged standing users, and education programs to prevent foot-related issues.

Effectiveness of footwear and foot orthoses in reducing medial metatarsophalangeal joint pressure in women with hallux valgus

BACKGROUND

Hallux valgus is a common condition where the subluxation of the first metatarsophalangeal joint and lateral deviation of the hallux at the interphalangeal joint creates difficulty with footwear fit. Footwear and foot orthoses are commonly prescribed nonsurgical treatments for hallux valgus.

RESEARCH QUESTION

Do extra-width footwear and foot orthoses influence peak pressure at the medial aspect of the metatarsophalangeal and interphalangeal joints in women with hallux valgus?

METHODS

Community-dwelling women with symptomatic hallux valgus underwent gait testing when wearing their own shoes and when wearing extra-width footwear fitted with three-quarter length, arch-contouring prefabricated foot orthoses. Peak pressure (kPa) on the medial aspect of the metatarsophalangeal and medial interphalangeal joints and on the plantar surface of the foot (hallux, lesser toes, metatarsophalangeal joint 1, metatarsophalangeal joints 2-5, midfoot and heel) were measured using the novel pedar®-X system with the pedar® pad and pedar® insole, respectively (Novel, GmbH, Munich, Germany). Paired samples t-tests were used to calculate the differences between the two conditions, and the magnitude of observed differences was calculated using Cohen's d.

RESULTS

We tested 28 participants (aged 44-80 years, mean 60.7, standard deviation 10.7). Compared to their own footwear, wearing the intervention footwear and orthoses was associated with a statistically significant decrease in pressure on the medial aspect of the metatarsophalangeal joint (58.3 ± 32.8 versus 42.6 ± 32.8, p=0.026, d=0.49), increased pressure under the midfoot (70.7 ± 25.7 versus 78.7 ± 23.6, p=0.029, d=0.33) and decreased pressure underneath the heel (137.3 ± 39.0 versus 121.3 ± 34.8, p=0.019, d=0.45).

SIGNIFICANCE

The intervention footwear and orthoses significantly decreased peak pressure on the medial aspect of the first metatarsophalangeal joint but had no significant effect on the interphalangeal joint. Further studies are required to determine whether these changes are associated with improvements in symptoms associated with hallux valgus.

Effect of three different running gait cues on vertical tibial acceleration

BACKGROUND

Repetitive impacts during running are associated with some running injuries. Tibial acceleration is a proxy for tibial loading, and interventions that can decrease it are likely to be of interest to the running community.

RESEARCH QUESTION

What effect do running gait cues have on peak vertical tibial acceleration at a comfortable and moderate running pace, and how will these cues be executed?

METHODS

Twenty-seven participants ran on a treadmill according to the following cues in random order: run softly and lightly, run with shorter steps, and increase preferred step rate by 7.5 %. Participants maintained each condition for one minute before returning to their 'preferred' running pattern for two minutes. Two tibia-mounted inertial measurement unit sensors were used to collect tibial acceleration data at a 'comfortable' and 'moderate' run pace. A repeated measures analysis of variance test was used to compare the means between running conditions.

RESULTS

Compared to preferred running, the decrease step length (-8 %, p = 0.002, Cohen's d=0.33) and run softly and lightly (-9 %, p = 0.040, Cohen's d=0.38) cues provided a significant reduction in peak vertical tibial acceleration during a comfortable run pace. No significant difference was observed with an increase in step rate. Compared to preferred running, there was no significant difference in peak vertical tibial acceleration with any of the running gait cues during a moderate run pace.

SIGNIFICANCE

Instructing runners to decrease step length or run softly and lightly can result in small reductions in peak vertical tibial acceleration during a comfortable run pace, but running gait cues during a moderate run pace provide no effects. Differences in the execution of each cue are likely to influence overall tibial loading throughout the stride cycle. These findings provide novel biomechanical evidence for the potential effects of running retraining strategies for reducing tibial accelerations at different running paces.

Validation of In-Shoe Force Sensors during Loaded Walking in Military Personnel

The loadsol^® wireless in-shoe force sensors can be useful for in-field measurements. However, its accuracy is unknown in the military context, whereby soldiers have to carry heavy loads and walk in military boots. The purpose of this study was to establish the validity of the loadsol^® sensors in military personnel during loaded walking on flat, inclined and declined surfaces. Full-time Singapore Armed Forces (SAF) personnel (n = 8) walked on an instrumented treadmill on flat, 10° inclined, and 10° declined gradients while carrying heavy loads (25 kg and 35 kg). Normal ground reaction forces (GRF), perpendicular to the contact surface, were simultaneously measured using both the loadsol^® sensors inserted in the military boots and the Bertec instrumented treadmill as the gold standard. A total of eight variables of interest were compared between loadsol^® and treadmill, including four kinetic (impact peak force, active peak force, impulse, loading rate) and four spatiotemporal (stance time, stride time, cadence, step length) variables. Validity was assessed using Bland-Altman plots and 95% Limits of Agreement (LoA). Bias was calculated as the mean difference between the values obtained from loadsol^® and the instrumented treadmill. Results showed similar force-time profiles between loadsol^® sensors and the instrumented treadmill. The bias of most variables was generally low, with a narrow range of LoA. The high accuracy and good agreement with standard laboratory equipment suggest that the loadsol^® system is a valid tool for measuring normal GRF during walking in military boots under heavy load carriage.

Effects of contoured insoles with different materials on plantar pressure offloading in diabetic elderly during gait

To investigate the effect of contoured insoles constructed of different insole materials, including Nora Lunalastik EVA, Nora Lunalight A fresh, Pe-Lite, and PORON Medical 4708 with Langer Biomechanics longitudinal PPT arch pads on offloading plantar pressure on the foot of the elderly with Type 1 or 2 diabetes during gait. Twenty-two elderly with Type 1 or 2 diabetes participated in the study. Their plantar pressure was measured by using an insole measurement system, while the participants walked 10 m in their bare feet or used each experimental insole in random order. The plantar surface was divided into four specific regions including the toes, forefoot, midfoot, and rearfoot. The mean peak pressure (MPP) and pressure-time integral (PTI) of ten steps with or without wearing one of the four insoles were analyzed on the dominant foot and the four specific plantar regions. After completion of the activities, the participants scored each insole from 1 (the least comfortable) to 10 (the most comfortable). The analysis of variance (ANOVA) factor of the insoles had significant effects on the MPP (P < 0.001) and PTI (P = 0.004) in the dominant foot during gait. Pairwise comparison results showed that the MPP and PTI in the dominant foot were significantly lower (P < 0.001) with PORON Medical 4708 than barefoot, Nora Lunalight A fresh, and Pe-Lite. Additionally, the insole materials had a significant effect for the forefoot (P < 0.001) and rearfoot (P < 0.001) in terms of the MPP and PTI compared with the barefoot condition during gait. Regardless of the plantar region, the MPP and PTI values were the lowest when PORON Medical 4708 was used as the insole material among four insole materials. Meanwhile, a significantly lower MPP and PTI can be found in the forefoot and rearfoot with the use of the four experimental insoles when compared with barefoot. The soft insole materials (i.e., PORON medical 4708 and Nora Lunalastik EVA) had a better performance than the rigid insole materials (i.e., Nora Lunalight A fresh, and Pe-Lite) on plantar pressure offloading for diabetic elderly.

Prefabricated contoured foot orthoses to reduce pain and increase physical activity in people with hip osteoarthritis: protocol for a randomised feasibility trial

INTRODUCTION

The aim of this randomised feasibility trial is to determine the feasibility of conducting an adequately powered randomised controlled trial (RCT) investigating the efficacy of prefabricated contoured foot orthoses in people with hip osteoarthritis (OA). The secondary aims of the trial are to compare the effect of prefabricated contoured foot orthoses to a flat shoe insert comparator on outcomes of hip-related pain, physical activity and quality of life. We hypothesise that the demand, implementation, acceptability and practicality of foot orthoses as a treatment option for people with hip OA will be deemed feasible, informing the development of an adequately powered RCT to evaluate the efficacy and long term outcomes.

METHODS AND ANALYSIS

We will recruit 28 people with hip OA who will be randomised to receive either prefabricated contoured foot orthoses or flat shoe inserts to use for a 6-week period. Both groups will receive standardised education on hip OA and physical activity. The study's primary outcome is the feasibility domains of demand, implementation, acceptability and practicality. The secondary outcomes include the change in Hip Osteoarthritis Outcome Score-12, Patient Health Questionnaire-9, Brief Fear of Movement Scale for OA, Physical activity accelerometry and the Physical Activity Questionnaire-short form. Descriptive statistics will be used to describe feasibility outcomes with limited efficacy analysis used for the secondary outcomes. Linear mixed models will be used to analyse between-group differences at 6 weeks, with baseline values used as covariates, treatment allocation as a fixed factor and participant as a random factor.

ETHICS AND DISSEMINATION

This trial has been approved by the La Trobe University Human Research Ethics Committee (HEC20427), St. Vincent's Hospital Melbourne, Human Research Ethics Committee (HREC 266/20) and Northern Health Research Governance (NH-2021-292862). The results will be disseminated via a peer-reviewed journal and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT05138380.

Immediate Effect of Customized Foot Orthosis on Plantar Pressure and Contact Area in Patients with Symptomatic Hallux Valgus

Foot orthotics are recommended for the treatment of hallux valgus. The effects of customized foot orthoses (FOs) designed with both medial longitudinal and transverse arch supports are poorly understood, however. This study aimed to investigate the immediate effect of customized FOs on the plantar pressure and contact area in patients with symptomatic hallux valgus. We recruited 18 patients with a mean hallux valgus angle of 27.3 ± 11.1°. Plantar pressure while walking with FOs or flat insoles (FIs) was monitored with a wireless in-shoe plantar pressure-sensing system. Peak pressure (PP), peak force (PF), pressure-time integral (PTI), force-time integral (FTI), and contact area with FOs and FIs were compared. The PF, PTI, and FTI of the midfoot were significantly higher (p < 0.05), and the PP and PTI of the rearfoot were significantly lower (p < 0.05) with the FOs than the FIs. The FOs significantly increased the contact area of the midfoot and rearfoot (p < 0.05) and reduced the contact area of the forefoot (p < 0.05). These results suggest that customized FOs redistribute plantar pressure and the contact area of the midfoot and rearfoot, improving the functional support of the midfoot for patients with hallux valgus.

Identifying lower limb problems and the types of safety footwear worn in the Australian wine industry: a cross-sectional survey

BACKGROUND

The Australian wine industry is a valuable part of the wider Australian economy worth approximately A$45 billion annually and employs 163,790 people either full time or part time. Australian agricultural industries are amongst the nation's most dangerous workplaces with joint, ligament, muscle and tendon injuries being commonplace along with wounds, lacerations and musculoskeletal diseases. It is therefore important to try and minimise the risk of injuries to workers. The aims of this study were to (1) identify whether lower limb problems occur in the Australian wine industry and (2) identify the types of safety footwear worn.

METHODS

Participants were recruited from the Australian wine industry. The study was a cross-sectional anonymous survey of 82 questions with n = 207 respondents. Questions related to job role performed, types of lower limb problems experienced, level of pain, restriction of activities, types of footwear worn, general health and physical health.

RESULTS

The main working roles were winery (73.4%), vineyard (52.2%), laboratory (39.6%), cellar door (32.4%) and office (8.2%), with 63.3% of participants working in more than one role. Lower back pain was the most commonly reported problem at 56% followed by foot pain (36.7%), knee pain (24.6%), leg pain (21.3%), ankle pain (17.9%), hip pain (15.5%), toe pain (13%) and heel pain (11.1%). The most popular footwear used by participants were elastic sided safety boots, followed by high cut lace up safety boots with side zip. Overall, although the pain experienced was moderate, it did not impact the workers ability to perform their duties and the majority self-reported as being in very good general and physical health.

CONCLUSION

To date no data have been published on the types of lower limb problems or the types of safety footwear worn in the Australian wine industry. This study is the first to demonstrate that elastic sided safety boots were the most popular amongst respondents and that lower limb problems occur with workers. Therefore, further research into the safety footwear used in the Australian wine industry is needed to better support workers health while working in their varied roles and conditions.

Insoles of uniform softer material reduced plantar pressure compared to dual-material insoles during regular and loaded gait

There is limited evidence on the efficacy of insole materials to reduce plantar pressure during regular walking and loaded walking. In-shoe plantar pressures and subjective footwear comfort were recorded in twenty healthy participants at a self-selected treadmill walking speed in six conditions: two commercial insoles or no insole, and with or without carrying a load in a backpack. A single-material insole, comprised of polyurethane, had reduced density and compressive stiffness compared to a dual-material insole with added viscoelastic material in rearfoot and forefoot regions. Load carriage increased peak pressure across the foot. Both insoles reduced plantar pressure in the rearfoot. Yet, the softer single-material insole also attenuated forefoot pressure and loaded walking did not appear to cause bottoming-out of the polyurethane. Plantar pressure changes did not affect perceived footwear comfort. The softer single-material insole was more effective in reducing plantar pressure, further research would confirm if this influences injury prevalence.

Effectiveness and Reliability of Foot Orthoses on Impact Loading and Lower Limb Kinematics When Running at Preferred and Nonpreferred Speeds

This study examined the effect of foot orthoses used on ground reaction forces, ankle, and knee kinematics when running at preferred and nonpreferred speeds. Sixteen runners ran on instrumented treadmills at various speeds (90%, 100%, and 110% of preferred speed) when wearing arch-support and flat-control orthoses. Two-way repeated analysis of variance (ANOVA) was performed on the mean and coefficient of variation of all variables. Results indicated that arch-support orthoses experienced larger maximum loading rates than flat-control orthoses (P = .017, 95% CI, 2.22 to 19.53). Slower speed was related to smaller loading rates (preferred: P = .002, 95% CI, -17.02 to -4.20; faster: P = .003, 95% CI, -29.78 to -6.17), shorter stride length (preferred: P < .001, 95% CI, -0.204 to -0.090; faster: P < .001, 95% CI, -0.382 to -0.237), and longer contact time (preferred: P < .001, 95% CI, 0.006-0.021; faster: 95% CI, 0.012-0.042). In arch-support condition, preferred speed induced higher stride length coefficient of variation (P = .046, 95% CI, 0.035-1.117) than faster speed, while displaying no differences in flat-control condition. These findings suggest that the use of arch-support orthoses would influence impact loading, but not spatial-temporal and joint kinematics in recreational runners.

Feasibility Study of a Rapid Evaluate and Adjust Device (READ) for Custom Foot Orthoses Prescription

OBJECTIVE

Custom foot orthoses (CFOs) are typically used for the prevention and cure of lower extremity injuries (LEIs). Typically, CFOs are designed and prescribed based on iterative loops including: (1) follow-up loops between the patient and the physician, and (2) design feedback loops between the physician and the fabricator. The current prescription methodology has some deficiencies, i.e. excessive time to satisfactory treatment, and low repeatability in custom fabrication because of missing alignment, soft tissue considerations, and subjective feedback. There are significant opportunities to develop a new CFOs prescription procedure which can improve accuracy prior to the fabrication process by reducing time through minimizing iterations.

METHODS

First, a novel "rapid evaluate and adjust device" (READ) prescription methodology is proposed for CFO design by combining the follow-up loops with design feedback loop. To support the idea of the READ prescription method a novel 3D ergonomic measurement system (3DEMS) is developed. The 3DEMS is designed for the following key targets to: (1) improve the communication between the patient/physician and the fabricator, (2) reduce time to satisfactory treatment, (3) improve repeatability by considering the alignment and the soft tissue deformations, (4) archive digitally with minimal data, (5) reduce the system complexity, and (6) validate with plantar pressure measurements (i.e. Novel Pedar^®). The design process of the 3DEMS involved the following steps: (1) 3D data collection at the desired loading, (2) nested optimization to determine optimal segment design, and (3) system fabrication considering alignment and feedback control.

RESULTS

The results show that the READ prescription method with 3DEMS can be used to recreate the medial longitudinal arch for a range of arch height indices (AHI) by using a minimal number of parameters i.e. 6 parameters, and significant increases in mean peak pressure are observed between optimized and barefoot or flat segments.

CONCLUSION

This study establishes that the proposed READ prescription method with the 3DEMS may be used for CFOs prescription due to better communication between individuals in the follow-up and design loops, less time for satisfactory treatment, improved repeatability, archivable data, and low system complexity.

SIGNIFICANCE

The developed system may be used as measurement systems for CFOs, and in the future the proposed 3DEMS may prove highly important for the measurement of CFOs for flat feet.