Contoured, prefabricated foot orthoses demonstrate comparable mechanical properties to contoured, customised foot orthoses: a plantar pressure study

Patellar tendon bearing brace: combined effect of heel clearance and ankle status on foot plantar pressure

BACKGROUND

Heel clearance and ankle status (free or locked) are of major determinants affecting peak plantar pressures and contact area in patellar tendon bearing brace and have been separately studied by many researchers. This study investigated the combined effect of ankle status and heel clearance on contact area and peak plantar pressure in different areas of foot (hindfoot, midfoot, and forefoot).

STUDY DESIGN

Before-after repeated measurement trial.

METHODS

Nine healthy male volunteers walked 8 m with normal shoe and four conditions of patellar tendon bearing brace wear. Repeated-measure analysis of variance test was used to compare contact area and plantar pressure changes in three areas of the foot.

RESULTS

Application of patellar tendon bearing brace significantly reduced overall plantar pressure and contact area (p < 0.01). Although both contact area and plantar pressure significantly decreased in hindfoot and midfoot, plantar pressure increased in forefoot area (p < 0.05).

CONCLUSIONS

Application of the patellar tendon bearing brace can reduce the overall peak plantar pressure in the foot but increases focal plantar pressure in forefoot. Excessive lifting of the heel seems to minimize the contact area, thus increase focal pressure in forefoot. Overall, plantar pressure seems to be more effectively off-loaded by combining maximum heel clearance and restriction of the ankle joint.

CLINICAL RELEVANCE

Although effective parameters of patellar tendon bearing brace have been separately addressed in previous studies, no study was found that investigated the combined effect of ankle status and heel clearance. This study investigates the combined effect of these parameters and provides detailed information on clinical application of the patellar tendon bearing brace.

The use of 'off-the-shelf' foot orthoses in the reduction of foot symptoms in patients with early rheumatoid arthritis

BACKGROUND

Foot pain in patients diagnosed with early rheumatoid arthritis is common.

OBJECTIVES

To investigate effects of off-the-shelf foot orthoses on outcomes of swollen and tender joints, and pain, in patients with early rheumatoid arthritis.

METHODS

Thirty-five patients with painful and swollen foot joints were recruited. None had previously used foot orthoses or had contraindications to their use. Any patients with concomitant musculoskeletal disease, endocrine disorders, and neurological disease, were excluded. At baseline, participants were prescribed a customised off-the-shelf foot orthosis with chair-side modifications. Data was collected at baseline, three and six months. Foot pain (using Visual Analogue Scale) and the number of tender and swollen foot joints was measured.

RESULTS

There was a trend towards a reduction in the number of swollen and tender joints by 3 months with a further improvement by 6 months. Statistically (p<0.05) and clinically significant reductions in pain levels were also noted.

CONCLUSION

Patients diagnosed with early RA may benefit from using off-the-shelf foot orthoses with the majority of their pain reduction occurring within the first 3 months of use, but with some small further symptomatic improvement up to 6 months. There was a tendency to a reduction in swollen and tender joints although more studies are required to substantiate these findings.

Foot orthoses custom-made by vacuum forming on the non-load-bearing foot: preliminary results in male children with calcaneal apophysitis (Sever's disease)

BACKGROUND AND AIM

To our knowledge, the technique of molding orthoses to the non-load-bearing foot is still not widely investigated. The aim of this work is, therefore, first, to describe an off-loading custom-made technique and, second, to explain how it can be specifically adapted to treat Sever's disease.

TECHNIQUES

A technique of directly molding orthoses to the non-load-bearing foot by vacuum forming an insole to the foot fabricated with a combination of polyvinyl chloride and polyester resins, 30 Shore A hardness and 148 kg/m(3) density polyethylene-ethylene-vinyl-alcohol, and a cushioning heel cup of 22 Shore A polyurethane, using a directly molding orthoses technique to the non-load-bearing foot by vacuum.

DISCUSSION

Results show that this new technique could be a good alternative to traditional insoles in the management of Sever's disease pain.

The effect of removing plugs and adding arch support to foam based insoles on plantar pressures in people with diabetic peripheral neuropathy

Background

Removable plug insoles appear to be beneficial for patients with diabetic neuropathic feet to offload local plantar pressure. However, quantitative evidence of pressure reduction by means of plug removal is limited. The value of additional insole accessories, such as arch additions, has not been tested. The purpose of this study was to evaluate the effect of removing plugs from foam based insoles, and subsequently adding extra arch support, on plantar pressures.

Methods

In-shoe plantar pressure measurements were performed on 26 patients with diabetic neuropathic feet at a baseline condition, in order to identify the forefoot region with the highest mean peak pressure (MPP). This was defined as the region of interest (ROI) for plug removal.The primary outcome was measurement of MPP using the pedar® system in the baseline and another three insole conditions (pre-plug removal, post-plug removal, and post-plug removal plus arch support).

Results

Among the 26 ROIs, a significant reduction in MPP (32.3%, P<0.001) was found after removing the insole plugs. With an arch support added, the pressure was further reduced (9.5%, P<0.001). There were no significant differences in MPP at non-ROIs between pre- and post-plug removal conditions.

Conclusions

These findings suggest that forefoot plantar pressure can be reduced by removing plugs and adding arch support to foam-based insoles. This style of insole may therefore be clinically useful in managing patients with diabetic peripheral neuropathy.

The effect of prefabricated and proprioceptive foot orthoses on plantar pressure distribution in patients with flexible flatfoot during walking

BACKGROUND

Previous studies have suggested that orthoses with different constructions could alter gait parameters in flexible flatfoot. However, there is less evidence about the effect of insoles with proprioceptive mechanism on plantar pressure distribution in flatfoot.

OBJECTIVES

To assess the effect of orthoses with different mechanisms on plantar pressure distribution in subjects with flexible flatfoot.

STUDY DESIGN

Quasi-experimental.

METHODS

In total, 12 flatfoot subjects were recruited for this study. In-shoe plantar pressure in walking was measured by Pedar-X system under three conditions including wearing the shoe only, wearing the shoe with a proprioceptive insole, and wearing the shoe with a prefabricated foot insole.

RESULTS

Using the proprioceptive insoles, maximum force was significantly reduced in medial midfoot, and plantar pressure was significantly increased in the second and third rays (0.94 ± 0.77 N/kg, 102.04 ± 28.23 kPa) compared to the shoe only condition (1.12 ± 0.88 N/kg and 109.79 ± 29.75 kPa). For the prefabricated insole, maximum force was significantly higher in midfoot area compared to the other conditions (p < 0.05).

CONCLUSIONS

Construction of orthoses could have an effect on plantar pressure distribution in flatfeet. It might be considered that insoles with sensory stimulation alters sensory feedback of plantar surface of foot and may lead to change in plantar pressure in the flexible flatfoot.

CLINICAL RELEVANCE

Based on the findings of this study, using orthoses with different mechanisms such as proprioceptive intervention might be a useful method in orthotic treatment. Assessing plantar pressure can also be an efficient quantitative outcome measure for clinicians in evidence-based foot orthosis prescription.

The effect of customised and sham foot orthoses on plantar pressures

Background

The effectiveness of foot orthoses has been evaluated in many clinical trials with sham foot orthoses used as the control intervention in at least 10 clinical trials. However, the mechanical effects and credibility of sham orthoses has been rarely quantified. This study aimed to: (i) compare the effects on plantar pressures of three sham foot orthoses to a customised foot orthosis, and (ii) establish the perceived credibility and the expected benefit of each orthotic condition.

Methods

Thirty adults aged between 18 and 51 participated in this study. At 0 and 4 weeks, plantar pressure data were collected for the heel, midfoot and forefoot using the pedar^®-X in-shoe system for the following five randomly assigned conditions: (i) shoe alone, (ii) customised foot orthosis, (iii) contoured polyethylene sham foot orthosis, (iv) contoured EVA sham foot orthosis, and (v) flat EVA sham foot orthosis. At the initial data collection session, each participant completed a Credibility/Expectancy Questionnaire (CEQ) to determine the credibility and expected benefit of each orthotic condition.

Results

Compared to the shoe alone at week 0, the contoured polyethylene sham orthosis was the only condition to not significantly effect peak pressure at any region of the foot. In contrast, the contoured EVA sham orthosis, the flat EVA sham orthosis and the customised orthosis significantly reduced peak pressure at the heel. At the medial midfoot, all sham orthoses provided the same effect as the shoe alone, which corresponded to effects that were significantly different to the customised orthosis. There were no differences in peak pressure between conditions at the other mask regions, the lateral midfoot and forefoot. When the conditions were compared at week 4, the differences between the conditions were generally similar to the findings observed at week 0. With respect to credibility and expected benefit, all orthotic conditions were considered the same with the exception of the contoured polyethylene sham orthosis, which was perceived as being less credible and less likely to provide benefits.

Conclusion

The findings of this study indicate that all of the sham orthoses tested provided the same effect on plantar pressures at the midfoot and forefoot as a shoe alone. However, the contoured EVA sham orthosis and the flat EVA sham orthosis significantly reduced peak pressure under the heel, which was similar to the customised orthosis. In contrast, the contoured polyethylene sham orthosis had no significant effect on plantar pressure and was comparable to the shoe alone at all regions of the foot. Hence, lower plantar pressures were found under the heel with some sham orthoses, but not with others. Importantly, participants perceived the polyethylene sham orthosis – the sham that had no effect on plantar pressure – to be the least credible orthosis and the least likely to provide benefits. This may be critical for the design of future clinical trials as it may introduce confounding effects that produce inaccurate results. These findings provide some evidence for the mechanical effects, treatment credibility and expected benefit of sham foot orthoses, which should be considered when they are used as a control intervention in a clinical trial.

Effect of an antipronation foot orthosis on ankle and subtalar kinematics

INTRODUCTION/PURPOSE

The aim of this study was to describe the effect of an antipronation foot orthosis on motion of the heel relative to the leg and explore the individual contributions of the ankle and subtalar joints to this effect.

METHODS

Five subjects were investigated using invasive intracortical pins to track the movement of the tibia, talus, and calcaneus during walking with and without a foot orthosis.

RESULTS

The antipronation foot orthosis produced small and unsystematic reductions in eversion and abduction of the heel relative to the leg at various times during stance. Changes in calcaneus-tibia motion were comparable with those described in the literature (1°-3°). Changes at both the ankle and subtalar joints contributed to this orthotic effect. However, the nature and scale of changes were highly variable between subjects. Peak angular position, range of motion, and angular velocity in frontal and transverse planes were affected to different degrees in different subjects. In some cases, changes occurred mainly at the ankle; in other cases, changes occurred mainly at the subtalar joint.

CONCLUSION

The changes in ankle and subtalar kinematics in response to the foot orthosis contradict existing orthotic paradigms that assume that changes occur only at the subtalar joint. The kinematic changes due to the orthosis are indicative of a strong interaction between the often common function of the ankle and subtalar joints.

The effect of different depths of medial heel skive on plantar pressures

Background

Foot orthoses are often used to treat lower limb injuries associated with excessive pronation. There are many orthotic modifications available for this purpose, with one being the medial heel skive. However, empirical evidence for the mechanical effects of the medial heel skive modification is limited. This study aimed to evaluate the effect that different depths of medial heel skive have on plantar pressures.

Methods

Thirty healthy adults (mean age 24 years, range 18–46) with a flat-arched or pronated foot posture and no current foot pain or deformity participated in this study. Using the in-shoe pedar-X® system, plantar pressure data were collected for the rearfoot, midfoot and forefoot while participants walked along an 8 metre walkway wearing a standardised shoe. Experimental conditions included a customised foot orthosis with the following 4 orthotic modifications: (i) no medial heel skive, (ii) a 2 mm medial heel skive, (iii) a 4 mm medial heel skive and (iv) a 6 mm medial heel skive.

Results

Compared to the foot orthosis with no medial heel skive, statistically significant increases in peak pressure were observed at the medial rearfoot – there was a 15% increase (p = 0.001) with the 4 mm skive and a 29% increase (p < 0.001) with the 6 mm skive. No significant change was observed with the 2 mm medial heel skive. With respect to the midfoot and forefoot, there were no significant differences between the orthoses.

Conclusions

This study found that a medial heel skive of 4 mm or 6 mm increases peak pressure under the medial rearfoot in asymptomatic adults with a flat-arched or pronated foot posture. Plantar pressures at the midfoot and forefoot were not altered by a medial heel skive of 2, 4 or 6 mm. These findings provide some evidence for the effects of the medial heel skive orthotic modification.

Neuromuscular activity of the peroneal muscle after foot orthoses therapy in runners

PURPOSE

Foot orthoses are a standard option to treat overuse injury. Biomechanical data providing mechanisms of foot orthoses' effectiveness are sparse. Stability of the ankle joint complex might be a key factor. The purpose was therefore to analyze neuromuscular activity of the musculus peroneus longus in runners with overuse injury symptoms treated with foot orthoses.

METHODS

A total of 99 male and female runners with overuse injury symptoms randomized in a control group (CO) and an orthoses group (OR) were analyzed on a treadmill at 3.3 m·s(-1) before and after an 8-wk foot orthoses intervention. Muscular activity of the musculus peroneus longus was measured and quantified in the time domain (initial onset of activation (T(ini)), time of maximal activity (T(max)), total time of activation (T(tot))) and amplitude domain (amplitude in preactivation (A(pre)), weight acceptance (A(wa)), push-off (A(po))).

RESULTS

Peroneal activity in the time domain did not differ initially between CO and OR, and no effect was observed after therapy (T(ini): CO = -0.88 ± 0.09, OR = -0.88 ± 0.08/T(max): CO = 0.14 ± 0.06, OR = 0.15 ± 0.06/T(tot): CO = 0.40 ± 0.09, OR = 0.41 ± 0.09; P > 0.05). In preactivation (A(pre)), muscle activity was higher in OR after intervention (CO = 0.97 ± 0.32, 95% confidence interval = 0.90-1.05; OR = 1.18 ± 0.43, 95% confidence interval = 1.08-1.28; P = 0.003). There was no group or intervention effect during stance (A(wa): CO = 2.33 ± 0.66, OR = 2.33 ± 0.74/A(po): CO = 0.80 ± 0.41, OR = 0.88 ± 0.40; P > 0.05).

CONCLUSIONS

Enhanced muscle activation of the musculus peroneus longus in preactivation suggests an altered preprogrammed activity, which might lead to better ankle stability providing a possible mode of action for foot orthoses therapy.

Evaluation of the pressure-redistributing properties of prefabricated foot orthoses in older people after at least 12 months of wear

Foot problems are highly prevalent in older people. To treat such problems in this age-group prefabricated ('off-the-shelf') foot orthoses are frequently prescribed. However, such devices are susceptible to material compression and deformation, which may reduce their effectiveness over time. Therefore, the aim of this study was to compare the pressure-redistributing properties of new prefabricated orthoses to orthoses worn for at least 12 months. Thirty-one adults (10 males, 21 females) aged over 65 years (mean 75.4, SD 5.2) participated. Plantar pressure data were collected under the rearfoot, midfoot and forefoot using the Pedar(®) in-shoe system while participants walked along an 8m walkway wearing shoes only, new orthoses and old orthoses (orthoses were full length, dual-density prefabricated Formthotic™ devices). Compared to the shoe-only condition, both the new and old orthoses produced significant reductions in peak pressure and maximum force in the rearfoot with corresponding increases in force and contact area in the midfoot. Compared to the new orthoses, the old orthoses exhibited small but significant increases in peak pressure in the rearfoot (6%, p=0.001) and maximum force in the rearfoot (5%, p<0.001) and forefoot (2%, p=0.032). These findings indicate that the prefabricated orthoses evaluated in this study are only slightly less effective at redistributing plantar pressure after at least 12 months of wear.

Diabetic Foot Prevention: Repeatability of the Loran Platform Plantar Pressure and Load Distribution Measurements in Nondiabetic Subjects during Bipedal Standing—A Pilot Study

This study was designed to assess the repeatability of the Loran Platform and evaluate the variability of plantar pressure and postural balance, during barefoot standing in nondiabetic subjects, for future diabetic foot clinical evaluation. Measurements were taken for eight nondiabetic subjects (4 females, 4 males, aged 47±7.2 years) who had no musculoskeletal symptoms. Five variables were measured with the platform in the barefoot standing position. Ten measurements were taken using two different techniques for feet and posture positioning, during three sessions, once a week. For most measurements, no significant effect over time was found with Student'st-test (P<.000125). The ANOVA test of statistical significance confirmed that measurement differences between subjects showed higher variations than measurements taken from the same subject (P<.001). The measurements taken by the Loran Platform system were found to be repeatable.

Augmented low dye taping changes muscle activation patterns and plantar pressure during treadmill running

STUDY DESIGN

Randomized, crossover study.

OBJECTIVE

To examine changes in muscle activity and plantar pressure during running with the application of augmented low Dye (ALD) taping.

BACKGROUND

ALD taping is used clinically as part of management for lower limb injury. As of yet, no studies have examined the effect of this taping method on muscle activity and plantar pressure during running, simultaneously.

METHODS

Thirteen healthy recreational runners(mean ± SD age, 31.7 ± 4.9 years; height, 181.7 ± 4.6 cm; body mass, 81.6 ± 5.9 kg) completed a 6-minute run on a treadmill at a speed of 10 km·h⁻¹, with 3 different taping conditions (ALD, control tape, no tape), applied in randomized order. Peak and average EMG signal amplitude, onset time, and burst duration were calculated for the vastus medialis, vastus lateralis, and the gluteus medius. In-shoe plantar pressures were also recorded. All data were calculated based on an average of 20 steps collected after 5 minutes of treadmill running.

RESULTS

ALD taping significantly altered muscle activity and plantar pressure during treadmill running by (1) delaying the onset of the EMG signal of the gluteus medius, vastus medialis, and vastus lateralis, and (2) increasing lateral midfoot plantar pressure.

CONCLUSION

ALD taping significantly alters plantar pressure and muscle activation patterns during treadmill running. These findings give insight into the neuromuscular effect of a taping procedure that is used commonly in a clinical setting.

A case-series study to explore the efficacy of foot orthoses in treating first metatarsophalangeal joint pain

Background

First metatarsophalangeal (MTP) joint pain is a common foot complaint which is often considered to be a consequence of altered mechanics. Foot orthoses are often prescribed to reduce 1^st MTP joint pain with the aim of altering dorsiflexion at propulsion. This study explores changes in 1^st MTP joint pain and kinematics following the use of foot orthoses.

Methods

The effect of modified, pre-fabricated foot orthoses (X-line^®) were evaluated in thirty-two patients with 1^st MTP joint pain of mechanical origin. The primary outcome was pain measured at baseline and 24 weeks using the pain subscale of the foot function index (FFI). In a small sub-group of patients (n = 9), the relationship between pain and kinematic variables was explored with and without their orthoses, using an electromagnetic motion tracking (EMT) system.

Results

A significant reduction in pain was observed between baseline (median = 48 mm) and the 24 week endpoint (median = 14.50 mm, z = -4.88, p < 0.001). In the sub-group analysis, we found no relationship between pain reduction and 1^st MTP joint motion, and no significant differences were found between the 1^st MTP joint maximum dorsiflexion or ankle/subtalar complex maximum eversion, with and without the orthoses.

Conclusions

This observational study demonstrated a significant decrease in 1^st MTP joint pain associated with the use of foot orthoses. Change in pain was not shown to be associated with 1^st MTP joint dorsiflexion nor with altered ankle/subtalar complex eversion. Further research into the effect of foot orthoses on foot function is indicated.

Foot orthoses: how much customisation is necessary?

The relative merit of customised versus prefabricated foot orthoses continues to be the subject of passionate debate among foot health professionals. Although there is currently insufficient evidence to reach definitive conclusions, a growing body of research literature suggests that prefabricated foot orthoses may produce equivalent clinical outcomes to customised foot orthoses for some conditions. Consensus guidelines for the prescription of customised foot orthoses need to be developed so that the hypothesised benefits of these devices can be thoroughly evaluated.