The evaluation of modified foot orthosis on muscle activity and kinetic in a subject with flexible flat foot : single case study

An evaluation of a bespoke modified UCBL foot orthosis on subjects with flat foot using kinetic measurements and user comfort scores: A randomized controlled trial

AIM

The purpose of this study was to assess and evaluate the effect of a bespoke Modified UCBL Foot Orthosis (MUFO) using both kinetic parameters (Centre of Pressure (CoP) and the Ground Reaction Force (GRF) pattern) and comfort scores in subjects diagnosed with flat foot.

METHOD

This study included thirty-four young adults with symptomatic flatfeet. Two Kistler force plates (100 Hz) were used to record the CoP sway and GRF pattern during four conditions; 1) an MUFO and standard-fit shoe; 2) the University of California-Berkley Lab (UCBL) insole and standard-fit shoe; 3) barefoot and 4) standard-fit shoe only. The magnitude of subject comfort with UCBL and MUFO also was measured by a 10 cm Visual Analogue Scale (VAS) during walking.

RESULTS

The MUFO decreased mean lateral displacement in the initial phase and midstance of gait compared to barefoot walking. During the propulsion phase use of the new MUFO produced more lateral excursion with a mean difference of 3 mm) P < 0.001(compared to barefoot walking and standard shoe wear. No significant difference in comfort rate was found between the MUFO and UCBL (P = 0.165).

CONCLUSION

The MUFO produced effective pronation control and decreased the CoP displacement in all of stance phase.

Effect of Insoles Treatment on School-Age Children with Symptomatic Flexible Flatfoot: A 2-Year Follow-Up Study

Background

Flatfoot is common among children. Symptomatic flexible flatfoot is one of the various types which needs treatment. Wearing insoles is considered one of the conservative therapies, but its effects are still uncertain. This study aims to provide evidence for the efficacy of insoles treatment among school-aged children with symptomatic flexible flatfoot.

Methods

Patient who were Children who were diagnosed with symptomatic flexible flatfoot and received insoles treatment in authors' institute were retrospectively included. Their ages, body mass index, pain positions, pain frequency, valgus angle, arch index and visual analogue scale (VAS) score were collected before and after insole treatment.

Results

A total of 32 children were included in this study. The results showed that wearing insoles for 2 years caused a significant improvement in pain frequency, valgus angle, arch index and VAS score.

Conclusions

This study indicated that pediatric symptomatic flexible flatfoot could be relieved by wearing insoles for 2 years. Insole treatment might be a workable option for pediatric symptomatic flexible flatfoot in children older than 6 years old.

Decision Tree-Based Foot Orthosis Prescription for Patients with Pes Planus

Pes planus, one of the most common foot deformities, includes the loss of the medial arch, misalignment of the rearfoot, and abduction of the forefoot, which negatively affects posture and gait. Foot orthosis, which is effective in normalizing the arch and providing stability during walking, is prescribed for the purpose of treatment and correction. Currently, machine learning technology for classifying and diagnosing foot types is being developed, but it has not yet been applied to the prescription of foot orthosis for the treatment and management of pes planus. Thus, the aim of this study is to propose a model that can prescribe a customized foot orthosis to patients with pes planus by learning from and analyzing various clinical data based on a decision tree algorithm called classification and regressing tree (CART). A total of 8 parameters were selected based on the feature importance, and 15 rules for the prescription of foot orthosis were generated. The proposed model based on the CART algorithm achieved an accuracy of 80.16%. This result suggests that the CART model developed in this study can provide adequate help to clinicians in prescribing foot orthosis easily and accurately for patients with pes planus. In the future, we plan to acquire more clinical data and develop a model that can prescribe more accurate and stable foot orthosis using various machine learning technologies.

The effects of foot orthoses and sensory facilitation on lower limb electromyography: A scoping review

Foot orthoses (FO) are used as a treatment for biomechanical abnormalities, overuse injuries, and neuropathologies, but study of their mechanism remains inconclusive. The neuromotor paradigm has proposed that FOs may manipulate sensory input from foot sole skin to reduce muscle activity for movement optimization. This review argues that a FO likely alters the incoming mechanical stimuli transmitted via cutaneous mechanoreceptors and nociceptors as the foot sole interfaces with the surface of the orthotic. Thus, all FOs with or without intentional sensory facilitation, likely changes sensory information from foot sole cutaneous afferents. Additionally, in light of understanding and applying knowledge pertaining to the cutaneous reflex loop circuitry, FO's increasing sensory input to the motorneuron pool can change EMG to either reflex sign (increase or decrease). The purpose of this scoping review was to synthesize FO and sensory augmentation literature and summarize how FO designs can capitalize on foot sole skin to modulate lower limb electromyography (EMG). Six database searches resulted in 30 FO studies and 22 sensory studies that included EMG as an outcome measure. Results revealed task and phase specific responses with some consistencies in EMG outcomes between testing modalities, however many inconsistencies remain. Electrical stimulation reflex research provides support for a likely sensory-to-motor factor contributing to muscle activity modulation when wearing FOs. The discussion divides trends in FO treatment modalities by desired increase or decrease in each compartment musculature. The results of this review provides a benchmark for future academics and clinicians to advance literature in support of a revised neuromotor paradigm while highlighting the importance of foot sole skin in FO design.

The Effect of Customized and Silicon Insoles on Mid- and Hindfoot in Adult Flexible Pes Planovalgus

BACKGROUND

Flexible flat foot or pes planovalgus is a common foot deformity, and silicone and customized insole are commonly used as a non-operative treatment modality of flexible planovalgus. However, there are inadequate data and limited evidence available regarding the immediate effects of their use in midfoot and hindfoot of adults. The aim of this study is to quantify and compare the radiological parameters immediately on weightbearing with silicon and customized insoles and without them to assess the effect on midfoot and hindfoot of the flexible planovalgus in adults.

METHODS

A total number of 11 (8 females and 3 males) subjects with flexible pes planovalgus deformity without any other foot deformity were included in the study. Each patient was assessed three times in a random sequence without and with use of either silicon insoles or customized insole. The radiographic parameters without insole, with silicon insole, and with customized insole conditions were calculated using online available computer software Kinovea.

RESULTS

One-way ANOVA analysis was performed between groups (without insole, with silicone insole and with customized insole). The hindfoot parameters depicted that calcaneal inclination angle (CIA) was significant increased (P = 0.000) and talar declination angle (TDA) was significantly decreased (P = 0.003) only with the use of customized insole compared to without insole. The midfoot parameters depicted that the first metatarsal angle (FMA) and talonavicular coverage angle (TCA) were significantly lower with customized insole (P = 0.00) as compared to other two groups and significantly lower with silicone insole (P = 0.00) as compared to without insole group.

CONCLUSION

The results imply that the compressibility of the insole material affects the forefoot and hindfoot biomechanics differently. This study concludes that silicone insole affects only the midfoot which bears 45% of bodyweight and customized insole affects both midfoot and more importantly the hindfoot which bears 55% of bodyweight.

Immediate effect of prefabricated and UCBL foot orthoses on alignment of midfoot and forefoot in young people with symptomatic flexible flatfoot: A radiographic evaluation

BACKGROUND

Radiographic imaging has been considered the gold standard in evaluating the skeletal alignment of the foot in static weightbearing. The effects of foot orthoses on the alignment of foot bones have been mostly evaluated using lateral view x-rays. The posterior-anterior view has not been investigated extensively.

OBJECTIVES

To investigate the effects of 2 foot orthoses: University of California Biomechanics Laboratory Orthosis (UCBL) and a prefabricated orthosis (P-FFO) on the alignment of foot bones on anterior-posterior x-rays in young people with symptomatic flexible flatfoot (SFF).

STUDY DESIGN

This is a randomized, crossover study.

METHODS

Fifteen participants (mean [SD], 23.67 ± 2 years) with SFF were randomly imaged in 3 different conditions: shoes only, shoes + P-FFO, and shoes + UCBL. The talonavicular coverage, the first and the second talometatarsal angles, the intermetatarsal angle, and the cuboid abduction angle (CAA) were measured on weightbearing, anterior-posterior x-ray images for each condition.

RESULTS

Both orthotic designs demonstrated a significant reduction in the talonavicular coverage, the first and the second talometatarsal angles, and the CAA compared with the shoe-only condition (P < .001). The talonavicular coverage angle reduced by ∼11% using P-FFO compared with UCBL (P < .005). No significant differences were observed for other angles between the 2 orthotic conditions.

CONCLUSIONS

Both orthotic conditions improved the talonavicular coverage, first and the second talometatarsal angle, and CAA in young people with SFF. The walls of the UCBL orthosis did not result in further correction of the talonavicular coverage angle compared with the prefabricated FFO design.

The effect of hydrodynamic insole on foot kinematics in individuals with flexible flatfoot: Case series using a single-subject design

The medial longitudinal arch of the foot is a dynamic structure while walking. The mobility of this structure in people with flexible flatfoot is partially or completely absent. The aim of this study was to investigate the efficacy of an insole that was designed to retrieve the medial longitudinal arch mobility in people with flatfoot. The study was a case series using a single-subject design. This single-subject design study was based on three subjects with flexible flatfoot. This study was designed in two phases: the baseline phase and the intervention phase. Each phase included five measurement sessions that were done in 5 consecutive weeks. We used the celeration-line method to detect the significant differences between the phases. Significant differences were recorded in the walking velocity, step length, and medial longitudinal arch mobility parameters when using the hydrodynamic insole. The results of this study showed that using the hydrodynamic insole may have a positive effect on the foot kinematics and gait parameters in people with flexible flatfoot.

Finite element model-based evaluation of tissue stress variations to fabricate corrective orthosis in feet with neutral subtalar joint

BACKGROUND

The subtalar joint position during static stance is a crucial determinant of the peak plantar pressures and forms ideal reference point for any intervention in foot-related problems for leprosy-affected patients.

OBJECTIVES

The study pursued the hypothesis through a three-dimensional model that stress will be minimal in the distal joints of the foot when the subtalar joint is in neutral static stance position.

STUDY DESIGN

Finite element model.

METHODS

The computed tomography images of the feet for five patients suffering from Hansen's disease having no muscle weakness and joint restriction were acquired. The gray intensities corresponding to the bones of the foot from the computed tomography images were three-dimensionally reconstructed. The three-dimensional model of the human foot, incorporating the realistic geometry, and the material properties of the hard tissues were then analyzed using a finite element solver for the stress distribution on bones of the foot.

RESULTS

The results demonstrate that the position of the calcaneum in the static stance position does contribute to the varying stress in the foot.

CONCLUSION

The stresses in the bones of the foot are minimal while the subtalar is in neutral position; this position will be suitable for foot orthotic fabrication. Clinical relevance The clinicians, therapists, and podiatrists having less engineering skills can quickly assess the patient and get optimal results on the stress associated with the joints of the foot.

Comparing the immediate effects of UCBL and modified foot orthoses on postural sway in people with flexible flatfoot

BACKGROUND

Different types of foot orthoses have been prescribed for patients with flatfoot. Results of several studies have shown that orthoses were able to change balance parameters in people with flatfoot. However, the possible effect of orthosis flexibility on balance has not yet been investigated.

OBJECTIVES

The aim of the current study was to investigate the immediate effect of a rigid University of California Berkeley Laboratory (UCBL) foot orthosis, a modified foot orthosis, and a normal shoe on the postural sway of people with flexible flatfoot.

STUDY DESIGN

Quasi-experimental.

METHODS

In all, 20 young adults with flatfoot (aged 23.5 ± 2.8 years) were invited to participate in this study. The Biodex Stability System was employed to perform standing balance tests under three testing conditions, namely, shoe only, UCBL, and modified foot orthosis. Total, medial-lateral, and anterior-posterior sway were evaluated for each condition.

RESULTS

The results of this study revealed no statistical difference in the medial-lateral and anterior-posterior stability indices between foot orthoses and shoed conditions. The overall stability index with the UCBL foot orthosis, however, was significantly lower than that with the modified foot orthosis.

CONCLUSION

The UCBL foot orthosis was able to decrease total sway and improve balance in people with flexible flatfoot.

CLINICAL RELEVANCE

Results of previous studies have indicated that foot orthoses were able to affect the balance of people with flatfeet. However, the possible effects of flexible orthoses on balance have not been examined. The results of this study may provide new insight into material selection for those people with balance disorders.