Pedobarographic and kinematic analysis in the functional evaluation of two post-operative forefoot offloading shoes

Functional evaluation of a novel fibreglass-reinforced polyamide custom dynamic AFO for foot drop patients: A pilot study

BACKGROUND

Ankle-foot orthoses (AFOs) are orthopaedic devices often prescribed to treat foot drop. For patients who are not satisfied with off-the-shelf solutions, custom AFOs personalized to the patient's lower limb anatomy are required. Dynamic AFOs provide stability while allowing for physiological ankle mobility in the stance phase of walking.

RESEARCH QUESTION

Can a morphology-based dynamic custom AFO made of fiberglass-reinforced polyamide restore a quasi-normal gait pattern and improve comfort in patients with foot drop?

METHODS

In this pilot study, the legs and feet of ten foot drop patients (age=64.9 ± 11.4 years; BMI=26.2 ± 2.1 kg/m2) were scanned using a Kinect-based 3D scanner. A custom AFO was designed and produced for each patient using a fiberglass-reinforced polyamide through selective laser sintering. To assess kinematics, skin markers were placed on relevant bony landmarks according to a validated protocol. Each patient was instructed to walk at a self-selected comfortable speed under three conditions: wearing the custom AFO, wearing an off-the-shelf orthosis (Codivilla spring), and without any AFO (shod condition). Muscle activation in the tibialis anterior, gastrocnemius, rectus femoris and biceps femoris muscles in both legs was recorded using wireless sEMG sensors. The comfort and of each AFO was evaluated using a Visual Analogue Scale.

RESULTS

The custom AFO resulted in significant increase of stride length and walking speed compared to the shod condition. Except for the hip joint, which exhibited greater maximum flexion and reduced range of motion, the kinematic parameters of all other joints were similar to those observed in a healthy control population. Furthermore, the custom AFO received significantly higher comfort scores compared to the Codivilla spring.

SIGNIFICANCE

This study has provided evidence supporting the effectiveness of custom orthotic solutions in restoring lower limb kinematics and improving the perceived comfort in foot drop patients compared to off-the-shelf solutions.

Effect of gait protocols and postoperative shoes on off-loading of forefoot in preoperative patients for forefoot disorders

OBJECTIVES

The purpose of this study was to clarify the effect of gait protocols and postoperative shoes on forefoot load in preoperative patients for forefoot disorders and compare footwear comfort between different types of postoperative shoes.

METHODS

Fourteen subjects scheduled to undergo forefoot surgeries were recruited. The maximum force under the forefoot region was measured during 10 m straight walking in two gait patterns with six different shoe types. Visual analogue scale (VAS) scores for footwear comfort, subjective lower thigh pain, and electrical activities of lower thigh muscles were also evaluated.

RESULTS

The body weight-normalized maximum force under the forefoot region significantly decreased in step-to gait compared to normal gait regardless of the shoe types used. Under the same gait condition, no significant difference was observed in the forefoot off-loading effect between the different shoe types used. Significantly worse VAS scores, significantly higher tibialis anterior muscle activities, and complaints of lower thigh pain were demonstrated in the gait with the reverse camber shoe.

CONCLUSIONS

Gait protocol of step-to gait had more forefoot off-loading effect than postoperative shoes. The forefoot off-loading effect did not differ among the postoperative shoes, suggesting that postoperative shoes can be selected with an emphasis on footwear comfort.

Clinical and Radiological Outcomes of Forefoot Offloading Versus Rigid Flat Shoes in Patients Undergoing Surgery of the First Ray

BACKGROUND

It is common clinical practice to use either flat or reverse camber shoes to protect the foot for up to 6 weeks after surgery for hallux valgus or hallux rigidus. To date there is a paucity of evidence as to whether there is any difference between these 2 postoperative shoes, in either patient satisfaction or clinical outcomes.

METHODS

One hundred consecutive patients undergoing scarf/Akin osteotomies or first metatarsophalangeal joint (MTPJ) arthrodesis were recruited. Patients were randomized 50:50 to either flat or reverse camber postoperative shoes. Patients undergoing ancillary lesser toe procedures were not excluded. Patient satisfaction was assessed by visual analog scale (VAS) pain score and Likert satisfaction survey. Radiographic outcomes were reviewed at 1 year observing differences in fusion rates or deformity recurrence. There were 47 patients in the reverse cam and 43 in the flat shoe group. No difference in primary forefoot operation, additional operation, age at surgery, or preop VAS pain score was seen.

RESULTS

At 6 weeks, there was no significant difference in postop VAS pain score. The flat shoe group was significantly more likely to be satisfied with their general mobility (86.0% vs 61.7%; P = .01) and with their stability in the shoe (90.7% vs 69.6%; P = .03). No significant difference was seen between groups for nonunion or hallux valgus recurrence rates.

CONCLUSION

Both forms of postoperative footwear were effective in enabling patients to mobilize and in preventing adverse outcomes. Patients were more likely to be satisfied with a flat postoperative shoe due to improved stability and ease of mobilizing. The results of this study aid surgeon decision making for postoperative footwear in forefoot surgery.

LEVEL OF EVIDENCE

Level II, prospective randomized controlled trial.

Comparison of two different designs of forefoot off-loader shoes and their influence on gait and spinal posture

BACKGROUND

The purpose of forefoot off-loader shoes (FOS) is to unload the operated region of the foot in order to allow early mobilization and rehabilitation. However, little is known about the actual biomechanical effects of different designs of FOS on gait, pelvis and spine.

RESEARCH QUESTION

Aim of this study was to analyse and compare the effects of two different designs of forefoot unloader shoes.

METHODS

Ortho-Wedge (FOS A) and Relief-Dual® (FOS B) were evaluated in this study during standing and while walking. Changes of the pelvic position and spinal posture were measured with a surface topography system and an instrumented treadmill. Gait phases were detected automatically by a built-in pressure plate.

RESULTS

Both FOS resulted in a significant increase of pelvic obliquity, pelvic torsion, lateral deviation and surface rotation (p < 0.001) while standing. Between both shoe models, pelvic obliquity and lateral deviation (p < 0.05) were significantly different. During walking, both FOS had a significant effect on spine and pelvis (p < 0.05), however only minor differences were found between the designs. All gait parameters were affected more, wearing FOS A than B. Step length were significantly longer by wearing FOS (p < 0.005). However stance phase raised and swing phase is reduced on the leg wearing FOS A (p < 0.001).

SIGNIFICANCE

The study showed that FOS lead to significant changes in pelvic position and spinal posture during standing and while walking. A compensating shoe on the contralateral side is therefore recommend. Gait parameters however were affected more by the traditional FOS A half-shoe. The sole- design and shape of FOS B leads to a more physiological roll-over of the foot.

Fluoroscopic and Gait Analyses for the Functional Performance of a Custom-Made Total Talonavicular Replacement

The present study evaluated the restoration of joint function in a special clinical case: a professional rock climber who underwent an original total talonavicular replacement with a custom-made prosthesis after a complex articular fracture. Full body gait analysis and 3-dimensional joint kinematics using single-plane fluoroscopy were performed on the same day at the 30-month follow-up examination. Gait analysis was performed using stereophotogrammetric, dynamometric, electromyographic, and baropodometric systems. Gait analysis showed good restoration of rotation, as well as moment patterns in the main lower limb and foot joints in the operated leg. At the artificial tibiotalar joint, videofluoroscopic analysis revealed a flexion capability of about 20°, together with a few degrees of motion in the frontal and transverse planes. The neighboring joints of the foot did not present with severe kinematic abnormalities. A full talonavicular replacement can be a viable and effective solution for complex ankle injury sequelae, even in patients with highly demanding functionality.

Lower-extremity dynamics of walking in neuropathic diabetic patients who wear a forefoot-offloading shoe

BACKGROUND

A forefoot-offloading shoes has a negative-heel rocker outsole and is used to treat diabetic plantar forefoot ulcers, but its mechanisms of action and their association with offloading and gait stability are not sufficiently clear.

METHODS

Ten neuropathic diabetic patients were tested in a forefoot-offloading shoe and subsequently in a control shoe with no specific offloading construction, both worn on the right foot (control shoe on left), while walking at 1.2m/s. 3D-instrumented gait analysis and simultaneous in-shoe plantar pressure measurements were used to explain the shoe's offloading efficacy and to define centre-of-pressure profiles and left-to-right symmetry in ankle joint dynamics (0-1, 1:maximum symmetry), as indicators for gait stability.

FINDINGS

Compared to the control shoe, peak forefoot pressures, vertical ground reaction force, plantar flexion angle, and ankle joint moment, all in terminal stance, and the proximal-to-distal centre-of-pressure trajectory were significantly reduced in the forefoot-offloading shoe (P<0.01). Peak ankle joint power was 51% lower in the forefoot-offloading shoe compared to the control shoe: 1.61 (0.35) versus 3.30 (0.84) W/kg (mean (SD), P<0.001), and was significantly associated with forefoot peak pressure (R²=0.72, P<0.001). Left-to-right symmetry in the forefoot-offloading shoe was 0.39 for peak ankle joint power.

INTERPRETATION

By virtue to their negative-heel rocker-outsole design, forefoot-offloading shoes significantly alter a neuropathic diabetic patient's gait towards a reduced push-off power that explains the shoe's offloading efficacy. However, gait symmetry and stability are compromised, and may be factors in the low perceived walking discomfort and limited use of these shoes in clinical practice. Shoe modifications (e.g. less negative heel, a more cushioning insole) may resolve this trade-off between efficacy and usability.

In shoe pressure measurements during different motor tasks while wearing safety shoes: The effect of custom made insoles vs. prefabricated and off-the-shelf

Health and safety regulations in many countries require workers at risk to wear safety shoes in a factory environment. These shoes are often heavy, rigid, and uncomfortable. Wearing safety shoes daily leads to foot problems, discomfort and fatigue, resulting also in the loss of numerous working days. Currently, knowledge of the biomechanical effects of insoles in safety shoes, during working activities, is very limited. Seventeen workers from a metalworking factory were selected and clinically examined for any foot conditions. Workers feet were 3D scanned, with regards to their plantar view, and the images used to design 34 custom-insoles, based on foot and safety shoe models. Three insoles were blind-tested by each worker: custom (CUS); prefabricated with the safety-shoe (PSS), and off-the-shelf (OTS). Foot-to-insole pressure distribution was measured in seven motor tasks replicating typical working activities: single and double-leg standing; weight lifting; stair ascending and descending; normal and fast walking. Wearing CUS within safety shoes resulted in a greater uniform pressure distribution across plantar regions for most of the working activities. Peak pressure at the forefoot during normal walking was the lowest in the custom insole (CUS 275.9±55.3kPa; OTS 332.7±75.5kPa; PSS 304.5±54.2kPa). Normal and fast walking were found to be the most demanding activities in terms of peak pressure. Wearing safety shoes results in high pedobarographic parameters in several foot regions. The use of custom insoles designed on the foot morphology helps decrease peak pressure and pressure-time integral compared to prefabricated featureless insoles.