Can orthotic wedges change the lower-extremity and multi-segment foot kinematics during gait in people with plantar fasciitis?

BACKGROUND

Orthotic wedges with medial posting of the forefoot and rearfoot have been shown to be effective in controlling excessive foot pronation in people with plantar fasciitis (PF), however the best prescription remains unclear.

RESEARCH QUESTION

The aim of this study was to determine the biomechanical effects of two designs of orthotic wedges within a shoe on the hip, knee, rearfoot, and forefoot kinematics in individuals with PF.

METHODS

Thirty-five participants with PF were recruited. They were asked to walk under three randomized conditions; shod, shod with orthotic wedges with foot assessment technique 1 (W1), and shod with orthotic wedges from a new assessment technique (W2). Biomechanical outcomes included lower limb and multi-segment foot kinematics in each subphase of the stance gait, including contact phase, midstance phase, and propulsive phase.

RESULTS

Compared with shod, the W1 significantly increased rearfoot dorsiflexion, decreased peak forefoot dorsiflexion, and peak rearfoot eversion during the contact phase. In addition, W1 increased rearfoot inversion, decreased hallux dorsiflexion, and peak hallux dorsiflexion during the propulsive phase. For W2, the wedge significantly decreased peak knee internal rotation, decreased forefoot abduction, peak forefoot dorsiflexion, and peak rearfoot eversion during the contact phase. In addition, W2 increased rearfoot inversion, decreased hallux dorsiflexion, and decreased peak hallux dorsiflexion during the propulsive phase. When comparing W1 and W2, W1 showed greater rearfoot dorsiflexion during the contact phase.

SIGNIFICANCE

These findings suggest that the use of forefoot varus wedges, and the combination of forefoot and rearfoot varus wedges, can change the lower limb kinematics, the multi-segment foot kinematics estimated using markers fixed to the shoe, and the relative length of the plantar fascia which can be associated with a reduction in pain and symptoms during walking.

Effect of custom-made and prefabricated foot orthoses on kinematic parameters during an intense prolonged run

Foot orthoses are one of the most used strategies by healthy runners in injury prevention and performance improvement. However, their effect on running kinematics throughout an intense prolonged run in this population is unknown. Moreover, there is some controversy regarding the use of custom-made versus prefabricated foot orthoses. This study analysed the effect of different foot orthoses (custom-made, prefabricated and a control condition) on spatio-temporal and angular (knee flexion and foot eversion) kinematic parameters and their behaviour during an intense prolonged run. Twenty-four recreational runners performed three similar tests that consisted of running 20 min on a treadmill at 80% of their maximal aerobic speed, each one with a different foot orthosis condition. Contact and flight time, and stride length and stride rate were measured every 5 min by an optical measurement photoelectric cell system. Knee flexion and foot eversion kinematic parameters were measured by two high-speed cameras. No significant differences were found between the different foot orthoses in any of the time points studied and between the interaction of foot orthosis and behaviour over time, in any of the variables studied (P > 0.05). The use of custom-made and prefabricated foot orthoses during an intense prolonged run does not produce changes in spatio-temporal and kinematic parameters in healthy runners. These results suggest that a healthy runner maintains its ideal movement pattern throughout a 20 minute prolonged run, regardless the type of foot orthosis used.

Experimental and numerical investigation of a polypropylene orthotic device for assistance in level ground walking

This study investigates the use of an orthotic device for improving pathologic gait lacking a heel-strike and its effect on the joint loads. The orthosis is fabricated from 10-mm thick polypropylene sheets joined together using a bolted joint. The gait trials are recorded using a Qualisys motion capture system and Kistler's force platform. The data recorded in this study comprise five male and five female participants, executing level ground gait under barefoot, shod and orthotic conditions. Computed tomography reconstructed foot bone-tissue model and computer-aided design model of the orthosis are used to predict the mechanical behaviour with and without orthosis under static loading. A one-way analysis of variance is conducted to compare the peak gait parameters in the early and late stance phase between the three walking conditions. The experimental results show that the orthosis reduces the peak joint forces and the rate of change of moment at the hip, knee and ankle joints. The finite element analysis results present a decrease in foot plantar pressure from 0.74 to 0.32 MPa with orthotic usage. The results of this study indicate that the orthosis can eliminate the heel-ground gap while retaining sufficient ankle motion and providing peak joint force reduction.

Effects of medially posted insoles on foot and lower limb mechanics across walking and running in overpronating men

Anti-pronation orthoses, like medially posted insoles (MPI), have traditionally been used to treat various of lower limb problems. Yet, we know surprisingly little about their effects on overall foot motion and lower limb mechanics across walking and running, which represent highly different loading conditions. To address this issue, multi-segment foot and lower limb mechanics was examined among 11 overpronating men with normal (NORM) and MPI insoles during walking (self-selected speed 1.70±0.19m/s vs 1.72±0.20m/s, respectively) and running (4.04±0.17m/s vs 4.10±0.13m/s, respectively). The kinematic results showed that MPI reduced the peak forefoot eversion movement in respect to both hindfoot and tibia across walking and running when compared to NORM (p<0.05-0.01). No differences were found in hindfoot eversion between conditions. The kinetic results showed no insole effects in walking, but during running MPI shifted center of pressure medially under the foot (p<0.01) leading to an increase in frontal plane moments at the hip (p<0.05) and knee (p<0.05) joints and a reduction at the ankle joint (p<0.05). These findings indicate that MPI primarily controlled the forefoot motion across walking and running. While kinetic response to MPI was more pronounced in running than walking, kinematic effects were essentially similar across both modes. This suggests that despite higher loads placed upon lower limb during running, there is no need to have a stiffer insoles to achieve similar reduction in the forefoot motion than in walking.

Foot orthotics for low back pain: The state of our understanding and recommendations for future research

PURPOSE

The purpose of the article is to evaluate the literature on the use of foot orthotics for low back pain and to make specific recommendations for future research.

METHODS

Database searches were conducted using PubMed, EBSCO, GALE, Google Scholar, and clinicaltrials.gov. The biomedical literature was reviewed to determine the current state of knowledge on the benefits of foot orthotics for low back pain related to biomechanical mechanisms and clinical outcomes.

RESULTS

It may be argued that foot orthotics are experimental, investigational, or unproven for low back pain due to lack of sufficient evidence for their clinical effectiveness. This conclusion is based upon lack of high quality randomized controlled trials (RCTs). However, there is extensive research on biomechanical mechanisms underlying the benefits of orthotics that may be used to address this gap. Additionally, promising pilot studies are beginning to emerge in the literature and ongoing large-scale RCTs are addressing effects of foot orthotics on chronic low back pain.

CONCLUSIONS

Based upon the critical evaluation of the current research on foot orthotics related to biomechanical mechanisms and clinical outcomes, recommendations for future research to address the evidence-practice gaps on the use of foot orthotics for low back pain are presented.

The relationship of foot and ankle mobility to the frontal plane projection angle in asymptomatic adults

Background

The frontal plane projection angle (FPPA) is frequently used as a measure of dynamic knee valgus during functional tasks, such as the single leg squat. Increased dynamic knee valgus is observed in people with knee pathologies including patellofemoral pain and anterior cruciate injury. As the foot is the primary interface with the support surface, foot and ankle mobility may affect the FPPA. This study investigated the relationship between foot and ankle mobility and the FPPA in asymptomatic adults.

Methods

Thirty healthy people (aged 18–50 years) performed 5 single leg squats. Peak FPPA and FPPA excursion were determined from digital video recordings. Foot mobility was quantified as the difference in dorsal midfoot height or midfoot width, between non-weightbearing and bilateral weightbearing positions. Ankle joint dorsiflexion range was measured as the maximum distance in centimetres between the longest toe and the wall during a knee-to-wall lunge. Linear regressions with generalised estimating equations were used to examine relationships between variables.

Results

Higher midfoot width mobility was associated with greater peak FPPA (β 0.90, p < 0.001, odds ratio [OR] 2.5), and FPPA excursion (β 0.67, p < 0.001, OR 1.9). Lower midfoot height mobility was associated with greater peak FPPA (β 0.37, p = 0.030, OR 1.4) and FPPA excursion (β 0.30, p = 0.020, OR 1.3). Lower ankle joint dorsiflexion was also associated with greater peak FPPA (β 0.61, p = 0.008, OR 1.8) and greater FPPA excursion (β 0.56, p < 0.001, OR 1.7).

Conclusions

Foot and ankle mobility was significantly related to the FPPA during the single leg squat in healthy individuals. Specifically, higher midfoot width mobility, or lower ankle joint dorsiflexion range and midfoot height mobility, were associated with a greater FPPA. These foot mobility factors should be considered in the clinical management of knee-related disorders that are associated with a high FPPA.