Evaluation and selection of shoe wear and orthoses for the runner

Impact of bilateral motion control shoes with outsole adjustment on gait asymmetry in individuals with mild leg length discrepancy

BACKGROUND

Footwear adjustment is recommended in the management plan of leg length discrepancy. However, it is not clear how the outsole of motion control shoe adjustment influences trunk symmetry and walking performance.

RESEARCH QUESTION

Does bilateral adjustment of the outsole affect trunk and pelvis symmetry and ground reaction force during walking in individuals with leg length discrepancy?

METHODS

20 mild leg length discrepancy participants were recruited into a cross-sectional study. All subjects performed a walking trial with their habitual shoes to determine the outsole adjustment. Four trials of walking were carried out in the order of unadjusted and bilateral adjusted motion control air-cushion shoes. Shoulder level differences and trunk and pelvic motion were assessed, while the ground reaction force at the heel strike was reported. A paired t-test was performed to compare the differences between the conditions with a significance level at p < 0.05.

RESULTS

During walking trials, mild leg length discrepancy participants with the adjusted shoe displayed lower variations in the maximum shoulder height differences (p = 0.001) and trunk rotation angle (p = 0.002) than those with the unadjusted shoe. Also, there was a significant reduction in the vertical ground reaction force (p = 0.030), but not in the anteroposterior or mediolateral directions, during walking in the adjusted shoe condition compared to the unadjusted shoe condition.

SIGNIFICANCE

The outsole adjustment of the bilateral motion control shoes can improve trunk symmetry while decreasing the ground impact at the heel strike. The study provides additional information to prescribe or recommend footwear adjustment to improve walking symmetry in leg length discrepancy participants.

Effect of 3D printed foot orthoses stiffness and design on foot kinematics and plantar pressures in healthy people

BACKGROUND

Foot orthoses (FOs) have been widely prescribed to alter various lower limb disorders. FOs' geometrical design and material properties have been shown to influence their impact on foot biomechanics. New technologies such as 3D printing provide the potential to produce custom shapes and add functionalities to FOs by adding extra-components.

RESEARCH QUESTION

The purpose of this study was to determine the effect of 3D printed FOs stiffness and newly design postings on foot kinematics and plantar pressures in healthy people.

METHODS

Two pairs of ¾ length prefabricated 3D printed FOs were administered to 15 healthy participants with normal foot posture. FOs were of different stiffness and were designed so that extra-components, innovative flat postings, could be inserted at the rearfoot. In-shoe multi-segment foot kinematics as well as plantar pressures were recorded while participants walked on a treadmill. One-way ANOVAs using statistical non-parametric mapping were performed to estimate the effect of FOs stiffness and then the addition of postings during the stance phase of walking.

RESULTS

Increasing FOs stiffness altered frontal and transverse plane foot kinematics, especially by further reducing rearfoot eversion and increasing the rearfoot abduction. Postings had notable effect on rearfoot frontal plane kinematics, by enhancing FOs effect. Looking at plantar pressures, wearing FOs was associated with a shift of the loads from the rearfoot to the midfoot region. Higher peak pressures under the rearfoot and midfoot (up to +31.7 %) were also observed when increasing the stiffness of the FOs.

SIGNIFICANCE

3D printing techniques offer a wide range of possibilities in terms of material properties and design, providing clinicians the opportunity to administer FOs that could be modulated according to pathologies as well as during the treatment by adding extra-components. Further studies including people presenting musculoskeletal disorders are required.

Running in highly cushioned shoes increases leg stiffness and amplifies impact loading

Running shoe cushioning has become a standard method for managing impact loading and consequent injuries due to running. However, despite decades of shoe technology developments and the fact that shoes have become increasingly cushioned, aimed to ease the impact on runners' legs, running injuries have not decreased. To better understand the shoe cushioning paradox, we examined impact loading and the spring-like mechanics of running in a conventional control running shoe and a highly cushioned maximalist shoe at two training speeds, 10 and 14.5 km/h. We found that highly cushioned maximalist shoes alter spring-like running mechanics and amplify rather than attenuate impact loading. This surprising outcome was more pronounced at fast running speed (14.5 km/h), where ground reaction force impact peak and loading rate were 10.7% and 12.3% greater, respectively, in the maximalist shoe compared to the conventional shoe, whereas only a slightly higher impact peak (6.4%) was found at the 10 km/h speed with the maximalist shoe. We attribute the greater impact loading with the maximalist shoes to stiffer leg during landing compared to that of running with the conventional shoes. These discoveries may explain why shoes with more cushioning do not protect against impact-related running injuries.

Effect of foot orthosis design on lower limb joint kinematics and kinetics during walking in flexible pes planovalgus: A systematic review and meta-analysis

BACKGROUND

Foot orthoses are commonly used for the management of excessive foot pronation in people with pes planovalgus. However, results are inconsistent due to variability in orthosis geometrical designs. This systematic review with meta-analysis aimed to classify and investigate the effects of foot orthoses, based on their design, in terms of lower limb kinematics and kinetics in people with pes planovalgus.

METHODS

Electronic databases were searched up until August 2017. Peer-reviewed journal studies including adult participants with flexible pes planovalgus and reporting kinematics and kinetics effects of foot orthoses during walking were included and classified based on the orthosis design. Eleven studies were retained and assessed according to methodological (mean 76.1%; range [63.2%-84.2%] - high) and biomechanical (mean 71.6%; range [44.4%-100%] - moderate) qualities. Meta-analysis was performed by calculating the effect size, using standardized mean differences, between control and orthotics conditions.

FINDINGS

Meta-analysis revealed less rearfoot eversion with the use of foot orthoses including medial forefoot or both forefoot and rearfoot posting. However, no significant effect of foot orthoses with arch support and neutral rearfoot posting to control excessive foot pronation were found. In terms of kinetics, none of the foot orthoses showed effects.

INTERPRETATION

Using medial posting is the most effective foot orthotic feature to reduce the peak rearfoot eversion and to control excessive foot pronation. Nevertheless, heterogeneity between study protocols contributes to the low evidences of foot orthoses effects on kinematics and kinetics during walking in people with pes planovalgus.

Runner's knowledge of their foot type: do they really know?

BACKGROUND

The use of correct individually selected running shoes may reduce the incidence of running injuries. However, the runner needs to be aware of their foot anatomy to ensure the "correct" footwear is chosen.

OBJECTIVES

The purpose of this study was to compare the individual runner's knowledge of their arch type to the arch index derived from a static footprint.

METHODS

We examined 92 recreational runners with a mean age of 35.4±11.4 (12-63) years. A questionnaire was used to investigate the knowledge of the runners about arch height and overpronation. A clinical examination was undertaken using defined criteria and the arch index was analysed using weight-bearing footprints.

RESULTS

Forty-five runners (49%) identified their foot arch correctly. Eighteen of the 41 flat-arched runners (44%) identified their arch correctly. Twenty-four of the 48 normal-arched athletes (50%) identified their arch correctly. Three subjects with a high arch identified their arch correctly. Thirty-eight runners assessed themselves as overpronators; only four (11%) of these athletes were positively identified. Of the 34 athletes who did not categorize themselves as overpronators, four runners (12%) had clinical overpronation.

CONCLUSION

The findings of this research suggest that runners possess poor knowledge of both their foot arch and dynamic pronation.

Application of wedged foot orthosis effectively reduces pain in runners with pronated foot: a randomized clinical study

OBJECTIVE

To examine the effects of foot orthosis intervention during a 60-minute running test in pronated-foot runners with overuse knee or foot pain during running.

DESIGN

A randomized, controlled design.

SETTING

Sports gym.

PARTICIPANTS

Twenty-four runners with pronated foot who experienced pain over anterior knee or foot region during running were recruited and randomized into the treatment, or the control, group.

INTERVENTIONS

A soft insole with a semi-rigid rearfoot medial wedge was given to the treatment group, and a soft insole without corrective posting was applied to the control group.

OUTCOME MEASURES

The immediate and short-term effects of orthosis application on incidence of pain, pain intensity and onset time were evaluated using the 60-minutes treadmill test.

RESULTS

Immediately after wearing the foot orthosis, pain incidence reduced in the treatment group but not in the control group (P = 0.04). After two weeks, seven (58%) subjects in the treatment group and one (8%) in the control group were free of pain during the test (P = 0.01). The pain intensity score decreased significantly after orthosis application, from 35.5 to 17.2 (immediate effect, P = 0.014), then to 12.3 (short-term effect, P < 0.001).

CONCLUSION

The rearfoot medially-wedged insole was a useful intervention for preventing or reducing painful knee or foot symptoms during running in runners with pronated foot.

The effects of enhanced plantar sensory feedback and foot orthoses on midfoot kinematics and lower leg neuromuscular activation

Excessive foot pronation has been associated with injuries of the lower extremity. No research has investigated the effect of enhancing plantar sensory feedback on foot pronation. The aim of this study was to determine whether a shoe with enhanced plantar sensory feedback reduces midfoot pronation. Midfoot kinematics and electromyography of the peroneus longus, tibialis anterior and medial gastrocnemius of 21 males (age: 21.0±4.0 years, height: 176.8±5.0 cm, mass: 73.3±6.5 kg) were recorded whilst walking in a neutral shoe, a neutral shoe with a prefabricated foot orthotic and a neutral shoe with nodules located on the plantar-medial insole (experimental shoe). Friedman's ANOVA and Wilcoxon tests were used to evaluate differences between shoe conditions. Mean midfoot-tibia angles during ground contact were significantly more supinated when wearing the experimental shoe (+7.14°, p=0.023) or orthotic (+3.83°, p=0.006) compared to the neutral shoe. During the loading phase, midfoot angles were significantly more supinated when wearing the experimental shoe compared to the orthotic (+5.53°, p=0.008) or neutral shoe (+6.20°, p=0.008). In the midstance phase, midfoot supination was significantly higher in the orthotic compared to the neutral shoe (+2.79°, p=0.006). Finally, supination was increased during the propulsive phase when wearing the experimental shoe compared to the orthotic (+7.43°, p=0.010) or neutral shoe (+10.83°, p=0.009). No significant (p<0.05) differences in muscle activation were observed. These results suggest that increasing plantar sensory feedback to the medial aspect of the foot reduces midfoot pronation during an acute bout of walking. Further work is needed to explore whether these effects remain over longer time periods.

Effect of motion control running shoes compared with neutral shoes on tibial rotation during running

OBJECTIVE

To determine whether a motion control running shoe reduces tibial rotation in the transverse plane during treadmill running.

DESIGN

An experimental study measuring tibial rotation in volunteer participants using a repeated measures design.

SETTING

Human Movement Laboratory, School of Health Professions, University of Brighton.

PARTICIPANTS

Twenty-four healthy participants were tested. The group comprised males and females with size 6, 7, 9 and 11 feet. The age range for participants was 19 to 31 years.

MAIN OUTCOME MEASURES

The total range of proximal tibial rotation was measured using the Codamotion 3-D Movement Analysis System.

RESULTS

A one-tailed paired t-test indicated a statistically significant decrease in the total range of proximal tibial rotation when a motion control shoe was worn (mean difference 1.38°, 95% confidence interval 0.03 to 2.73, P=0.04).

CONCLUSIONS

There is a difference in tibial rotation in the transverse plane between a motion control running shoe and a neutral running shoe. The results from this study have implications for the use of supportive running shoes as a form of injury prevention.

Comparative biomechanical effectiveness of over-the-counter devices for individuals with a flexible flatfoot secondary to forefoot varus

OBJECTIVES

Evaluate effects of a new off-the-shelf insert on frontal plane foot biomechanics and compare effectiveness of the new and an existing off-the-shelf insert and a motion-control shoe in neutralizing frontal plane foot biomechanics.

DESIGN

Descriptive.

SETTING

Biomechanics laboratory.

PARTICIPANTS

Fifteen uninjured subjects with a flexible flatfoot secondary to forefoot varus.

ASSESSMENT OF RISK FACTORS

Three-dimensional kinematic and kinetic data were collected as subjects walked and jogged at their self-selected speed while wearing a motion-control running shoe, the shoe with a new off-the-shelf insert, and the shoe with an existing off-the-shelf insert.

MAIN OUTCOME MEASURES

Frontal plane kinematics and rearfoot kinetics were evaluated during stance. Statistical analysis was performed using a repeated measures analysis of variance and Student-Newman-Keuls post hoc tests (α ≤ 0.05).

RESULTS

The new insert and motion-control shoe placed the forefoot in a less-everted position than the existing off-the-shelf insert during walking. There were no differences in forefoot kinematics during jogging, nor were there differences in rearfoot motion during walking or jogging. The rearfoot eversion moment was significantly lower with the new off-the-shelf insert compared with the motion-control shoe and the existing insert during walking and jogging.

CONCLUSIONS

A new off-the-shelf device is available that promotes more neutral frontal plane biomechanics, thus providing a theoretical rationale for using this device for injury prevention and treatment. The comparative biomechanical effectiveness of a motion-control shoe and the orthotic inserts may assist health care professionals in selecting a device to correct the flatfoot structure.

Effect of medial arch-heel support in inserts on reducing ankle eversion: a biomechanics study

Background

Excessive pronation (or eversion) at ankle joint in heel-toe running correlated with lower extremity overuse injuries. Orthotics and inserts are often prescribed to limit the pronation range to tackle the problem. Previous studies revealed that the effect is product-specific. This study investigated the effect of medial arch-heel support in inserts on reducing ankle eversion in standing, walking and running.

Methods

Thirteen pronators and 13 normal subjects participated in standing, walking and running trials in each of the following conditions: (1) barefoot, and shod condition with insert with (2) no, (3) low, (4) medium, and (5) high medial arch-heel support. Motions were captured and processed by an eight-camera motion capture system. Maximum ankle eversion was calculated by incorporating the raw coordinates of 15 anatomical positions to a self-compiled Matlab program with kinematics equations. Analysis of variance with repeated measures with post-hoc Tukey pairwise comparisons was performed on the data among the five walking conditions and the five running conditions separately.

Results

Results showed that the inserts with medial arch-heel support were effective in dynamics trials but not static trials. In walking, they successfully reduced the maximum eversion by 2.1 degrees in normal subjects and by 2.5–3.0 degrees in pronators. In running, the insert with low medial arch support significantly reduced maximum eversion angle by 3.6 and 3.1 degrees in normal subjects and pronators respectively.

Conclusion

Medial arch-heel support in inserts is effective in reducing ankle eversion in walking and running, but not in standing. In walking, there is a trend to bring the over-pronated feet of the pronators back to the normal eversion range. In running, it shows an effect to restore normal eversion range in 84% of the pronators.