Effect of an antipronation foot orthosis on ankle and subtalar kinematics

Do different multi-segment foot models detect the same changes in kinematics when wearing foot orthoses?

Background

Different multi-segment foot models have been used to explore the effect of foot orthoses. Previous studies have compared the kinematic output of different multi-segment foot models, however, no study has explored if different multi-segment foot models detect similar kinematic changes when wearing a foot orthoses. The aim of this study was to compare the ability of two different multi-segment foot models to detect kinematic changes at the hindfoot and forefoot during the single and double support phases of gait when wearing a foot orthosis.

Methods

Foot kinematics were collected during walking from a sample of 32 individuals with and without a foot orthosis with a medial heel bar using an eight-camera motion capture system. The Oxford Foot Model (OFM) and a multi-segment foot model using the Calibrated Anatomical System Technique (CAST) were applied simultaneously. Vector field statistical analysis was used to explore the kinematic effects of a medial heel bar using the two models, and the ability of the models to detect any changes in kinematics was compared.

Results

For the hindfoot, both models showed very good agreement of the effect of the foot orthosis across all three anatomical planes during the single and double support phases. However, for the forefoot, the level of agreement between the models varied with both models showing good agreement of the effect in the coronal plane but poorer agreement in the transverse and sagittal planes.

Conclusions

This study showed that while consistency exists across both models for the hindfoot and forefoot in the coronal plane, the forefoot in the transverse and sagittal planes showed inconsistent responses to the foot orthoses. This should be considered when interpreting the efficacy of different interventions which aim to change foot biomechanics.

Human ankle joint movements during walking are probably not determined by talar morphology

Knowledge about the orientation of a representative ankle joint axis is limited to studies of tarsal morphology and of quasistatic movements. The aim of our study was therefore to determine the development of the axis orientation during walking. Intracortical bone pins were used to monitor the kinematics of the talus and tibia of five healthy volunteers. The finite helical axis was determined for moving windows of 10% stance phase and its orientation reported if the rotation about the axis was more than 2°. A representative axis for ankle dorsi- and plantarflexion was also estimated based on tarsal morphology. As reported by literature, the morphology-based axis was inclined more medially upwards for dorsiflexion than for plantarflexion. However, when a mean of the finite helical axis orientations was calculated for each walking trial for dorsiflexion (stance phase 15–25%) and for plantarflexion (stance phase 85–95%), the inclination was less medially upwards in dorsiflexion than in plantarflexion in four out of five participants. Thus, it appears that the inclination of a representative ankle joint axis for dynamic loading situations cannot be estimated from either morphology or quasi-static experiments. Future studies assessing muscle activity, ligament behaviour and articulating surfaces may help to identify the determining factors for the orientation of a representative ankle joint axis.

Acute cardiac autonomic and haemodynamic responses to leg and arm isometric exercise

OBJECTIVES

Acute cardiovascular responses following a single session of isometric exercise (IE) have been shown to predict chronic adaptations in blood pressure (BP) regulation. It was hypothesised that exercises which recruit more muscle mass induce greater reductions in BP compared to exercises using smaller muscle mass. To test this hypothesis, the current study aimed to compare the acute haemodynamic and autonomic responses to a single session of isometric wall squat (IWS) and isometric handgrip (IHG) training.

METHODS

Twenty-six sedentary participants performed a single IWS and IHG session in a randomised cross-over design, with training composed of 4 × 2-min contractions, with 2-min rest, at 95 HR_peak and 30% MVC respectively. Haemodynamic and cardiac autonomic variables were recorded pre, during, immediately post, and 1-h post-exercise, with the change from baseline for each variable used for comparative analysis.

RESULTS

During IWS exercise, there was a significantly greater increase in systolic BP (P < 0.001), diastolic BP (P < 0.001), mean BP (P < 0.001), heart rate (P < 0.001), and cardiac output (P < 0.001), and a contrasting decrease in baroreflex effectiveness index (BEI) and cardiac baroreceptor sensitivity (cBRS). In the 10-min recovery period following IWS exercise, there was a significantly greater reduction in systolic BP (P = 0.005), diastolic BP (P = 0.006), mean BP (P = 0.003), total peripheral resistance (TPR) (P < 0.001), BEI (P = 0.003), and power spectral density (PSD-RRI) (P < 0.001). There were no differences in any variables between conditions 1-h post exercise.

CONCLUSIONS

Isometric wall squat exercise involving larger muscle mass is associated with a significantly greater post-exercise hypotensive response during a 10-min recovery window compared to smaller muscle mass IHG exercise. The significantly greater reduction in TPR may be an important mechanism for the differences in BP response.

Biomechanical effects of foot orthoses with and without a lateral bar in individuals with cavus feet during comfortable and fast walking

Background/purpose

The biomechanical effects of foot orthoses (FOs) with and without a lateral bar compared to a control condition during walking at different speeds are still unknown. The objective of this study was to compare the biomechanical effects of functional FOs with and without a lateral bar to a control condition during comfortable walking in individuals with cavus feet and determine if their effects change at a fast speed.

Methods

Fifteen individuals with cavus feet (age: 25.3 ± 5.8 yrs) walked under two experimental conditions (FOs with and without a lateral bar) and a control condition (shoes only) at comfortable (CW) and fast (FW) speeds. The outcome measures were ankle and knee angles and gluteus medius, vastus lateralis, gastrocnemius lateralis, gastrocnemius medialis, peroneus longus and tibialis anterior electromyography (EMG) amplitudes during the stance phase of walking and were compared between the FOs and a control condition using one-dimensional statistical parametric mapping.

Results

During CW, both FOs decreased ankle dorsiflexion and increased knee extension angles compared to no FOs. FOs with a lateral bar also decreased peroneus longus EMG amplitudes. During FW, FOs with and without a lateral bar decreased ankle dorsiflexion angles compared to no FOs.

Conclusion

Both types of FOs had different effects on the biomechanics of the lower limb compared to a control condition. The decreased peroneus longus EMG amplitudes during CW in individuals with cavus feet could have important clinical implications in other populations, such as individuals with painful cavus feet. The orthoses only affected the ankle dorsiflexion angles at a fast speed and no EMG amplitude or knee kinematics effects were observed. Further studies assessing the ankle kinematics and kinetics effects of these orthoses are needed to improve our understanding of their mechanism of action and inform future efficacy trials.

The immediate effects of sensorimotor foot orthoses on foot kinematics in healthy adults

BACKGROUND

Sensorimotor foot orthoses is an alternative concept, which in addition to mechanical effects, are designed to change muscle activation by altering sensory input to the plantar surface of the foot. However, there is little evidence of how these affect the kinematics of the foot during gait.

RESEARCH QUESTION

The aim of the study was to explore the immediate effect of calcaneal medial heel bars and retrocapital bars on foot kinematics during the stance phase of gait.

METHODS

Kinematic data were collected from 32 healthy individuals using an eight camera motion capture system and a six-degrees-of-freedom multi-segment foot model in three different orthotic conditions; calcaneal medial heel bar, retrocapital bar, and no orthosis. Vector field statistical analysis was performed to explore the effect of the orthotic conditions over the kinematic time series curves during stance phase. Peak median and interquartile ranges were also reported during the different phases of stance.

RESULTS

The calcaneal medial bar significantly decreased rearfoot eversion for the majority of the stance phase and compensatory increased midfoot eversion during the entire stance phase compared to the no orthosis condition. The retrocapital bar rotated the foot externally significantly abducting the rearfoot for the entire stance phase and the midfoot for the majority of stance phase.

SIGNIFICANCE

The calcaneal medial heel bar and retrocapital bar significantly altered the foot kinematics in a way that may benefit patients with abnormal pronation and intoeing gait.

Effects of foot orthosis on ground reaction forces and perception during short sprints in flat-footed athletes

Prefabricated foot orthosis (FO) is commonly worn for flat foot management. This study aimed to investigate the kinetic and perceptual effects of wearing prefabricated FO among flat-footed athletes during bouts of sprints. Twenty male sprint-based sports athletes who had flat foot bilaterally ran at three test speeds (5, 6, 7 m/s) under two conditions: prefabricated FO and sham FO. Ground reaction force (GRF) variables and subjective perceptions were recorded. Kinetic variability of GRF variables were computed to indicate step-to-step variance. Biomechanically, wearing prefabricated FOs increased vertical impact force (p =.005), loading rate (p =.001), and kinetic variability of peak propulsive force (p =.038) and loading rate (p =.019) during sprinting speeds across 5 to 7 m/s. Subjectively, prefabricated FO provided better arch support (p =.001) but resulted in reduced forefoot cushioning (p =.001), heel cushioning (p =.002), and overall comfort (p =.008).

Immediate Effects of Medially Posted Insoles on Lower Limb Joint Contact Forces in Adult Acquired Flatfoot: A Pilot Study

Flatfoot is linked to secondary lower limb joint problems, such as patellofemoral pain. This study aimed to investigate the influence of medial posting insoles on the joint mechanics of the lower extremity in adults with flatfoot. Gait analysis was performed on fifteen young adults with flatfoot under two conditions: walking with shoes and foot orthoses (WSFO), and walking with shoes (WS) in random order. The data collected by a vicon system were used to drive the musculoskeletal model to estimate the hip, patellofemoral, ankle, medial and lateral tibiofemoral joint contact forces. The joint contact forces in WSFO and WS conditions were compared. Compared to the WS group, the second peak patellofemoral contact force (p < 0.05) and the peak ankle contact force (p < 0.05) were significantly lower in the WSFO group by 10.2% and 6.8%, respectively. The foot orthosis significantly reduced the peak ankle eversion angle (p < 0.05) and ankle eversion moment (p < 0.05); however, the peak knee adduction moment increased (p < 0.05). The reduction in the patellofemoral joint force and ankle contact force could potentially inhibit flatfoot-induced lower limb joint problems, despite a greater knee adduction moment.

Can foot orthoses impose different gait features based on geometrical design in healthy subjects? A systematic review and meta-analysis

OBJECTIVE

Foot orthoses (FOs) are popular treatment to alleviate several abnormalities of lower extremity. FO designs might alter lower extremity biomechanics differently, but the association is not yet known. This review aimed to evaluate how different FO designs, namely FO with medial posting, lateral posting, arch support, or arch & heel support, change lower limb kinematics and kinetics during walking.

LITERATURE SURVEY

Electronic database search were conducted from inception to March 2019, and 25 papers passed the inclusion criteria. Two independent reviewers checked the quality using a modified Downs and Black checklist (73.7±5.5%) and a biomechanical quality checklist (71.4±17.1%). Effect sizes for differences between with- and without- FO walking were calculated, and meta-analysis was performed whenever at least two studies reported the same variable.

RESULTS

Medial posting reduced peak ankle eversion moment. Lateral posting brought about higher peak ankle dorsiflexion and peak ankle eversion for kinematics, as well as higher peak ankle abduction moment, lower peak knee adduction moment, and higher peak mediolateral ground reaction force (GRF) for kinetics. FOs with either arch support or arch & heel support tended to decrease vertical ground reaction force, but it was not significant.

CONCLUSION

The findings of this review reveal that medial or lateral posting work efficiently to change foot and knee kinematics and kinetics. However, the impact force is just slightly decreased by arch-supported and heel supported FOs. Due to the small number of available studies, and heterogeneity in meta-analysis findings, further research with more standardized biomechanical approach are required.

Acute effect of foot orthoses on frequency domain of ground reaction forces in male children with flexible flatfeet during walking

BACKGROUND

Flatfoot is a structural and functional abnormality of the foot that may cause lower limb mechanical damage during walking. The aim of this study was to investigate the acute effect of foot orthoses on the frequency domain of ground reaction forces in children with flatfeet during the stance phase of walking.

METHODS

Bilateral gait data were collected from fifteen male children suffering from flatfeet syndrome. Two Kistler force platforms were used to record the ground reaction forces of each limb during level walking. Arc support foot orthoses were used as an intervention.

RESULTS

No significant differences in the frequency content of the dominant limb ground reaction forces were found in the three directions in the two conditions (P>0.05). However, the use of foot orthoses decreased non-dominant limb medio-lateral ground reaction force frequency with a power of 99.5% (P=0.015). Overall, for both limbs, the amplitude of the three-dimensional ground reaction force components during walking with foot orthoses were lower than those obtained without foot orthoses (P<0.05). For both dominant and non-dominant limbs, the essential number of harmonics in three directions during walking with and without foot orthoses were similar (P>0.05).

CONCLUSIONS

Foot orthoses decreased medio-lateral ground reaction force frequency in the non-dominant limb, but have little effect on other ground reaction frequency components. Decreased frequency phenomena due to foot orthoses in children with flatfeet suggest an attenuation of ground reaction forces during walking. Frequency domain analysis thus offered new insights on the gait improvements associated with using foot orthoses.

Predictors of the Biomechanical Effects of Customized Foot Orthoses in Adults With Flat-Arched Feet

OBJECTIVE

To determine the potential presence and characteristics of biomechanical responders to customized foot orthoses during walking in adults with flat-arched feet.

DESIGN

Experimental, repeated-measures.

SETTING

University clinic and laboratory.

PARTICIPANTS

Eighteen symptom-free adults with flat-arched feet.

INTERVENTIONS

Customized foot orthoses.

MAIN OUTCOME MEASURES

In-shoe foot biomechanics were measured during walking with and without customized foot orthoses using 3D analysis. Selected kinematic and kinetic variables during baseline walking were compared between subgroups who displayed reductions in calcaneal eversion with foot orthoses to those with no change or increases.

RESULTS

Biomechanical responders displayed significantly greater peak calcaneal eversion (+2.2 degrees, P = 0.009). Time to peak calcaneal eversion (-11%, P = 0.006), peak dorsiflexion of the hallux (-6 degrees, P = 0.001), and medial-lateral excursion of the center of pressure during loading response were all reduced in the responder subgroup (-2 mm, P ≤ 0.001). Variables significantly different between subgroups were moderately associated with the response to foot orthoses (canonical correlation = 0.687, effect size = 0.47, P = 0.063).

CONCLUSIONS

Individuals with increased dynamic foot pronation were more likely to show a favorable biomechanical response to customized foot orthoses, providing preliminary evidence to support the stratified use of foot orthoses to optimize their effectiveness.

Effects of different medial arch support heights on rearfoot kinematics

Background

Foot orthoses are usually assumed to be effective by optimizing mechanically dynamic rearfoot configuration. However, the effect from a foot orthosis on kinematics that has been demonstrated scientifically has only been marginal. The aim of this study was to examine the effect of different heights in medial arch-supported foot orthoses on rear foot motion during gait.

Methods

Nineteen asymptomatic runners (36±11years, 180±5cm, 79±10kg; 41±22km/week) participated in the study. Trials were recorded at 3.1 mph (5 km/h) on a treadmill. Athletes walked barefoot and with 4 different not customized medial arch-supported foot orthoses of various arch heights (N:0 mm, M:30 mm, H:35 mm, E:40mm). Six infrared cameras and the `Oxford Foot Model´ were used to capture motion. The average stride in each condition was calculated from 50 gait cycles per condition. Eversion excursion and internal tibia rotation were analyzed. Descriptive statistics included calculating the mean ± SD and 95% CIs. Group differences by condition were analyzed by one factor (foot orthoses) repeated measures ANOVA (α = 0.05).

Results

Eversion excursion revealed the lowest values for N and highest for H (B:4.6°±2.2°; 95% CI [3.1;6.2]/N:4.0°±1.7°; [2.9;5.2]/M:5.2°±2.6°; [3.6;6.8]/H:6.2°±3.3°; [4.0;8.5]/E:5.1°±3.5°; [2.8;7.5]) (p>0.05). Range of internal tibia rotation was lowest with orthosis H and highest with E (B:13.3°±3.2°; 95% CI [11.0;15.6]/N:14.5°±7.2°; [9.2;19.6]/M:13.8°±5.0°; [10.8;16.8]/H:12.3°±4.3°; [9.0;15.6]/E:14.9°±5.0°; [11.5;18.3]) (p>0.05). Differences between conditions were small and the intrasubject variation high.

Conclusion

Our results indicate that different arch support heights have no systematic effect on eversion excursion or the range of internal tibia rotation and therefore might not exert a crucial influence on rear foot alignment during gait.

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.

The effect of intracortical bone pin application on kinetics and tibiocalcaneal kinematics of walking gait

Bone anchored markers using intracortical bone pins are one of the few available methods for analyzing skeletal motion during human gait in-vivo without errors induced by soft tissue artifacts. However, bone anchored markers require local anesthesia and may alter the motor control and motor output during gait. The purpose of this study was to examine the effect of local anesthesia and the use of bone anchored markers on typical gait analysis variables. Five subjects were analyzed in two different gait analysis sessions. In the first session, a protocol with skin markers was used. In the second session, bone anchored markers were added after local anesthesia was applied. For both sessions, three dimensional infrared kinematics of the calcaneus and tibia segments, ground reaction forces, and plantar pressure data were collected. 95% confidence intervals and boxplots were used to compare protocols and assess the data distribution and data variability for each subject. Although considerable variation was found between subjects, within-subject comparison of the two protocols revealed non-systematic effects on the target variables. Two of the five subjects walked at reduced gait speed during the bone pin session, which explained the between-session differences found in kinetic and kinematic variables. The remaining three subjects did not systematically alter their gait pattern between the two sessions. Results support the hypothesis that local anesthesia and the presence of bone pins still allow a valid gait pattern to be analyzed.

Effects of two types of foot orthoses on lower limb muscle activity before and after a one-month period of wear

The purpose of this study was to quantify the effects of two types of foot orthoses (FOs) on muscle activity during walking. Twenty-one healthy participants were recruited to walk on a five-meter walkway with a control condition (no FOs) and two experimental conditions (FOs and FOs with lateral bar). The experimental protocol was performed before and after a one-month period of wear for each experimental condition. Electromyographic signals were recorded for six muscles (gluteus medius, vastus lateralis, medial gastrocnemius, lateral gastrocnemius, peroneus longus and tibialis anterior). Mean muscle activity was analyzed during the contact, the combined midstance/terminal stance and the pre-swing phases of gait. Peak amplitude and time to peak amplitude were quantified during the stance phase. Unacceptable level of variability was observed between the testing sessions. Therefore, no comparisons were performed to compare the effects of the experimental conditions between testing sessions. After a one-month period of wear, FOs with lateral bar decreased peak amplitude and mean activity of the peroneus longus muscle during the combined midstance/terminal stance phase and FOs decreased peak amplitude and mean activity of the tibialis anterior muscle during the contact phase compared to a control condition. In conclusion, repeated-test design should be used with caution when assessing the muscular adaptation to the wear of FOs for a certain period of time. More studies are needed to determine if the decreased activity of the peroneus longus muscle could be of benefit to treat pathologies such as peroneal tendinopathy or lateral ankle instability.

Effect of antipronation foot orthosis geometry on compression of heel and arch soft tissues

This study aimed to understand how systematic changes in arch height and two designs of heel wedging affect soft tissues under the foot. Soft tissue thickness under the heel and navicular was measured using ultrasound. Heel pad thickness was measured when subjects were standing on a flat surface and standing on an orthosis with 4 and 8 degree extrinsic wedges and 4 mm and 8 mm intrinsic wedges (n = 27). Arch soft tissue thickness was measured when subjects were standing and when standing on an orthosis with -6 mm, standard, and +6 mm increments in arch height (n = 25). Extrinsic and intrinsic heel wedges significantly increased soft tissue thickness under the heel compared with no orthosis. The 4 and 8 degree extrinsic wedges increased tissue thickness by 28% and 27.6%, respectively, while the 4 mm and 8 mm intrinsic wedges increased thickness by 23% and 14.6%, respectively. Orthotic arch height significantly affected arch soft tissue thickness. Compared with the no orthosis condition, the -6 mm, standard, and +6 mm arch heights decreased arch tissue thickness by 9%, 10%, and 11.8%, respectively. This study demonstrates that change in orthotic geometry creates different plantar soft tissue responses that we expect to affect transmission of force to underlying foot bones.

Analysis of medial deviation of center of pressure after initial heel contact in forefoot varus

BACKGROUND/PURPOSE

After initial heel contact, the rearfoot everts and causes medial deviation of the center of pressure (CoP). Although rearfoot angle in single-limb stance has been associated with forefoot varus (FV) ≥ 8°, medial CoP deviation has not.

METHODS

After 12 participants with FV < 8° (neutral group) and 11 participants with FV ≥ 8° (FV group) stepped one heel initially onto an array of pressure sensors parallel to its Y coordinate axis, when the CoP of array deviated most medially, the X coordinate of the CoP of each row was calculated to find the most medial CoP of the row. Starting since the row with the most medial CoP just began to have the same sensors with pressures >0 kPa as when it had the most medial CoP, the medial deviations of the CoP of the array, the most medial CoP of the row, and its relative position in the row (CoP%), were compared between neutral and FV groups.

RESULTS

The medial deviations of the most medial CoP of the row (1.1 ± 0.6 vs. 1.6 ± 0.3 mm, p = 0.049) and CoP% (2.9 ± 1.4 vs. 4.2 ± 1.1%, p = 0.023) were significantly different between neutral and FV groups, whereas that of the CoP of the array (1.1 ± 0.6 vs. 1.4 ± 0.6 mm, p = 0.36) was not.

CONCLUSION

The most medial CoP of the row and CoP% detected increased medial CoP deviation in FV ≥ 8°, and may be applied to other clinical conditions where rearfoot angle and CoP of the array after initial heel contact cannot detect significant differences.

Coupling between 3D displacements and rotations at the glenohumeral joint during dynamic tasks in healthy participants

BACKGROUND

Glenohumeral displacements assessment would help to design shoulder prostheses with physiological arthrokinematics and to establish more biofidelic musculoskeletal models. Though displacements were documented during static tasks, there is little information on their 3D coupling with glenohumeral angle during dynamic tasks. Our objective was to characterize the 3D glenohumeral displacement-rotation couplings during dynamic arm elevations and rotations.

METHODS

Glenohumeral displacements were measured from trajectories of reflective markers fitted on intracortical pins inserted into the scapula and humerus. Bone geometry was recorded using CT-scan. Only four participants were recruited to the experiment due to its invasiveness. Participants performed dynamic arm abduction, flexion and axial rotations. Linear regressions were performed between glenohumeral displacements and rotations. The pin of the scapula of one participant moved, his data were removed from analysis, and results are based on three participants.

FINDINGS

The measurement error of glenohumeral kinematics was less than 0.15mm and 0.2°. Maximum glenohumeral displacements were measured along the longitudinal direction and reached up to +12.4mm for one participant. Significant couplings were reported especially between longitudinal displacement and rotation in abduction (adjusted R(2) up to 0.94).

INTERPRETATION

The proposed method provides the potential to investigate glenohumeral kinematics during all kinds of movements. A linear increase of upward displacement during dynamic arm elevation was measured, which contrasts with results based on a series of static poses. The systematic investigation of glenohumeral displacements under dynamic condition may help to provide relevant recommendation for the design of shoulder prosthetic components and musculoskeletal models.

Foot orthoses for adults with flexible pes planus: a systematic review

BACKGROUND

Foot orthoses are widely used in the management of flexible pes planus, yet the evidence to support this intervention has not been clearly defined. This systematic review aimed to critically appraise the evidence for the use of foot orthoses for flexible pes planus in adults.

METHODS

Electronic databases (Medline, CINAHL, Cochrane, Web of science, SportDiscus, Embase) were systematically searched in June 2013 for randomised controlled, controlled clinical and repeated measure trials where participants had identified flexible pes planus using a validated and reliable measure of pes planus and the intervention was a rigid or semi-rigid orthoses with the comparison being a no-orthoses (shoes alone or flat non-posted insert) condition. Outcomes of interest were foot pain, rearfoot kinematics, foot kinetics and physical function.

RESULTS

Of the 2,211 articles identified by the searches, 13 studies met the inclusion criteria; two were randomised controlled trials, one was a controlled trial and 10 were repeated measure studies. Across the included studies, 59 relevant outcome measures were reported with 17 calculated as statistically significant large or medium effects observed with use of foot orthoses compared to the no orthoses condition (SMD range 1.13 to -4.11).

CONCLUSIONS

No high level evidence supported the use of foot orthoses for flexible pes planus. There is good to moderate level evidence that foot orthoses improve physical function (medial-lateral sway in standing (level II) and energy cost during walking (level III)). There is low level evidence (level IV) that foot orthoses improve pain, reduce rearfoot eversion, alter loading and impact forces; and reduce rearfoot inversion and eversion moments in flexible pes planus. Well-designed randomised controlled trials that include appropriate sample sizes, clinical cohorts and involve a measure of symptom change are required to determine the efficacy of foot orthoses to manage adult flexible pes planus.

Dose-response effects of customised foot orthoses on lower limb kinematics and kinetics in pronated foot type

Despite the widespread use of customised foot orthoses (FOs) for the pronated foot type there is a lack of reliable information on the dose-response effect on lower limb mechanics. This study investigated these effects in subjects with normal and pronated foot types. Customised FOs were administered to 12 participants with symptomatic pronated foot type and 12 age and gender matched controls. A computer-aided design (CAD) software was used to design nine FOs per participant with dose incrementally changed by varying only the rearfoot post angle. This was done in 2° increments from 6° lateral to 10° medial posting. A 3D printing method was used to manufacture the FOs. Quantification of the dose-response effect was performed using three-dimensional gait analyses for selected rearfoot and knee kinematics and kinetics. Under these experimental conditions, significant and linear effects of posting were seen for the peak (p<0.001) and mean (p<0.001) rearfoot eversions, peak (p=0.003) and mean (p<0.001) ankle eversion moments and peak (p=0.017) and mean (p=0.005) knee adduction moment variables. Group effects were observed for the peak (p=0.007) and mean (p=0.007) forefoot abduction and for the peak (p=0.007) knee adduction moment. A significant interaction between posting and group was seen for internal tibial rotation (p=0.004). These data indicate that a dose-response effect, with a linear trend for both the rearfoot and knee, exists for customised FOs used to treat pronated foot type.