Biomechanical effects of three types of foot orthoses in individuals with posterior tibial tendon dysfunction

BackgroundPosterior tibial tendon dysfunction (PTTD) is characterized by degeneration of this tendon leading to a flattening of the medial longitudinal arch of the foot. Foot orthoses (FOs) can be used as a treatment option, but their biomechanical effects on individuals with PTTD are not yet fully understood.Research questionThe aim of this study was to investigate the effects of three types of FOs on gait biomechanics in individuals with PTTD.MethodsFourteen individuals were recruited with painful stage 1 or 2 PTTD based on Johnson and Strom’s classification. Quantitative gait analysis of the affected limb was performed in four conditions: shoes only (Shoe), prefabricated FO (PFO), neutral custom FO (CFO) and custom varus FO (CVFO) with a 5° medial wedge and a 4 mm medial heel skive. A curve analysis, using 1D statistical parametric mapping, was undertaken to assess differences in lower limb joint motion, joint moments and muscle activity over the stance phase of gait across conditions.ResultsDecreased hindfoot eversion angles, decreased ankle inversion moments and increased ankle eversion moments were observed with custom FOs compared to the Shoe and PFO conditions (p < 0.001). CFOs and CVFOs induced an increased knee abduction moment compared to Shoe (p < 0.001). No changes in hip kinematics and kinetics or in EMG activity of tested muscles were observed between conditions.SignificanceCustom orthoses may be more suitable than PFOs to decrease the pathological biomechanical outcomes observed in PTTD. Decreased ankle inversion moments during the stance phase could explain why custom orthoses are effective at reducing pain in PTTD patients. However, clinicians should be careful when prescribing custom orthoses for PTTD since unwanted collateral biomechanical effects can be observed at the knee.     

The biomechanical effects of 3D printed and traditionally made foot orthoses in individuals with unilateral plantar fasciopathy and flat feet

BackgroundFoot orthoses (FOs) are used to manage foot pathologies such as plantar fasciopathy. 3D printed custom-made FOs are increasingly being manufactured. Although these 3D-printed FOs look like traditionally heat-moulded FOs, there are few studies comparing FOs made using these two different manufacturing processes.Research questionHow effective are 3D-printed FOs (3D-Print) compared to traditionally-made (Traditional) or no FOs (Control), in changing biomechanical parameters of flat-footed individuals with unilateral plantar fasciopathy?MethodsThirteen participants with unilateral plantar fasciopathy walked with shoes under three conditions: Control, 3D-print, and Traditional. 2 × 3 repeated measures analysis of variance (ANOVAs) with Bonferroni post-hoc tests were used to compare discrete kinematic and kinetic variables between limbs and conditions. Waveform analyses were also conducted using statistical parametric mapping (SPM).ResultsThere was a significant condition main effect for arch height drop (p = 0.01; ηp² =0.54). There was 0.87 mm (95% CI [−1.84, −0.20]) less arch height drop in 3D-print compared to Traditional. The SPM analyses revealed condition main effects on ankle moment (p < 0.001) and ankle power (p < 0.001). There were significant differences between control condition and both 3D-print and Traditional conditions. For ankle moment and power, there were no differences between 3D-print and Traditional conditions.Significance3D-printed FOs are more effective in reducing arch height drop, whist both FOs lowered ankle plantarflexion moment and power compared to no FOs. The results support the use of 3D-printed FOs as being equally effective as traditionally-made FOs in changing lower limb biomechanics for a population of flat-footed individuals with unilateral plantar fasciopathy.     

In-shoe plantar pressure measurements for the evaluation and adaptation of foot orthoses in patients with rheumatoid arthritis: A proof of concept study

ObjectivesImproving foot orthoses (FOs) in patients with rheumatoid arthritis (RA) by using in-shoe plantar pressure measurements seems promising. The objectives of this study were to evaluate (1) the outcome on plantar pressure distribution of FOs that were adapted using in-shoe plantar pressure measurements according to a protocol and (2) the protocol feasibility.MethodsForty-five RA patients with foot problems were included in this observational proof-of concept study. FOs were custom-made by a podiatrist according to usual care. Regions of Interest (ROIs) for plantar pressure reduction were selected. According to a protocol, usual care FOs were evaluated using in-shoe plantar pressure measurements and, if necessary, adapted. Plantar pressure–time integrals at the ROIs were compared between the following conditions: (1) no-FO versus usual care FO and (2) usual care FO versus adapted FO. Semi-structured interviews were held with patients and podiatrists to evaluate the feasibility of the protocol.ResultsAdapted FOs were developed in 70% of the patients. In these patients, usual care FOs showed a mean 9% reduction in pressure–time integral at forefoot ROIs compared to no-FOs (p = 0.01). FO adaptation led to an additional mean 3% reduction in pressure–time integral (p = 0.05). The protocol was considered feasible by patients. Podiatrists considered the protocol more useful to achieve individual rather than general treatment goals. A final protocol was proposed.ConclusionsUsing in-shoe plantar pressure measurements for adapting foot orthoses for patients with RA leads to a small additional plantar pressure reduction in the forefoot. Further research on the clinical relevance of this outcome is required.     

Does the use of orthoses improve self-reported pain and function measures in patients with plantar fasciitis? A meta-analysis

ObjectivesTo perform a meta-analysis examining the effects of foot orthoses on self-reported pain and function in patients with plantar fasciitis.Data SourcesMEDLINE, SPORTDiscus, and CINAHL were searched from their inception until December 2007 using the terms “foot”, “plantar fascia”, “arch”, “orthotic”, “orthoses” and “plantar fasciitis”.Study SelectionOriginal research studies which met these criteria were included: (1) randomised controlled trials or prospective cohort designs, (2) the patients had to be suffering from plantar fasciitis at the time of recruitment, (3) evaluated the efficacy of foot orthoses with self-reported pain and/or function, (4) means, standard deviations, and sample size of each group had to be reported.ResultsWe utilised the Roos, Engstrom, and Soderberg (Roos, E., Engstrom, M., & Soderberg, B. (2006). Foot orthoses for the treatment of plantar fasciitis. Foot and Ankle International, 8, 606–611) night splint condition to compare our pooled orthoses results. The meta-analysis results showed significant reductions in pain after orthotic intervention. The Roos et al.' (Roos, E., Engstrom, M., & Soderberg, B. (2006). Foot orthoses for the treatment of plantar fasciitis. Foot and Ankle International, 8, 606–611) study also showed significant reduction in pain after night splint treatment. The meta-analysis results also showed significant increases in function after orthotic use. In contrast, the Roos et al.' (Roos, E., Engstrom, M., & Soderberg, B. (2006). Foot orthoses for the treatment of plantar fasciitis. Foot and Ankle International, 8, 606–611) study did not show a significant increase in function after night splinting for 12 weeks.ConclusionThe use of foot orthoses in patients with plantar fasciitis appears to be associated with reduced pain and increased function.     

Immediate effects of foot orthoses on lower limb biomechanics,pain, and confidence in individuals with patellofemoral osteoarthritis

BackgroundFoot orthoses are a recommended treatment for patellofemoral (PF) pain and a number of lower limb osteoarthritic (OA) conditions. However, their mechanism of effect is poorly understood.Research questionTo compare the immediate effects of foot orthoses and flat inserts on lower limb biomechanics, knee pain and confidence in individuals with PFOA.MethodsTwenty-one participants (14 females; mean ± SD age 58 ± 8 years) with PFOA underwent three-dimensional motion analysis during level-walking, stair ascent, and stair descent under three footwear conditions: (i) their own shoes; (ii) prefabricated foot orthoses; and (iii) flat shoe inserts. Participants reported their average levels of knee pain and confidence after each task. Data were analysed with repeated-measures analysis of variance (ANOVA), effect sizes (partial eta squared), and Bonferroni post-hoc tests.ResultsDuring level-walking, there was a significant main effect of foot orthoses on peak ankle dorsiflexion angle (F₂ = 0.773, p < 0.001, ƞ² = 0.773) and peak ankle external dorsiflexion moment (F₂ = 0.356, p = 0.046, ƞ² = 0.356). Foot orthoses decreased the peak ankle dorsiflexion angle compared to the flat insert and shoe conditions, and decreased the peak ankle external dorsiflexion moment relative to flat inserts. During stair descent, there was a significant main effect of foot orthoses on peak ankle external dorsiflexion moment (F₂ = 0.823, p = 0.006, ƞ² = 0.738), with a trend towards lower peak dorsiflexion moment for foot orthoses compared to the flat insert and shoe conditions. No significant main effects were observed during stair ascent. No other lower limb biomechanical changes were observed across all three conditions. Knee pain and confidence scores were not significantly different across the three conditions.SignificancePrefabricated foot orthoses altered sagittal plane biomechanics of the ankle during level-walking and stair descent in individuals with PFOA. Further research is required to determine whether these changes are clinically beneficial.     

Immediate effects of foot orthoses on gait biomechanics in individuals with persistent patellofemoral pain

BackgroundThe efficacy of foot orthoses in reducing patellofemoral pain (PFP) is well documented; however, the mechanisms by which foot orthoses modulate pain and function are poorly understood.Research questionThis within-subject study investigated the immediate effects of foot orthoses on lower limb kinematics and angular impulses during level walking and stair ambulation in individuals with persistent PFP.MethodsForty-two participants with persistent PFP (≥3 months duration) underwent quantitative gait analysis during level walking, stair ascent and stair descent while using: (i) standard running sandals (control); and (ii) standard running sandals fitted with prefabricated foot orthoses. Hip, knee, and ankle joint kinematics and angular impulses were calculated and statistically analyzed using paired t-tests (p < 0.05).ResultsRelative to the control condition, foot orthoses use was associated with small but significant decreases in maximum ankle inversion angles during walking (mean difference [95% confidence interval]: −1.00° [−1.48 to −0.53]), stair ascent (−1.06° [−1.66 to −0.45]) and stair decent (−0.94° [−1.40 to −0.49]). Foot orthoses were also associated with decreased ankle eversion impulse during walking (−9.8Nms/kg [−12.7 to −6.8]), and decreased ankle dorsiflexion and eversion impulse during stair ascent (−67.6Nms/kg [−100.7 to −34.6] and −17.5Nms/kg [−23.6 to −11.4], respectively) and descent (−50.4Nms/kg [−77.2 to −23.6] and −11.6Nms/kg [−15.6 to −7.5], respectively). Ankle internal rotation impulse decreased when participants ascended stairs with foot orthoses (−3.3Nms/kg [−5.4 to −1.3]). Limited changes were observed at the knee and hip.SignificanceIn individuals with persistent PFP, small immediate changes in kinematics and angular impulses – primarily at the ankle – were observed when foot orthoses were worn during walking or stair ambulation. The clinical implications of these small changes, as well as the longer-term effects of foot orthoses on lower limb biomechanics, are yet to be determined.     

Dose–response effects of customised foot orthoses on lower limb muscle activity and plantar pressures in pronated foot type

Customised foot orthoses (FOs) featuring extrinsic rearfoot posting are commonly prescribed for individuals with a symptomatic pronated foot type. By altering the angle of the posting it is purported that a controlled dose–response effect during the stance phase of gait can be achieved, however these biomechanical changes have yet to be characterised. Customised FOs were administered to participant groups with symptomatic pronated foot types and asymptomatic normal foot types. The electromyographic (EMG) and plantar pressure effects of varying the dose were measured. Dose was varied by changing the angle of posting from 6° lateral to 10° medial in 2° steps on customised devices produced using computer aided orthoses design software. No effects due to posting level were found for EMG variables. Significant group effects were seen with customised FOs reducing above knee muscle activity in pronated foot types compared to normal foot types (biceps femoris p = 0.022; vastus lateralis p < 0.001; vastus medialis p = 0.001). Interaction effects were seen for gastrocnemius medialis and soleus. Significant linear effects of posting level were seen for plantar pressure at the lateral rearfoot (p = 0.001), midfoot (p < 0.001) and lateral forefoot (p = 0.002). A group effect was also seen for plantar pressure at the medial heel (p = 0.009). This study provides evidence that a customised FOs can provide a dose response effect for selected plantar pressure variables, but no such effect could be identified for muscle activity. Foot type may play an important role in the effect of customised orthoses on activity of muscles above the knee.     

Effects of assistive insole feedback training on immediate and multi-day partial weight bearing retention during walking: A pilot study

BackgroundAdherence to partial weight bearing (PWB) plays a crucial role in early rehabilitation and motor control. Dynamic biofeedback insole systems provide a supportive function on immediate PWB adherence, while important long-term retention effects and potential advantages to a conventional static training remain unknown.Research questionIs acoustic insole feedback training effective for the retention of prescribed PWB adherence and is there any advantage relative to static training using a conventional bathroom scale? Methods Twenty-four volunteers were randomized into two groups receiving biofeedback training (N = 12) via a mobile insole system (Loadsol®) or conventional training using a bathroom scale (N = 12). After initial PWB training (20 kg) of one randomized leg, the immediate and one-week retention effects were analysed using mean and maximum load (N) and overload rate (%). Statistical analysis was performed using a two-way repeated measures ANOVA with post-hoc pairwise comparisons (p < 0.05).ResultsA significantly (p < 0.001) improved immediate and long-term PWB adherence was found for the insole feedback group during walking. A significant (p < 0.001) reduction of the overload rate by 86% was found for the insole feedback group when compared to the conventional training group after one week. Significant (p < 0.01) reductions by 51% and 46% was also found for the mean and maximum load in the insole feedback group when compared to the conventional training group.SignificanceThe use of insole feedback systems can serve as a viable tool to become familiar with PWB and to provide optimal retention of specified loads. Therefore, such systems serve as an advantageous training intervention to maintain a prescribed PWB during locomotion.     

Effect of foot orthoses on the medial longitudinal arch in children with flexible flatfoot deformity: A three-dimensional moment analysis

Foot orthoses are often used to correct altered gait patterns. The purpose of this study was to investigate how foot orthoses can modify the magnitude of three dimensional moments of ankle, knee, and hip joints during a stride of gait in children with flexible flat feet. Bilateral gait data were collected from fourteen male children (age 10.2 ± 1.4 years) suffering from flat feet syndrome. In order to obtain the kinematics data, a Vicon system with six cameras (100 Hz) was used and two Kistler force plates (1000 Hz) to record the kinetics data under each leg. Arc support foot orthoses were used as an intervention. Paired-sample T-test was used for within-group comparisons (α = 0.05). The results of data analysis showed that foot orthoses can decrease the ankle evertor moment, knee and hip abductor moments and hip flexor moment in dominant lower limb. In non-dominant lower limb, using the orthoses can decrease evertor and internal rotator moments at the ankle, flexor and internal rotator moments at the knee and extensor moment at the hip, while it can increase dorsiflexor moment at the ankle. The findings imply that effects of orthoses on three dimensional moments differ in dominant and non-dominant lower limbs. Furthermore, results demonstrated that dominant and non-dominant lower limbs would also show different responses to the same intervention.     

A comparison of the efficacy of textured insoles on balance performance in older people with versus without plantar callosities

BackgroundTextured insoles have been suggested to enhance foot sensation, which contributes to controlling upright balance. However, the interaction between plantar callosity and the textured surface has not been studied.Research questionFirstly, to compare the efficacy of textured insoles on balance performance and foot position sense between two groups of older people: one group had plantar callosity, and the other did not. Secondly, to investigate the efficacy of textured insoles within each study group.MethodsThirty older people with a history of falls (15 with plantar callosity and 15 without callosity) participated in this study. All participants underwent assessments of postural sway on a force plate, joint position sensation of the ankle with a slope box, and mobility using the "Timed Up and Go" test under three insole surface conditions: 1) smooth (control), 2) placebo and 3) textured surface. Two-way analyses of variance were used to compare the outcomes of the two groups and three conditions.ResultsOlder people with plantar callosity had worse ankle joint position sense and slower antero-posterior and mediolateral postural sway velocity than their peers who did not have plantar callosity. The textured insoles improved ankle joint position sense and mobility regardless of callus status in the plantar surface of older peoples’ feet. The insole-callosity interaction was not significant for any study outcome.SignificanceTextured insoles could be beneficial to older people with and without callosity as they have shown immediate improvements in ankle joint position sense and mobility.     

Age related progression of clinical measures and gait in ambulant children and youth with bilateral cerebral palsy without a history of surgical intervention

BackgroundAge related progression needs to be considered when assessing current status and treatment outcomes in cerebral palsy (CP).Research questionWhat is the association between age, gait kinematics and clinical measures in children with bilateral CP?MethodA retrospective database review was conducted. Subjects with bilateral CP with baseline and follow-up 3D gait analyses, but no history of intervening surgery were identified. Clinical and summary kinematic measures were examined for age related change using repeat measures correlation. Interactions with GMFCS classification and whether surgery was recommended were examined using robust linear regression. Timeseries kinematic data for baseline and most recent follow-up analyses were analysed using statistical parametric mapping.Results180 subjects were included. 75% of participants were classified as GMFCS I or II at baseline. Mean time to follow-up was 4.89 (2.8) years (range 1–15.9 years) with a mean age of 6.4 (2.4) at baseline and 11.3 (3.4) at final follow-up. 15.5% of subjects demonstrated an improvement in GMFCS classification while GDI remained stable. Age related progression was noted across many clinical measures with moderate correlations (r ≥ 0.5) noted for reduced popliteal angle, long lever hip abduction and internal hip rotation range. In gait, there was reduced hip extension in late stance (p < 0.001), increased knee flexion in mid-stance (p < 0.001), reduced peak knee flexion in swing (p < 0.001) and increased ankle dorsiflexion in stance (p < 0.001). In the coronal plane, there was reduced hip abduction in swing (p < 0.001). In the transverse plane, increased external rotation of the knee (p < 0.001) and reduced external ankle rotation were noted in early stance and through swing (p < 0.001). There were no changes in foot progression or hip rotation.SignificanceIndividuals with CP show age related progression of clinical and kinematic variables. Treatment can only be deemed successful if outcomes exceed or match these age-related changes.     

Extrinsic foot muscle forces and joint contact forces in flexible flatfoot adult with foot orthosis: A parametric study of tibialis posterior muscle weakness

BackgroundThe posterior tibialis tendon dysfunction (PTTD) is typically associated with progressive flatfoot deformity, which could be alleviated with foot orthosis. However, the evaluation of tibialis posterior (TP) weakness on lower limb mechanics of flatfoot adults with foot orthoses is scarce and requires further investigation.Research questionThis study aimed to examine the effects of TP weakness on lower limb mechanics in flatfoot adults with foot orthosis through gait analysis and musculoskeletal modelling.MethodsFifteen young adults with flatfoot were recruited from University to perform a gait experiment with and without foot orthoses. Data collected from the motion capture system were used to drive the musculoskeletal modelling for the estimation of the joint force and extrinsic muscle forces of the lower limb. A parametric analysis was conducted by adjusting the TP muscle strength from 40 % to 100 %. Two-way repeated measures ANOVA was used to compare the peak extrinsic foot muscle forces and joint forces among different levels of TP weakness and insole conditions.ResultsTP weakness significantly increased ankle joint force superoinferiorly (F = 125.9, p < 0.001) and decreased anteroposteriorly (F = 125.9, p < 0.001), in addition to a significant increase in the muscle forces of flexor hallucis longus (p < 0.001) and flexor digitorum longus (p < 0.001). Besides, the foot orthosis significantly reduced most peak muscle forces whilst significantly reduced the second peak knee force and peak ankle force compared to the control condition (F = 8.79–30.9, p < 0.05).SignificanceThe increased extrinsic foot muscle forces (flexor hallucis longus and flexor digitorum longus) and ankle joint forces in the TP weakness condition indicated that TP weakness may induce compensatory muscle activation and attenuated joint load. The abnormal muscle and joint mechanics in flatfoot adults with TP weakness might be restored by the orthosis.     

Effect of a carbon reinforcement for maximizing shoe outsole bending stiffness on plantar pressure and walking comfort in people with diabetes at high risk of foot ulceration

BackgroundDifferent shoe design features can reduce peak plantar pressure to help prevent foot ulcers in people with diabetes. A carbon reinforcement of the shoe outsole to maximize bending stiffness is commonly applied in footwear practice, but its effect has not been studied to date.Research questionWhat is the effect of a carbon shoe-outsole reinforcement on peak plantar pressure and walking comfort in people with diabetes at high risk of foot ulceration?MethodsIn 24 high-risk people with diabetes, in-shoe regional peak pressures were measured during walking at a comfortable speed in two different shoe conditions: an extra-depth diabetes-specific shoe with a non-reinforced outsole and the same type of shoe with a 3-mm-thick full-length carbon reinforcement of the outsole. The same custom-made insole was worn in both shoe conditions. Walking comfort was assessed using a Visual Analogue Scale (0–10, 10 being highest possible comfort).ResultsSignificantly lower metatarsal head peak pressures (by a median 10–22 kPa) were found with the reinforced shoe compared to the non-reinforced shoe (p < .001). In >83% of cases with the reinforced shoe and >71% with the non-reinforced shoe metatarsal head peak pressures were <200 kPa. At the hindfoot, peak pressures were significantly higher (by a median 24 kPa) with the reinforced shoe (p = .001). No significant shoe effects were found for the toes. No significant shoe effects were found for walking comfort: median 6.1 for the reinforced shoe versus 5.6 for the non-reinforced shoe.SignificanceAdding a full-length carbon reinforcement to the outsole of a diabetes-specific shoe significantly reduces peak pressures at the metatarsal heads, where ulcers often occur, in high-risk people with diabetes, and this does not occur at the expense of patient-perceived walking comfort.     

The effect of dual tasking on foot kinematics in people with functional ankle instability

BackgroundSome cases of repeated inversion ankle sprains are thought to have a neurological basis and are termed functional ankle instability (FAI). In addition to factors local to the ankle, such as loss of proprioception, cognitive demands have the ability to influence motor control and may increase the risk of repetitive lateral sprains.ObjectiveThe purpose of this study was to investigate the effect of cognitive demand on foot kinematics in physically active people with functional ankle instability.Methods21 physically active participants with FAI and 19 matched healthy controls completed trials of normal walking (single task) and normal walking while performing a cognitive task (dual task). Foot motion relative to the shank was recorded. Cognitive performance, ankle kinematics and movement variability in single and dual task conditions was characterized.ResultsDuring normal walking, the ankle joint was significantly more inverted in FAI compared to the control group pre and post initial contact. Under dual task conditions, there was a statistically significant increase in frontal plane foot movement variability during the period 200 ms pre and post initial contact in people with FAI compared to the control group (p < 0.05). Dual task also significantly increased plantar flexion and inversion during the period 200 ms pre and post initial contact in the FAI group (p < 0.05).Conclusionparticipants with FAI demonstrated different ankle movement patterns and increased movement variability during a dual task condition. Cognitive load may increase risk of ankle instability in these people.     

The effects of foot orthosis and low-dye tape on lower limb joint angles and moments during running in individuals with pes planus

BackgroundPes Planus or Flat feet is one of the most common lower limb abnormalities. When runners with this abnormality participate in recreational running, interventional therapies could help in pain alleviation and enhance performance. To determine the most effective treatment, however, a biomechanical examination of the effects of each treatment modality is required.Research questionThe aim of the present study was to investigate the effects of Foot Orthoses (FOs) and Low-Dye Tape (LDT) on lower limb joint angles and moments during running in individuals with pes planus.Methodskinematic and kinetic data of 20 young people with pes planus were measured during running in three conditions: (1) SHOD (2) with shoes and FOs (3) with shoes and LDT. One-way repeated measure ANOVA was used to investigate the impacts of the FOs and LDT on the lower limb joint angles and moments throughout the stance phase of the running cycle.ResultsThe results showed that FOs reduced ankle eversion compared to SHOD and LDT (P < 0.001) and decreased the dorsiflexion angle (P = 0.005) and the plantarflexor moment compared to the SHOD (P < 0.001). FOs increased knee adduction angle (P = 0.021) and knee external rotator moment (P < 0.001) compared to both conditions and increased knee extensor and abductor moments compared to SHOD (P < 0.001). At the hip joint, FOs only increased hip external rotation compared with the LDT condition (P = 0.031); and LDT increased hip extensor moment compared to SHOD and FOs (P = 0.037) and also increased hip adduction angle compared to SHOD (P = 0.037).SignificanceFOs with a medial wedge appears to increase the external knee adduction moment and knee adduction angles, which are risk factors for the development and progression of knee osteoarthritis. Further, usage of FOs seems to reduce the ankle joint role in propulsion as it impacts the ankle sagittal angles and moments.     

How an acute mastering of balance on a seesaw can improve the relationship between "static" and "dynamic" upright postural control

Foot orthoses (FO) are commonly used in the treatment of numerous lower limb problems, pains and injuries. Whilst many studies report their positive effects, and most practitioners would confirm those findings, the available information appears to be anecdotal. As such, the exact mechanisms in which FO work are not fully understood. Therefore, a need exists to study the influence of the inter-practitioner variability in the assessment of orthoses performance. This investigation is central to the understanding of the performance variations in custom-made foot orthoses (CFO). Eleven practitioners took part in the study. Each practitioner completed a clinical assessment of one subject, after which a pair of foot orthoses was manufactured based on casts of the subject's feet using a neutral non-weight bearing plaster cast. Ten trials per condition were recorded during which kinematic and kinetic data were collected. CFO did not have any systematic significant effects (p<0.05) on any kinetic except for the right-leg peak active force. In addition, systematic kinematic effects could be observed mainly for the sagittal plane for forefoot-to-hindfoot and hindfoot-to-tibia peak angles. The results from this study demonstrate that inter-practitioner variability is a major factor in orthotic intervention in treating a single patient and for a specific pathology. It is therefore strongly recommended to use caution when drawing general conclusions from research studies using custommade foot orthoses. The results suggest that CFO effects can differ between limbs. More importantly, their effects are also practitioner-dependant. Great caution should be used when comparing studies on CFO with different practitioners as conclusions could vastly differ.     

Influence of foot posture on immediate biomechanical responses during walking to variable-stiffness supported lateral wedge insole designs

BackgroundNovel designs of lateral wedge insoles with arch support can alter walking biomechanics as a conservative treatment option for knee osteoarthritis. However, variations in foot posture may influence individual responses to insole intervention and these effects are not yet known.Research questionHow does foot posture influence biomechanical responses to novel designs of lateral wedge insoles with arch support?MethodsThis exploratory biomechanical investigation categorized forty healthy volunteers (age 23–34) into pronated (n = 16), neutral (n = 15), and supinated (n = 9) foot posture groups based on the Foot Posture Index. Three-dimensional gait analysis was conducted during walking with six orthotic insole conditions: flat control, lateral wedge, uniform-stiffness arch support, variable-stiffness arch support, and lateral wedge + each arch support. Frontal plane knee and ankle/subtalar joint kinetic and kinematic outcomes were compared among insole conditions and foot posture groups using a repeated measures analysis of variance.ResultsThe lateral wedge alone and lateral wedge + variable-stiffness arch support were the only insole conditions effective at reducing the knee adduction moment. However, the lateral wedge + variable-stiffness arch support had a smaller increase in peak ankle/subtalar eversion moment than the lateral wedge alone. Supinated feet had smaller ankle/subtalar eversion excursion and moment impulse than neutral and pronated feet, across all insole conditions.SignificanceSupinated feet have less mobile ankle/subtalar joints than neutral and pronated feet and, as a result, may be less likely to respond to biomechanical intervention from orthotic insoles. Supported lateral wedge insoles incorporating an arch support design that is variable-stiffness may be better than uniform-stiffness since reductions in the knee adduction moment can be achieved while minimizing increases in the ankle/subtalar eversion moment.     

Movement compensations during a step ascent task are associated with stair climbing performance in people with multiple sclerosis

BackgroundThe biomechanical mechanisms underlying stair climbing limitations are poorly understood in people with multiple sclerosis (MS).Research QuestionsAre trunk and pelvis motion and lower extremity joint moments during step ascent different between MS and control groups? Are step ascent biomechanics and stair climbing performance associated in people with MS?Methods20 people with MS (49 ± 12 years, EDSS range: 1.5–5.5) and ten control participants (48 ± 12 years) underwent three-dimensional motion analysis while ascending a 15.2-cm step and also completed a timed Functional Stair Test. Main effects of group (MS vs Control) and limb (Stronger/Dominant vs Weaker/Non-dominant) and interactions were assessed using two-way analyses of variance. Associations between movement patterns during the step ascent and Functional Stair Test performance were performed using Pearson’s correlations and backward stepwise linear regression.ResultsSignificant group main effects were observed in greater sagittal pelvis excursion (p < 0.001), greater sagittal (p = 0.013) and frontal (p = 0.001) trunk excursion, and lower trail limb peak ankle plantar flexion moment (p < 0.001) of the MS group. Significant limb main effects were observed with greater sagittal trunk excursion (p = 0.037) and peak trail limb ankle plantar flexion moment (p = 0.037) in the stronger/dominant limb. A significant interaction was observed in peak knee extensor moment (p = .002). Stair climbing performance in the MS group correlated with sagittal (r = .607, p=<0.001) and frontal pelvis excursions (r = 0.385, p = 0.014), sagittal trunk excursion (r = .411, p = 0.008), and ankle plantar flexion moments (r=-0.415, p = 0.008). Sagittal and frontal pelvis excursion and bilateral handrail use explained a significant amount of variability in stair climbing performance (Adj R² = 0.775).SignificanceIn conclusion, despite the presence of proximal and distal lower extremity movement pattern compensations during a step ascent task, larger pelvis angular excursions are associated with impaired stair climbing performance in people with MS and may serve as targets for future rehabilitation interventions.     

Footsteps required for reliable and valid in-shoe plantar pressure assessment during gait per foot region in people with hallux valgus

BackgroundPlantar pressure assessment is commonly performed to identify pathognomonic gait characteristics and evaluate therapeutics against them in people with various foot disorders. Little is known about the reliability and validity of this assessment in people with hallux valgus (HV) per foot region.Research questionThis study aimed to assess the reliability and validity of the in-shoe plantar pressure measurement method during gait in people with HV and the required number of footsteps, as an intra-subject sample size, to ensure a reliable and valid use of this method.MethodsWith an inserted disposable insole plantar pressure sensor in shoes, 17 females with HV (HV angle > 15°) completed three gait trials over the ground at a comfortable speed. Peak plantar pressure data and its distribution in 15 stance phases on the foot clinically diagnosed with HV in each participant were extracted by dividing the foot into eight regions. The intraclass correlation coefficient per foot region and the number of footsteps required to produce a valid peak plantar pressure and distribution (intraclass correlation coefficient > 0.90) were used to measure reliability. Based on the limit of agreement analysis, the coefficient of variation between the averaged value from each incremental footstep (2–14 footsteps) and 15 reference footsteps was calculated.ResultsThe intraclass correlation coefficient of plantar pressure assessment with the in-shoe sensor was 0.606–0.847 in the eight foot regions in people with HV. Additionally, the number of steps required for a valid assessment ranged from two to nine. Hence, the application of averaged values from more than nine footsteps is recommended for this evaluation.SignificanceThis reference sample size is intended to be used in future studies and clinical settings to determine the efficacy of HV treatment.