Dynamic plantar pressure patterns in children and adolescents with Charcot-Marie-Tooth disease

BackgroundThe dynamic plantar pressure patterns of children and adolescents with Charcot-Marie-Tooth (CMT) disease and its relationship to musculoskeletal alterations may help to understand the natural history of the disease and improve therapeutic interventions.Research questionThe study compared dynamic plantar pressure patterns in children and adolescents with and without CMT. It also tested the associations between isometric muscle strength (IMS), passive range of motion (ROM), foot posture and dynamic plantar pressure patterns in CMT.MethodsThis cross-sectional study compared children and adolescents (aged 8–18 years) with CMT (n = 40) with a typical group (n = 40). The plantar pressure distribution during gait was recorded, and the contact area (CA), peak pressure (PP), contact time (CT) and pressure-time integral (PTI) in five foot regions (rearfoot, midfoot lateral, midfoot medial, lateral forefoot and medial forefoot) were analysed. The IMS of the dorsiflexors and plantar flexors, passive ROM, and foot posture were also recorded.ResultsPP (medial midfoot and medial forefoot) and PTI (rearfoot, lateral midfoot and medial forefoot) were higher in children with CMT compared with the typical group. The adolescents with CMT presented a less CA (whole foot) and a higher CT (medial midfoot) when compared with typical group. For CMT, in the medial midfoot, plantar flexor IMS associated with PP (β=-11.54, p = 0.01) and PTI (β=-3.38, p = 0.04); supinated foot posture associated with PP (β = 33.89, p = 0.03) and PTI (β = 12.01, p = 0.03).SignificanceChildren with CMT showed clear changes in most of the dynamic plantar pressure variables, while adolescents with CMT showed changes mostly in CA and CT. This information together with the associations established between supinated foot, dorsiflexion ROM and plantar flexions IMS can be useful for guiding rehabilitation professionals in their therapies.     

Altered forefoot function following a military training activity

BackgroundInjury rates are high in populations that regularly undertake weight-bearing physical activity, particularly military populations. Military training activities, that often include load carriage, have been associated with lower limb injury occurrence, specifically stress fractures.Research questionRecent work identified plantar loading variables as risk factors for lower limb stress fractures in Royal Marines recruits that were assessed during barefoot running. This study aimed to quantify how those plantar loading variables changed in Royal Marines recruits following a prolonged military load carriage activity, to further understand potential mechanisms for lower limb stress fractures.MethodsBilateral, synchronised plantar pressure and lower limb kinematic data were recorded during barefoot running at 3.6 m s⁻¹ (±5%) pre- and post- a 12.8-km training activity (∼150 min). The training activity was completed with an average speed typical of walking (1.4 m.s^-1), and 35.5 kg of additional load was carried throughout. Data were collected from 32 male Royal Marines recruits who completed the training activity in week-21 of the 32-week training programme. Plantar pressure variables and ankle dorsiflexion were compared between pre- and post-activity.ResultsPost-activity there was reduced loading under the forefoot and increased loading under the rearfoot and midfoot. There was no change in dorsiflexion touchdown angle, but an increase in peak dorsiflexion and range of motion post-activity.SignificanceThe increased rearfoot loading, reduced forefoot loading and increased ankle dorsiflexion following a prolonged military load carriage activity suggest a reduced transfer of loading from the rearfoot to the forefoot during stance, which may have implications for the development of stress fractures, particularly of the metatarsals.     

Differences in lower-extremity kinematics between the male military personnel with and without plantar fasciitis

ObjectiveTo evaluate the factors that influence gait by comparing lower extremity kinematics during the stance phase of the gait cycle between individuals with and without plantar fasciitis.DesignA cross-sectional study.SettingMotion analysis research laboratory.ParticipantsThirty subjects with plantar fasciitis and 30 aged-matched controls.Main outcome measure(s)Range of motion of the lower extremity and multi-segment foot during gait using a three-dimensional motion analysis system.ResultsThe plantar fasciitis group showed significant differences in motion in the multi-segment foot, ankle, knee, and hip from the control group during various subphases of the stance phase. Specifically, relative to the control group, the plantar fasciitis group had more rearfoot adduction, forefoot eversion, ankle abduction, and hip abduction. They also had less midfoot dorsiflexion, forefoot dorsiflexion, knee extension, knee external rotation, and hip extension (all Ps < 0.05).ConclusionsIndividuals with plantar fasciitis exhibited more flexibility in the ankle-foot complex and poorer quality of lower-extremity movement than the group that did not have plantar fasciitis. Thus, differences in structures in both the ankle-foot complex as well as those in the hip and knee joints appear to be associated with the presence of plantar fasciitis.     

Postural instability in Charcot-Marie-Tooth 1A disease

The aim of this study was to evaluate the influence of somatosensory impairment, distal muscle weakness and foot deformities on the balance in 21 CMT1A patients using a baropodometric platform.Stabilometric analysis by measuring sway area and velocity of a centre of pressure (CoP) both at open and closed eyes were used to assess postural imbalance. Static analysis, by measuring the load and the plantar surface of forefoot, midfoot and hindfoot was used to define the footprint shape and to assess as a whole foot deformities. Stabilometric and static results were compared with those of a control group. In CMT1A patients, stabilometric findings were correlated with static parameters, Achilles’ tendon retraction, distal muscle strength and CMT examination score (CMTES). CMT1A patients compared to controls had lower plantar surface and load on midfoot, and higher load on a forefoot. CMT1A patients had a greater postural instability, since they had a higher CoP velocity, both at open and closed eyes. Moreover, the CoP velocity correlated inversely with the strength of ankle dorsi-flexion muscles and directly with CMTES as whole and with the item “motor symptoms legs”. Postural imbalance was not correlated with sensory impairment and foot deformities as expressed by static analysis and Achilles’ tendon retraction.In this study we demonstrated an altered balance in CMT1A patients during upright standing. The imbalance in our CMT patients seems to be related to the weakness of ankle dorsi-flexor muscles rather than sensory impairment or foot deformities. These results could be due to a mildly affected CMT1A population, evaluated in an early stage of the disease.     

Midfoot and ankle motion during heel rise and gait are related in people with diabetes and peripheral neuropathy

BackgroundMidfoot and ankle movement dysfunction in people with diabetes mellitus and peripheral neuropathy (DMPN) is associated with midfoot deformity and increased plantar pressures during gait. If midfoot and ankle motion during heel rise and push-off of gait have similar mechanics, heel rise performance could be a clinically feasible way to identify abnormal midfoot and ankle function during gait.Research questionIs midfoot and ankle joint motion during a heel rise associated with midfoot and ankle motion at push-off during gait in people with DMPN?MethodsSixty adults with DMPN completed double-limb heel rise, single-limb heel rise, and walking. A modified Oxford multi-segment foot model (forefoot, hindfoot, shank) was used to analyze midfoot (forefoot on hindfoot) and ankle (hindfoot on shank) sagittal angle during heel rise and gait. Pearson correlation was used to test the relationship between heel rise and gait kinematic variables (n = 60). Additionally, we classified 60 participants into two subgroups based on midfoot and ankle position at peak heel rise: midfoot and ankle dorsiflexed (dorsiflexed; n = 23) and midfoot and ankle plantarflexed (plantarflexed; n = 20). Movement trajectories of midfoot and ankle motion during single-limb heel rise and gait of the subgroups were examined.ResultsPeak double-limb heel rise and gait midfoot and ankle angles were significantly correlated (r = 0.49 and r = 0.40, respectively). Peak single-limb heel rise and gait midfoot and ankle angles were significantly correlated (r = 0.63 and r = 0.54, respectively). The dorsiflexed subgroup, identified by heel rise performance showed greater midfoot and ankle dorsiflexion during gait compared to the plantarflexed subgroup (mean difference between subgroups: midfoot 3°, ankle 3°).SignificancePeople with DMPN who fail to plantarflex the midfoot and ankle during heel rise have difficulty plantarflexing the midfoot and ankle during gait. Utilizing a heel rise task may help identify midfoot and ankle dysfunction associated with gait in people with DMPN.     

Understanding the role of foot biomechanics on regional foot orthosis deformation in flatfoot individuals during walking

BackgroundFoot orthoses (FOs) are one of the most common interventions to restore normal foot mechanics in flatfoot individuals. New technologies have made it possible to deliver customized FOs with complex designs for potentially better functionalities. However, translating the individuals’ biomechanical needs into the design of customized FOs is not yet fully understood.Research questionOur objective was to identify whether the deformation of customized FOs is related to foot kinematics and plantar pressure during walking.MethodsThe kinematics of multi-segment foot and FOs contour were recorded together with plantar pressure in 17 flatfoot individuals while walking with customized FOs. The deformation of FOs surface was predicted from its contour kinematics using an artificial neural network. Plantar pressure map and deformation were divided into five anatomically based regions defined by the corresponding foot segments. Forward stepwise linear mixed models were built for each of the four gait phases to determine the feet-FOs interaction.ResultsIt was observed that some associations existed between foot kinematics and pressure with regional FOs deformation. From heel-strike to foot-flat, longitudinal arch angle was associated with FOs deformation in forefoot. From foot-flat to midstance, rearfoot eversion accounted for variation in the deformation of medial FOs regions, and forefoot abduction for the lateral regions. From midstance to heel-off, rearfoot eversion, longitudinal arch angle, and plantar pressure played significant role in deformation. Finally, from heel-off to toe-off, forefoot adduction affected the deformation of forefoot and midfoot.SignificanceThis study provides guidelines for designing customized FOs. Flatfoot individuals with excessive rearfoot eversion or very flexible medial arches require more support on medial FOs regions, while the ones with excessive forefoot abduction need the support on lateral regions. However, a compromise should be made between the level of support and the level of increase in plantar pressure to avoid stress on foot structures.     

The effect of foot type on in-shoe plantar pressure during walking and running

The purpose of this study was to determine if low arch feet have altered plantar loading patterns when compared to normal feet during both walking and running. Fifty healthy subjects (34 normal feet, 16 flat feet) walked and ran five trials each at standard speeds. In-shoe pressure data were collected at 50 Hz. Contact area, peak pressure, maximum force, and force-time integral were analyzed in eight different regions of the foot. Foot type was determined by examining navicular height, arch angle, rearfoot angle, and a clinical score. A series of 2 x 2 repeated measures ANOVAs were used to determine statistical differences (alpha<0.05). A significant interaction existed between foot type and movement type for the maximum force in the medial midfoot. Total foot contact area, maximum force and peak pressure were significantly increased during running. Contact area in each insole area, except for the rearfoot, was significantly increased during running. Peak pressure and maximum force were significantly increased during running in each of the foot regions. However, the force-time integral was significantly decreased during running in the rearfoot, lateral midfoot, middle forefoot, and lateral forefoot. Significant differences between foot types existed for contact area in the medial midfoot and maximum force and peak pressure in the lateral forefoot. The maximum force and peak pressures were significantly decreased for the flat foot type. Therefore, individuals with a flat foot could be at a lower risk for lateral column metatarsal stress fractures, indicating that foot type should be assessed when determining an individual's risk for metatarsal stress fractures.     

An optimized design of in-shoe heel lifts reduces plantar pressure of healthy males

Conventional heel lift with a flat surface increases the risk of foot problems related to higher plantar pressure and decreased stability. In this study, an optimized design of in-shoe heel lifts developed to maintain the midfoot function was tested to investigate if the plantar pressure distribution was improved. The design was based on three dimensional foot plantar contour which was captured by an Infoot 3D scanning system while the heel was elevated by a heel wedge. To facilitate midfoot function, an arch support was designed to support the lateral longitudinal arch, while allowing functional movement of the medial longitudinal arch. Twenty healthy male subjects were asked to walk along an 8 m walkway while wearing high-cut footwear with and without the optimized heel lift. Peak pressure, contact area and force–time integral were measured using the Pedar insole system. Range and velocity of medial-lateral center of pressure during forefoot contact phase and foot flat phase were collected using a Footscan pressure plate. Compared to the shoe only condition, peak pressure under the rearfoot decreased with the optimized heel lift, while no increase of peak pressure was observed under the forefoot and midfoot regions, indicating improved plantar pressure distribution. The findings of this study suggest that this optimized heel lift has better biomechanical performance than a conventional flat heel lift. Results from this study may have implications for insole and shoe last design, especially for people who need additional heel height without sacrificing midfoot function.     

The mechanics behind the image: foot and ankle pathology associated with gastrocnemius contracture

Contracture of the gastrocnemius musculature is a prevalent finding in the setting of foot and ankle pathology. Tightness of the posterior musculotendinous structures in the leg limits ankle range of motion and affects an equinus posture of the foot. Increased contact pressures are generated in the plantar foot with weightbearing. The resultant overload of the ligaments and the intrinsic muscles of the midfoot and forefoot is manifest in a variety of pathologic processes. The altered mechanics contributes to, among other conditions, ankle impingement, plantar fasciitis, midfoot arthritis, posterior tibial tendon dysfunction, forefoot overload, diabetic ulceration, and Charcot arthropathy. Effective management of these conditions includes addressing the underlying gastrocnemius contracture as well as the related foot and ankle pathology. Here we describe the underlying biomechanical abnormalities and radiographic findings in these pathological conditions of the foot and ankle associated with gastroequinus contracture. An awareness and understanding of the pathomechanics should enable the radiologist to better appreciate the form and function associated with the image.     

Foot pronation during walking is associated to the mechanical resistance of the midfoot joint complex

BackgroundThe demonstration of the relationship between midfoot passive mechanical resistance and foot pronation during gait may guide the development of assessment and intervention methods to modify foot motion during gait and to alter midfoot passive mechanical resistance.Research questionIs foot pronation during the stance phase of gait related to the midfoot passive mechanical resistance to inversion?MethodsThe resistance torque and stiffness provided by midfoot soft tissues of 33 participants (21 females and 12 males) with average of 26.21 years were measured. In addition, the participants’ forefoot and rearfoot kinematic data during the stance phase of gait were collected with the Qualisys System (Oqus 7+). Correlation Coefficients were calculated to test the association between kinematic variables representing pronation (forefoot-rearfoot inversion, forefoot-rearfoot dorsiflexion and rearfoot-shank eversion) and maximum resistance torque and maximum stiffness of the midfoot with α = 0.05.ResultsReduced maximum midfoot resistance torque was moderately associated with increased forefoot-rearfoot inversion peak (p = 0.029; r = 0.38), with forefoot-rearfoot dorsiflexion peak (p = 0.048; r = −0.35) and with rearfoot-shank eversion peak (p = 0.008; r = −0.45). Maximum midfoot stiffness was not associated to foot pronation.SignificanceThe smaller the midfoot resistance torque, the greater the forefoot-rearfoot inversion and dorsiflexion peaks and the rearfoot-shank eversion peak during gait. The findings suggest the existence of a relationship between foot pronation and midfoot passive mechanical resistance. Thus, changes in midfoot passive mechanical resistance may affect foot pronation during gait.     

The biomechanical effects of pronated foot function on gait. An experimental study

The relationship between foot kinematics and the development of lower extremity musculoskeletal disorders (MSD) has been the focus of recent attention. However, most studies evaluated static foot type and not dynamic foot function. The purpose was to compare lower limb and foot kinematics, and plantar pressures during gait in physically active individuals with pronated and non-pronated foot function. Foot function in 154 adult participants was documented as pronated (n = 63) or neutral (n = 91) using 2 established methods: The Foot Posture Index and the Center of Pressure Excursion Index. Difference between the groups in triplanar motion of the lower limb during barefoot gait was evaluated using a 3D motion capture system incorporating the Oxford Foot Model. Dynamic parameters of plantar pressure were recorded using a pressure platform. Anterior-posterior pelvic tilt range of motion (ROM), peak knee internal rotation, forefoot dorsiflexion ROM, peak forefoot abduction, and rearfoot eversion were all increased in those with pronated foot function. Hallux contact time and time to peak force under the medial forefoot were increased with pronated foot function, and maximal force under the lateral forefoot was reduced. Pronated foot function affected the whole lower limb kinematic chain during gait. These kinematic alterations could increase the risk of developing MSD. Further studies should elucidate the relationship between pronated foot function and MSD, and, if confirmed, foot function should be evaluated in clinical practice for patients with lower limb and low back pain.     

Forefoot pathology in relation to plantar pressure distribution in patients with rheumatoid arthritis: A cross-sectional study in the Amsterdam Foot cohort

BackgroundIn patients with rheumatoid arthritis (RA), both high and low forefoot plantar pressures have been reported. Better understanding of pathology in the forefoot associated with altered pressure distribution in patients with RA could help to better formulate and specify goals for treatment with foot orthoses or therapeutic footwear.ObjectivesTo investigate the association of plantar pressure with disease activity and deformity in the forefoot in patients with rheumatoid arthritis and forefoot symptoms.MethodsA cross sectional study, using data of 172 patients with rheumatoid arthritis and forefoot symptoms, was conducted. Peak pressure (PP) and pressure time integral (PTI) in the forefoot were measured with a pressure platform. Forefoot deformity was assessed using the Platto score. Forefoot disease activity was defined as swelling and/or pain assessed by palpation of the metatarsophalangeal joints. The forefoot was divided in a medial, central and lateral region, in which the following conditions could be present: 1) no pathology, 2) disease activity, 3) deformity or 4) disease activity and deformity. A multilevel analysis was performed using condition per forefoot region as independent variable and PP or PTI in the corresponding region as dependent variable.ResultsStatistically significant higher plantar pressures were found in forefoot regions with deformities (RR 1.2, CI 1.1-1.3, P<0.0001), compared to forefoot regions without forefoot pathology. No significant differences in plantar pressures were found when solely forefoot disease activity was present in forefoot regions.SignificanceForefoot deformities are related to higher plantar pressures measured in the corresponding forefoot regions. The absence of an association between local disease activity and plantar pressure might be explained by the low prevalence of metatarsophalangeal joint pain or swelling. Future research with sensitive imaging measures to detect disease activity is recommended to reveal the effect of forefoot disease activity on plantar pressure.     

Foot function is well preserved in children and adolescents with juvenile idiopathic arthritis who are optimally managed

PurposeThe objective of this study was to compare disease activity, impairments, disability, foot function and gait characteristics between a well described cohort of juvenile idiopathic arthritis (JIA) patients and normal healthy controls using a 7-segment foot model and three-dimensional gait analysis.MethodsFourteen patients with JIA (mean (standard deviation) age of 12.4 years (3.2)) and a history of foot disease and 10 healthy children (mean (standard deviation) age of 12.5 years (3.4)) underwent three-dimensional gait analysis and plantar pressure analysis to measure biomechanical foot function. Localised disease impact and foot-specific disease activity were determined using the juvenile arthritis foot disability index, rear- and forefoot deformity scores, and clinical and musculoskeletal ultrasound examinations respectively. Mean differences between groups with associated 95% confidence intervals were calculated using the t distribution.ResultsMild-to-moderate foot impairments and disability but low levels of disease activity were detected in the JIA group. In comparison with healthy subjects, minor trends towards increased midfoot dorsiflexion and reduced lateral forefoot abduction within a 3–5° range were observed in patients with JIA. The magnitude and timing of remaining kinematic, kinetic and plantar pressure distribution variables during the stance phase were similar for both groups.ConclusionIn children and adolescents with JIA, foot function as determined by a multi-segment foot model did not differ from that of normal age- and gender-matched subjects despite moderate foot impairments and disability scores. These findings may indicate that tight control of active foot disease may prevent joint destruction and associated structural and functional impairments.     

Are in-shoe pressure characteristics in symptomatic idiopathic pes cavus related to the location of foot pain?

People who have extremely high arched feet may be subject to substantial levels of foot pain, despite the lack of obvious pathology. This study sought to investigate the effect of pes cavus on pain intensity and location and on the magnitude and distribution of foot pressure. Measurements were derived from the more symptomatic foot of 130 participants with painful, idiopathic pes cavus. Data were collected using Pedar in-shoe pressure sensors and averaged over nine randomly selected steps. Participant information, including location and intensity of pain, Foot Posture Index values and anthropometric and "quality of life" variables, were also recorded. Painful idiopathic pes cavus seems to provoke a more cautious gait pattern than normal, with reduced peak and mean pressure values, particularly in the fore- and rear-foot regions. In particular, participants with pain confined to the rear-foot exhibit an antalgic gait pattern, with lower pressure values and a longer period of foot-ground contact in the heel region than those with pain only in the fore-foot. We determined no clear predictors of pain in terms of foot posture or demographics, although people with high body mass index values are more likely to have pain in several regions. The relationship between the posture of the foot and the presentation of pain remains unclear, however we believe that the presence of heel pain in pes cavus may be more restricting than fore-foot pain.     

Pressure-relieving properties of various shoe inserts in older people with plantar heel pain

Plantar heel pain is one of the most common musculoskeletal conditions affecting the foot and it is commonly experienced by older adults. Contoured foot orthoses and some heel inserts have been found to be effective for plantar heel pain, however the mechanism by which they achieve their effects is largely unknown. The aim of this study was to investigate the effects of foot orthoses and heel inserts on plantar pressures in older adults with plantar heel pain. Thirty-six adults aged over 65 years with plantar heel pain participated in the study. Using the in-shoe Pedar(?) system, plantar pressure data were recorded while participants walked along an 8 m walkway wearing a standardised shoe and 4 different shoe inserts. The shoe inserts consisted of a silicon heel cup, a soft foam heel pad, a heel lift and a prefabricated foot orthosis. Data were collected for the heel, midfoot and forefoot. Statistically significant attenuation of heel peak plantar pressure was provided by 3 of the 4 shoe inserts. The greatest reduction was achieved by the prefabricated foot orthosis, which provided a fivefold reduction compared to the next most effective insert. The contoured nature of the prefabricated foot orthosis allowed for an increase in midfoot contact area, resulting in a greater redistribution of force. The prefabricated foot orthosis was also the only shoe insert that did not increase forefoot pressure. The findings from this study indicate that of the shoe inserts tested, the contoured prefabricated foot orthosis is the most effective at reducing pressure under the heel in older people with heel pain.     

Evaluation of the pressure-redistributing properties of prefabricated foot orthoses in older people after at least 12 months of wear

Foot problems are highly prevalent in older people. To treat such problems in this age-group prefabricated (‘off-the-shelf’) foot orthoses are frequently prescribed. However, such devices are susceptible to material compression and deformation, which may reduce their effectiveness over time. Therefore, the aim of this study was to compare the pressure-redistributing properties of new prefabricated orthoses to orthoses worn for at least 12 months. Thirty-one adults (10 males, 21 females) aged over 65 years (mean 75.4, SD 5.2) participated. Plantar pressure data were collected under the rearfoot, midfoot and forefoot using the Pedar^® in-shoe system while participants walked along an 8 m walkway wearing shoes only, new orthoses and old orthoses (orthoses were full length, dual-density prefabricated Formthotic™ devices). Compared to the shoe-only condition, both the new and old orthoses produced significant reductions in peak pressure and maximum force in the rearfoot with corresponding increases in force and contact area in the midfoot. Compared to the new orthoses, the old orthoses exhibited small but significant increases in peak pressure in the rearfoot (6%, p = 0.001) and maximum force in the rearfoot (5%, p < 0.001) and forefoot (2%, p = 0.032). These findings indicate that the prefabricated orthoses evaluated in this study are only slightly less effective at redistributing plantar pressure after at least 12 months of wear.     

Replicating and redesigning ankle-foot orthoses with 3D printing for children with Charcot-Marie-Tooth disease

BackgroundChildren with the most common inherited neuropathy, Charcot-Marie-Tooth disease (CMT), are often prescribed ankle-foot orthoses (AFOs) to improve walking ability and prevent falls by reducing foot drop, postural instability, and other gait impairments. These externally worn assistive devices are traditionally custom-made using thermoplastic vacuum forming. This labour-intensive manufacturing process often results in AFOs which are cumbersome due to limited design options, and are associated with low acceptability, discomfort, and suboptimal impact on gait. The aim of this study was to determine how 3D printing can be used to replicate and redesign AFOs in children with CMT.MethodsTraditional AFOs, 3D printed replica AFOs (same design as traditional AFOs), 3D printed redesigned AFOs and a shoes only control condition were compared in 12 children with CMT. 3D printed AFOs were manufactured using material extrusion in Nylon-12. 3D gait analysis (temporal-spatial, kinematic, kinetic), in-shoe pedobarography and self-reported satisfaction were used to compare conditions. The primary kinematic and kinetic outcome measures were maximum ankle dorsiflexion in swing and maximum ankle dorsiflexor moment in loading response, to capture foot drop and an absent of heel rocker.ResultsThe 3D printed replica AFOs were comparable to traditional AFOs for all outcomes. The 3D printed replica AFOs improved foot position at initial contact and during loading response and significantly reduced pressure beneath the whole foot, rearfoot and forefoot compared to the shoes only. The 3D printed redesigned AFOs produced a device that was significantly lighter (mean −35.2, SD 13.3%), and normalised maximum ankle dorsiflexor moment in loading response compared to shoes only and traditional AFOs.Significance3D printing can be used to replicate traditional handmade AFOs and to redesign AFOs to produce a lighter device with improved biomechanics by incorporating novel design features.     

Medial contact and smaller plantar loads characterize individuals with Patellofemoral Pain Syndrome during stair descent

ObjectivesTo investigate plantar pressure distribution in individuals with and without Patellofemoral Pain Syndrome during the support phase of stair descent.DesignObservational case–control study.Participants30 young adults with Patellofemoral Pain Syndrome and 44 matched controls.Main outcome measuresContact area, peak pressure and pressure–time integral (Novel Pedar-X system) were evaluated in six plantar areas (medial, central and lateral rearfoot; midfoot; medial and lateral forefoot) during stair descent.ResultsContact area was greater in the Patellofemoral Pain Syndrome Group at medial rearfoot (p = 0.019) and midfoot (p < 0.001). Subjects with Patellofemoral Pain Syndrome presented smaller peak pressures (p < 0.001).ConclusionThe pattern of plantar pressure distribution during stair descent in Patellofemoral Pain Syndrome subjects was different from controls. This seems to be related to greater medial rearfoot and midfoot support. Smaller plantar loads found in Patellofemoral Pain Syndrome subjects during stair descent reveal a more cautious motor pattern in a challenging task.