Intra- and inter-foot coordination in quiet standing: footwear and posture effects

Intra-foot coordination between center of pressure (COP) of the ball and heel of the foot in single leg standing and inter-foot coordination of the right and left foot during bipedal stance was examined as a function of postural stance (two legs, one leg, and toe postures), footwear (barefoot, different area based high heel shoes) and postural training (ballet group and regular exercising group). Young adult females performed three 20s trials in each postural condition. In general, the traditional variability measures of COPnet motion increased under the less stable postural support conditions and ballet dancers had better balance in single leg standing. Regularity analysis revealed a negative relation between the variability of foot coupling (both intra- and inter-foot) and the standard deviation of COPnet that was mediated by the interaction of shoe support and postural stance. The findings show that shoe support and postural stance modulate collective postural motion (COPnet) through the adaptability of the coupling of foot dynamics.     

The effect of unstable sandals on instability in gait in healthy female subjects

Unstable footwear generally lacks thorough peer-review published research to support concepts and marketing claims. The purpose of this study was to investigate the instability induced by four (FitFlop, Masai Barefoot Technology, Reebok Easy-Tone and Skechers Tone-Ups) commercially available unstable sandals and one stable control sandal (Earth) in walking in 15 females (mean ± SD age was 29 ± 6.7 years, mass 62.6 ± 6.9 kg and height 167.1 ± 4.2 cm). Three-dimensional motion with synchronised electromyography and kinetic data were collected. Walking speed and step length remained consistent between conditions, however double support time decreased in Masai Barefoot Technology. Centre of pressure data identified no consistent difference between the stable control and the unstable sandals, however Masai Barefoot Technology reduced the anterior–posterior range of centre of pressure. Muscle activity differed significantly at the ankle in the unstable footwear. FitFlop, Reebok and Skechers increased peroneal activity during pre-swing, whereas Masai Barefoot Technology increased medial gastrocnemius and decreased tibialis anterior activity in loading response and mid-stance. The larger rocker sole of the Masai Barefoot Technology altered gait and muscle activation with regard to braking and progression in the sagittal plane. Reebok, Skechers and FitFlop, with softer, less stable foreparts increased evertor action at toe-off, having their effect in the coronal plane. The study highlighted that any instability induced by the shoes is design-specific.     

A comparison of young children’s spatiotemporal measures of walking and running in three common types of footwear compared to bare feet

BackgroundClinicians and footwear manufacturers often advise young children to wear soft-soled footwear when they are first learning to walk. There is limited evidence as to why this advice is given, and if soft-soled shoes are as close to barefoot as thought.Research questionWhat are the differences in spatiotemporal measures of gait during walking and running in three common types of children’s footwear with a soft-soled compared to barefoot in young children?MethodsThe study used a quasi-experimental design, with the condition order randomised using a Latin square sequence. Forty-seven children were recruited (2 - 4 years). Participants walked or ran the length of a GAITrite mat in a randomized order for barefoot and soft-soled sneaker, boot and sandal conditions. Linear regression analyses were used to investigate the main effect of each soft-soled footwear compared to bare feet in the different gait parameters.ResultsFor walking and running trials, cadence decreased whereas step time and stride length increased in all footwear types compared to the barefoot condition. While wearing sneakers and sandals increased the stance percentage for walking and running trials, compared to barefoot, this difference was only apparent during the running trial for the boots. Likewise, although double support time increased for both the boots and sneakers in walking and running, compared to barefoot, this difference was only observed in the sandals during walking.SignificanceThis research found that various types of soft-soled footwear impacted gait compared to the barefoot condition, with some differences seen between walking and running trials. These findings challenge the assumption that soft-soled footwear facilitate a similar gait to barefoot walking and running, although the clinical significance of these differences is unknown.     

Foot motion in children shoes: a comparison of barefoot walking with shod walking in conventional and flexible shoes

The increased prevalence for flatfoot and hallux valgus in modern societies may be the consequence of inadequate footwear in childhood. Based on the assumption that barefoot walking represents the best condition for the development of a healthy foot the objective of this study was to monitor the influence of commercial footwear on children's foot motion during walking. Furthermore, an attempt was made to reduce this influence by changing the physical properties of standard footwear. Children's barefoot motion pattern was monitored by a marker-based optical 3D-tracking method using a multi-segment foot model. In the study's first stage, barefoot walking was compared to walking with a commercial product. In the second stage it was compared to both, the pattern with the commercial product and with the shoe modified on the basis of the findings of the first stage of the study. Eighteen children (8.2+/-0.7 years old) with no foot deformity and with the same shoe size were recruited for this study. It was found that tibio-talar ROM increased in the commercial shoe (26.6 degrees ) compared to the barefoot condition (22.5 degrees , p=0.001) whereas the medial arch changes for push-off were diminished since the variation in arch length was reduced from 9.9% (barefoot) to 5.9% (shoe, p<0.001). Further, ROM in foot torsion along the long foot axis was reduced from 9.8 degrees (bare) to 4.7 degrees (shoe, p<0.001). These parameters could be improved with more flexible footwear. The present study shows that slimmer and more flexible children's shoes do not change foot motion as much as conventional shoes and therefore should be recommended not only for children in this age but for healthy children in general.     

Sagittal subtalar and talocrural joint assessment between barefoot and shod walking: A fluoroscopic study

BackgroundWhile wearing shoes is common in daily activities, most foot kinematic models report results on barefoot conditions. It is difficult to describe foot position inside shoes. This study used fluoroscopic images to determine talocrural and subtalar motion.Research QuestionWhat are the differences in sagittal talocrual and subtalar kinematics between walking barefoot and while wearing athletic walking shoes?MethodsThirteen male subjects (mean age 22.9 ± 2.9 years, mean weight 77.2 ± 6.9 kg, mean height 178.2 ± 3.7 cm) screened for normal gait were tested. A fluoroscopy unit was used to collect images during stance. Sagittal motion of the talocrural and subtalar joints of the right foot were analyzed barefoot and in an athletic walking shoe.ResultsShod talocrural position at heel strike was 6.0° of dorsiflexion and shod peak talocrural plantarflexion was 4.2°. Barefoot talocrural plantarflexion at heel strike was 4.2° and barefoot peak talocrural plantarflexion was 10.9°. Shod subtalar position at heel strike was 2.6° of plantarflexion and peak subtalar dorsiflexion was 1.5°. The barefoot subtalar joint at heel strike was in 0.4° dorsiflexion and barefoot peak subtalar dorsiflexion was 3.5°. As the result of wearing shoes, average walking speed and stride length increased and average cadence decreased. Comparing barefoot to shod walking there was a statistical significance in talocrural dorsiflexion and at heel strike and peak talocrural dorsiflexion, subtalar plantarflexion at heel strike and peak subtalar dorsiflexion, walking speed, stride length, and cadence.SignificanceThis work demonstrates the ability to directly measure talocrural and subtalar kinematics of shod walking using fluoroscopy. Future work using this methodology can be used to increase understanding of hindfoot kinematics during a variety of non-barefoot activities.     

A comparison of the spatiotemporal parameters, kinematics, and biomechanics between shod, unshod, and minimally supported running as compared to walking

Recreational running has many proven benefits which include increased cardiovascular, physical and mental health. It is no surprise that Running USA reported over 10 million individuals completed running road races in 2009 not to mention recreational joggers who do not wish to compete in organized events. Unfortunately there are numerous risks associated with running, the most common being musculoskeletal injuries attributed to incorrect shoe choice, training errors and excessive shoe wear or other biomechanical factors associated with ground reaction forces. Approximately 65% of chronic injuries in distance runners are related to routine high mileage, rapid increases in mileage, increased intensity, hills or irregular surface running, and surface firmness. Humans have been running barefooted or wearing minimally supportive footwear such as moccasins or sandals since the beginning of time while modernized running shoes were not invented until the 1970s. However, the current trend is that many runners are moving back to barefoot running or running in “minimal” shoes. The goal of this masterclass article is to examine the similarities and differences between shod and unshod (barefoot or minimally supportive running shoes) runners by examining spatiotemporal parameters, energetics, and biomechanics. These running parameters will be compared and contrasted with walking. The most obvious difference between the walking and running gait cycle is the elimination of the double limb support phase of walking gait in exchange for a float (no limb support) phase. The biggest difference between barefoot and shod runners is at the initial contact phase of gait where the barefoot and minimally supported runner initiates contact with their forefoot or midfoot instead of the rearfoot. As movement science experts, physical therapists are often called upon to assess the gait of a running athlete, their choice of footwear, and training regime. With a clearer understanding of running and its complexities, the physical therapist will be able to better identify faults and create informed treatment plans while rehabilitating patients who are experiencing musculoskeletal injuries due to running.     

Comparison of two different designs of forefoot off-loader shoes and their influence on gait and spinal posture

BackgroundThe purpose of forefoot off-loader shoes (FOS) is to unload the operated region of the foot in order to allow early mobilization and rehabilitation. However, little is known about the actual biomechanical effects of different designs of FOS on gait, pelvis and spine.Research questionAim of this study was to analyse and compare the effects of two different designs of forefoot unloader shoes.MethodsOrtho-Wedge (FOS A) and Relief-Dual® (FOS B) were evaluated in this study during standing and while walking. Changes of the pelvic position and spinal posture were measured with a surface topography system and an instrumented treadmill. Gait phases were detected automatically by a built-in pressure plate.ResultsBoth FOS resulted in a significant increase of pelvic obliquity, pelvic torsion, lateral deviation and surface rotation (p < 0.001) while standing. Between both shoe models, pelvic obliquity and lateral deviation (p < 0.05) were significantly different. During walking, both FOS had a significant effect on spine and pelvis (p < 0.05), however only minor differences were found between the designs. All gait parameters were affected more, wearing FOS A than B. Step length were significantly longer by wearing FOS (p < 0.005). However stance phase raised and swing phase is reduced on the leg wearing FOS A (p < 0.001).SignificanceThe study showed that FOS lead to significant changes in pelvic position and spinal posture during standing and while walking. A compensating shoe on the contralateral side is therefore recommend. Gait parameters however were affected more by the traditional FOS A half-shoe. The sole- design and shape of FOS B leads to a more physiological roll-over of the foot.     

Efficacy of motion control shoes for reducing excessive rearfoot motion in fatigued runners

ObjectivesExcessive foot pronation and fatigue in running are possible risk factors for injuries. Motion control footwear was designed to limit excessive foot motion in runners, but its clinical efficacy has not been well reported. This study investigated the rearfoot kinematics in runners when running with different footwear before and after fatigue of the lower leg muscles.DesignWithin subjects repeated measures.SettingUniversity gait laboratory.Participants25 female recreational runners.Main outcome measuresA Vicon three-dimensional motion analysis system was used to capture the rearfoot motions of 25 recreational runners who had excessive foot pronation, when running with motion control shoes and neutral shoes before and after fatigue of the lower leg muscles.ResultsThe findings with neutral shoe testing revealed a significant increase in rearfoot angle of 6.5° (95% CI 4.7–8.2°) (p<0.01) when the muscles were fatigued. However, the findings with motion control shoes revealed that rearfoot angle was marginally insignificant (p=0.06) in subjects before and after muscle fatigue. Moreover, rearfoot motion when running with neutral shoes was higher than that with motion control shoes in both pre- (p<0.01) and post-fatigue states (p<0.01).ConclusionsMotion control shoes can control excessive rearfoot movements in runners with over-pronation regardless of the state of leg muscle fatigue.     

Children’s school footwear: The impact of fit on foot function,comfort and jump performance in children aged 8 to 12 years

BackgroundThere is a common perception that poorly fitting footwear will negatively impact a child’s foot, however, there is limited evidence to support this.AimTo determine the effect of shoe size on foot motion, perceived footwear comfort and fit during walking, maximal vertical jump height and maximal standing broad jump distance in children aged 8–12 years.MethodsFourteen participants completed 3D walking gait analysis and jumping tasks in three different sizes of school shoes (one size bigger, fitted for size, one size smaller). In-shoe motion of the hindfoot, midfoot and 1st metatarsophalangeal joint (1st MTPJ) were calculated using a multi-segment kinematic foot model. Physical performance measures were calculated via maximal vertical jump and maximal standing broad jump. Perceived footwear comfort and fit (heel, toes and overall) was assessed using a 100 mm visual analog scale (VAS). Differences were compared between shoe sizes using repeated measures ANOVA, post-hoc tests and effect sizes (Cohen’s d).ResultsCompared to the fitted footwear, the smaller sizing restricted hindfoot eversion (−2.5°, p = 0.021, d = 0.82), 1st MTPJ dorsiflexion (−3.9°, p = 0.012, d = 0.54), and compared to the bigger footwear, smaller sizing restricted sagittal plane midfoot range-of-motion during walking (−2.5°, p = 0.047, d = 0.59). The fitted footwear was rated as more comfortable overall with the smaller size rated as too tight in both the heel (mean difference 11.5 mm, p = 0.042, d = 0.58) and toes (mean difference 12.1 mm, p = 0.022, d = 0.59), compared to the fitted size. Vertical and standing broad jump distance were not impacted by footwear size (p = 0.218−0.836).SignificanceFootwear that is too small restricts foot motion during walking in children aged 8–12 years. Jump performance was not affected. Children were able to recognise shoes that were not correctly matched to their foot length, reinforcing that comfort is an important part of the fitting process.     

The effects of shoes on the torsion and rearfoot motion in running.

Excessive pronation is accepted as a good indicator for various running injuries. The least amount of pronation takes place when running barefoot. The latest investigations show that this is connected to a large torsional movement between forefoot and rearfoot which can be influenced by the shoe sole construction. The shoes which are in use among runners in track and field are basically of two types, running shoes (in general torsionally stiff) and spikes (torsionally flexible). The possibly varying effect of these shoes on the shoe/foot motion in running is not known. The purpose of this investigation was therefore to show whether the pronation angle and the torsion angle differ when running barefoot, with spikes, and with running shoes (forefoot touchdown, N = 9 left and right). A film analysis provided the angular movements of the lower leg, rearfoot, and forefoot as well as pronation and torsion in the frontal plane. The results show that at touchdown the torsional movements with both shoe types are quite different from those of running barefoot. With shoes, the torsion angle is reduced back to zero--with running shoes more than with spikes--and the pronation angle is increased beyond the barefoot values (P less than 0.01). In order to reduce the risk of injury, both shoe types should be improved--the running shoes with respect to torsion and the spikes with respect to pronation.     

Acute effect of engineered thermoplastic polyurethane elastomer knockoff running footwear on foot loading and comfort during heel-to-toe running

BackgroundBetter midsole materials and comfort have been incorporated into more expensive shoes and are popular with runners. Consequently, knockoff running shoes are currently widely distributed in the Chinese market and and cost only 30%–50% of the total price of genuine branded products.Research questionUncertainty exists concerning the beneficial effects of advanced shoe material application in decreasing foot loading or impact force during running. Additionally, using comfort as a criterion to identify genuine branded running shoes may exclude brand factor.MethodsFifteen healthy male volunteers were asked to perform two different tests, including running and a comfort evaluation. Each participant was asked to identify which footwear was the Adidas brand shoe based on their perception of comfort.ResultsTime to the first peak of the vertical ground reaction force occurred significantly later when subjects wore the genuine branded shoe compared to knockoff shoe 1 (p = 0.003) and knockoff shoe 2 (p = 0.015) footwea. The genuine branded shoe (p = 0.005) and knockoff shoe 1 (p = 0.029) were significantly more comfortable compared to the knockoff shoe 2. Only four subjects selected the genuine branded shoe, whereas six subjects selected both the genuine branded shoe and knockoff shoe 1.SignificanceKnockoff running footwear significantly increases impact loading compared to the genuine branded product, thereby posing greater risk of running injury.     

Influence of footwear on postural sway: A systematic review and meta-analysis on barefoot and shod bipedal static posturography in patients and healthy subjects

BackgroundBipedal static posturography is widely used to assess postural control. However, standardized methods and evidence on the influence of footwear on balance in comparison to barefoot stance is sparse.Research questionsIs bipedal static posturography applied in a standardized way with respect to demographics and the experimental set-up (systematic review)? Does habitual footwear influence postural control in comparison to barefoot condition during bipedal static posturography in adult patients and healthy subjects (meta-analysis)?MethodsFor this systematic review and meta-analysis, a comprehensive follow-up literature search was conducted from March 2009 until January 2020 according to the PRISMA guidelines. Original, research articles reporting on bipedal, unsupported, static posturography in adults (≥18 years) were included according to inclusion criteria (age, sex, height, weight, duration, repetitions, visual/foot condition, sampling frequency). Studies comparing habitual footwear with barefoot condition during bipedal static posturography were included for the meta-analysis. Center of pressure parameters (sway velocity, range, root mean square, paths lengths) with subjects having eyes closed (EC) or open (EO) were analyzed using random effects models.ResultsFor this systematic review and meta-analysis, 207 and eight out of 5189 studies with 12'341 and 156 subjects, respectively, were eligible. Most studies (89%) reported barefoot, 5% shod, and 6% barefoot and shod measurements. Less than half of studies (44%) included patients of which the minority (13%) suffered from neurological disease. Sway velocity in the anterior-posterior direction was higher in habitual shoes compared to barefoot with EC (SMD: 1.08; 95% CI: 0.68–1.48; p < 0.01; I² = 0%), with EO (SMD: 0.68; 95% CI: 0.11–1.26; p = 0.02; I² = 1%), and in the medio-lateral direction with EC (SMD: 1.30; 95% CI: 0.76–1.85, p < 0.01; I² = 37%).SignificanceMethodical heterogeneity of bipedal static posturography hampers studies’ comparability. Thus, we provide a standardized approach to increase knowledge whether habitual footwear decrease postural control in comparison to barefoot stance.     

Barefoot-shod running differences: shoe or mass effect?

The higher oxygen consumption reported when shod running is compared to barefoot running has been attributed to the additional mass of the shoe. However, it has been reported that wearing shoes also modified the running pattern. The aim of this study was to distinguish the mass and shoe effects on the mechanics and energetics when shod running. Twelve trained subjects ran on a 3-D treadmill ergometer at 3.61 m . s (-1) in six conditions: barefoot, using ultra thin diving socks unloaded, loaded with 150 g, loaded with 350 g, and two shoe conditions, one weighing 150 g and another 350 g. The results show that there was a significant mass effect but no shoe effect for oxygen consumption. Stride frequency, anterior-posterior impulse, vertical stiffness, leg stiffness, and mechanical work were significantly higher in barefoot condition compared to shod. Net efficiency, which has metabolic and mechanical components, decreased in the shod condition. The mechanical modifications of running showed that the main role of the shoe was to attenuate the foot-ground impact by adding damping material. However, these changes may lead to a decrease of the storage and restitution of elastic energy capacity which could explain the lower net efficiency reported in shod running.     

Center of pressure in a walking boot shifts posteriorly in patients following lower leg fracture

BackgroundStudies have shown that the ambulatory behavior and amount of weight bearing performed by lower leg fracture patients, increases over time. It is likely that gait features, such as center of pressure (CoP), also change over time.Research QuestionThe purpose of this study was to characterize changes in CoP exhibited by lower leg fracture patients wearing a walking boot during the recovery period.MethodsApproximately 2 weeks post-surgery, seven lower leg fracture patients were fitted with a MaxTrax walking boot which was integrated with the Ambulatory Tibia Load Analysis System, an underfoot load monitoring system. Patients wore the walking boot for 2–12 weeks resulting in continuous load data during the recovery period. Ambulation was filtered from the raw data and daily average CoP values were calculated by averaging the CoP vectors from all steps in a given day.ResultIn general, the CoP vector varied in both the x and y directions during the initial stages of recovery but was more uniform during the later stages of healing. In 6/7 patients, the CoP in the y direction was closer to the forefoot during the initial stages of healing but shifted posteriorly as time post-surgery increased. The single patient that did not exhibit a posterior shift in CoP was also the only patient to develop a non-union. CoP in the x direction show a less clear trend. CoP in the x direction exhibited a medial shift in 5 patients and a lateral shift in 2 patients.SignificanceDuring lower leg fracture recovery in a walking boot, the CoP in the y direction shifts posteriorly as time post-surgery increases and CoP monitoring may become a useful tool to monitor individual patient healing progression.     

The effect of textured ballet shoe insoles on ankle proprioception in dancers

BackgroundImpaired ankle inversion movement discrimination (AIMD) can lead to ankle sprain injuries. The aim of this study was to explore whether wearing textured insoles improved AIMD compared with barefoot, ballet shoes and smooth insoles, among dancers.MethodsForty-four adolescent male and female dancers, aged 13–19, from The Australian Ballet School were tested for AIMD while barefoot, wearing ballet shoes, smooth insoles, and textured insoles.ResultsNo interaction was found between the four different footwear conditions, the two genders, or the two levels of dancers in AIMD (p > .05). An interaction was found between the four different footwear conditions and the three tertiles when tested in ballet shoes (p = .006). Although significant differences were found between the upper tertiles and the lower tertiles when tested with ballet shoes, barefoot and with smooth insoles (p < .001; p < .001; p = .047, respectively), when testing with textured insoles dancers in the lower tertile obtained similar scores to those obtained by dancers in the upper tertile (p = .911).ConclusionTextured insoles improved the discrimination scores of dancers with low AIMD, suggesting that textured insoles may trigger the cutaneous receptors in the plantar surface, increasing the awareness of ankle positioning, which in turn might decrease the chance of ankle injury.     

Barefoot walking changed relative timing during the support phase but not ground reaction forces in children when compared to different footwear conditions

BackgroundThere is a paucity of available biomechanical kinetic data comparing shod and barefoot conditions in children.Research questionDo children wearing footwear have comparable gait velocity, ground reaction forces (GRF), spatiotemporal parameters, propulsive and braking impulses when compared to children walking barefoot?MethodsSeventy-five children were divided into four groups: Group 1 females aged 4–9 years old (n = 29). Group 2 females aged 3–5 years old (n = 16). Group 3 males aged 6–9 years old (n = 13). Group 4 males aged 4–8 years old (n = 17). Children walked at a self-selected pace over a walkway of force platforms. Each footwear and barefoot represented a separate condition. The order of conditions was randomized. A repeated-measures ANOVA was performed to investigate the effects of the footwear type on gait parameters in each group. Multiple comparisons with Bonferroni corrections were conducted when appropriate.ResultsThere were no statistical differences in velocity or in vertical and anteroposterior GRF across conditions for all groups. There was a significant effect of the footwear worn on time to loading response peak (p = 0.008), time to midstance force (p = 0.006), and time to propulsive peak (p < 0.001). For Group 3, there was a significant effect of the footwear worn on time to braking peak (p < 0.001) and time to propulsive peak (p < 0.001). Regarding impulses for Group 1, there was a significant effect of the footwear worn on the loading response impulse (p = 0.016) and terminal stance and pre-swing impulse (p = 0.001). For Group 4, there was a significant effect of the footwear worn on the loading response impulse (p = 0.028).SignificanceThere is no influence of the evaluated children’s footwear on gait velocity or GRF.     

Spatial and temporal gait characteristics of elderly individuals during backward and forward walking with shoes and barefoot

Backward walking (BW) is an inherent component of mobility and function in daily activities, particularly indoors, when it is more likely that a person is barefoot. No studies to date have compared the spatio-temporal characteristics of BW with and without shoes in elderly individuals.This study compared spatio-temporal measures of BW and forward walking (FW) among elderly individuals while barefoot or wearing shoes. Forty-seven elderly individuals (13 men and 34 women, 76.7 ± 7.7 years of age) were evaluated. Participants were requested to walk at a comfortable, self-selected pace across the GAITRite^® walkway for three trials under each of four conditions: walking forward (FW) and BW wearing their own comfortable low-heeled walking shoes and FW and BW walking without shoes. Gait speed, stride length and cadence were significantly reduced in BW versus FW, with an increase in double limb support (DLS), both with and without shoes. Barefoot BW resulted in significantly increased gait speed and cadence, and decreased DLS compared to BW with shoes. BW stride length was not affected by footwear. While barefoot FW was also associated with a significant increase in cadence and decrease in DLS time compared to walking with shoes, it decreased stride length and had no detrimental effect on gait speed. Assessment of the spatio-temporal parameters of walking barefoot and with shoes during FW and BW can contribute to our understanding of the ability of elderly individuals to adapt to changing walking conditions, and should be included in the assessment of functional mobility of elderly individuals.     

Kinematic gait pattern in children with cerebral palsy and leg length discrepancy: Effects of an extra sole

The gait pattern in children with cerebral palsy (CP) often differs from normal, with slow velocity, problem with foot clearance and increased stress on joints. Several factors, such as muscle tone, impaired motor control, muscle contractures, skeletal deformities and leg length discrepancy affect gait. Leg length discrepancy can be treated surgically or with elevation of the shoe on the short leg. The purpose of this study was to examine whether compensating for leg length discrepancy, with elevation of the sole, leads to a change in movement pattern during walking in children with spastic CP. Results: Ten children with spastic CP, able to walk without aids, and 10 typically developing (TD) children aged between seven and 14 years were assessed with 3D gait analysis: 1) barefoot, 2) with shoes and 3) with an extra sole beneath the shoe for the shorter leg. All children with CP had a leg length discrepancy of more than or equal to 1.0 cm. In the barefoot condition, the velocity was slower and the stride length was shorter, in children with CP compared with TD. The stride length and gait velocity increased in children with CP with shoes and shoe + sole and the stance time became more symmetrical. Among children with CP, there was more flexion in the longer leg relative to the short leg during barefoot walking. Differences in the kinematic pattern between the long and the short leg decreased with the extra sole.     

Casework-related DNA transfer on footwear in consideration of the shedder status

DNA evidence on shoes can play an important role in solving a variety of crimes. We investigated the transfer, persistence, prevalence and recovery of DNA (DNAtppr) on shoes (sneakers) and their soles in realistic handling scenarios taking into account the shedder status. This study aims to increase the understanding of the expected composition of DNA profiles and their probative value, providing a basis for activity level assessments. Samples were analyzed using a direct lysis method, suggesting its versatility and increasing the DNA typing success compared to previous studies on footwear. The data showed surface-dependent background DNA (bDNA) levels on shoe soles and prevalence of bDNA on the upper parts of the shoe. The owner of the shoe was allocatable to the mixture for almost every shoe and sampling location. Alternating scenarios of shoe handling were simulated through different pairs of shedders to distinguish shoe owner and subsequent user. Secondary users were attributable to DNA mixtures regardless of shedder status after wearing shoes a single time. The influence of the shedder status follows specific trends in this context. However, particularly intermediate shedders show inconsistent results. The prevalence of bDNA appears to have a greater effect on the impact of the shedder status on DNA profile composition than previously reported. The data help researchers to better resolve suspect statements and determine if a person of interest wore the shoes relevant to the investigation.