Influence of high-heeled shoe parameters on biomechanical performance of young female adults during stair ascent motion

BackgroundHigh-heeled shoes are currently preferred by women due to contemporary aesthetics. However, high-heeled shoes may increase the effort required to ascend stairs and, hence, alter biomechanical performance.Research question: How do high-heel shoe parameters affect the pelvis position, lower extremities kinematics, and ground reaction force in young women during stair ascent motion?MethodsStair ascent experiments were performed with 20 healthy adult women. The participants were instructed to ascend a 3-step staircase, wearing heeled shoes of different heel heights and heel types and one pair of flat shoes as the control group. Changes in lower body biomechanics were analyzed with kinematics and ground reaction force variables collected from the dominant limb. A two-way repeated ANOVA was performed to determine which variables were affected by heel type and which were affected by heel height or a combination of both.ResultsAs the heel height increased, an increased range of ankle dorsiflexion-plantarflexion, as well as pelvic rotation, was observed(P = 0.039 and P = 0.003, respectively). A thinner heel type displayed a larger pelvic forward tilt movement(P = 0.026)and 1st peak vertical force(P = 0.025), as well as a smaller 2nd peak vertical force (P = 0.002). With high heels, increased external rotation of the knee, inversion and plantar flexion, and flexion values of the knee were observed. We also observed decreased external rotation of the pelvis, ankle eversion, varum, and dorsiflexion.SignificanceTo stabilize body posture during stair ascent motion with high-heeled shoes, compensatory response including increasd pelvic range of motion and changing the joint angles of the lower extremities.     

Long-term effects of shoe mileage on knee and ankle joints muscle co-contraction during walking in females with genu varus

BackgroundShoe mileage may influence the risk of sustaining injuries during walking.Research questionWhat are the effects of shoe mileage on knee and ankle muscle co-contraction during walking in females with genu varus?MethodsFifteen healthy and 15 women diagnosed with genu varus received a new pair of running shoes. They were asked to wear these shoes over 6 months. Pre and post intervention, muscle activities of the dominant limb were recorded during a walking test at preferred gait speed. Two dependent variables were assessed to examine muscle co-contraction: (1) directed co-contraction ratios of agonists and antagonists, and (2) general joint muscle co-contraction.FindingsResults demonstrated significant main effects of the “shoe” factor for general ankle co-contraction during the push-off phase (p = 0.013, d = 1.503). Irrespective of experimental group, paired comparisons revealed significantly lower general ankle co-contraction during the push-off phase after the intervention. A significant main effects of “shoe” for general knee co-contraction during loading phase (p = 0.025, d = 0.895) was also observed. In both groups, paired comparison revealed significantly lower general knee co-contraction during the push-off phase in the post condition. We did not find any significant main effect of group nor group-by-shoe interaction for general ankle co-contraction during the stance phase. Likewise, we did not observe any significant main effect of “shoe”, “group” and “group-by-shoe” interaction for mediolateral directed knee co-contraction during stance phase of walking (p > 0.05).SignificanceOur findings showed that the shoe mileage but not the genu varus condition affects the general and directed co-contraction of the muscles stabilizing the knee and ankle joints. Together with the observed findings on ankle and knee muscle co-contraction, it is essential to change running shoes after a long wearing time in both healthy and genu varus females.     

Influence of shoe midsole hardness on plantar pressure distribution in four basketball-related movements

This study examined how shoe midsole hardness influenced plantar pressure in basketball-related movements. Twenty male university basketball players wore customized shoes with hard and soft midsoles (60 and 50 Shore C) to perform four movements: running, maximal forward sprinting, maximal 45° cutting and lay-up. Plantar loading was recorded using an in-shoe pressure measuring system, with peak pressure (PP) and pressure time integral (PTI) extracted from 10 plantar regions. Compared with hard shoes, subjects exhibited lower PP in one or more plantar regions when wearing the soft shoes across all tested movements (Ps < 0.05). Lower PTI was also observed in the hallux for 45° cutting, and the toes and forefoot regions during the first step of lay-up in the soft shoe condition (Ps < 0.05). In conclusion, using a softer midsole in the forefoot region may be a plausible remedy to reduce the high plantar loading experienced by basketball players.     

Leg stiffness during running in highly cushioned shoes with a carbon-fiber plate and traditional shoes

BackgroundNike ZoomX Vaporfly (NVF) improves running economy and performance. The biomechanical mechanisms of these shoes are not fully understood, although thicker midsoles and carbon fiber plates are considered to play an important role in the spring-like leg characteristics during running. Leg stiffness (k_leg) in the spring-mass model has been commonly used to investigate spring-like running mechanics during running.Research questionDoes k_leg during running differ between NVF and traditional (TRAD) shoes?MethodsEighteen male habitual forefoot and/or midfoot strike runners ran on a treadmill at 20 km/h with NVF and TRAD shoes, respectively. k_leg, vertical oscillation of the center of mass (∆CoM), spatiotemporal parameters, and mechanical loading were determined.Resultsk_leg was 4.8% lower in the NVF shoe condition than in the TRAD condition, although no significant difference was observed. ∆CoM was not significantly different between shoe conditions. Spatiotemporal parameters and mechanical loading were also not significantly different between shoe conditions.SignificanceThe NVF shoe is well known as improving the running economy and running performance for the cause by characteristics of better spring function. Contrary to expectation, k_leg and other parameters were not significantly different during running in the NVF compared to TRAD shoe at 20 km/h. These findings indicate that well-trained runners’ spring-like running mechanics would not alter even if wearing the NVF shoes.     

Validity and reproducibility of foot motion analysis using a stretch strain sensor

BackgroundMulti-segment foot analysis is traditionally challenging to perform while subjects are wearing footwear or a foot orthosis and is difficult to apply in the clinical setting. A recently developed stretch strain sensor (STR), that is thin and highly flexible, may solve this limitation because it does not require observation using a camera and is highly portable.Research questionThis study aimed to examine the reproducibility and validity of foot motion analysis using the STR during walking and running by comparing it with a conventional motion capture system.MethodsTwenty-one healthy participants were examined in this study. The STR was placed on the participant's foot in one of two locations in separate experiments (spring ligament; SL and navicular drop; ND methods). Foot kinematic data during walking and running were simultaneously recorded using the STR and a three-dimensional motion capture system. Intra-class correlation (ICC) was used to assess test-retest reproducibility of the STR method. Cross-correlation coefficient evaluated the similarity of the pattern of the signals between the two systems. Pearson and Spearman correlation analysis was used to evaluate the relationships between the STR measurement and angular excursion of the forefoot or hindfoot.ResultsThe ICCs of the SL method were 0.95 and 0.96, and those of the ND method were 0.93 and 0.71 during walking and running, respectively. In the SL method, the pattern of the signals between the STR and forefoot frontal motion was strongly correlated. The STR measurement was significantly correlated with forefoot eversion excursion (walking: r=-0.67, running: r=-0.64, p < 0.01 each). In the ND method, the STR signal was not associated with forefoot and hindfoot kinematics.SignificanceOur results showed that the STR has acceptable reproducibility and validity of foot motion analysis. This system may enable measurement of foot motion while subjects are wearing shoes and outside the laboratory.     

The effect of different unstable footwear constructions on centre of pressure motion during standing

BackgroundThe aim of this study was to test the effect different unstable footwear constructions have on centre of pressure motion when standing.MethodsSixteen young female volunteers were tested in five conditions, three unstable footwear (Reebok Easy-Tone™, FitFlop™ and Skechers Shape-Ups™), a standard shoe and barefoot in a randomised order. Double and single leg balance on a force plate was assessed via centre of pressure excursions and displacements in each condition.ResultsFor double leg and single leg standing centre of pressure excursions in the anterior–posterior direction were significantly increased wearing Skechers Shape-Ups™ compared to barefoot and the standard shoe. For the Reebok Easy Tone™ during single leg standing excursions in the anterior–posterior direction were significantly greater compared to the barefoot condition. Cumulative displacement of the centre of pressure in medial-lateral direction increased significantly during single leg standing when wearing Skechers Shape-Ups™ compared to barefoot and standard shoe as well as for Reebok Easy Tone™ vs. barefoot.DiscussionIt would appear from these quiet standing results that the manner of the construction of instability shoes effects the CoP movement which is associated with induced instability. Greater CoP excursion occurred in the A–P direction while the cumulative displacements were greater in the M–L direction for those shoes with the rounded sole and soft foam and those with airpods. The shoe construction with altered density foam did not induce any change in the CoP movement, during quite standing, which tends to suggest that it is not effective at inducing balance. Not all instability shoes are effective in altering the overall instability of the wearer.     

Effects of Longitudinal Bending Stiffness of forefoot rocker profile shoes on ankle kinematics and kinetics

IntroductionRocker profile shoes with a proximally placed apex are currently one of the most prescribed shoe modifications for treatment and prevention of lower leg deficits. Three geometrical rocker design parameters apex position (AP), apex angle (AA) and rocker radius (RR) influence both plantar pressure redistribution and kinetic and kinematic alterations of the lower leg. In addition, longitudinal bending stiffness (LBS) of the outsole influences these parameters as well. This study aims to investigate the effects of the LBS in combination with different forefoot radii of rocker shoes on kinematics and kinetics of the lower limb.Methods10 participants walked in standard shoes and six experimental shoe conditions with high and low LBS and three different forefoot rocker radii with the same (proximal) AP and AA. Lower extremity kinematics and kinetics were collected while walking on an instrumented treadmill at preferred walking speed and analysed with a repeated measures ANOVA and Statistical Parametric Mapping (SPM) (α = .05; post hoc α = .05/6).ResultsSPM analyses revealed no significant differences for LBS and interaction LBS*RR for most research variables in terminal stance (ankle angle, ankle moment, ankle power, foot-to-horizontal angle, shank-to-vertical angle, external ankle moment, ground reaction force angle). A significant LBS effect was found for anterior-posterior position of the centre of pressure during pre-swing and peak ankle dorsiflexion angle. No relevant significant differences were found in spatio-temporal parameters and total work at the ankle between low and high LBS.ConclusionThis study showed that longitudinal bending stiffness does not affect the biomechanical working mechanism of rocker profile shoes as long as toe plantarflexion is restricted. Providing that the forefoot rocker radius supports at least a normal foot-to-horizontal angle at toe-off, there is no reason to increase sole stiffness to change ankle kinematics and kinetics.     

Sling-based infant carrying affects lumbar and thoracic spine neuromechanics during standing and walking

BackgroundRegular infant carrying might be a contributing factor for the development and progression of low back and pelvic girdle pain in mothers after childbirth. However, the neuromechanical adaptations of the spine due to different sling-based carrying techniques are not sufficiently well understood in order to provide evidence-based carrying recommendations.Research questionWhat are the immediate effects of different sling-based infant carrying techniques on trunk neuromechanics?MethodsUsing a Vicon motion capture and a wireless surface electromyography system, three-dimensional pelvis and spinal kinematics as well as activation patterns of eight trunk muscles were derived from fifteen healthy young women during upright standing and level walking without carrying a load and while carrying a 6 kg-dummy with a sling in front and on either side. Data were analyzed using Statistical Parametric Mapping, allowing group comparisons of discrete parameters (standing) as well as continuous data (walking). To distinguish between clinically relevant and clinically not relevant kinematic findings, statistically significant differences were only considered in case of ≥5°.ResultsCompared to unloaded walking, carrying the dummy in front was mainly associated with increased lumbar lordosis (standing: (Δ8.8°, p = 0.006; walking: (Δ ≥ 8.2°, 1–100% of gait cycle [%GC], p < 0.001). When carrying the dummy on the preferred side, increased thoracic kyphosis (standing: ≥6.4°, p ≤ 0.003; walking: Δ ≥ 5.6°, 1–100%GC, p < 0.001) and axial rotation towards the ipsilateral side (standing: Δ5.3°, p = 0.003; walking: Δ ≥ 5.0°, 46–58%GC, p = 0.002) were observed. All three conditions entailed increased paraspinal muscle activity during walking, although only unilaterally in side carrying (lumbar, preferred condition: Δ ≥ 13.2%maxMVIC, 49–57%GC, p < 0.001; thoracic, non-preferred condition: Δ ≥ 5.3%maxMVIC, 47–58%GC, p < 0.001).SignificanceCarrying an infant alternating on both sides using a sling could be advantageous for preventing musculoskeletal pain resulting from excessive lumbar hyperextension and paraspinal muscle hyperactivation in women after childbirth.     

Effects of rocker radii with two longitudinal bending stiffnesses on plantar pressure distribution in the forefoot

IntroductionOutsole parameters of the shoe can be adapted to offload regions of pain or region of high pressures. Previous studies already showed reduced plantar pressures in the forefoot due to a proximally placed apex position and higher longitudinal bending stiffness (LBS). The aim of this study was to determine the effect of changes in rocker radii and high LBS on the plantar pressure profile during gait.Method10 participants walked in seven shoe conditions of which one control shoe and six rocker shoes with small, medium and large rocker radii and low and high longitudinal bending stiffness. Pedar in-shoe plantar pressure measuring system was used to quantify plantar pressures while walking on a treadmill at self-selected walking speed. Peak plantar pressure, maximum mean pressure and force-time integral were analyzed with Generalized Estimated Equation (GEE) and Tukey post hoc correction (α = .05).ResultsSignificantly lower plantar pressures were found in the first toe, toes 2–5, distal and proximal forefoot in all rocker shoe conditions as compared to the control shoe. Plantar pressures in the first toe and toes 2–5 were significantly lower in the small radius compared to medium and large radii. For the distal forefoot both small and medium radii significantly reduced plantar pressure compared to large radii. Low LBS reduced plantar pressure at the first toe significantly compared to high LBS independent of the rocker radius. Plantar pressures in the distal forefoot and toes 2–5 were lower in high LBS compared to low LBS.ConclusionManipulation of the rocker radius and LBS can effectively reduce peak plantar pressures in the forefoot region during gait. In line with previous studies, we showed that depending on the exact target location for offloading, different combinations of rocker radius and LBS need to be adopted to maximize treatment effects.     

Influence of carrying a backpack on pelvic tilt, rotation, and obliquity in female college students

The purpose of this investigation was to examine the influence of different methods of backpack carriage on pelvic tilt, obliquity and rotation of college-age females. Thirty subjects (mean age 22.4 years) participated in three conditions: walking without a backpack, carrying a backpack unilaterally, and carrying a backpack over both shoulders. The backpack was loaded with material that comprised 15% of the subject's body weight. Gait was analyzed using the Oxford Metrics VICON Clinical Manager system while the subject walked with no backpack, with a backpack unilaterally and bilaterally. Repeated measures analysis of variance was used to determine differences in angular motion and range of motion in pelvic tilt, rotation, and obliquity in three complete trials during the three walking conditions. Angular pelvic tilt was greatest with bilateral backpack carriage compared to unilateral carriage or walking without a backpack. Angles of pelvic obliquity and rotation were not changed across the three walking conditions. Range of motion for pelvic obliquity and rotation was significantly decreased when walking with a backpack. These results suggest that backpack carriage could cause permanent posture deviations in young female college students. More study is required to evaluate compressive forces during various walking conditions.     

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.     

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.     

Trunk,pelvis and lower limb walking biomechanics are similarly altered in those with femoroacetabular impingement syndrome regardless of cam morphology size

BackgroundStudies of walking in those with femoroacetabular impingement syndrome have found altered pelvis and hip biomechanics. But a whole body, time-contiuous, assessment of biomechanical parameters has not been reported. Additionally, larger cam morphology has been associated with more pain, faster progression to end-stage osteoarthritis and increased cartilage damage but differences in walking biomechanics between large compared to small cam morphologies have not been assessed.Research questionAre trunk, pelvis and lower limb biomechanics different between healthy pain-free controls and individuals with FAI syndrome and are those biomechanics different between those with larger, compared to smaller, cam morphologies?MethodsTwenty four pain-free controls were compared against 41 participants with FAI syndrome who were stratified into two groups according to their maximum alpha angle. Participants underwent three-dimensional motion capture during walking. Trunk, pelvis, and lower limb biomechanics were compared between groups using statistical parametric mapping corrected for walking speed and pain.ResultsCompared to pain-free controls, participants with FAI syndrome walked with more trunk anterior tilt (mean difference 7.6°, p < 0.001) as well as less pelvic rise (3°, p < 0.001), hip abduction (-4.6°, p < 0.05) and external rotation (-6.5°, p < 0.05). They also had lower hip flexion (-0.06Nm⋅kg⁻¹, p < 0.05), abduction (-0.07Nm⋅kg⁻¹, p < 0.05) and ankle plantarflexion moments (-0.19Nm⋅kg⁻¹, p < 0.001). These biomechanical differences occurred throughout the gait cycle. There were no differences in walking biomechanics according to cam morphology size.SignificanceResults do not support the hypothesis that larger cam morphology is associated with larger differences in walking biomechanics but did demonstrate general differences in trunk, pelvis and lower limb biomechanics between those with FAI sydrome and pain-free controls. Altered external biomechanics are likely the result of complex sensory-motor strategy resulting from pain inhibition or impingement avoidance. Future studies should examine internal loading in those with FAI sydnrome.     

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.     

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.     

Biomechanics of slow running and walking with a rocker shoe

Evidence suggests a link between the loading of the Achilles tendon and the magnitude of the ankle internal plantar flexion moment during late stance of gait, which is clinically relevant in the management of Achilles tendinopathy. Some studies showed that rocker shoes can reduce the ankle internal plantar flexion moment. However, the existing evidence is not conclusive and focused on walking and scarce in running. Sixteen healthy runners participated in this study. Lower extremity kinetics, kinematics and electromyographic (EMG) signals of triceps surae and tibialis anterior were quantified for two types of shoes during running and walking. The peak ankle plantar flexion moment was reduced significantly in late stance of running (0.27 Nm/kg; p < 0.001) and walking (0.24 Nm/kg; p < 0.001) with the rocker shoe compared to standard shoe. The ankle power generation and plantar flexion moment impulse were also reduced significantly when running and walking with the rocker shoe (p < 0.001). No significant changes in the knee and hip moments were found in running and walking. A significant delay of the EMG peak, approximately 2% (p < 0.001), was present in the triceps surae when walking with rocker shoes. There were no significant changes in the EMG peak amplitude of triceps surae in running and walking. The peak amplitude of tibialis anterior was significantly increased (64.7 μV, p < 0.001) when walking with rocker shoes. The findings show that rocker shoes reduce the ankle plantar flexion moment during the late stance phase of running and walking in healthy people.     

Full length foot orthoses have an immediate treatment effect and modify gait of children with idiopathic toe walking

BackgroundThere remains a substantial lack of evidence to support the use of foot orthoses as a conservative treatment option for idiopathic toe walking (ITW). Encouraging heel contact during gait is one of the primary goals of most interventions in paediatric ITW.Research QuestionDoes the combined treatment of high-top boots and orthoses increase the number of heel contacts during gait and change spatio-temporal gait parameters?MethodsThis within subject designed randomised controlled trial recruited fifteen children diagnosed with ITW (n = 10 males). They were fitted with bilateral custom made rigid contoured carbon fibre foot orthoses placed inside high-top boots. To analyze the effect of this treatment, heel contacts and spatio-temporal parameters measured by an 8.3 m Gaitrite® mat were compared to barefoot walking and shod walking.ResultsAn immediate increase in heel contact (p = 0.021) was observed in the combined treatment only. Gait changes included a large increase in stride time in the combined treatment condition compared to barefoot walking (p = 0.006). This was associated with a decrease in the percentage of swing phase in the gait cycle (p < 0.010), an increase in stance phase (p < 0.010) and an increase in double support time (p < 0.001).SignificanceThese results suggest the hardness and thickness of the shoe and stiffness of the orthosis midsole may lead to improved local dynamic stability and foot position awareness with increased sensory feedback provided through the entire length of the foot. Further research is indicated to validate this treatment option on long term outcomes in this population group.     

Kinematic compensations as children reciprocally ascend and descend stairs with unilateral and bilateral solid AFOs

The aim of this study was to identify the compensations made when a child with normal motor control ascends and descends stairs while wearing a solid AFO. Ten healthy children were asked to ascend and descend stairs with shoes, right and bilateral AFOs. Repeated measures ANOVA identified differences in selected kinematic parameters. Peak-to-peak excursion of pelvic rotation, pelvic obliquity, and hip ab/adduction increased with AFO use (P<0.05). Mean anterior pelvic tilt increased with AFO use (P<0.05). Compensations at the trunk and the pelvis facilitated limb advancement and clearance. This information may be helpful in developing strategies for training patients with motor planning difficulties.     

Comparing walking biomechanics of older females in maximal,minimal, and traditional shoes

BackgroundKnee osteoarthritis (OA) is a degenerative joint disease that affects millions of individuals each year. Several biomechanical variables during walking have been identified as risk factors for developing knee OA, including the peak external knee adduction moment (KAM) and the knee flexion angle at initial contact. Many interventions have been studied to help mitigate these risk factors, including footwear. However, it is largely unknown how varying shoe cushioning may affect walking biomechanics related to knee OA risk.Research QuestionWhat is the effect of maximally and minimally cushioned shoes on walking biomechanics compared to a traditionally cushioned shoe in older females?MethodsWalking biomechanics in three shoes (maximal, traditional, minimal) were collected on 16 healthy females ages 50–70 using an 8-camera 3D motion capture system and two embedded force plates. Key biomechanical variables related to knee OA disease risk were compared between shoes using repeated measures ANOVAs.ResultsThe KAM was significantly larger in the maximal shoe (p = 0.005), while the knee flexion angle at initial contact was significantly larger in both the maximal and minimal shoe compared to the traditional shoe (p = .000). Additionally, the peak knee flexion angle (p = .000) and the loading rates of the vertical ground reaction force were (instantaneous: p = 0.001; average: p = .010) were significantly higher in the minimal shoe.SignificanceWhile these results are specific to the shoes used in this study, clinicians should exercise caution in prescribing maximal or minimal shoes to females in this age group who may be at risk of knee OA given these results. Research is needed on the effect of these shoes in patients with knee OA.     

Increased shoe sole hardness results in compensatory changes in the utilized coefficient of friction during walking

Based on mechanical testing, harder soled shoes have been shown to provide less available friction than soft soled shoes. Whether or not humans adjust their utilized coefficient of friction (COFu) and gait kinematics to accommodate the decrease in available friction while wearing hard soled shoes is not known. Fifty-six young adults participated in this study. Ground reaction forces, full body kinematics, stride characteristics and subjective perception of footwear slipperiness were recorded under both hard and soft soled shoe conditions. Paired t-tests were used to identify the differences between two shoes conditions. Results indicated that the peak COFu was significantly less when wearing the hard soled shoes compared to when wearing the soft soled shoes (0.23 vs. 0.26, P < 0.001). The decrease in peak COFu was the result of a decrease in the resultant shear forces at the time of peak COFu as no difference in the vertical ground reaction forces was observed. When wearing hard soled shoes, subjects demonstrated decreased total body center of mass (COM) acceleration prior to and immediately following initial contact, decreased walking velocity, shortened stride length, and reduced ankle dorsiflexion angle at initial contact. Taken together, we believe that these gait modifications represent behavioral adaptations to wearing shoes that are perceived to be more slippery.