The influence of shoe aging on children running biomechanics

Athletic children are prone to overuse injuries, especially at the heel and knee. Since footwear is an extrinsic factor of lower limb injury risk, the aim of this study was to assess the influence of shoe aging on children running biomechanics. Fourteen children active in sports participated in a laboratory biomechanical evaluation. A new pair of shoes was provided to each participant at an inclusion visit. Four months later, the participants performed a running task and their kinematics and kinetics were assessed both with their used shoes and with a new pair of shoes identical to the first. Furthermore, mechanical cushioning properties of shoes were evaluated before and after in-vivo aging. After 4 months of use, the sole stiffness increased by 16% and the energy loss capacity decreased by 18% (p < 0.001). No ankle or knee kinematic adjustment was found at foot strike in used shoes but changes were observed later during stance. Running with used shoes produced a higher loading rate of the vertical ground reaction force (+23%, p = 0.016), suggesting higher compressive forces under the heel and placing children at risk to experience impact-related injuries. Nevertheless, the decreased peak ankle and knee power absorption in used shoes (−11%, p = 0.010 and −12%, p = 0.029, respectively) suggests a lower ankle and knee joints loading during the absorption phase that may be beneficial regarding stretch-related injuries.     

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.     

Footwear characteristics are related to running mechanics in runners with patellofemoral pain

Running footwear is known to influence step rate, foot inclination at foot strike, average vertical loading rate (VLR) and peak patellofemoral joint (PFJ) force. However, the association between the level of minimalism of running shoes and running mechanics, especially with regards to these relevant variables for runners with patellofemoral pain (PFP), has yet to be investigated. The objective of this study was to explore the relationship between the level of minimalism of running shoes and habitual running kinematics and kinetics in runners with PFP. Running shoes of 69 runners with PFP (46 females, 23 males, 30.7 ± 6.4 years) were evaluated using the Minimalist Index (MI). Kinematic and kinetic data were collected during running on an instrumented treadmill. Principal component and correlation analyses were performed between the MI and its subscales and step rate, foot inclination at foot strike, average VLR, peak PFJ force and peak Achilles tendon force. Higher MI scores were moderately correlated with lower foot inclination (r = −0.410, P < 0.001) and lower peak PFJ force (r = −0.412, P < 0.001). Moderate correlations also showed that lower shoe mass is indicative of greater step rate (ρ = 0.531, P < 0.001) and lower peak PFJ force (ρ = −0.481, P < 0.001). Greater shoe flexibility was moderately associated with lower foot inclination (ρ = −0.447, P < 0.001). Results suggest that greater levels of minimalism are associated with lower inclination angle and lower peak PFJ force in runners with PFP. Thus, this population may potentially benefit from changes in running mechanics associated with the use of shoes with a higher level of minimalism.     

Effect of shoe type on plantar pressure: A gender comparison

Despite the differences in materials, racing flats have begun to be used not only for racing, but also for daily training. As there are data suggesting a gender difference in overuse injuries in runners, shoe choice may affect loading patterns during running. The purpose was to determine differences in plantar pressure between genders when running in training shoes and racing flats. In-shoe plantar pressure data were collected from 34 subjects (17m, 17f) who ran over-ground in both a racing flat and training shoe. Contact area (CA), maximum force (MF), and contact time under the entire foot and beneath eight foot regions were collected. Each variable was analyzed using a shoe by gender repeated measures ANOVA (α = 0.05). In men, MF was increased in the racing flats (p = 0.016) beneath the medial midfoot (MMF), yet was increased beneath the medial forefoot (MFF) in the training shoe (p = 0.018). Independent of gender, CA was decreased in the racing flats beneath the entire foot (p = 0.029), the MMF (p = 0.013), and the MFF (p = 0.030), and increased beneath the lateral forefoot (LFF) (p = 0.023). In the racing flats, MF was increased beneath the entire foot (p < 0.001) and the LFF (p < 0.001). Independent of the shoe, CA was decreased in men beneath the MFF (p = 0.007) and middle forefoot (p < 0.001), while MF was increased in the LFF (p = 0.002). The LFF is an area of increased stress fracture risk in men. Based on the gender differences in loading, running shoe design should be gender specific in an attempt to prevent injuries.     

Effects of footwear on treadmill running biomechanics in preadolescent children

While recent research debates the topic of natural running in adolescents and adults, little is known about the influence of footwear on running patterns in children. The purpose of this study was to compare shod and barefoot running gait biomechanics in preadolescent children. Kinematic and ground reaction force data of 36 normally developed children aged 6–9 years were collected during running on an instrumented treadmill. Running conditions were randomized for each child in order to compare barefoot running with two different shod conditions: a cushioned and a minimalistic running shoe. Primary outcome was the ankle angle at foot strike. Secondary outcomes were knee angle, maximum and impact ground reaction forces, presence of rear-foot strike, step width, step length and cadence. Ankle angle at foot strike differed with statistical significance (p < 0.001) between conditions. Running barefoot reduced the ankle angle at foot strike by 5.97° [95% CI, 4.19; 7.75] for 8 km h⁻¹ and 6.18° [95% CI, 4.38; 7.97] for 10 km h⁻¹ compared to the cushioned shoe condition. Compared to the minimalistic shoe condition, running barefoot reduced the angle by 1.94° [95% CI, 0.19°; 3.69°] for 8 km h⁻¹ and 1.38° [95% CI, −3.14°; 0.39°] for 10 km h⁻¹. Additionally, using footwear significantly increased maximum and impact ground reaction forces, step length, step width and rate of rear-foot strike. In conclusion, preadolescent running biomechanics are influenced by footwear, especially by cushioned running shoes. Health professionals and parents should keep this in mind when considering footwear for children.     

3D gait analysis with and without an orthopedic walking boot

IntroductionOrthopedic walking boots have been widely used in place of traditional fiberglass casts for a variety of orthopedic injuries and post-surgical interventions. These walking boots create a leg length discrepancy (LLD). LLD has been shown to alter the kinematics and kinetics of gait and are associated with lumbar and lower limb conditions such as: foot over pronation, low back pain, scoliosis, and osteoarthritis of the hip and knee joints. Past gait analyses research with orthopedic boots is limited to findings on the ipsilateral limb. Thus, the purpose of the study was to examine bilateral gait kinematics & kinetics with and without a walking boot.MethodsForty healthy participants (m = 20, f = 20, age 20.7 ± 1.8 yrs., ht. 171.6 ± 9.5 cm, wt. 73.2 ± 11.0 kg, BMI 24.8 ± 3.2) volunteered. An eight camera Vicon Motion Capture System with PIG model and two AMTI force plates were utilized to record the walking trial conditions: (1) bilateral tennis shoes (2) boot on right foot, tennis shoe on left foot (3) boot on right foot, barefoot on left foot. Data were processed in Nexus 2.2.3 and exported to Visual 3D for analysis.ResultsWhen wearing the boot, there were significant differences in most joint angles and moments, with larger effects on long limb.ConclusionThe walking boot alters the gait in the same way as those with existing LLD, putting them at risk for development of secondary knee, hip, and low back pain during treatment protocol.     

The effect of footwear and footfall pattern on running stride interval long-range correlations and distributional variability

The presence of long-range correlations (self-similarity) in the stride-to-stride fluctuations in running stride interval has been used as an indicator of a healthy adaptable system. Changes to footfall patterns when running with minimalist shoes could cause a less adaptable running gait. The purpose of this study was to investigate stride interval variability and the degree of self-similarity of stride interval in runners wearing minimalist and conventional footwear. Twenty-six trained habitual rearfoot footfall runners, unaccustomed to running in minimalist footwear, performed 6-min sub-maximal treadmill running bouts at 11, 13 and 15 km·h⁻¹ in minimalist and conventional shoes. Force sensitive resistors were placed in the shoes to quantify stride interval (time between successive foot contacts). Footfall position, stride interval mean and coefficient of variation (CV), were used to assess performance as a function of shoe type. Long-range correlations of stride interval were assessed using detrended fluctuation analysis (α). Mean stride interval was 1-1.3% shorter (P = 0.02) and 27% of runners adopted a midfoot footfall (MFF) in the minimalist shoe. There was a significant shoe effect on α and shoe*speed*footfall interaction effect on CV (P < 0.05). Runners that adopted a MFF in minimalist shoes, displayed reduced long-range correlations (P < 0.05) and CV (P < 0.06) in their running stride interval at the 15 km·h⁻¹ speed. The reduced variability and self-similarity observed for runners that changed to a MFF in the minimalist shoe may be suggestive of a system that is less flexible and more prone to injury.     

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.     

Sagittal spinopelvic alignment predicts hip function after total hip arthroplasty

The aim of this study was to investigate the association between preoperative sagittal spinopelvic alignment and postoperative clinical outcomes after total hip arthroplasty (THA). This retrospective study included 92 patients with hip osteoarthritis who underwent primary THA between May 2013 and October 2015. Patients’ characteristics, radiographic sagittal spinopelvic parameters and modified Harris Hip Scores, including function scores (gait scores and functional activities scores), were investigated. Multivariate linear regression analysis was performed to determine the associations between each preoperative sagittal spinopelvic parameter and postoperative hip function The preoperative sagittal spinopelvic parameters that were associated with postoperative gait scores were sagittal vertical axis (adjusted β-coefficient = − 0.28, P = 0.02), lumbar lordosis angle (adjusted β-coefficient = 0.29, P = 0.0089), pelvic tilt (adjusted β-coefficient = − 0.25, P = 0.045), sacral slope (adjusted β-coefficient = 0.27, P = 0.017) and pelvic incidence minus lumbar lordosis angle (adjusted β-coefficient = − 0.31, P = 0.01). The preoperative sagittal spinopelvic parameters that were related to the postoperative functional activities scores were sagittal vertical axis (adjusted β-coefficient = − 0.38, P = 0.0051) and pelvic incidence minus lumbar lordosis angle (adjusted β-coefficient = − 0.39, P = 0.0033). Patients with preoperative imbalanced sagittal alignment such as larger sagittal vertical axis, larger pelvic incidence minus lumbar lordosis and retroversion of pelvis had poorer clinical outcomes than others after THA. While, those preoperative imbalanced patients with anteversion of pelvis may have a compensatory ability which could correct the abnormal sagittal alignment after THA. Preoperative sagittal spinopelvic alignment affected postoperative clinical outcomes after THA.     

The association between intersegmental coordination in the lower limb and gait speed in elderly females

Human multi-segmental motion is a complex task requiring motor coordination. Uncoordinated motor control may contribute to the decline in mobility; however, it is unknown whether the age-related decline in intersegmental coordination relates to the decline in gait performance. The aim of this study was to clarify the association between intersegmental coordination and gait speed in elderly females. Gait measurements were performed in 91 community-dwelling elderly females over 60 years old. Foot, shank, and thigh sagittal motions were assessed. Intersegmental coordination was analyzed using the mean value of the continuous relative phase (mCRP) during four phases of the gait cycle to investigate phase differences in foot–shank and shank–thigh motions during a normal gait. The results showed that foot–shank mCRP at late stance had negative correlations with gait speed (r = −0.53) and cadence (r = −0.54) and a positive correlation with age (r = 0.25). In contrast, shank–thigh mCRP at late stance had positive correlations with gait speed (r = 0.37) and cadence (r = 0.56). Moreover, partial correlation, controlling age, height, and weight, revealed that foot–shank mCRP at late stance had negative correlations with gait speed (r = −0.52) and cadence (r = −0.54). Shank–thigh mCRP at late stance had a positive correlation with gait speed (r = 0.28) and cadence (r = 0.51). These findings imply that the foot–shank and shank–thigh coordination patterns at late stance relate to gait speed, and uncoordinated lower limb motion is believed to be associated with the age-related decline in cadence.     

Gait characteristics of people with diabetes-related peripheral neuropathy,with and without a history of ulceration

Biomechanical alterations in diabetes are believed to contribute to plantar neuropathic ulceration. This exploratory study documents clinical measures of flexibility and strength, alongside three-dimensional biomechanical gait data of the lower limb, in 10 patients with a history of neuropathic ulceration (DNU; n = 10). Comparative data is presented from age and gender matched groups with; diabetes peripheral neuropathy and no ulcer history (DWN; n = 10), diabetes and no peripheral neuropathy (DNN; n = 10) and a non-diabetes reference group (NOND; n = 10). Biomechanical data were collected at a comfortable walking speed with a Vicon motion analysis system. Clinical measures showed a non-significant trend toward decreased static range of motion at the ankle and first metatarsophalangeal joints, with worsening neuropathy status. Of the diabetes groups, knee and ankle strength was significantly lower in those with an ulcer history (p = 0.01–0.03), with the exception of knee extension. In the DNU group, walking speed was on average 0.17 ms slower compared to NOND (p = 0.04). The DNU group demonstrated a lower range of motion than NOND at the: hips (frontal plane, by 25%: p = 0.03); hips and knees (transverse plane, 31%: p = 0.01 and 32%: p < 0.01); ankles (sagittal plane, 22%: p < 0.01) and first metatarsophalangeal joints (sagittal plane, 32%: p = 0.01), with less foot rotation (24%: p = 0.04). Kinetic alterations in DNU included lower: ankle maximum power (21%: p = 0.03) and vertical ground reaction force 2nd peak (6%: p < 0.01). The study findings identified gait alterations in people with clinically severe peripheral neuropathy and related plantar foot ulcer history. Further research is needed to explore potential casual pathways.     

The effects of high custom made shoes on gait characteristics and patient satisfaction in hemiplegic gait

ObjectiveTo determine the effects of a temporary high custom made orthopaedic shoe on functional mobility, walking speed, and gait characteristics in hemiplegic stroke patients. In addition, interference of attentional demands and patient satisfaction were studied.DesignClinical experimental study.SettingUniversity Medical Centre.ParticipantsNineteen stroke patients (12 males; mean age 55 years (standard deviation (SD) 10 years); mean time post onset 3.6 months (SD 1.4 months)) with a spastic paresis of the lower extremity.Main outcome measuresFunctional mobility was assessed with the timed up and go test, walking speed and gait characteristics were measured with clinical gait analysis and performed with and without a verbal dual task. Patient satisfaction was determined with a questionnaire.ResultsWalking with the high orthopaedic shoe resulted in improved functional mobility (22%; p < .001), walking speed (37%; p < .001) and gait characteristics compared to walking with normal shoes. The dual task interfered with functional mobility during walking. The interference was equally big for normal shoes as for the orthopaedic shoe. Patients evaluated walking with the high orthopaedic shoe as an improvement (p < .001). An average of 84% reported improvements in foot lifting, swing progression, taking weight, confidence while walking, safety, walking distance and walking speed.ConclusionIn the early recovery phase after stroke, when regaining walking ability, a temporary high orthopaedic shoe can improve hemiplegic gait, even with dual task interference.     

Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis

Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25 ± 0.14 N m/kg m) as compared with walking with control shoes (0.30 ± 0.19 N m/kg m); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R² = 0.44, P < 0.01). Masai Barefoot Technology shoes reduced the knee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis.     

A comprehensive evaluation of the variation in ankle function during gait in children and youth with Charcot–Marie–Tooth disease

A better understanding of gait dysfunction for children and youth with Charcot–Marie–Tooth (CMT) will assist in developing appropriate treatments and understanding prognosis for ambulation. The purpose of this retrospective study was to document the typical gait patterns in children and youth (12 ± 4 years) with CMT using motion analysis and relate these findings back to the clinical assessment at the ankle. All patients underwent a motion analysis as a component of treatment decision-making.Lower extremity kinematics and kinetics were evaluated in comparison to a typically developing age-matched reference control group collected in the same gait laboratory. Three patient subgroups were defined based on peak ankle dorsiflexion in terminal stance: greater than typical (n = 23), within typical range (n = 30) and less than typical (n = 13). The three subgroups showed statistically significant differences (p < 0.004) in degree of impairment for ankle plantar flexor and dorsiflexor weakness and ankle plantar flexor contracture. Patients with excessive dorsiflexion in terminal stance had the greatest ankle plantar flexor weakness (median 2) and the greatest dorsiflexor weakness (median 4). Patients with less than typical dorsiflexion in terminal stance were the only patients with a plantar flexor contracture (?2 ± 9°). Delayed peak dorsiflexion in stance was the most common kinematic finding and consistent with ankle plantar flexor weakness. All patients showed significantly less (p < 0.001) peak ankle moments and power generation in terminal stance than the typically developing controls. We concluded that children and youth with CMT present differently in terms of impairment and associated gait issues which therefore require patient specific treatment strategies.     

Is midsole thickness a key parameter for the running pattern?

Many studies have highlighted differences in foot strike pattern comparing habitually shod runners who ran barefoot and with running shoes. Barefoot running results in a flatter foot landing and in a decreased vertical ground reaction force compared to shod running. The aim of this study was to investigate one possible parameter influencing running pattern: the midsole thickness. Fifteen participants ran overground at 3.3 m s⁻¹ barefoot and with five shoes of different midsole thickness (0 mm, 2 mm, 4 mm, 8 mm, 16 mm) with no difference of height between rearfoot and forefoot. Impact magnitude was evaluated using transient peak of vertical ground reaction force, loading rate, tibial acceleration peak and rate. Hip, knee and ankle flexion angles were computed at touch-down and during stance phase (range of motion and maximum values). External net joint moments and stiffness for hip, knee and ankle joints were also observed as well as global leg stiffness. No significant effect of midsole thickness was observed on ground reaction force and tibial acceleration. However, the contact time increased with midsole thickness. Barefoot running compared to shod running induced ankle in plantar flexion at touch-down, higher ankle dorsiflexion and lower knee flexion during stance phase. These adjustments are suspected to explain the absence of difference on ground reaction force and tibial acceleration. This study showed that the presence of very thin footwear upper and sole was sufficient to significantly influence the running pattern.     

Short-term step-to-step correlation in plantar pressure distributions during treadmill walking,and implications for footprint trail analysis

The gait cycle is continuous, but for practical reasons one is often forced to analyze one or only a few adjacent cycles, for example in non-treadmill laboratory investigations and in fossilized footprint analysis. The nature of variability in long-term gait cycle dynamics has been well-investigated, but short-term variability, and specifically correlation, which are highly relevant to short gait bouts, have not. We presently tested for step-to-step autocorrelation in a total of 5243 plantar pressure (PP) distributions from ten subjects who walked at 1.1 m/s on an instrumented treadmill. Following spatial foot alignment, data were analyzed both from three points of interest (POI): heel, central metatarsals, and hallux, and for the foot surface as a whole, in a mass-univariate manner. POI results revealed low average step-to-step autocorrelation coefficients (r = 0.327 ± 0.094; mean ± st. dev.). Formal statistical testing of the whole-foot r distributions reached significance over an average of only 0.42 ± 0.52% of the foot's surface, even for a highly conservative uncorrected threshold of p < 0.05. The common assumption, that short gait bouts consist of independent cycles, is therefore not refuted by the present PP results.     

A new method for measuring AFO deformation,tibial and footwear movement in three dimensional gait analysis

Solid ankle-foot orthoses (AFOs) are designed to immobilise the ankle but numerous studies have measured a considerable ankle range of motion (ROM) in AFO users. Measurement of ankle kinematics may be affected by soft-tissue artefact (STA) of the knee marker, deformation of the AFO or tibial movement within the AFO. A new model based on the Conventional Gait Model (CGM) was developed to calculate these effects. Although movement of the AFO within the shoe should not affect the measured ankle joint angle the model also allows an estimation of this movement.Seven children (13 limbs) with spastic diplegic cerebral palsy were assessed to present the benefits of the new model compared to the CGM. STA of the knee marker was estimated to result in a 1.5° overestimation of total ankle ROM (from 8.2° to 9.7°). STA error was strongly related to angle of knee flexion (r = 0.82) with an average maximum error of 3.8°. AFO deformation contributed approximately two thirds of the ankle ROM (6.0 ± 4.3°) with the remaining third from tibial movement relative to the AFO (2.8 ± 0.9°). Movement of the AFO within the footwear was very small (1.8 ± 0.8°). A strong positive relationship (r = 0.9) was found between body mass (kg) and AFO deformation which was statistically significant (p < 0.001). This is the first model to attempt to quantify different contributions to ankle dorsiflexion measured during gait analysis of people wearing AFOs.     

Relationships between segmental foot mobility and plantar loading in individuals with and without diabetes and neuropathy

The purpose of our study was to examine dynamic foot function during gait as it relates to plantar loading in individuals with DM (diabetes mellitus and neuropathy) compared to matched control subjects. Foot mobility during gait was examined using a multi-segment kinematic model, and plantar loading was measured using a pedobarograph in subjects with DM (N = 15), control subjects (N = 15). Pearson product moment correlation was used to assess the relationship between variables of interest. Statistical significance and equality of correlations were assessed using approximate tests based on Fisher's Z transformation (α = 0.05). In individuals with DM, first metatarsal sagittal plane excursion during gait was negatively associated with pressure time integral under the medial forefoot (r = ?0.42 and ?0.06, DM and Ctrl, P = 0.02). Similarly, lateral forefoot sagittal plane excursion during gait was negatively associated with pressure time integral under the lateral forefoot (r = ?0.56 and ?0.11, DM and Ctrl, P = 0.02). Frontal plane excursion of the calcaneus was negatively associated with medial (r = ?0.57 and 0.12, DM and Ctrl, P < 0.01) and lateral (r = ?0.51 and 0.13, DM and Ctrl, P < 0.01) heel and medial forefoot pressure time integral (r = ?0.56 and ?0.02, DM and Ctrl, P < 0.01). The key findings of our study indicate that reductions in segmental foot mobility were accompanied by increases in local loading in subjects with DM. Reduction in frontal plane calcaneal mobility during walking serves as an important functional marker of loss of foot flexibility in subjects with DM.     

Ankle-foot orthoses that restrict dorsiflexion improve walking in polio survivors with calf muscle weakness

In polio survivors with calf muscle weakness, dorsiflexion-restricting ankle-foot orthoses (DR-AFOs) aim to improve gait in order to reduce walking-related problems such as instability or increased energy cost. However, evidence on the efficacy of DR-AFOs in polio survivors is lacking. We investigated the effect of DR-AFOs on gait biomechanics, walking energy cost, speed, and perceived waking ability in this patient group.Sixteen polio survivors with calf muscle weakness underwent 3D-gait analyses to assess gait biomechanics when walking with a DR-AFOs and with shoes only. Ambulant registration of gas-exchange during a 6 min walk test determined walking energy cost, and comfortable gait speed was calculated from the walked distance during this test. Perceived walking ability was assessed using purposely-designed questionnaires.Compared with shoes-only, walking with the DR-AFOs significantly increased forward progression of the center of pressure (CoP) in mid-stance and it reduced ankle dorsiflexion and knee flexion in mid- and terminal stance (p < 0.05). Furthermore, walking energy cost was lower (−7%, p = 0.052) and gait speed was higher (p = 0.005). Patients were significantly more satisfied, felt safer, and less exhausted with the DR-AFO, compared to shoes-only (p < 0.05). DR-AFO effects varied largely across patients. Patients who walked with limited forward CoP progression and persisting knee extension during the shoes-only condition seemed to have benefitted least from the DR-AFO.In polio survivors with calf muscle weakness, DR-AFOs improved gait biomechanics, speed, and perceived walking ability, compared to shoes-only. Effects may depend on the shoes-only gait pattern, therefore further study is needed to determine which patients benefit most from the DR-AFO.