Effects of medially wedged insoles on the biomechanics of the lower limbs of runners with excessive foot pronation and foot varus alignment

BackgroundExcessive foot pronation during running in individuals with foot varus alignment may be reduced by medially wedged insoles.Research questionThis study investigated the effects of a medially wedged insole at the forefoot and at the rearfoot on the lower limbs angles and internal moments of runners with excessive foot pronation and foot varus alignment.MethodsKinematic and kinetic data of 19 runners (11 females and 8 males) were collected while they ran wearing flat (control condition) and medially wedged insoles (insole condition). Both insoles had arch support. We used principal component analysis for data reduction and dependent t-test to compare differences between conditions.ResultsThe insole condition reduced ankle eversion (p = 0.003; effect size = 0.63); reduced knee range of motion in the transverse plane (p = 0.012; effect size = 0.55); increased knee range of motion in the frontal plane in early stance and had earlier knee adduction peak (p = 0.018; effect size = 0.52); reduced hip range of motion in the transverse plane (p = 0.031; effect size = 0.48); reduced hip adduction (p = 0.024; effect size = 0.50); reduced ankle inversion moment (p = 0.012; effect size = 0.55); and increased the difference between the knee internal rotation moment in early stance and midstance (p = 0.012; effect size = 0.55).SignificanceInsoles with 7˚ medial wedges at the forefoot and rearfoot are able to modify motion and moments patterns that are related to lower limb injuries in runners with increased foot pronation and foot varus alignment with some non-desired effects on the knee motion in the frontal plane.     

Lower extremity joint moments throughout gait at two speeds more than 4 years after ACL reconstruction

BackgroundLong-term gait adaptations after anterior cruciate ligament reconstruction (ACLR) have been reported. However, it is still unclear if they persist more than 4 years after surgery and if they are affected by gait speed.Research question: To investigate differences between groups, legs and walking speeds for ankle, knee and hip joint moments in three planes throughout the stance phase of gait.MethodsReconstructed participants (n = 20 males, 32.5 years, 5.5 years post-ACLR) and healthy controls (n = 20 males, 30.6 years) took part in the study. Gait analysis was performed in two different speeds (self-selected and 30% faster). Sagittal, frontal and transverse plane external moments were measured for ankle, knee and hip and compared throughout the stance phase using 95% confidence intervals. Significant differences were established as a consecutive 5% of gait cycle in which 95% confidence interval did not overlap.ResultsThe reconstructed leg did not demonstrate higher joint moments; there were largely no differences while there was lower knee external rotation moment compared to the non-preferred leg of the control group. Higher joint moments were observed during fast speed walking on sagittal plane for knee and hip moments in both groups, and in the frontal and transverse plane for ankle moments.SignificanceGait kinetics appear to be largely normalized at a minimum of 4 years after ACLR. Faster walking speed increase lower extremity joint moments.     

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

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

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

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

Effects of artificially induced bilateral internal rotation gait on gait kinematics and kinetics

BackgroundBilateral internal rotation gait is a common gait abnormality in children with bilateral cerebral palsy, but still not fully understood.Research questionThe aim of this clinical study was to analyze the effects of artificially induced bilateral internal rotation gait on kinematics and kinetics. Our hypothesis was, that the internal rotation gait defined as increased dynamic internal hip rotation itself causes significant alterations in gait kinematics and kinetics.Methods30 typically developing children with a mean age of 12 (SD 3) years (range 8 – 16) performed three-dimensional gait analysis in two different conditions: with unaffected gait and with artificially induced bilateral internal rotation gait with two rotation bandages worn in order to internally rotate the hips. Kinematic and kinetic changes between these two conditions were calculated and compared using a mixed linear model with “gait condition” as fixed effect and both “limb” and “patient” as random effects.ResultsThe rotation bandages induced a significant increase in internal hip rotation and foot progression angle towards internal without affecting pelvic rotation. The peak hip internal rotator moment during loading response and the peak hip external rotator moment during the first half of stance phase increased significantly and the peak hip internal rotator moment during the second half of stance phase decreased significantly. Anterior pelvic tilt, hip flexion, knee flexion and ankle dorsiflexion increased significantly. The first peak of the frontal hip moment decreased, and the second increased significantly. The second peak of the frontal knee moment decreased significantly, while the first didn’t change significantly.SignificanceThe data suggest, that the bilaterally increased dynamic internal hip rotation itself has a relevant impact on frontal hip moments. The increased anterior pelvic tilt, hip and knee flexion may be either induced by the pull of the rotation bandage or a secondary gait deviation.     

The relationship between supination resistance and the kinetics and kinematics of the foot and ankle during gait

BackgroundClinical tests of foot posture and mobility are not strongly related to the dynamic kinematics of the foot during gait. These measures may be more directly related to foot and ankle kinetics. The supination resistance test (SRT) is a clinical test that may more directly measure forces acting on the weightbearing foot to provide clinicians with insight about the loading of foot structures.Research QuestionWhat is the relationship between the SRT in relaxed calcaneal stance and in single-leg-stance and the kinetics and kinematics of the foot and ankle during gait?Methods10 healthy adults between the ages of 18 and 65 were recruited to participate in this study. Three-dimensional motion analysis was performed using the Oxford Foot Model during gait. The results of the SRT were compared with peak midfoot and ankle joint moments, power generation and absorption, joint angles, and peak angular velocities and accelerations. Correlation coefficients were calculated to assess the strength of relationships between these variables and the SRT.ResultsThe SRT demonstrated significant relationships with several variables. In relaxed calcaneal stance, the SRT was inversely related to maximum midfoot pronation moments (r = −0.51), maximum midfoot plantarflexion moments (rho = −0.71), and peak midfoot power generation (r = −0.61). In single-leg-stance, the SRT was significantly related to maximum midfoot plantarflexion moments (rho = −0.55) and peak midfoot power generation (r = −0.47).SignificanceThe SRT is significantly associated to several kinetic variables that quantify midfoot loading during gait. Interventions that decrease supination resistance may have the potential to increase midfoot power generation.     

Modified conventional gait model vs. Six degrees of freedom model: A comparison of lower limb kinematics and associated error

BackgroundThe conventional gait model (CGM) is commonly utilised within clinical motion analysis but has a number of inherent limitations. To overcome some of these limitations modifications have been made to the CGM and six-degrees of freedom models (6DoF) have been developed.Research QuestionHow comparable are lower limb kinematics calculated using modified CGM and 6DoF models and what is the error associated with the output of each model during walking?MethodsTen healthy males attended two gait analysis sessions, in which they walked at a self-selected pace, while a 10-camera motion capture system recorded lower limb kinematics. Hip, knee and ankle joint kinematics in all three anatomical planes were calculated using a modified CGM, with medial anatomical markers and a three-dimensional foot added, and 6DoF. Mean absolute differences were calculated on a point-by-point basis over the walking gait cycle and interpreted relative to a 5° threshold to explore the comparability of model outputs. The standard error of the measurement (SEM) was also calculated on a point-by-point basis over the walking gait cycle for each model.ResultsMean absolute differences above 5° were reported between the two model outputs in 58–86% of the walking gait cycle at the knee in the frontal plane, and over the entire walking gait cycle at the hip and knee in the transverse plane. SEM was typically larger for the modified CGM compared to the 6DoF, with the highest SEM values reported at the knee in the frontal plane, and the hip and the knee in the transverse plane.SignificanceCaution should be taken when looking to compare findings between studies utilising modified CGM and 6DoF outside of the sagittal plane, especially at the hip and knee. The reduced SEM associated with the 6DoF suggests this modelling approach may be preferable.     

Fatigue matters: An intense 10 km run alters frontal and transverse plane joint kinematics in competitive and recreational adult runners

BackgroundFatigue is an essential component of distance running. Still, little is known about the effects of running induced fatigue on three-dimensional lower extremity joint movement, in particular in the frontal and transverse planes of motion.Research questionHow are non-sagittal plane lower extremity joint kinematics of runners altered during a 10 km treadmill run with near-maximum effort?MethodsIn a cross-sectional study design, we captured three-dimensional kinematics and kinetics at regular intervals throughout a 10 km treadmill run in 24 male participants (subdivided into a competitive and recreational runner group) at a speed corresponding to 105 % of their season-best time. We calculated average and peak joint angles at the hip, knee and ankle during the stance phase.ResultsWe observed peak deviations of 3.5°, 3° and 5° for the hip (more adduction), knee (more abduction) and ankle (more eversion) in the frontal plane when comparing the final (10 km) with the first (0 km) measurement. At the end of the run peak knee internal rotation angles increased significantly (up to 3° difference). Running with a more abducted knee joint and with a higher demand for hip abductor muscles in the unfatigued state was related to greater fatigue-induced changes of joint kinematics at the knee and hip.SignificanceThe fatigue related change of non-sagittal joint kinematics needs to be considered when addressing risk factors for running-related injuries, when designing shoe interventions as well as strengthening and gait retraining protocols for runners. We speculate that strengthening ankle invertors and hip abductors and monitoring the dynamic leg axis during running appear to be promising in preventing fatigue induced alterations of non-sagittal joint kinematics.     

Dynamic loading of the knee and hip joint and compensatory strategies in children and adolescents with varus malalignment

Three-dimensional gait analysis is a diagnostic tool that can be used to gain a better understanding of the relationship between joint loading and the onset or progression of articular cartilage degeneration in subjects with varus malalignment. The purpose of the present study was to investigate knee and hip joint angles and moments in children and adolescents with pathological varus alignment of the knee without signs of knee osteoarthritis (OA). Moreover, we wanted to know if compensatory mechanisms are present in this young patient group. Fourteen, otherwise healthy patients with varus malalignment of the knee and 15 healthy control subjects were analysed. Patients showed a reduced knee extension and a significantly lower maximum knee extension moment in terminal stance compared to controls. The maximum knee adduction moment in mid and terminal stance and the maximum hip abduction moment in loading response were significantly higher in the patient group. In the transverse plane, abnormally increased knee internal rotation and hip external rotation moments were present in patients with varus malalignment. These findings imply that varus malalignment is not an isolated problem in the frontal plane. In contrast to adult patients with established medial knee OA, the young patients assessed in the present study did not show typical compensatory mechanisms such as increased foot progression angle or reduced walking speed. This suggests that children and adolescents with varus malalignment of the knee probably do not need to alter their spatio-temporal gait parameters in order to decrease knee joint loading.     

The modified Shriners Hospitals for Children Greenville (mSHCG) multi-segment foot model provides clinically acceptable measurements of ankle and midfoot angles: A dual fluoroscopy study

BackgroundSeveral multi-segment foot models have been developed to evaluate foot and ankle motion using skin-marker motion analysis. However, few multi-segment models have been evaluated against a reference standard to establish kinematic accuracy.Research questionHow accurately do skin-markers estimate foot and ankle motion for the modified Shriners Hospitals for Children Greenville (mSHCG) multi-segment foot model when compared against the reference standard, dual fluoroscopy (DF), during gait, in asymptomatic participants?MethodsFive participants walked overground as full-body skin-marker trajectory data and DF images of the foot and shank were simultaneously acquired. Using the mSHCG model, ankle and midfoot angles were calculated throughout stance for both motion analysis techniques. Statistical parametric mapping assessed differences in joint angles and marker positions between skin-marker and DF motion analysis techniques. Paired t tests, and linear regression models were used to compare joint angles and range of motion (ROM) calculated from the two techniques.ResultsIn the coronal plane, the skin-marker model significantly overestimated ROM (p = 0.028). Further, the DF model midfoot ROM was significantly positively related to differences between DF and skin-marker midfoot angles (p = 0.035, adjusted R² = 0.76). In the sagittal plane, skin-markers underestimated ankle angles by as much as 7.26°, while midfoot angles were overestimated by as much as 9.01°. However, DF and skin-marker joint angles were not significantly different over stance. Skin-markers on the tibia, calcaneus, and fifth metatarsal had significantly different positions than the DF markers along the direction of walking for isolated portions that were less than 10 % of stance. Euclidean distances between DF and skin-markers positions were less than 9.36 mm.SignificanceAs the accuracy of the mSHCG model was formerly unknown, the results of this study provide ranges of confidence for key angles calculated by this model.     

Spatial-temporal parameters,pelvic and lower limb movements during gait in individuals with reduced passive ankle dorsiflexion

BackgroundProper ankle dorsiflexion range of motion (ADF-ROM) allows the anterior roll of the tibia relative to the foot during the midstance phase of gait, which contributes to forward movement of the body. Individuals with reduced passive ADF-ROM may present altered movement patterns during gait due to an inefficient anterior tibial roll over the support foot during the stance phase.Research question: What is the influence of reduced passive ADF-ROM on the pelvic and lower limb movements and spatiotemporal parameters during gait?MethodThirty-two participants divided into two groups according to the degree of passive ADF-ROM—less than 10° (lower ADF-ROM group) or greater than 15° (higher ADF-ROM group) —were subjected to gait assessment using a three-dimensional motion analysis system. Independent t-tests were used to compare the pelvic and lower limb movements and spatiotemporal gait parameters between the groups on this cross-sectional study.ResultsThe lower ADF-ROM group had shorter step length, lower peak of pelvic ipsilateral rotation angle, and lower hip and knee maximum flexion angles in the stance phase (p < 0.05). In addition, the peaks of the ankle and forefoot-rearfoot dorsiflexion angles were smaller in the reduced ADF-ROM group (p < 0.05). The between-group differences presented effect sizes varying from moderate to large.SignificanceIndividuals with reduced passive ADF-ROM presented reduced foot and ankle dorsiflexion, knee and hip flexion, and pelvis rotation movements and shorter step length during gait. However, no differences in foot pronation were noted between groups. Therefore, individuals with reduced passive ADF-ROM present alterations in the lower limb and pelvic movements during gait.     

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

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

Influence of spino-pelvic and postural alignment parameters on gait kinematics

IntroductionPostural alignment is altered with spine deformities that might occur with age. Alteration of spino-pelvic and postural alignment parameters are known to affect daily life activities such as gait. It is still unknown how spino-pelvic and postural alignment parameters are related to gait kinematics.Research questionTo assess the relationships between spino-pelvic/postural alignment parameters and gait kinematics in asymptomatic adults.Methods134 asymptomatic subjects (aged 18–59 years) underwent 3D gait analysis, from which kinematics of the pelvis and lower limbs were extracted in the 3 planes. Subjects then underwent full-body biplanar X-rays, from which skeletal 3D reconstructions and spino-pelvic and postural alignment parameters were obtained such as sagittal vertical axis (SVA), center of auditory meatus to hip axis plumbline (CAM-HA), thoracic kyphosis (TK) and radiologic pelvic tilt (rPT). In order to assess the influence of spino-pelvic and postural alignment parameters on gait kinematics a univariate followed by a multivariate analysis were performed.ResultsSVA was related to knee flexion during loading response (β = 0.268); CAM-HA to ROM pelvic obliquity (β = −0.19); rPT to mean pelvic tilt (β = −0.185) and ROM pelvic obliquity (β = −0.297); TK to ROM hip flexion/extension in stance (β = −0.17), mean foot progression in stance (β = −0.329), walking speed (β = −0.19), foot off (β = 0.223) and step length (β = −0.181).SignificanceThis study showed that increasing SVA, CAM-HA, TK and rPT, which is known to occur in adults with spinal deformities, could alter gait kinematics. Increases in these parameters, even in asymptomatic subjects, were related to a retroverted pelvis during gait, a reduced pelvic obliquity and hip flexion/extension mobility, an increased knee flexion during loading response as well as an increase in external foot progression angle. This was associated with a decrease in the walking pace: reduced speed, step length and longer stance phase.     

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

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

Rate of torque development is the primary contributor to quadriceps avoidance gait following total knee arthroplasty

BackgroundFollowing rehabilitation for total knee arthroplasty, “quadriceps avoidance gait”, defined by limited knee flexion angle excursion during walking, persists and contributes to poor long-term outcomes. Given the presence of several post-surgical impairments, identifying the contribution of multiple factors to knee flexion angle excursion is important to developing targeted interventions to improve recovery after total knee arthroplasty.Research questionsWhich outcomes continue to improve following rehabilitation for total knee arthroplasty? What are the primary contributors to impaired knee flexion angle excursion during walking following total knee arthroplasty?MethodsPeak muscle strength and rate of torque development of the quadriceps, hip abductors, and hip external rotators, five-time sit-to-stand test, Knee Injury & Osteoarthritis Outcome Score, and gait mechanics were assessed in 24 participants at three and six months post-surgery. Paired sample t-tests or Wilcoxon Signed-Rank tests were used to compare outcomes between assessments. Stepwise multiple linear regression were used to assess the contribution of each measure to knee flexion angle excursion.ResultsSignificant improvements were noted in all outcomes except hip external rotation rate of torque development, gait speed, and knee flexion angle excursion. Quadriceps rate of torque development and knee pain significantly contributed to knee flexion angle excursion at three months (Adjusted R² = 0.342), while quadriceps rate of torque development and peak hip external rotation strength significantly contributed at six months (Adjusted R² = 0.436).SignificanceWhile higher pain levels at three months and greater peak hip external rotation muscle strength at six months contribute to impaired knee flexion angle excursion, quadriceps rate of torque development was the primary contributor to knee flexion angle excursion at both three and six months after surgery. Implementing strategies to maximize quadriceps rate of torque development during rehabilitation may help to reduce quadriceps avoidance gait after total knee arthroplasty.     

Foot rotation—A potential target to modify the knee adduction moment

Isolating the particular joints/limb segments associated with knee adductor moment variability may provide clinically important data that could help to identify strategies to reduce medial tibiofemoral joint load. The aim of this study was to examine whether or not foot and thigh rotation during human locomotion are significant determinants of knee adductor moment variability.Three-dimensional gait analyses were performed on 32 healthy adult women (mean age 54 ± 12 years, mean BMI 25 ± 4 kg m⁻²) with radiologically normal knees. The relationships between foot rotation, thigh rotation and the external knee adduction moment were examined during early and late-stance phases of the gait cycle.The degree of foot rotation correlated significantly with the magnitude of the peak knee adduction moment during late stance (r = 0.40, p = 0.024). No significant associations were apparent between thigh rotation and the peak knee adduction moment.The association between foot rotation and the knee adduction moment in this study suggests that women who walk with external rotation at the foot reduce their knee adduction moment during late stance. This result implies that changes in foot kinematics can modify the medial tibiofemoral load during gait, which may be important in the prevention and management of knee osteoarthritis.     

Effect of 3D printed foot orthoses stiffness and design on foot kinematics and plantar pressures in healthy people

BackgroundFoot orthoses (FOs) have been widely prescribed to alter various lower limb disorders. FOs’ geometrical design and material properties have been shown to influence their impact on foot biomechanics. New technologies such as 3D printing provide the potential to produce custom shapes and add functionalities to FOs by adding extra-components.Research questionThe purpose of this study was to determine the effect of 3D printed FOs stiffness and newly design postings on foot kinematics and plantar pressures in healthy people.MethodsTwo pairs of ¾ length prefabricated 3D printed FOs were administered to 15 healthy participants with normal foot posture. FOs were of different stiffness and were designed so that extra-components, innovative flat postings, could be inserted at the rearfoot. In-shoe multi-segment foot kinematics as well as plantar pressures were recorded while participants walked on a treadmill. One-way ANOVAs using statistical non-parametric mapping were performed to estimate the effect of FOs stiffness and then the addition of postings during the stance phase of walking.ResultsIncreasing FOs stiffness altered frontal and transverse plane foot kinematics, especially by further reducing rearfoot eversion and increasing the rearfoot abduction. Postings had notable effect on rearfoot frontal plane kinematics, by enhancing FOs effect. Looking at plantar pressures, wearing FOs was associated with a shift of the loads from the rearfoot to the midfoot region. Higher peak pressures under the rearfoot and midfoot (up to +31.7 %) were also observed when increasing the stiffness of the FOs.Significance3D printing techniques offer a wide range of possibilities in terms of material properties and design, providing clinicians the opportunity to administer FOs that could be modulated according to pathologies as well as during the treatment by adding extra-components. Further studies including people presenting musculoskeletal disorders are required.     

Anatomical and dynamic rotational alignment in spastic unilateral cerebral palsy

BackgroundEven in mild unilateral cerebral palsy increased internal hip rotation can be noted on physical- and gait examination. The influence of spasticity on femoral growth in the transverse plane is not clear. These deviations and asymmetry in movement pattern may negatively affect efficiency of gait and cause psychological concerns about appearance.Research questionIs increased internal hip rotation on the involved side in mild unilateral CP common and is there compensatory external pelvic rotation to keep foot progression symmetrical?MethodsThis prospective study included 45 individuals with unilateral cerebral palsy, mean age 17.7 (13.0−24.0) years. All were Gross Motor Function Classification Level I. Physical examination, three-dimensional gait analysis and magnetic resonance imaging for assessment of rotational alignment was performed.ResultsOn physical examination internal hip rotation was mean 50.6 (SD 10.4) degrees on the involved side and 44.3 (SD 10.3) on the non-involved side, p = 0.001.In gait analysis calculating the whole gait cycle, internal hip rotation was mean 2.3 (6.2) degrees on the involved side, and on the non-involved side external 1.8 (7.6) degrees, p = 0.004.Increased external pelvic rotation was noted on the involved side, mean 2.0 (4.3) degrees with corresponding internal rotation on the non-involved side, mean 3.6 (4.4), p = 0.001. There was no difference in foot progression, p = 0.067, with mean 5.1 (8.6) and 3.9 (6.4) external respectively.Magnetic resonance imaging revealed femoral torsion on the involved side mean 17.3 (11.3) degrees compared to 11.4 (10.8) on the non-involved side, p = 0.001.SignificanceTransverse plane asymmetry in the femur was noted in mild unilateral cerebral palsy. Increased anatomical and dynamic internal rotation was compensated for by external pelvic rotation. Rotational malalignment may contribute to gait deviations in this mild group and should be part of the overall assessment.     

Physiological coxa varus–genu valgus influences internal knee and ankle joint moments in females during crossover cutting

This study evaluated the ankle and knee electromyographic, kinematic, and kinetic differences of 20 nonimpaired females with either neutral (group 1) or coxa varus–genu valgus (group 2) alignment during crossover cutting stance phase. Two-way mixed model ANOVA (group, session) assessed mean differences (p<0.05) and correlation analysis further delineated relationships. During impact absorption, group 2 displayed earlier peak horizontal braking (anterior-posterior) ground reaction force timing, decreased and earlier peak internal knee extension moments (eccentric function), and earlier peak internal ankle dorsiflexion moment timing (eccentric function). During the pivot phase, group 2 displayed later and eccentrically-biased peak ankle plantar flexion moments, increased peak internal knee flexion moments (eccentric function), and later peak knee internal rotation timing. Correlation analysis revealed that during impact absorption, subjects with coxa varus–genu valgus alignment (group 2) displayed a stronger relationship between knee internal rotation velocity and peak internal ankle dorsiflexion moment onset timing (r=–0.64 vs r =–0.26) and between peak horizontal braking ground reaction forces and peak internal ankle dorsiflexion moment onset timing (r=0.61 vs r=0.24). During the pivot phase these subjects displayed a stronger relationship between peak horizontal braking ground reaction forces and peak internal ankle plantar flexion moment onset timing (r=–0.63 vs r=–0.09) and between peak horizontal braking forces and peak internal ankle plantar flexion moments (r=–0.72 vs r=–0.26). Group differences suggest that subjects with coxa varus–genu valgus frontal-plane alignment have an increased dependence on both ankle dorsiflexor and plantar flexor muscle group function during crossover cutting. Greater dependence on ankle muscle group function during the performance of a task that requires considerable 3D dynamic knee joint control suggests a greater need for frontal and transverse plane weight bearing tasks that facilitate eccentric ankle muscle group function to optimize injury prevention conditioning and post-surgical rehabilitation programs.     

Kinematic changes in patients with severe knee osteoarthritis are a result of reduced walking speed rather than disease severity

BackgroundKinematic changes in patients with knee osteoarthritis (OA) have been extensively studied. Concerns have been raised whether the measured spatiotemporal and kinematic alterations are associated with disease progression or merely a result of reduced walking speed.Research question: The purpose of this study was to investigate the effect of walking speed on kinematic parameters in patients with knee OA using statistical parametric mapping (SPM).MethodsTwenty-three patients with unilateral knee OA scheduled for a total knee replacement and 28 age matched control subjects were included in this study. Spatiotemporal parameters and sagittal plane kinematics were measured in the hip, knee, and ankle using the inertial sensors system RehaGait® while walking at a self-selected normal (patients and controls) and slow walking speed (controls) for a distance of 20 m. Gait parameters were compared between groups for self-selected walking speed and for matched walking speed using SPM with independent sample t tests.ResultsAt self-selected walking speed, patients had significantly lower knee flexion during stance (maximum difference, -6.8°) and during swing (-11.0°), as well as higher ankle dorsiflexion during stance phase (+12.5°) and lower peak hip extension at the end of stance compared to controls (+4.2°). At matched speed, there were no significant differences in joint kinematics between groups.SignificanceDifferences in sagittal plane gait kinematics between patients with knee OA and asymptomatic controls appear to be mainly a result of reduced walking speed. These results emphasize the importance of considering walking speed in research on gait kinematics in patients with knee OA and in clinical trials using gait parameters as outcome measures.