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Background: The ankle dorsiflexion range of motion (ADF-ROM) during single support phase allows elastic energy storage in the calcaneal tendon, contributing to advance the body forward. Reduced ADF-ROM may influence lower limb kinetics and stiffness., Research Question: What is the influence of reduced passive ADF-ROM on lower limb internal moments and stiffness during gait?, Methods: Thirty-two participants, classified into two groups according to passive ADF-ROM (smaller than 10° and greater than 15°), were submitted to gait assessment at self-selected speed with a force platform and a three-dimensional motion analysis system. Statistical parametrical mapping (SPM) analyses were used to compare the lower limbs' internal moments between groups. Independent t-tests analyzed the differences between groups on lower limb stiffness during gait., Results: The lower ADF-ROM group had greater knee flexor moment (terminal stance and push-off), greater ankle abductor (i.e., shank internal rotator) moment in terminal stance and greater knee internal rotator moment in mid to terminal stance. The lower ADF-ROM group also had higher lower limb stiffness during gait., Significance: Individuals with reduced passive ADF-ROM had greater lower limb stiffness and adopted a gait pattern with increased knee and ankle moments, suggesting increased loading at these joints., Competing Interests: Declaration of Competing Interest None of the authors had any conflict of interest during this study., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Proper 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?, Method: Thirty-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., Results: The 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., Significance: Individuals 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., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: The Rizzoli Foot Model (RFM) and Oxford Foot Model (OFM) are used to analyze segmented foot kinematics with independent tracking markers. Alternatively, rigid marker clusters can be used to improve markers' visualization and facilitate analyzing shod gait., Research Question: Are there differences in angles from the RFM and OFM, obtained with independent and clustered tracking markers, during the stance phase of walking?, Methods: Walking kinematics of 14 non-disabled participants (25.2 years (SD 2.8)) were measured at self-selected speed. Rearfoot-shank and forefoot-rearfoot angles were measured from two models with two tracking methods: RFM, OFM, RFM-cluster, and OFM-cluster. In RFM-cluster and OFM-cluster, the rearfoot and forefoot tracking markers were rigidly clustered, fixed on rods' tips attached to a metallic base. Statistical Parametric Mapping (SPM) One-Way Repeated Measures ANOVAs and SPM Paired t-tests were used to compare waveforms. Coefficients of Multiple Correlation (CMC) quantified the similarity between waveforms. One-way Repeated Measures ANOVAs were conducted to compare the ranges of motion (ROMs), and pre-planned contrasts investigated differences between the models and tracking methods. Intraclass Correlation Coefficients (ICC) were computed to verify the similarity between ROMs., Results: Differences occurred mostly in small parts of the stance phase for the cluster vs. non-cluster comparisons and the RFM vs. OFM comparisons. ROMs were slightly different between the models and tracking methods in most comparisons. The curves (CMC ≥ 0.71) were highly similar between the models and tracking methods. The ROMs (ICC ≥ 0.67) were moderatetly to highly similar in most comparisons. RFM vs. RFM-cluster (forefoot-rearfoot angle - transverse plane), OFM vs. OFM-cluster and RFM vs. OFM (forefoot-rearfoot angle - frontal plane) were not similar (non-significant)., Significance: Rigid clusters are an alternative for tracking rearfoot-shank and forefoot-rearfoot angles during the stance phase of walking. However, specific differences should be considered to contrast results from different models and tracking methods., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Hip external rotation stiffness, midfoot passive mechanical resistance and foot alignment may influence on ankle, knee and hip movement in the frontal and transverse planes during gait., Research Question: Are hip stiffness, midfoot mechanical resistance and foot alignment associated with ankle, knee and hip kinematics during gait?, Methods: Hip stiffness, midfoot mechanical resistance, and foot alignment of thirty healthy participants (18 females and 12 males) with average age of 25.4 years were measured. In addition, lower limb kinematic data during the stance phase of gait were collected with the Qualisys System (Oqus 7+). Stepwise multiple linear regressions were performed to identify if hip stiffness, midfoot torque, midfoot stiffness and foot alignment were associated with hip and knee movement in the transverse plane and ankle movement in the frontal plane with α = 0.05., Results: Reduced midfoot torque was associated with higher hip range of motion (ROM) in the transverse plane (r 2  = 0.18), reduced hip stiffness was associated with higher peak hip internal rotation (r 2  = 0.16) and higher ROM in the frontal plane (r 2  = 0.14), reduced midfoot stiffness was associated with higher peak knee internal rotation (r 2  = 0.14) and increased midfoot torque and midfoot stiffness were associated with higher peak knee external rotation (r 2  = 0.36)., Significance: These findings demonstrated that individuals with reduced hip and midfoot stiffness have higher hip and knee internal rotation and higher ankle eversion during the stance phase of gait. On the other hand, individuals with increased midfoot torque and stiffness have higher knee external rotation. These relationships can be explained by the coupling between ankle movements in the frontal plane and knee and hip movements in the transverse plane. Finally, this study suggests that midfoot passive mechanical resistance and hip stiffness should be assessed in individuals presenting altered ankle, knee and hip movement during gait., Competing Interests: Declaration of Competing Interest None., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Decisions about the use of baby walker are in part predicated on caregivers´ beliefs about its effect on gait development. The actual effects of baby walkers, however, have not been established., Research Question: What are the effects of the use of baby walker prior to gait onset on age of acquisition of this milestone and on early walking kinematics?, Methods: Thirty-two toddlers, 16 in the baby walker group (BWG) and 16 in the non-users group (BWNG), were evaluated in the week of gait acquisition and monthly up to six months after this event. Spatial and temporal gait parameters and lower limb kinematics during walking were assessed using a tridimensional motion analysis system. An independent t-test compared age of gait acquisition between groups. A mixed ANOVA examined the effects of group, moment of assessment and the group x moment of assessment interaction effect on the amplitude of joint motions during walking and on spatial and temporal gait parameters., Results: The age of gait acquisition was not different between groups. BWG had lower gait speed (specifically in the first, third, fourth, and fifth months after gait acquisition) and longer duration of stance and swing phases than BWNG. Additionally, BWG had smaller knee amplitude and greater hip amplitude in sagittal plane than BWNG in the week of gait acquisition., Significance: The results demonstrated that there is no delay in the age of gait acquisition, but there are differences in kinematics. These results can contribute to evidence-based recommendations by health care professionals about the use of baby walker by toddlers during emergence and early development of gait., Competing Interests: Declaration of Competing Interest None declared., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: The 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 Question: Is foot pronation during the stance phase of gait related to the midfoot passive mechanical resistance to inversion?, Methods: The 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., Results: Reduced 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., Significance: The 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., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Although mild leg length discrepancy is related to lower limb injuries, there is no consensus regarding its effects on the biomechanics of the lower limbs during gait. Biomechanical data of 19 healthy participants were collected while they walked under different conditions as described: (1) control condition-wearing flat thick sandals; (2) short limb condition-wearing a flat thick sandal on the left and a flat thin sandal on the right foot; (3) long limb condition: wearing flat thin sandal on the left and flat thick sandal on the right foot. The thick and thin sandals had 1.45cm of mean thickness difference. The right lower limb data were analyzed for all conditions. Ankle, knee, hip and pelvis kinematics and internal moments were measured with a motion capture system and six force platforms. Principal component analysis was used to compare differences between conditions. The scores of the principal components were compared between conditions using one-way repeated measures ANOVA. Twelve gait variables were different between conditions: rearfoot dorsiflexion and inversion (p<0.001); ankle dorsiflexion and inversion moments (p<0.001); knee flexion angle and moment (p<0.001); knee adduction moment (p<0.001); hip flexion angle and moment (p<0.001); hip adduction angle (p=0.001) and moment (p=0.022); and pelvic ipsilateral drop (p<0.001). Mild leg length discrepancy caused compensatory changes during gait, apparently to equalize the functional length of the lower limbs. However, these strategies did not fully succeed, since both short and long limb conditions affected pelvic motion in the frontal plane. These results suggest that mild leg length discrepancy should not be overlooked in clinical settings., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Increased unilateral foot pronation may cause biomechanical changes on the lower limbs during gait. We investigated the effects of increased unilateral foot pronation on the biomechanics of lower limbs and pelvis during gait., Methods: Kinematic and kinetic data of 22 participants were collected while they walked wearing flat and laterally wedged sandals. Principal omponent analysis was used to compare differences between conditions., Findings: Wearing the wedged sandal on the ipsilateral side increased ankle eversion moment (p<0.001; effect size=0.97); rearfoot eversion angle (p<0.001; effect size=0.76); shank internal rotation (p=0.009; effect size=0.53); increased and reduced knee internal rotation angle during early and late stance, respectively (p<0.001; effect size=0.89); increased femur internal rotation (p=0.005; effect size=0.90); reduced hip internal rotation moment during late stance (p=0.001; effect size=0.68); and increased pelvic ipsilateral drop (p=0.02; effect size=0.48) of the ipsilateral side. Wearing the wedged sandal on the contralateral side increased pelvic contralateral drop (p=0.001; effect size=0.63); hip adduction moment throughout stance (p=0.027; effect size=0.46); and increased and reduced the knee adduction moment in early and late stance, respectively (p<0.001; effect size=0.79)., Interpretation: The increased lower limb internal rotation caused by the wedged sandal reinforces the assumption that rearfoot eversion is coupled with shank internal rotation. The increased pelvic contralateral drop caused by the wedged sandal on the contralateral side may explain the increased hip and knee adduction moments on the ipsilateral side. Increased unilateral foot pronation causes biomechanical changes on both lower limbs that are associated with the occurrence of injuries., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The gait acquisition is an important milestone of motor development. Structural modifications observed during this period add complexity to the process, and the child needs to use appropriate neuromuscular strategies to walk independently. The objective of this study was to document the longitudinal modifications in neuromuscular mechanisms and in functional anthropometric measures during independent gait acquisition in typically developing children. Twelve children were followed for 2 months after gait acquisition, with its initial period documented by the standardized test Alberta Infant Motor Scale. Quantification of the EMG signals of six muscles in the right lower limb allowed the calculation of the co-contraction indexes (CCI) considering pairs of antagonistic muscles, representing the hip, knee and ankle joints. The CCIs were summed up to yield a total index. Anthropometric measures were transformed into gravitational torque (mLg) values for stance and swing phases of gait. Statistical analyses included repeated measures ANOVA models with one factor (week post-acquisition) for the dependent variables mLg and normalized CCI (CCI/mLg). A significant increase was observed in the mLg during the period evaluated both in stance and swing phases (p=0.0001). In addition, there was a decrease in the value of the normalized hip and total CCIs in both phases of gait (p<0.05). The results revealed changes in the neuromuscular mechanisms used by typical children to deal with the demands involved in the process of gait acquisition., (Copyright 2005 Elsevier B.V.)