Midstance Of Gait Research Articles

Loading during Midstance of Gait Is Associated with Magnetic Resonance Imaging of Cartilage Composition Following Anterior Cruciate Ligament Reconstruction

Loading during Midstance of Gait Is Associated with Magnetic Resonance Imaging of Cartilage Composition Following Anterior Cruciate Ligament Reconstruction

Loading during Midstance of Gait Is Associated with Magnetic Resonance Imaging of Cartilage Composition Following Anterior Cruciate Ligament Reconstruction.

ObjectiveA complex association exists between aberrant gait biomechanics and posttraumatic knee osteoarthritis (PTOA) development. Previous research has primarily focused on the link between peak loading during the loading phase of stance and joint tissue changes following anterior cruciate ligament reconstruction (ACLR). However, the associations between loading and cartilage composition at other portions of stance, including midstance and late stance, is unclear. The objective of this study was to explore associations between vertical ground reaction force (vGRF) at each 1% increment of stance phase and tibiofemoral articular cartilage magnetic resonance imaging (MRI) T1ρ relaxation times following ACLR.DesignTwenty-three individuals (47.82% female, 22.1 ±4.1 years old) with unilateral ACLR participated in a gait assessment and T1ρ MRI collection at 12.25 ± 0.61 months post-ACLR. T1ρ relaxation times were calculated for the articular cartilage of the weightbearing medial and lateral femoral (MFC, LFC) and tibial (MTC, LTC) condyles. Separate bivariate, Pearson product moment correlation coefficients (r) were used to estimate strength of associations between T1ρ MRI relaxation times in the medial and lateral tibiofemoral articular cartilage with vGRF across the entire stance phase.ResultsGreater vGRF during midstance (46%-56% of stance phase) was associated with greater T1ρ MRI relaxation times in the MFC (r ranging between 0.43 and 0.46).ConclusionsBiomechanical gait profiles that include greater vGRF during midstance are associated with MRI estimates of lesser proteoglycan density in the MFC. Inability to unload the ACLR limb during midstance may be linked to joint tissue changes associated with PTOA development.

Peroneus Longus overload caused by soft tissue deficiencies associated with early adult acquired flatfoot: A finite element analysis

BackgroundPeroneus Longus tendinopathy has been related to overload from cavus and ankle instability. The etiology of isolated Peroneus Longus tendon synovitis has not been elucidated. Loss of foot arch integrity as a cause of isolated Peroneus Longus overload is difficult to establish using cadaver modeling. Our objective was to analyze Peroneus Longus stress changes in pathological scenarios related to flatfoot development. MethodsA three-dimensional finite element foot model which included the foot bones and main soft tissues that maintain the arch was used. Simulations were performed in midstance of gait. Tendon's maximum principal stress and von Mises were calculated in scenarios where the plantar fascia, spring ligament and the posterior tibial tendon were weakened. FindingsDecreasing plantar fascia stiffness thus weakening arch integrity increases Peroneus Longus stresses by over three times. Additional failure of tissues that support arch, such as the spring ligament and tibialis posterior tendon further overloads this tendon. The absence of Peroneus Longus also affects stresses in tissues that maintain the arch. Stress concentrations increase in the plantar component of the Peroneus Longus. InterpretationResults offer an explanation into isolated Peroneus Longus overload synovitis. Recognition of failing medial arch structures that occur in early acquired flatfoot as a cause of Peroneus Longus overload could help in its treatment. We caution the practice of transfer of peroneus brevis to longus in surgical treatment of flatfoot as it may further overload an overloaded tendon and focus should be on restoration of arch stability to offload stresses within it.

Loading during midstance of gait is associated with tibiofemoral articular cartilage composition following anterior cruciate ligament reconstruction

Loading during midstance of gait is associated with tibiofemoral articular cartilage composition following anterior cruciate ligament reconstruction

Quasi-stiffness of intrinsic foot joints during the mid-stance of gait in a healthy population

Quasi-stiffness has been used as a parameter revealing the global mechanical behaviour of lower limb joints during locomotion and more particularly that of the ankle. This parameter has been define...

Neutral boundary alignment in total knee arthroplasty: a novel concept

The goal of total knee arthroplasty (TKA) surgery is to provide a stable and functional knee joint using current implant designs. Several alignment philosophies and surgical techniques have been introduced to provide a stable and functional knee joint, such as mechanical alignment (MA), kinematic alignment (KA), and anatomical alignment (AA). Recently, functional alignment (FA) is proposed. In this concept article, we propose a TKA approach, which we termed “Neutral Boundary Alignment (NBA).” The proposed approach seeks to establish the overall limb alignment in the direction of gravity at the midstance of gait cycle; consequently, a potential native knee can be restored from an arthritic state by establishing the joint line parallel to the ground. Herein, the NBA approach is described, and an iterative algorithm of structural layout patterns of truss is developed. The following three hypotheses are proposed: 1) The joint line should be parallel to the ground during the midstance of gait as an important initial condition for stability when transitioning toward gait propulsion in the gait cycle; 2) The NBA stability criteria purports that the leg is stable when the direction of gravity is simultaneously situated within the hip, knee and ankle during the midstance of gait, which generally agrees with the Varus/Valgus 3 degree envelope of MA; 3) Femoral and tibial resections that are made parallel to the ground remain within 1.5 degrees of traditional mechanical alignment resections.

Calcaneal Eversion Affects Coupled Knee Rotation During Gait

It has been suggested that ankle motion (specifically, subtalar (ST) and tibiotalar (TT) joints) may contribute to knee pathologies such as patellofemoral pain syndrome. Yet, in-depth understanding of knee and ankle joint coupling remains elusive due to challenges in accurately measuring three dimensional (3D) bone motion in vivo. PURPOSE: To determine coupled knee and ankle kinematics during the weight-bearing phase of gait in healthy adults. METHODS: Dynamic biplane radiography was used to measure coupled kinematics during walking in 12 ankles and knees from six healthy volunteers (ages 18 - 35 yrs.). Synchronized biplane radiographs were collected at 100hz over the entire support phase of gait, from foot-strike through toe-off. Next, CT scans were acquired and subject-specific models of each bone were generated and used to track the 3D bone motion during each trial using a validated technique with sub-millimeter and sub-degree accuracy. Six degrees of freedom ankle and knee kinematics were normalized to percent stance and divided into loading, mid-stance, and push-off phases. The coupled outcome kinematics were 1) ST inversion and knee internal rotation, and 2) TT dorsiflexion and knee flexion. Associations between ankle and knee coupled kinematics were evaluated using Spearman’s rho with significance set at p<0.05. RESULTS: During midstance, the knee internal rotation always accompanied ST inversion while external rotation accompanied eversion (R2=0.63, p=0.085) (Figure 1). During mid-stance TT plantar flexion always occurred with knee extension (R2=0.12, p=0.71). CONCLUSIONS: In healthy knees, ST inversion/eversion appears to play a role in knee internal rotation during the mid-stance of gait. This finding suggests assessing coupled motion between the knee and ankle may be beneficial for evaluating single joint pathology. This work was supported by NIH Grant: R44HD066831.Figure 1: Chart showing coupled ST inversion and knee external rotation during mid stance of gait.

Progressive resistance training for adolescents with cerebral palsy: the STAR randomized controlled trial.

To evaluate the effect of progressive resistance training of the ankle plantarflexors on gait efficiency, activity, and participation in adolescents with cerebral palsy (CP). Sixty-four adolescents (10-19y; 27 females, 37 males; Gross Motor Function Classification System [GMFCS] levels I-III) were randomized to 30 sessions of resistance training (10 supervised and 20 unsupervised home sessions) over 10 weeks or usual care. The primary outcome was gait efficiency indicated by net nondimensional oxygen cost (NNcost). Secondary outcomes included physical activity, gross motor function, participation, muscle strength, muscle and tendon size, and muscle and tendon stiffness. Analysis was intention-to-treat. Median attendance at the 10 supervised sessions was 80% (range 40-100%). There was no between-group difference in NNcost at 10 (mean difference: 0.02, 95% confidence interval [CI] -0.07 to 0.11, p=0.696) or 22 weeks (mean difference: -0.08, 95% CI -0.18 to 0.03, p=0.158). There was also no evidence of between-group differences in secondary outcomes at 10 or 22 weeks. There were 123 adverse events reported by 27 participants in the resistance training group. We found that 10 supervised sessions and 20 home sessions of progressive resistance training of the ankle plantarflexors did not improve gait efficiency, muscle strength, activity, participation, or any biomechanical outcome among adolescents with CP. Thirty sessions of progressive resistance training of the ankle plantarflexors over 10 weeks did not improve gait efficiency among ambulatory adolescents with cerebral palsy. Resistance training did not improve muscle strength, activity, or participation. Ninety percent of participants experienced an adverse event. Most adverse events were expected and no serious adverse events were reported.

Medial Longitudinal Arch Angle Presents Significant Differences Between Foot Types: A Biplane Fluoroscopy Study.

The structure of the medial longitudinal arch (MLA) affects the foot's overall function and its ability to dissipate plantar pressure forces. Previous research on the MLA includes measuring the calcaneal-first metatarsal angle using a static sagittal plane radiograph, a dynamic height-to-length ratio using marker clusters with a multisegment foot model, and a contained angle using single point markers with a multisegment foot model. The objective of this study was to use biplane fluoroscopy to measure a contained MLA angle between foot types: pes planus (low arch), pes cavus (high arch), and normal arch. Fifteen participants completed the study, five from each foot type. Markerless fluoroscopic radiostereometric analysis (fRSA) was used with a three-dimensional model of the foot bones and manually matching those bones to a pair of two-dimensional radiographic images during midstance of gait. Statistically significant differences were found between barefoot arch angles of the normal and pes cavus foot types (p = 0.036), as well as between the pes cavus and pes planus foot types (p = 0.004). Dynamic walking also resulted in a statistically significant finding compared to the static standing trials (p = 0.014). These results support the classification of individuals following a physical assessment by a foot specialist for those with pes cavus and planus foot types. The differences between static and dynamic kinematic measurements were also supported using this novel method.

Partitioning of knee joint internal forces in gait is dictated by the knee adduction angle and not by the knee adduction moment

Medial knee osteoarthritis is a debilitating disease. Surgical and conservative interventions are performed to manage its progression via reduction of load on the medial compartment or equivalently its surrogate measure, the external adduction moment. However, some studies have questioned a correlation between the medial load and adduction moment. Using a musculoskeletal model of the lower extremity driven by kinematics–kinetics of asymptomatic subjects at gait midstance, we aim here to quantify the relative effects of changes in the knee adduction angle versus changes in the adduction moment on the joint response and medial/lateral load partitioning. The reference adduction rotation of 1.6° is altered by ±1.5° to 3.1° and 0.1° or the knee reference adduction moment of 17Nm is varied by ±50% to 25.5Nm and 8.5Nm. Quadriceps, hamstrings and tibiofemoral contact forces substantially increased as adduction angle dropped and diminished as it increased. The medial/lateral ratio of contact forces slightly altered by changes in the adduction moment but a larger adduction rotation hugely increased this ratio from 8.8 to a 90 while in contrast a smaller adduction rotation yielded a more uniform distribution. If the aim in an intervention is to diminish the medial contact force and medial/lateral load ratio, a drop of 1.5° in adduction angle is much more effective (causing respectively 12% and 80% decreases) than a reduction of 50% in the adduction moment (causing respectively 4% and 13% decreases). Substantial role of changes in adduction angle is due to the associated alterations in joint nonlinear passive resistance. These findings explain the poor correlation between knee adduction moment and tibiofemoral compartment loading during gait suggesting that the internal load partitioning is dictated by the joint adduction angle.

Effects of plantar fascia on first metatarsophalangeal joint stress in different foot types

Osteoarthritis (OA) is the leading cause of disability in older adults [1] and 1st metatarsophalangeal joint (MTPJ) OA, is the most common form of OA in the foot [2]. Many foot pathologies are of a biomechanical nature and often associated with one foot type over another [3,4]. OA is postulated to result from elevated joint stress. However, the link between stress distribution in the 1st MTPJ and different foot types is not well understood. Furthermore the tension band effect of the plantar fascia upon 1st MTP joint function is also not well understood. A high resolution 7 Tesla MRI was used to create a geometrically accurate 3D model of the 1st MTPJ using Mimics v14 imaging software. To simulate rectus, planus and cavus feet, 1st metatarsal declination angles of 20.2°, 10.1° and 30.7° were constructed. Plantar fascia material properties were altered. Physiological material properties and boundary conditions were applied to solve for stress, using ABAQUS. The ligaments were simulated by linear spring elements. The base of the first metatarsal bone was mechanically grounded in this model. Plantar loading conditions were applied, based on plantar pressure data collected from different foot types. Results of our static 3D FE model (Figure ​(Figure1)1) during mid-stance of gait showed peak stresses in the distal 1st MTPJ cartilage of 0.61 MPa, 0.97 MPa and 1.10 MPa for the rectus, cavus and planus foot type, respectively (Figure ​(Figure1).1). First MTP joint stress is largest for planus and cavus foot types and least for well-aligned rectus feet. Global foot alignment affected the magnitude and location of peak stress within the joint. Peak stress decreases as the k increases suggesting that the plantar fascia plays an important ‘tension band’ effect (Figure ​(Figure2).2). Future research should develop methods of tuning plantar fascia material properties to represent a specific patient. Figure 1 1st MTPJ stress a) rectus, b) planus, and c) cavus foot types Figure 2 Fascia stiffness effects

Relationship between leg extensor muscle strength and knee joint loading during gait before and after total knee arthroplasty

ObjectiveThe aim of the present study was to evaluate an isometric maximal voluntary contraction (MVC) force of the leg extensor muscles and its relationship with knee joint loading during gait prior and after total knee arthroplasty (TKA). MethodsCustom-made dynamometer was used to assess an isometric MVC force of the leg extensor muscles and 3-D motion analysis system was used to evaluate the knee joint loading during gait in 13 female patients (aged 49–68years) with knee osteoarthritis. Patients were evaluated one day before, and three and six months following TKA in the operated and non-operated leg. ResultsSix months after TKA, MVC force of the leg extensor muscles for the operated leg did not differ significantly as compared to the preoperative level, whereas it remained significantly lower for the non-operated leg and controls. The knee flexion moment and the knee joint power during mid stance of gait was improved six months after TKA, remaining significantly lowered compared with controls. Negative moderate correlation between leg extensor muscles strength and knee joint loading for the operated leg during mid stance was noted three months after TKA. ConclusionsThe correlation analysis indicates that due to weak leg extensor muscles, an excessive load is applied to knee joint during mid stance of gait in patients, whereas in healthy subjects stronger knee-surrounding muscles provide stronger knee joint loading during gait.Level of Evidence: III (correlational study)

Ankle dynamic in stroke patients: Agonist vs. antagonist muscle relations

Introduction: Atypical ankle patterns of muscle activity during gait are commonly reported in patients with stroke. These findings can be due to changes between tibialis anterior (TA) and soleus (SOL) coactivation mechanisms.Objective: To compare the electromyographic activity (EMGa) of SOL and TA muscles and antagonist coactivation (C) level in the contralateral (CONTRA) and ipsilateral (IPSI) limbs to the side of the stroke lesion during the stance phase of the gait cycle.Methods: Twelve subjects with a stroke episode participated in this study. The electromyographic signal of TA and SOL and ground reaction forces were acquired while subjects walked at their self-selected speed. Values of ground reaction forces were used to divide the stance phase of gait into initial contact, midstance, and terminal stance. In each sub-phase, the magnitude of TA and SOL was calculated as well as the level of the antagonist C.Results: Although no statistical differences were found, mean values of SOL EMGa were lower in the IPSI limb in all stance phases in relation to the CONTRA limb, and the opposite was observed in the TA EMGa. Moreover, higher mean levels of antagonist C were only found during the initial contact sub-phase in the CONTRA limb and in the other sub-phases in the IPSI limb. Besides, statistical differences were observed only during midstance.Conclusion: In stroke subjects, the antagonist C level during midstance of gait may reflect the dysfunction of the neuronal system over the IPSI limb.

The effect of isolated gastrocnemius contracture and gastrocnemius recession on lower extremity kinematics and kinetics during stance

BackgroundIsolated gastrocnemius contracture limits ankle dorsiflexion with full knee extension and is potentially problematic during mid-stance of gait when 10° of dorsiflexion and full knee extension are needed. It is during this time that patients with isolated gastrocnemius contracture may demonstrate altered kinematics and/or kinetics. When conservative management fails to resolve painful foot pathologies associated with non-spastic isolated gastrocnemius contracture, gastrocnemius recession surgery has been suggested to resolve contracture and improve function and strength. However, there are no published reports on lower extremity kinematics/kinetics in the non-spastic isolated gastrocnemius contracture population. Assessment of alterations in gait mechanics is necessary to examine the effects of this potential surgical intervention. MethodsLower extremity kinematics and kinetics were assessed in 6 patients clinically diagnosed with isolated gastrocnemius contracture pre- and post-surgical recession compared with 33 healthy control participants. FindingsPre-operatively, patients with isolated gastrocnemius contracture demonstrated significantly increased peak knee flexion angles and knee flexion moments during mid-stance. There were no differences in peak ankle dorsiflexion angle or peak plantar flexion moment. Gastrocnemius recession did not alter gait kinematics/kinetics following surgery. Joint kinematic strategies utilized to compensate for isolated gastrocnemius contracture varied minimally between participants with IGC; most employed a flexed knee strategy, while one participant utilized a reduced ankle dorsiflexion strategy. InterpretationSelect post-surgical gait mechanics were unaltered; however, gait mechanics were not similar between non-spastic isolated gastrocnemius contracture patients and healthy control participants. Surgical intervention for patients with isolated gastrocnemius contracture does not appear to create any negative gait adaptations; however, patients may benefit from gait retraining post-recession as maladaptive gait patterns persist post operatively.

Measuring hindfoot alignment radiographically: the long axial view is more reliable than the hindfoot alignment view

BackgroundHindfoot malalignment is a recognized cause of foot and ankle disability. For preoperative planning and clinical follow-up, reliable radiographic assessment of hindfoot alignment is important. The long axial radiographic view and the hindfoot alignment view are commonly used for this purpose. However, their comparative reliabilities are unknown. As hindfoot varus or valgus malalignment is most pronounced during mid-stance of gait, a unilateral weight-bearing stance, in comparison with a bilateral stance, could increase measurement reliability. The purpose of this study was to compare the intra- and interobserver reliability of hindfoot alignment measurements of both radiographic views in bilateral and unilateral stance.Materials and methodsA hindfoot alignment view and a long axial view were acquired from 18 healthy volunteers in bilateral and unilateral weight-bearing stances. Hindfoot alignment was defined as the angular deviation between the tibial anatomical axis and the calcaneus longitudinal axis from the radiographs. Repeat measurements of hindfoot alignment were performed by nine orthopaedic examiners.ResultsMeasurements from the hindfoot alignment view gave intra- and interclass correlation coefficients (CCs) of 0.72 and 0.58, respectively, for bilateral stance and 0.91 and 0.49, respectively, for unilateral stance. The long axial view showed, respectively, intra- and interclass CCs of 0.93 and 0.79 for bilateral stance and 0.91 and 0.58 for unilateral stance.ConclusionThe long axial view is more reliable than the hindfoot alignment view or the angular measurement of hindfoot alignment. Although intra-observer reliability is good/excellent for both methods, only the long axial view leads to good interobserver reliability. A unilateral weight-bearing stance does not lead to greater reliability of measurement.