Phases Of Gait Cycle Research Articles

Investigation and Finite Element Analysis of The Distal Weight-Bearing Implant

General Background: Osseointegration. a critical advancement in prosthetics, significantly benefits individuals with transfemoral amputations by enhancing their quality of life through innovative implant systems. Specific Background: The study examines a novel distal weight-bearing implant from 17 global systems, featuring a composite nanocoating of hydroxyapatite and silica, evaluated through finite element analysis and mechanical testing. Knowledge Gap: Research on nanocoating's impact on mechanical performance and its integration into advanced prosthetic designs is limited, despite extensive exploration of various implant systems. Aims: The study evaluates the distal weight-bearing implant's effectiveness, focusing on the nanocoating's role in shock absorption and mechanical stability during various gait cycle phases. Results: The design process involved creating a Ti-6Al-4V femoral stem and UHMWPE spacer, with the implant subjected to FEA under gait cycle conditions. Nanocoated samples demonstrated effective shock absorption, though with slightly reduced mechanical properties. The implant’s performance was evaluated for heel strike, midstance, and pre-swing phases, showing adequate load-bearing capacity within safe thresholds. Novelty: This study introduces a detailed analysis of nanocoating impacts on implant performance and integrates biomechanical forces into FEA for enhanced prosthetic design evaluation. Implications: Research indicates nanocoating enhances shock absorption, but further studies are needed to balance mechanical properties with biocompatibility and biological response, potentially improving amputee care outcomes. Highlights: Advanced Implant Design: Transition from transfemoral to knee disarticulation. Nanocoating Impact: Enhances shock absorption; minor mechanical property reduction. FEA Results: Confirms load-bearing capacity through gait cycle phases. Keywords: osseointegration, distal weight-bearing implant, nanocoating, finite element analysis, gait cycle

Gait phase normalization resolves the problem of different phases being compared in gait cycle normalization

For time-continuous analysis of gait, the problem of variations in cycle durations is resolved by normalizing to the gait cycle, but results depend on the definition of the cycle start. Gait cycle normalization ignores variations in gait phase durations, which results in averaging and comparing data across different phases. We propose gait phase normalization as part of a comprehensive method for independently analyzing magnitude and timing differences. First, gait phases are identified and differences in absolute and/or relative timing of phase durations or any point of interest between conditions or groups are analyzed using standard statistics. Next, time-continuous gait data is normalized to gait phases, and statistical parametric mapping (SPM) is used to assess magnitude differences in gait data. This approach is demonstrated on data recorded from ten young healthy adults walking on a treadmill at five different speeds. Sagittal knee angle was normalized to gait cycle or gait phase using five different gait cycle start events. Walking at different speeds resulted in significant changes in gait phase durations, highlighting a problem ignored by gait cycle normalization. SPM results for knee angle normalized to gait cycle varied from normalization to gait phases. Gait phase normalized SPM results were robust to the definition of the cycle start, in contrast to gait cycle normalized data. The approach of analyzing phase durations and normalizing data to gait phases overcomes previous limitations and enables a comprehensive analysis of magnitude and timing differences in time-continuous gait data and could be readily adapted to other tasks.

Effects of Cognitive-Motor and Motor-Motor Dual Tasks on Gait Performance in Older Adults with Sarcopenia.

With the advent of global aging, the health of the older population has become a critical public health challenge. The purpose of this study was to investigate the effect of dual-tasking on gait performance in patients with sarcopenia. Thirty participants with sarcopenia (age: 70.73 ± 4.12 yr, MMSE score: 26.90 ± 3.00), including 14 males and 16 females, were selected according to the diagnostic criteria of the Asian Working Group on Sarcopenia. All participants were instructed to perform the gait test in three modes: single task (ST), cognitive-motor dual task (CMDT), and motor-motor dual task (MMDT). Statistical analyses were performed using one-way ANOVA to evaluate the effects of different task types on gait parameters of the participants. (1) Compared with ST walking, gait frequency, step length, and step speed decreased, and the gait cycle and double-support phase increased in patients with sarcopenia during dual-task walking (p < 0.05); (2) Compared with ST walking, gait variability indices such as stride frequency, stride length, and support period significantly increased in patients with sarcopenia during dual-task walking (p < 0.05). The increased difficulty in postural control caused by dual-task interference may reduce the safety of motor strategies in patients with sarcopenia and increase the risk of falls. Future studies should focus on the effects of exercise interventions on multitasking patterns in people with sarcopenia to promote balance function in these populations.

Ground Reaction Forces and Joint Moments Predict Metabolic Cost in Physical Performance: Harnessing the Power of Artificial Neural Networks

Understanding metabolic cost through biomechanical data, including ground reaction forces (GRFs) and joint moments, is vital for health, sports, and rehabilitation. The long stabilization time (2–5 min) of indirect calorimetry poses challenges in prolonged tests. This study investigated using artificial neural networks (ANNs) to predict metabolic costs from the GRF and joint moment time series. Data from 20 participants collected over 270 walking trials, including the GRF and joint moments, formed a detailed dataset. Two ANN models were crafted, netGRF for the GRF and netMoment for joint moments, and both underwent training, validation, and testing to validate their predictive accuracy for metabolic cost. NetGRF (six hidden layers, two input delays) showed significant correlations: 0.963 (training), 0.927 (validation), 0.883 (testing), p &lt; 0.001. NetMoment (three hidden layers, one input delay) had correlations of 0.920 (training), 0.956 (validation), 0.874 (testing), p &lt; 0.001. The models’ low mean squared errors reflect their precision. Using Partial Dependence Plots, we demonstrated how gait cycle phases affect metabolic cost predictions, pinpointing key phases. Our findings show that the GRF and joint moments data can accurately predict metabolic costs via ANN models, with netGRF being notably consistent. This emphasizes ANNs’ role in biomechanics as a crucial method for estimating metabolic costs, impacting sports science, rehabilitation, assistive technology development, and fostering personalized advancements.

The Effect of Proprioceptive Insoles on Gait Kinematics in Healthy Participants

ABSTRACT Introduction Proprioceptive neuromuscular stimulating insoles (PNIs) enhance somatosensory information from the plantar region, thus modifying standing posture, balance, and ambulatory function. The present study investigated the short-term effects of customized PNIs on lower-limb kinematics during human locomotion. Materials and Methods Fifteen able-bodied volunteers were recruited and first examined with clinical evaluation of postural and feet behavior. Subjects performed 3-dimensional gait analysis (GA) while walking at self-selected speed in three different conditions: baseline, subjects barefoot; placebo, subjects wearing neutral insoles; and proprioceptive, subjects wearing PNIs. Spatiotemporal and kinematics data of the main lower-limb joints were acquired through a system of six photogrammetric infrared cameras acquiring at a sampling frequency of 100 Hz. Then, acquired parameters were compared in the three different conditions. Results We found a significant difference in the percentage of double-support phase (P = 0.022) and in ankle plantarflexion values during the toe-off phase of gait cycle (P = 0.022) between the three conditions. Post hoc analysis revealed that subjects wearing PNIs presented a significant reduction in percentage of double-support phase (P = 0.009) and reduced values of ankle plantarflexion during the toe-off phase of gait cycle (P = 0.02), compared with subjects in placebo condition. Conclusions Results suggest that proprioceptive insoles may induce modifications of gait biomechanics in able-bodied subjects, thus modulating movement strategies during human locomotion. Clinical Relevance These findings provide a basis for future investigation of the efficacy of these foot devices in a long-term period in able-bodied individuals and potentially in subjects with neurological impairment.

Analysis of Gait Pattern Affected by Various Disease : A Review

Gait is pattern of walking of individual, is unique pattern of a person. The gait pattern is affected by various disease, ill condition of a person. In this review article we discuss about various diseases by which gait of an individual gets affected. Some disease are ; Parkinson's disease (PD) is a degenerative brain disorder causing shuffled gait, impaired balance, and freezing of gait. Morquio A syndrome, a group of disorders called mucopolysaccharidosis, can lead to vision, hearing, bone, brain, and heart problems. The anterior cruciate ligament (ACL) is a key stabilizer in the knee, and a torn ACL can cause instability when walking or changing directions. Examination of the gait pattern of a those person who having a disease such as ; Parkinson’s disease, Morquio A syndrome, Anterior Crucial Ligament, etc. In normal human the Gait Cycle has two phases ; Stance and swing phase. The stance phase covers approx 60% gait cycle and swing phase covers remaining 40% of gait cycle. In further studies we can analysis on how this cycle varies in abnormal walking.These review article summarises about gait pattern affected by various diseases. Study of gait pattern used for solving criminal cases as we can recognize various abnormalities a person may have by the analysis of his or her gait pattern. It is used as secondary evidence. By using gait pattern we can find out individuals age, sex, and height.

Investigating the roles of reflexes and central pattern generators in the control and modulation of human locomotion using a physiologically plausible neuromechanical model

Objective. Studying the neural components regulating movement in human locomotion is obstructed by the inability to perform invasive experimental recording in the human neural circuits. Neuromechanical simulations can provide insights by modeling the locomotor circuits. Past neuromechanical models proposed control of locomotion either driven by central pattern generators (CPGs) with simple sensory commands or by a purely reflex-based network regulated by state-machine mechanisms, which activate and deactivate reflexes depending on the detected gait cycle phases. However, the physiological interpretation of these state machines remains unclear. Here, we present a physiologically plausible model to investigate spinal control and modulation of human locomotion. Approach. We propose a bio-inspired controller composed of two coupled CPGs that produce the rhythm and pattern, and a reflex-based network simulating low-level reflex pathways and Renshaw cells. This reflex network is based on leaky-integration neurons, and the whole system does not rely on changing reflex gains according to the gait cycle state. The musculoskeletal model is composed of a skeletal structure and nine muscles per leg generating movement in sagittal plane. Main results. Optimizing the open parameters for effort minimization and stability, human kinematics and muscle activation naturally emerged. Furthermore, when CPGs were not activated, periodic motion could not be achieved through optimization, suggesting the necessity of this component to generate rhythmic behavior without a state machine mechanism regulating reflex activation. The controller could reproduce ranges of speeds from 0.3 to 1.9 m s−1. The results showed that the net influence of feedback on motoneurons (MNs) during perturbed locomotion is predominantly inhibitory and that the CPGs provide the timing of MNs’ activation by exciting or inhibiting muscles in specific gait phases. Significance. The proposed bio-inspired controller could contribute to our understanding of locomotor circuits of the intact spinal cord and could be used to study neuromotor disorders.

Adaptive Threshold-Based ZUPT for Single IMU-Enabled Wearable Pedestrian Localization

Without dependence on external anchors, the Micro-Electro-Mechanical System Inertia Measurement Unit (MIMU) allowing autonomous localization has promised great potential in wearable IoT applications, including kinematic analysis in sports, medical treatment, elderly care, and disaster rescue. However, the miniaturization of devices for unobtrusive sensing, algorithms minimizing the inherent accumulative errors of inertial devices, and the adaptivity of algorithms for various motion modalities are the key challenges. The removal of accumulative error in the continuous gait cycles with adaptive algorithms is a critical issue regarding localization accuracy, especially for low-cost devices. This investigation proposes an adaptive threshold-based Zero-velocity Update (ZUPT) algorithm to separate the timing of gait cycle phases and compensate for the residual velocity with a linear fitting approximation. The key contributions include: (1) a lightweight threshold-based zero-velocity detection algorithm to split the gait cycle phases of continuous walking; (2) a quaternion-based Extended Kalman Filter (EKF) algorithm to reduce the errors of the non-linear operations for attitude prediction; (3) a linear fitting method for compensating the residual velocity in each gait cycle of continuous walking; (4) the design of a miniature single-MIMU based foot-mountable wearable device and the corresponding experimental studies to verify the proposed methods. Results show that the relative error is less than 3.0% for 2D and 3D trajectories, and the tests with different locomotion patterns demonstrate the adaptivity of the proposed algorithm compared to its peers. The results show that the presented techniques are capable of handling accumulative errors for low-cost MIMU-based systems with good adaptivity.

Design and Evaluation of a Smooth-Locking-Based Customizable Prosthetic Knee Joint

Abstract Limb loss affects many people from a variety of backgrounds around the world. The most advanced commercially available prostheses for transfemoral amputees are fully active (powered) designs but remain very expensive and unavailable in the developing world. Consequently, improvements of low-cost, passive prostheses have been made to provide high-quality rehabilitation to amputees of any background. This study explores the design and evaluation of a smooth-locking-based bionic knee joint to replicate the swing phase of the human gait cycle. The two-part design was based on the condyle geometry of the interface between the femur and tibia obtained from magnetic resonance (MR) images of the human subject, while springs were used to replace the anterior and posterior cruciate ligaments. A flexible four-bar linkage mechanism was successfully achieved to provide not only rotation along a variable instantaneous axis but also slight translation in the sagittal plane, similar to the anatomical knee. We systematically evaluated the effects of different spring configurations in terms of stiffness, position, and relaxion length on knee flexion angles during walking. A good replication of the swing phase was achieved by relatively high stiffness and increased relaxation length of springs. The stance phase of the gait cycle was improved compared to some models but remained relatively flat, where further verification should be conducted. In addition, 3D printing technique provides a convenient design and manufacturing process, making the prosthesis customizable for different individuals based on subject-specific modeling of the amputee’s knee.

The Novel Method for Prediction of Neurodegenerative Diseases Using Human GAIT Analysis

Abstract: Analyzing human motion is essential for diagnosing movement disorders and guiding neurodegenerative diseases like Parkinson’s diseases and Alzheimer’s diseases. Optical motion capture systems are the standard for estimating diseases, but the equipment is expensive and requires a predefined space, while wearable sensors systems can estimate in any environment and the use of these technological instruments can be of great support in both clinical diagnosis and severity assessment of these pathologies. Here the sensors, features and processing methodologies have been reviewed in order to provide a highly consistent work that explores the issues related to human gait analysis. First, the phase of human gait cycle are briefly explained, along with some non-normal gait patterns (gait abnormalities) typical of some neurodegenerative diseases. Then the most common processing techniques for both feature selection and extraction and for classification and clustering. Finally, a conclusive discussion on current open problem and future directions is outlined.

Numerical Analysis of a Transtibial Prosthesis Socket Using 3D-Printed Bio-Based PLA

Lower-limb prosthesis design and manufacturing still rely mostly on the workshop process of trial-and-error using expensive unrecyclable composite materials, resulting in time-consuming, material-wasting, and, ultimately, expensive prostheses. Therefore, we investigated the possibility of utilizing Fused Deposition Modeling 3D-printing technology with inexpensive bio-based and bio-degradable Polylactic Acid (PLA) material for prosthesis socket development and manufacturing. The safety and stability of the proposed 3D-printed PLA socket were analyzed using a recently developed generic transtibial numeric model, with boundary conditions of donning and newly developed realistic gait cycle phases of a heel strike and forefoot loading according to ISO 10328. The material properties of the 3D-printed PLA were determined using uniaxial tensile and compression tests on transverse and longitudinal samples. Numerical simulations with all boundary conditions were performed for the 3D-printed PLA and traditional polystyrene check and definitive composite socket. The results showed that the 3D-printed PLA socket withstands the occurring von-Mises stresses of 5.4 MPa and 10.8 MPa under heel strike and push-off gait conditions, respectively. Furthermore, the maximum deformations observed in the 3D-printed PLA socket of 0.74 mm and 2.66 mm were similar to the check socket deformations of 0.67 mm and 2.52 mm during heel strike and push-off, respectively, hence providing the same stability for the amputees. We have shown that an inexpensive, bio-based, and bio-degradable PLA material can be considered for manufacturing the lower-limb prosthesis, resulting in an environmentally friendly and inexpensive solution.

The impact of obesity on static and proactive balance and gait patterns in sarcopenic older adults: an analytical cross-sectional investigation.

Obesity is increasingly recognized as a significant factor in the susceptibility of older adults to falls and related injuries. While existing literature has established a connection between obesity and reduced postural stability during stationary stances, the direct implications of obesity on walking dynamics, particularly among the older adults with sarcopenia, are not yet comprehensively understood. Firstly, to investigate the influence of obesity on steady-state and proactive balance, as well as gait characteristics, among older adults with sarcopenic obesity (SO); and secondly, to unearth correlations between anthropometric characteristics and balance and gait parameters in the same demographic. A cohort of 42 participants was categorized into control (CG; n = 22; age = 81.1 ± 4.0 years; BMI = 24.9 ± 0.6 kg/m²) and sarcopenic obese (SOG; n = 20; age = 77.7 ± 2.9 years; BMI = 34.5 ± 3.2 kg/m²) groups based on body mass index (BMI, kg/m²). Participants were assessed for anthropometric data, body mass, fat and lean body mass percentages (%), and BMI. Steady-state balance was gauged using the Romberg Test (ROM). Proactive balance evaluations employed the Functional Reach (FRT) and Timed Up and Go (TUG) tests. The 10-m walking test elucidated spatiotemporal gait metrics, including cadence, speed, stride length, stride time, and specific bilateral spatiotemporal components (stance, swing, 1st and 2nd double support, and single support phases) expressed as percentages of the gait cycle. The time taken to complete the TUG and ROM tests was significantly shorter in the CG compared to the SOG (p < 0.05). In contrast, the FRT revealed a shorter distance achieved in the SOG compared to the CG (p < 0.05). The CG exhibited a higher gait speed compared to the SOG (p < 0.05), with shorter stride and step lengths observed in the SOG compared to the CG (p < 0.05). Regarding gait cycle phases, the support phase was longer, and the swing phase was shorter in the SOG compared to the CG group (p < 0.05). LBM (%) showed the strongest positive correlation with the ROM (r = 0.77, p < 0.001), gait speed (r = 0.85, p < 0.001), TUG (r = -0.80, p < 0.001) and FRT (r = 0.74, p < 0.001). Obesity induces added complexities for older adults with sarcopenia, particularly during the regulation of steady-state and proactive balance and gait. The percentage of lean body mass has emerged as a crucial determinant, highlighting a significant impact of reduced muscle mass on the observed alterations in static postural control and gait among older adults with SO.

INFLUENCE OF GENDER IN HEMIPLEGIC GAIT - A KINEMATIC ANALYSIS

Background: Gait is considered as a factor of high quality inuencing rehabilitation and quality of life. Hemiplegics show asymmetric gait pattern and return of walking ability is an important indicator of successful rehabilitation. Gender based differences exist in hemiplegic gait. This can impact the outcome of rehabilitation. Though gait analyses have been carried out in different settings, there are very little studies regarding the inuence of gender in gait in hemiplegia. Hence our study, comparing the kinematics of hip, knee and ankle of the hemiplegic limb is carried out. Aims and Objectives: The objective of the study is a comparison of gait analysis parameters of stroke survivors based on gender using Instrumental Gait Analysis (IGA) system. The present study is the Methods: outcome of an observational study conducted in the Gait Laboratory of Department of Physical Medicine and Rehabilitation, Medical College Kottayam. 100 subjects were selected for the study fullling the inclusion criteria. ISen3.08 system and STT-IWS sensors were used to carry out the Gait analysis and kinematic data was collected. Quantitative data was analyzed by descriptive statistical analysis. Qualitative data was expressed as frequency and percentage. The mid stance knee and ankle and termi Results: nal stance knee were statistically signicant. In mid stance, mean knee angle in males was -1.90 whereas in females it was 0.26. In terminal stance, males showed 9.08 and females 12.28. The ankle in midstance showed a value of -0.33 in males and 1.30 in females. This study conrms that there are gender based variations in the angular kinematic paramet Conclusion: ers in hemiplegic gait. Females are more severely affected in various phases of gait cycle with signicant involvement in the mid stance and terminal stance phases.

Recruitment frequency of gastrocnemius lateralis in people with Parkinson’s disease during locomotion

Motor impairments are one of the most disabling symptoms related to Parkinson's disease (PD) and negatively affect quality of life [1]. Recently aberrant motor control in this population was investigated by means of surface electromyography (sEMG) in terms of timing of muscle activation [2]. Yet, insights on the recruitment frequency during gait are still lacking. Therefore, this study aims to characterize muscle recruitment frequency in PD with respect to healthy controls during walking. Twenty-five people with PD (age = 64 ± 10 years; BMI =26±3) and ten able bodied subjects (age = 62±6 years; BMI =28±3) were included and underwent sEMG while walking on a 8 m walkaway at BiomovLab (University of Padova, Italy). Three bilateral strides per subject were considered (105 strides in total). Electrical activity of gastrocnemius lateralis (GL) was recorded. To identify onset and offset of the muscle activation, the wavelet-based algorithm presented in [3] was adopted. Then, each signal was digitized in accordance with the detected activation timing (0 = no activation detected, 1 = activation detected) and used to provide activation maps [4] for both the assessed populations. The following Fig. 1 reports the activation map of GL activation for PD and control populations in function of the number of subjects of the specific population where muscular activity is observed. Horizontal bars are grey-level coded, according to the number of subjects of the population where a GL activity is detected; black = activity detected in all subjects, white = activity never detected. PD population presents a very frequent GL activity (close to 100%) between 35% and 55% of the gait cycle, as expected. A relatively poor activity is detected in the other gait cycle phases. Although GL in PD is more frequently recruited in the same gait cycle phase of controls (≈ 70%), healthy subjects displayed more homogeneous GL activity over the whole gait cycle. These outcomes seem to suggest that PD patients are characterized by a reduced ability to adapt to gait-related needs compared to age- matched control subjects.

Kinematic analysis of ankle joint during gait in drop foot patients wearing passive Ankle-Foot Orthosis *

The term ‘drop-foot’ refers to an uncommon presentation of degenerative diseases, derived from neurological, muscular or anatomical complications, resulting in difficulties in performing foot dorsiflexion. This causes an abnormal gait pattern, characterized by two complications: the ‘foot slap’ at the initial contact with the ground, and the ‘toe-drag’ during the swing phase. In order to support gait, a common non-surgical treatment is the use of lightweight ‘L’ shaped ankle-foot orthosis (AFO). In this study we combine gait analysis and biomechanical modeling tools to analyse the kinematics of ankle joint in gait with and without the support of a passive AFO, namely the ‘Codivilla’ spring. The study was conducted on a population of eighteen adult subjects suffering from unilateral drop-foot (7 females, age 58.1 ± 14.5 years, BMI 23.4 ± 4.60). The infrared multicamera system SMART DX by BTS Bioengineering (Milan, Italy), was used to acquire data relating the 3D position of 22 markers placed on patient’s body, following the Davis protocol, during walking trials performed in two conditions: barefoot and with the AFO mounted on the affected limb. Data were then imported in OpenSim (SimTK software) and used to solve an inverse kinematic problem in order to reproduce walking and compute the evolution of body joints angles. Ankle dorsiflexion and subtalar inversion signals were analysed using MATLAB (2022a) to compute the following metrics for each angle: Range of Motion (RoM), angle at Heel Strike (HS) and angle at Toe Off (TO). The two-way ANOVA statistical test was used to analyse the effects of two factors: walking condition (with versus without AFO) and limb (affected versus contralateral). The interaction factor (condition*limb) was also analysed. Fig. 1 shows the evolution over the gait cycle of the ankle and subtalar angles in the two walking conditions for each foot. Solid lines are obtained as the mean value of subjects’ averaged step. Shaded areas represent the variability among subjects. Table 1 reports the results of the two-way ANOVA test in terms of p-value. Results show that the AFO ‘Codivilla’ spring acts on the kinematics of ankle by reducing the RoM during walking, as it limits the plantar flexion of drop foot. However, it does not significantly affect the ankle angle at HS and TO, although the first is lower in the affected foot. Results also show that the evolution of subtalar angle in the affected foot is altered, not in the RoM, rather in values, in particular at the initial phases of gait cycle. However, the considered orthosis does not produce improvements in the kinematics of subtalar angle. This is probably due to the L-shape of the device, which does not limit ankle inversion/eversion. In conclusion our study confirms the alterations of the drop foot in the kinematics of the ankle joint, particularly at Heel Strike in which both the ankle and the subtalar angle are altered compared to the contralateral foot. The use of Codivilla spring results in a more physiological dorsiflexion of the ankle but has no significant effect on the kinematics of the subtalar joint.

Lower-limb joint-coordination and coordination variability during gait in children with cerebral palsy

BackgroundChildren with cerebral palsy present with poor motor control, altering their ability to perform tasks such as walking. Continuous relative phase analysis is a popular method to quantify motor control impairments via inter-joint coordination and coordination variability; however, it has not been explored in children with cerebral palsy. Methods45 children with cerebral palsy and 45 typically developing children walked while fit with retroreflective markers. Continuous relative phase analysis for knee-hip and ankle-knee joint pairs quantified inter-joint coordination and coordination variability. The Gait Profile Score estimated gait pathology. Group differences were assessed with unpaired t-tests for coordination amplitude and variability (knee-hip, ankle-knee) across gait events. For the cerebral palsy group, correlations assessed the relation between the gait profile score and coordination metrics. FindingsThe cerebral palsy group showed more in-phase patterns for knee-hip coupling compared to the typically developing group (initial contact, loading response, mid-stance, terminal swing) (p ≤ 0.03). The cerebral palsy group showed lower knee-hip coordination variability (mid-stance, mid-swing) (p ≤ 0.037) and lower ankle-knee coordination variability (initial contact, loading response, terminal swing) (p < 0.001). The gait profile score correlated weakly to moderately (r = [0.323–0.472]), and negatively with the knee-hip inter-joint coordination (initial contact, loading response, mid-stance, terminal swing) (p ≤ 0.042). InterpretationChildren with cerebral palsy showed a more in-phase gait strategy during challenging transitional gait cycle phases (beginning and end) and less flexible and adaptable motor behaviors. Moreover, the correlation between in-phase joint patterns and increased gait deviations (gait profile score) reinforces the relevance of coordination analysis to assess motor control impairment.

An investigation of the ankle contact forces in a foot with hammer toe deformity. A comparison of patient-specific approaches using finite element modeling and musculoskeletal simulation.

The internal forces and stresses in the tissue are important as they are linked to the risk of mechanical trauma and injuries. Despite their value, the internal stresses and forces cannot be directly measured in-vivo. A previously validated 3D finite element model (FEM) was constructed using Magnetic Resonance Imaging (MRI) of a person with diabetes and hammer toe deformity. The foot model simulated at five different instances during the stance phase of gait. The internal stress distribution on the talus that was obtained using the FEM simulation, was used to calculate the joint reaction force at the ankle joint. In addition, the musculoskeletal model (MSM) of the participant with hammer toe foot was developed based on the gait analysis and was used to determine the muscle forces and joint reactions. The result showed that the vertical reaction forces obtained from the FEM and MSM follow a similar trend through the stance phase of gait cycle and are significantly correlated ( R=0.99). The joint reaction forces obtained through the two methods do not differ for the first 25% of the gait cycle, while the maximum difference was ∼0.7 Body weight that was observed at 50% of the stance phase. Clinical Relevance: Finite element modeling and musculoskeletal simulation can shed light on the internal forces at the ankle in pathological conditions such as hammer toe. The similarities and differences observed in the joint reaction forces calculated from the two methods can have implications in assessing the effect of clinical interventions.

Abnormal Foot Progression Angle Kinematics in Cervical Dystonia Improved After Osteopathic Manipulative Medicine: A Prospective Case Series.

IntroductionCervical dystonia (CD), a rare disorder, is the most common form of dystonia, a movement disorder. Impairments in activities of daily living and quality of life may result from chronic pain, perceived stigma, difficulty walking, and/or lack of control over movements. Studies of treatments for difficulty walking in CD have been inconclusive. Osteopathic manipulative medicine (OMM) has been used to improve gait biomechanics in other health conditions. Foot progression angle (FPA) while walking indicates functional gait abnormalities that increase the risk of knee injury and osteoarthritis.ObjectiveThe aim of this study is to test if five-weekly treatments using an OMM sequence designed for CD improved abnormal gait biomechanics in individuals with CD by identifying and addressing somatic dysfunctions.MethodsIn this prospective case series, independently ambulating individuals with CD symptom onset before the age of 40 years, not due to traumatic injury, were evaluated utilizing validated scales for severity (Toronto western spasmodic torticollis rating scale [TWSTRsI]) and symptoms affecting quality of life (Cervical Dystonia Impact Profile [CDIP-58]), physical examination, and FPA before and after five-weekly OMM treatments. Lower body joint range of motion and angles were captured in a clinical gait lab by nine cameras collecting three-dimensional Whole-body position data during three trials of one gait cycle at participant-selected walking speed. The FPA waveforms during the gait cycle were quantified by Vicon Nexus and Polygon applications. Pretreatment and posttreatment results were compared to established healthy gait waveforms and tested by repeated measures ANOVA (α=0.05).ResultsPretreatment waveforms in CD had a mean 5.13° of excess FPA during gait cycle phases requiring lower-extremity pronation compared to previously published age-gender-matched healthy waveforms. There was 96% improvement in pronation after five treatments, with a mean 0.21° (p=0.041) of excess FPA. Mean TWSTRs and CDIP-58 scores improved. On physical examination, the rotational direction of C2 vertebrae was contralateral to neck muscle hypertonicity. Vertical sphenobasilar synchondrosis strains were present in those with anterotorticollis. Participants had ipsilateral anterolateral neck muscle and anterolateral abdominal wall muscle hypertonicity. All patients had pelvic somatic dysfunctions with left-side superior relative to right-side and restriction from lower-extremity pronation (i.e., supination dysfunctions).ConclusionThe FPA was significantly improved after treatment. This OMM sequence was well tolerated and may be useful for improving gait kinematics in individuals with CD. Randomized, controlled, long-term studies are needed to determine effectiveness.

Changes in hip joint contact stress during a gait cycle based on the individualized modeling method of “gait-musculoskeletal system-finite element”

ObjectiveTo construct a comprehensive simulation method of “gait-musculoskeletal system (MS)-finite element (FE)” for analysis of hip joint dynamics characteristics and the changes in the contact stress in the hip throughout a gait cycle.MethodsTwo healthy volunteers (male and female) were recruited. The 3D gait trajectories during normal walking and the CT images including the hip and femur of the volunteers were obtained. CT imaging data in the DICOM format were extracted for subjected 3D hip joint reconstruction. The reconstructed 3D model files were used to realize the subject-specific registration of the pelvis and thigh segment of general musculoskeletal model. The captured marker trajectory data were used to drive subject-specific musculoskeletal model to complete inverse dynamic analysis. Results of inverse dynamic analysis were exported and applied as boundary and load settings of the hip joint finite element in ABAQUS. Finally, the finite element analysis (FEA) was performed to analyze contact stress of hip joint during a gait cycle of left foot.ResultsIn the inverse dynamic analysis, the dynamic changes of the main hip-femoral muscle force with respect to each phase of a single gait cycle were plotted. The hip joint reaction force reached a maximum value of 2.9%BW (body weight) and appeared at the end of the terminal stance phase. Twin peaks appeared at the initial contact phase and the end of the terminal stance phase, respectively. FEA showed the temporal changes in contact stress in the acetabulum. In the visual stress cloud chart, the acetabular contact stress was mainly distributed in the dome of the acetabulum and in the anterolateral area at the top of the femoral head during a single gait cycle. The acetabular contact area was between 293.8 and 998.4 mm2, and the maximum contact area appear at the mid-stance phase or the loading response phase of gait. The maximum contact stress of the acetabulum reached 6.91 MPa for the model 1 and 6.92 MPa for the model 2 at the terminal stance phase.ConclusionsThe “Gait-MS-FE” technology is integrated to construct a comprehensive simulation framework. Based on human gait trajectories and their CT images, individualized simulation modeling can be achieved. Subject-specific gait in combination with an inverse dynamic analysis of the MS provides pre-processing parameters for FE simulation for more accurate biomechanical analysis of hip joint.Graphical abstract

Dopamine-conjugated hyaluronic acid delivered via intra-articular injection provides articular cartilage lubrication and protection

Due to its high molecular weight and viscosity, hyaluronic acid (HA) is widely used for viscosupplementation to provide joint pain relief in osteoarthritis. However, this benefit is temporary due to poor adhesion of HA on articular surfaces. In this study, we therefore conjugated HA with dopamine to form HADN, which made the HA adhesive while retaining its viscosity enhancement capacity. We hypothesized that HADN could enhance cartilage lubrication through adsorption onto the exposed collagen type II network and repair the lamina splendens. HADN was synthesized by carbodiimide chemistry between hyaluronic acid and dopamine. Analysis of Magnetic Resonance (NMR) and Ultraviolet spectrophotometry (Uv–vis) showed that HADN was successfully synthesized. Adsorption of HADN on collagen was demonstrated using Quartz crystal microbalance with dissipation (QCM-D). Ex vivo tribological tests including measurement of coefficient of friction (COF), dynamic creep, in stance (40 N) and swing (4 N) phases of gait cycle indicated adequate protection of cartilage by HADN with higher lubrication compared to HA alone. HADN solution at the cartilage-glass sliding interface not only retains the same viscosity as HA and provides fluid film lubrication, but also ensures better boundary lubrication through adsorption. To confirm the cartilage surface protection of HADN, we visualized cartilage wear using optical coherence tomography (OCT) and atomic force microscopy (AFM).