Altered Movement Research Articles

Functional Gastrointestinal Disorders in Patients With Epilepsy: Reciprocal Influence and Impact on Seizure Occurrence.

Introduction: The complex relationship between the microbiota-gut-brain axis (MGBA) and epilepsy has been increasingly investigated in preclinical studies. Conversely, evidence from clinical studies is still scarce. In recent years, the pivotal role of MGBA dysregulation in the pathophysiology of functional gastrointestinal disorders (FGID) has been recognized. With this background, we aimed to investigate the prevalence of FGID in patients with epilepsy (PWE) and the possible impact of bowel movement abnormalities on seizure recurrence.Methods: A total of 120 PWE and 113 age-, sex-, and BMI-matched healthy subjects (HS) were consecutively enrolled. A questionnaire to evaluate the presence of FGID (according to Rome III diagnostic criteria) was administrated to all participants. In a subgroup of drug-resistant patients, we administered an ad-hoc questionnaire combining Bristol stool charts and seizure diaries to evaluate seizure trends and bowel movement changes.Results: A higher prevalence of FGID in PWE (62.5%) than in HS (39.8%) was found (p < 0.001). The most frequently observed disorder was constipation, which was significantly higher in PWE than in HS (43.3 vs. 21.2%, p < 0.001), and was not associated with anti-seizure medication intake according to multivariable analysis. In drug-resistant patients, most seizures occurred during periods of altered bowel movements, especially constipation. A significant weak negative correlation between the number of days with seizures and the number of days with normal bowel movements was observed (p = 0.04). According to multivariable logistic regression analysis, FGID was significantly associated with temporal lobe epilepsy as compared with other lobar localization (p = 0.03).Conclusions: Our clinical findings shed new light on the complex relationship between epilepsy and the MGBA, suggesting a bidirectional link between bowel movement abnormalities and seizure occurrence. However, larger studies are required to better address this important topic.

Movement Patterns and Their Associations With Pain, Function, and Hip Morphology in Individuals With Femoroacetabular Impingement Syndrome: A Scoping Review.

The purpose of the study was to synthesize studies of movement patterns and their association with hip pain, function/activity, and morphology in individuals with femoroacetabular impingement syndrome (FAIS). PubMed, SPORTDiscus, CINAHL, Embase, and Scopus databases were searched using predefined terms. Two authors independently reviewed abstracts and full texts. Studies were included if they enrolled individuals with FAIS, reported kinematic or kinetic data during movement tasks, and tested the data's associations with hip pain, function/activity, or morphology. Exclusion criteria were studies that did not evaluate associations between movement patters and pain, function/activity, or hip morphology. Additionally, studies with hip conditions other than FAIS, case reports, conference proceedings, review articles, and non-English studies were excluded. Descriptive consolidation and qualitative synthesis were performed for the included studies. Of the 1155 potential studies, 5 studies metall eligibility criteria. Movement patterns were evaluated during walking (n = 4) and squatting (n = 1). Studies reported multiple associations between variables of interest. Statistically significant associations were identified between movement patterns and hip pain (n = 2), function/activity (n = 2), or morphology (n = 3). Significant associations included increased hip flexion moment impulse during walking was associated with worse pain, increased hip flexion moment during walking was associated with worse hip function, decreased hip external rotation during gait and hip internal rotation during squat were associated with larger cam deformity, and increased hip flexion moment impulse during walking was also associated with more severe acetabular cartilage abnormalities. Very little current evidence has evaluated the associations between altered movement patterns and hip pain, function/activity, or morphology in individuals with FAIS, and only low-intensity tasks have been tested. These studies found some preliminary associations between altered hip biomechanics and higher hip pain, worse hip function, and specific measures of hip morphology in individuals with FAIS. This review is a first step in gaining a better understanding of movement patterns and their associations with hip pain, function/activity, and morphology, which could ultimately assist with the development of movement retraining interventions and potentially improve rehabilitation outcomes for those with FAIS.

Fixational eye movements and visual functions in amblyopia

Amblyopic patients have a constellation of visual function deficits including reduced visual acuity and contrast sensitivity, abnormal stereopsis, and increased fixation instability of fellow and amblyopic eye. The fixation instability arises from presence of nystagmus and altered physiologic fixation eye movements (FEMs). The purpose of the study is to examine the effects of presence of nystagmus on binocular and monocular functions of the fellow and amblyopic eye.

Neuro-Ophthalmological Findings in Friedreich's Ataxia.

Friedreich ataxia (FRDA) is a progressive neurodegenerative disease caused by a severe autosomal recessive genetic disorder of the central nervous (CNS) and peripheral nervous system (PNS), affecting children and young adults. Its onset is before 25 years of age, with mean ages of onset and death between 11 and 38 years, respectively. The incidence is 1 in 30,000–50,000 persons. It is caused, in 97% of cases, by a homozygous guanine-adenine-adenine (GAA) trinucleotide mutation in the first intron of the frataxin (FXN) gene on chromosome 9 (9q13–q1.1). The mutation of this gene causes a deficiency of frataxin, which induces an altered inflow of iron into the mitochondria, increasing the nervous system’s vulnerability to oxidative stress. The main clinical signs include spinocerebellar ataxia with sensory loss and disappearance of deep tendon reflexes, cerebellar dysarthria, cardiomyopathy, and scoliosis. Diabetes, hearing loss, and pes cavus may also occur, and although most patients with FRDA do not present with symptomatic visual impairment, 73% present with clinical neuro-ophthalmological alterations such as optic atrophy and altered eye movement, among others. This review provides a brief overview of the main aspects of FRDA and then focuses on the ocular involvement of this pathology and the possible use of retinal biomarkers.

Gaze Accuracy Differences During Single-Leg Balance Following Anterior Cruciate Ligament Reconstruction.

Individuals following anterior cruciate ligament reconstruction (ACLR) demonstrate altered postural stability and functional movement patterns. It is hypothesized that individuals following ACLR may compensate with sensory adaptations with greater reliance on visual mechanisms during activities. It is unknown if visual compensatory strategies are implemented to maintain postural stability during functional tasks. To examine visual gaze accuracy during a single-leg balance task in individuals following ACLR compared with healthy, active controls. Case control. Controlled laboratory. A total of 20 individuals (10 ACLR and 10 healthy controls) participated in the study. Visual gaze patterns were obtained during 20-second single-leg balance trials while participants were instructed to look at presented targets. During the Stationary Target Task, the visual target was presented in a central location for the duration of the trial. The Moving Target Task included a visual target that randomly moved to 1 of 9 target locations for a period of 2 seconds. Targets were stratified into superior, middle, and inferior levels for the Moving Target Task. The Stationary Target Task demonstrated no differences in visual error between groups (P = .89). The Moving Target Task demonstrated a significant interaction between group and target level (F2,36 = 3.76, P = .033). Individuals following ACLR demonstrated greater visual error for the superior targets (ACLR = .70 [.44]m, healthy = .41 [.21]m, Cohen d = 0.83 [0.06 to 1.60]) and inferior targets (ACLR = .68 [.25]m, healthy = .33 [.16]m, Cohen d = 1.67 [0.81 to 2.52]). Individuals following ACLR demonstrate greater visual error during settings of high or low visual stimuli compared with healthy individuals to maintain single-limb postural stability. This population may rely on visual input to compensate for the somatosensory changes following injury.

Methamphetamine pollution elicits addiction in wild fish.

Illicit drug abuse presents pervasive adverse consequences for human societies around the world. Illicit drug consumption also plays an unexpected role in contamination of aquatic ecosystems that receive wastewater discharges. Here, we show that methamphetamine, considered as one of the most important global health threats, causes addiction and behavior alteration of brown trout Salmo trutta at environmentally relevant concentrations (1 µgl-1). Altered movement behavior and preference for methamphetamine during withdrawal were linked to drug residues in fish brain tissues and accompanied by brain metabolome changes. Our results suggest that emission of illicit drugs into freshwater ecosystems causes addiction in fish and modifies habitat preferences with unexpected adverse consequences of relevance at the individual and population levels. As such, our study identifies transmission of human societal problems to aquatic ecosystems.

Prevalence and risk factors of striae gravidarumin a cohort of multiracial postpartum Nepalese population.

Striae gravidarum (SG), popularly called as stretch marks, is a common pregnancy-related asymptomatic skin condition, but is a cosmetic concern for females. A few epidemiological studies have been reported from Asian countries. However, no such study has been done in Nepal. This study was aimed to know the prevalence and risk factors associated with SG in a cohort of multi-ethnic postpartum Nepalese women who had delivered after completion of 36weeks. A cross-sectional comparative study was conducted among 420 postpartum females who had delivered after completion of 36weeks of gestation. Data were collected in the form of a questionnaire and relevant physical examination was done. The severity of SG was assessed by using Davey's scoring. Out of 420 females, 260 (62%) had SG while 160 (38%) did not. According to the results of logistic regression analysis, young age (<25years), large abdominal circumference (>100cm), increased weight gain during pregnancy (>15kg), presence of family history of SG, gestational diabetes mellitus, altered bowel movement, and presence of striae on the breasts, thighs, and buttocks were found to be independent risk factors for SG. Future expectant mothers must be informed about the risk factors of SG development. They need to be made aware that SG can be prevented by considering the modifiable risk factors, such as excessive weight gain. They should also be informed that SG is permanent and currently there is no definite treatment.

Characterization of Cognitive-Motor Function in Women Who Have Experienced Intimate Partner Violence-Related Brain Injury.

Intimate partner violence (IPV) affects at least one in three women worldwide, and up to 92% report symptoms consistent with brain injury (BI). Although a handful of studies have examined different aspects of brain structure and function in this population, none has characterized potential deficits in cognitive-motor function. This knowledge gap was addressed in the current study by having participants who had experienced IPV complete the bimanual Object Hit & Avoid (OHA) task in a Kinesiological Instrument for Normal and Altered Reaching Movement (KINARM) End-Point Laboratory. BI load, post-traumatic stress disorder (PTSD), anxiety, depression, substance use, and history of abuse were also assessed. A stepwise multiple regression was undertaken to explore the relationship between BI load and task performance while accounting for comorbid psychopathologies. Results demonstrated that BI load accounted for a significant amount of variability in the number of targets hit and the average hand speed. PTSD, anxiety, and depression also contributed significantly to the variability in these measures as well as to the number and proportion of distractor hits, and the object processing rate. Taken together, these findings suggest that IPV-related BI, as well as comorbid PTSD, anxiety, and depression, disrupt the processing required to quickly and accurately hit targets while avoiding distractors. This pattern of results reflects the complex interaction between the physical injuries induced by the episodes of IPV and the resulting impacts that these experiences have on mental health.

Neuralgic amyotrophy.

This review focuses on the current insights and developments in neuralgic amyotrophy (NA), an auto-immune multifocal peripheral nervous system disorder that leaves many patients permanently impaired if not recognized and treated properly. NA is not as rare as previously thought. The phenotype is broad, and recent nerve imaging developments suggest that NA is the most common cause of acute anterior or posterior interosseous nerve palsy. Phrenic nerve involvement occurs in 8% of all NA patients, often with debilitating consequences. Acute phase treatment of NA with steroids or i.v. immunoglobulin may benefit patients. Long-term consequences are the rule, and persisting symptoms are mainly caused by a combination of decreased endurance in the affected nerves and an altered posture and movement pattern, not by the axonal damage itself. Patients benefit from specific rehabilitation treatment. For nerves that do not recover, surgery may be an option. NA is not uncommon, and has a long-term impact on patients' well-being. Early immunomodulating treatment, and identifying phrenic neuropathy or complete nerve paralysis is important for optimal recovery. For persistent symptoms a specific treatment strategy aiming at regaining an energy balance and well-coordinated scapular movement are paramount.

Viscosity Model for Nanoparticulate Suspensions Based on Surface Interactions.

In this paper, a widely mechanistic model was developed to depict the rheological behaviour of nanoparticulate suspensions with solids contents up to 20 wt.%, based on the increase in shear stress caused by surface interaction forces among particles. The rheological behaviour is connected to drag forces arising from an altered particle movement with respect to the surrounding fluid. In order to represent this relationship and to model the viscosity, a hybrid modelling approach was followed, in which mechanistic relationships were paired with heuristic expressions. A genetic algorithm was utilized during model development, by enabling the algorithm to choose among several hard-to-assess model options. By the combination of the newly developed model with existing models for the various physical phenomena affecting viscosity, it can be applied to model the viscosity over a broad range of solids contents, shear rates, temperatures and particle sizes. Due to its mechanistic nature, the model even allows an extrapolation beyond the limits of the data points used for calibration, allowing a prediction of the viscosity in this area. Only two parameters are required for this purpose. Experimental data of an epoxy resin filled with boehmite nanoparticles were used for calibration and comparison with modelled values.

Prelanding movement strategies among chronic ankle instability, coper, and control subjects

ABSTRACT We describe feedforward neuromuscular control during a maximal jump landing/cutting task among groups of chronic ankle instability (CAI), coper, and uninjured control subjects. Sixty-six volunteers participated (22 CAI, 22 copers, and 22 uninjured controls). The subjects completed five trials of a maximal jump landing/cutting manoeuvre. Three-dimensional ground reaction force, lower-extremity joint angles, and activation of eight muscles were collected from 150 ms prelanding to initial contact. Functional analyses of variance (FANOVA) were used to evaluate between-group differences for these outcome variables. Compared to uninjured controls, both CAI patients and copers demonstrated altered sagittal lower-extremity movements. However, only copers exhibited unique kinematic alterations in frontal lower-extremity kinematics in the ankle and hip joints. While CAI patients demonstrated decreased most of lower-extremity EMG activation, copers displayed increased EMG activation during prelanding. Current data suggest that both CAI patients and copers demonstrated alterations in feedforward neuromuscular control prior to initial contact during a demanding jump landing/cutting task. Altered movement strategies during prelanding were observed in both proximal (e.g., knee and hip) and distal (e.g., ankle) joints in CAI patients and copers, while copers presumably had more protective jump landing/cutting movement strategies than CAI patients.

Mitochondrial Dysfunction in Alzheimer's Disease: Opportunities for Drug Development.

Alzheimer's disease (AD) is one of the major reasons for 60-80% cases of senile dementia occurring as a result of the accumulation of plaques and tangles in the hippocampal and cortical neurons of the brain leading to neurodegeneration and cell death. The other pathological features of AD comprise abnormal microvasculature, network abnormalities, interneuronal dysfunction, increased β-amyloid production and reduced clearance, increased inflammatory response, elevated production of reactive oxygen species, impaired brain metabolism, hyperphosphorylation of tau, and disruption of acetylcholine signaling. Among all these pathologies, Mitochondrial Dysfunction (MD), regardless of it being an inciting insult or a consequence of the alterations, is related to all the associated AD pathologies. Observed altered mitochondrial morphology, distribution and movement, increased oxidative stress, dysregulation of enzymes involved in mitochondrial functioning, impaired brain metabolism, and impaired mitochondrial biogenesis in AD subjects suggest the involvement of mitochondrial malfunction in the progression of AD. Here, various pre-clinical and clinical evidence establishing MD as a key mediator in the progression of neurodegeneration in AD are reviewed and discussed with an aim to foster future MD based drug development research for the management of AD.

Development and First Tests of a Lab-Scale Electric Field for Investigating Potential Effects of Electric Barriers on Aquatic Invasive Invertebrates

Canals and other connected waterway systems, including the Chicago Area Waterway System (CAWS), have often facilitated the spread of non-native species. Electric barriers have recently emerged as a method for preventing this spread and protecting uninvaded ecosystems from new invaders. The largest system of electric barriers in the world is in the CAWS and is operated primarily to prevent the spread of invasive Asian carp. It is not known whether these barriers are effective for other species, particularly invasive invertebrates. Here, we provide data regarding the efficacy of an electric field that operates at the same parameters as the electric barrier in the CAWS in affecting behaviors of two invertebrate species, the red swamp crayfish Procambarus clarkii and the amphipod Hyalella azteca. We constructed an electric field within a tank that operates at the same parameters as the existing CAWS barriers and determined the effects of the electric field on our test species. At the electric field parameters of the CAWS barriers, the vast majority of P. clarkii individuals showed altered movement with maintained equilibrium. For H. azteca, behavioral responses were less extreme than for P. clarkii, with a majority of individuals experiencing altered movement. By measuring the orientation of organisms to the electric field, we determined that the test organisms are affected by the electric field, especially at lower field strengths where they exhibited no or little other behavioral response. At lower field strengths, P. clarkii exhibited changes in orientation, but at higher field strengths, individuals were less able to orient themselves. H. azteca exhibited changes in orientation to the electric field at all field strengths. The results of this study suggest that the existing electric barriers may not slow or prevent spread of invasive invertebrates—including amphipods and crayfish—through passive movement attached boats/barges or through downstream drift, but that the barriers may prevent spread by active upstream movement. Overall, our work gives new data regarding the efficacy of electric fields in preventing the spread of invasive invertebrates and can inform management decisions regarding current and future electric barriers in the CAWS.

Biomechanical adaptation to post-stroke visual field loss: a systematic review

BackgroundHomonymous visual field defects represent the most frequent type of visual field loss after stroke, affecting nearly 30% of individuals with unilateral post-chiasmal brain damage. This review aimed to gather the available evidence on the biomechanical changes to visual field loss following stroke.MethodsA systematic review was conducted inclusive of randomised controlled trials, cohort studies, before-after studies and case-controlled studies. Studies including adult and paediatric participants that investigated eye, head, or body movements in post-stroke visual field loss during visual exploration tasks were included. Search terms included a range of MESH terms as well as alternative terms relating to stroke, visual field loss, hemianopia, visual functions and scanning behaviour. Articles were selected by two authors independently. Data were extracted by one author and verified by a second. All included articles were assessed for risk of bias using checklists appropriate to the study design.ResultsThirty-six articles (1123 participants) were included in the overall review (Kappa 0.863) and categorised into simulated or true visual field loss (typically hemianopia). Seven studies identified the biomechanical alterations to simulated hemianopia compared to normal performance. Twenty-nine studies detailed eye, head and body movement parameters in true hemianopia. Hemianopic participants and healthy adults with simulated hemianopia differed significantly from controls in various fixation and saccade parameters as indicated by increased number and duration of fixations, number and duration of saccades and scan path length with shorter mean saccadic amplitude. Under simulated hemianopia, participants were consistently biased towards the sighted visual field while gaze behaviour in true hemianopia was biased in the direction of the blind hemifield.ConclusionsThere is considerable evidence on the altered eye movements that occur in true hemianopia and in healthy adults with simulated hemianopia. Successful performance in naturalistic tasks of visual exploration appears to be related to compensatory mechanisms of visual exploratory behaviour, namely, an increase in the amplitude and peak velocity of saccades, widening horizontally the distribution of eye movements, and a shift of the overall distribution of saccades into the blind field. This review highlights the lack of studies reporting head and other body movement parameters in hemianopia. Further studies with robust methodology and large sample sizes involving participants with post-stroke visual field loss are needed.Systematic review registrationPROSPERO CRD42020194403

Dynamic joint stiffness of the ankle in chronic ankle instability patients

BackgroundWhile Individuals with chronic ankle instability (CAI) exhibit altered ankle joint movement and moments during stance phase of gait, the interaction or dynamic joint stiffness (DJS) between these is not fully understood. Little attention has been placed on DJS during gait, limiting our understanding of how the most common dynamic task during daily life could affect cartilage loading. Research questionDo Individuals with CAI exhibit altered ankle DJS and mechanical energy exerted at the ankle joint during stance phase of gait? MethodsEighty-four physically active individuals, consisting of 42 individuals with CAI (12 M and 30 F) and 42 control (12 M and 30 F) participants were recruited in this study. Three-dimensional gait analysis was conducted. The sagittal ankle joint angle and moment during stance phase of walking gait were obtained. Stance phase was divided into three sub-phases: controlled plantarflexion, controlled dorsiflexion, and powered plantarflexion. Ankle DJS was represented by the slope of the joint moment plotted as a function of the joint angle. The coefficient of determination was calculated to determine how accurately data fit a linear model. Net work was calculated by the difference between work produced and absorbed. Further, sex specific exploratory analyses of DJS and work between individuals with and without CAI were conducted. ResultsLower DJS during the controlled plantarflexion (CPF) sub-phase, work produced, and net work was found in the CAI group. Males with CAI exhibited lower ankle moment changes during controlled dorsiflexion (CDF) sub-phase and work absorbed. Females with CAI exhibited lower ankle moment changes during CPF and CDF sub-phases, lower DJS during the CPF sub-phase, and lower net work. SignificanceIndividuals with CAI have alterations in DJS and work relative to uninjured controls. Females with CAI showed greater DJS related alterations, relative to controls, than their male CAI counterparts.

The relationship of trunk kinematics and kinetics with lower limb pathology during gait in children with spastic cerebral palsy

BackgroundTrunk control during gait in children with cerebral palsy (CP) is known to be impaired. While differentiation of trunk movement between CP subtypes (unilateral/bilateral) has been examined, differentiation of lower lumbar spinal loading has not been considered. Furthermore, the relationship between lower lumbar loading and lower limb pathology has not been reported. Research QuestionHow do lower lumbar spinal kinetics differ during unilateral and bilateral CP gait and what is the relationship between trunk kinematics and L5/S1 kinetics with lower limb pathology? MethodsThree-dimensional thorax kinematics and L5/S1 kinetics were measured during gait with children divided into 3 groups (unilateral CP (n = 21), bilateral CP (n = 31) and typical development (TD) (n = 26)). Differences in thorax kinematics and reactive forces and moments at L5/S1 between groups were analysed using Statistical Parametric Mapping. Correlation coefficients were calculated between Gait Profile Score (GPS) and kinematic measures of the thorax and kinetics at L5/S1. ResultsAn increased ipsilateral bending moment was present for unilateral CP in the coronal plane (55–70% Gait Cycle (GC), p < 0.001), while children with bilateral CP demonstrated two distinct increased peaks during mid-stance (10–30 % GC, p < 0.001) and mid-swing (60–80% GC, p = 0.004) compared to TD. RMS and RoM thorax flexion, side flexion and L5/S1 lateral bend moment demonstrated significant moderate correlations with GPS. SignificanceThis study confirmed an increased involvement at the trunk and of lower lumbar spinal loading for children with bilateral CP compared to unilateral CP. It has been suggested that altered trunk movement in CP gait may be a combination of both a compensation for lower limb pathology and an underlying deficit. Our result of positive yet moderate correlations between GPS and trunk movement and lower spinal loading support this theory.

Pleasure or Business-Travelling and the Pandemic Virus: Socio Legal Aspect

Ever since the corona pandemic hit the world with full rancour, people have gone into hiding thus restricting movement in all spheres, bringing their movement to a halt. It has been extrapolated since ages that movement of masses is the essence of economics. A man moves to earn, to seek visual pleasure, to seek social contact and as such the freedom to move freely, is both a legal and fundamental right, guaranteed under the Indian Constitution. The following research article aims to study the socio-legal aspect of restricted or altered human movement brought about by the pandemic and its effect on the tourism and hospitality industry. The study findings include the immense loss which the industry has suffered as result of the pandemic, followed by the path forward in terms of the new trends which may emerge in the year 2021, to cope with the loses. A further scope of study in the stated research topic may include developing fail-safe systems as method of check and balance to keep the tourism and hospitality industry afloat, in the event of such unforeseen crisis.

Copers adopt an altered movement pattern compared to individuals with chronic ankle instability and control groups in unexpected single-leg landing and cutting task

Individuals with chronic ankle instability (CAI) demonstrate altered ankle kinematics during landing compared to uninjured individuals. However, if copers may have adopted unique movement strategy to prevent repeated ankle sprains is unclear. The purpose of this study compares the lower-extremity joint kinematics and muscle activities of CAI (N = 8), coper (COP) (N = 8), and control (CON) (N = 8) groups in unexpected single-leg landing and cutting. Performance time (from initial contact to toe-off), number of mistakes in the jumping direction, low-extremity joint angle are assessed. Muscle activities were recorded from the tibialis anterior, medial gastrocnemius, and peroneus longus (PL), and mean muscle activity, co-contraction index (CI), and PL latency were analyzed. Results of performance time and CI are not significant. Significantly less number of mistakes in the jumping direction and a shorter PL latency were discovered in the COP and CON compared with the CAI group (P < 0.05). The peak hip joint flexion angle is significantly smaller in the COP than in the CON (P = 0.04). In dynamic tasks requiring quick judgments of ankle inclination, the COP may be able to accurately sense the inclination of the foot. Additionally, movement strategies differed between the COP and CON groups in an unexpected single-leg landing and cutting.

Kinematic and Kinetic Changes after Total Hip Arthroplasty during Sit-To-Stand Transfers: Systematic Review.

BackgroundTotal hip arthroplasty (THA) is a common and effective surgical procedure that allows patients with hip osteoarthritis to restore functional ability and relieve pain. Sit-to-stand transfers are common demanding tasks during activities of daily living and are performed more than 50 times per day. The purpose of this systematic review is to obtain a comprehensive understanding of biomechanical changes during sit-to-stand transfers after THA.MethodsRelevant articles were selected through MEDLINE, Scopus, Embase, and Web of Science. Articles were included if they met the following inclusion criteria: 1) participants underwent total hip arthroplasty without restriction on the arthroplasty design, 2) involved either kinematic or kinetic variables as the primary outcome measure, 3) evaluated sit-to-stand, and 4) were written in English.ResultsA total of 11 articles were included in the current systematic review. The THA group exhibited altered movement patterns as compared to healthy controls. Improvement in loading asymmetry was found up to 1 year after THA, but other kinetic changes indicate intensified contralateral limb loading. Limb differences were apparent, but whether these differences persist over 10 months after THA is still unknown.ConclusionDespite the inevitable changes in kinematics and kinetics in sit-to-stand transfers after THA, it appears to be important to resolve asymmetrical loading between the operative and nonoperative limbs to minimize risk for subsequent joint problems.

Characterizing gait pattern dynamics during symmetric and asymmetric walking using autoregressive modeling.

Gait asymmetry is often observed in populations with varying degrees of neuromuscular control. While changes in vertical ground reaction force (vGRF) peak magnitude are associated with altered limb loading that can be observed during asymmetric gait, the challenge is identifying techniques with the sensitivity to detect these altered movement patterns. Autoregressive (AR) modeling has successfully delineated between healthy and pathological gait during running; but has been little explored in walking. Thus, AR modeling was implemented to assess differences in vGRF pattern dynamics during symmetric and asymmetric walking. We hypothesized that the AR model coefficients would better detect differences amongst the symmetric and asymmetric walking conditions than the vGRF peak magnitude mean. Seventeen healthy individuals performed a protocol that involved walking on a split-belt instrumented treadmill at different symmetric (0.75m/s, 1.0 m/s, 1.5 m/s) and asymmetric (Side 1: 0.75m/s-Side 2:1.0 m/s; Side 1:1.0m/s-Side 2:1.5 m/s) gait conditions. Vertical ground reaction force peaks extracted during the weight-acceptance and propulsive phase of each step were used to construct a vGRF peak time series. Then, a second order AR model was fit to the vGRF peak waveform data to determine the AR model coefficients. The resulting AR coefficients were plotted on a stationarity triangle and their distance from the triangle centroid was computed. Significant differences in vGRF patterns were detected amongst the symmetric and asymmetric conditions using the AR modeling coefficients (p = 0.01); however, no differences were found when comparing vGRF peak magnitude means. These findings suggest that AR modeling has the sensitivity to identify differences in gait asymmetry that could aid in monitoring rehabilitation progression.