Decreased Stride Length Research Articles

The spring-mass model and other reductionist models of bipedal locomotion on inclines.

The spring-mass model is a model of locomotion aimed at giving the essential mathematical laws of the trajectory of the center of mass of an animal during bouncing gaits, such as hopping (one-dimensional) and running (two-dimensional). This reductionist mechanical system has been extensively investigated for locomotion over horizontal surfaces, whereas it has been largely neglected on other ecologically relevant surfaces, including inclines. For example, how the degree of inclination impacts the dynamics of the center of mass of the spring-mass model has not been investigated thoroughly. In this work, we derive a mathematical model which extends the spring-mass model to inclined surfaces. Among our results, we derive an approximate solution of the system, assuming a small angular sweep of the limb and a small spring compression during stance, and show that this approximation is very accurate, especially for small inclinations of the ground. Furthermore, we derive theoretical bounds on the difference between the Lagrangian and Lagrange equationsof the true and approximate system, and discuss locomotor stability questions of the approximate solutions. We test our models through a sensitivity analysis using parameters relevant to the locomotion of bipedal animals (quail, pheasant, guinea fowl, turkey, ostrich, and humans) and compare our approximate solution to the numerically derived solution of the exact system. We compare the two-dimensional spring-mass model on inclines with the one-dimensional spring-mass model to which it reduces under the limit of no horizontal velocity; we compare the two-dimensional spring-mass model on inclines with the inverted-pendulum model on inclines towards which it converges in the case of high stiffness-to-mass ratio. We include comparisons with historically prevalent no-gravity approximations of these models, as well. The insights we have gleaned through all these comparisons and the ability of our approximation to replicate some of the kinematic changes observed in animals moving on different inclines (e.g. reduction in vertical oscillation of the center of mass and decreased stride length) underlines the valuable and reasonable contributions that very simple, reductionist models, like the spring-mass model, can provide.

Stride Length and Torso Biomechanics As They Relate To Medial Elbow Injuries In Adolescent Aged Baseball pitchers: A Clinical Commentary

There is a limited amount of literature examining torso biomechanics and stride length while addressing their relationship to medial elbow injuries in the adolescent baseball pitcher. Anatomical changes, growth, early sport specialization, multiple team participation, mound distance, mound height, and high pitch counts place adolescent pitchers at an exceptionally higher risk for medial elbow injuries. Existing evidence indicates that decreased stride length and altered trunk rotation is correlated with increased medial elbow loading for the adolescent overhead athlete. Further research is required to quantify adequate parameters for torso kinematics, control, and their correlation to stride length, in order to positively affect the biomechanical transfer of energy and potentially prevent injuries during the overhead throwing motion. The purpose of this clinical commentary is to examine and summarize the role of torso biomechanics and stride length in relation to medial elbow injuries in adolescent baseball pitchers. Level of Evidence 5

Clinical Disease Severity Mediates the Relationship between Stride Length and Speed and the Risk of Falling in Parkinson's Disease.

The shuffling gait with slowed speed and reduced stride length has been considered classic clinical features in idiopathic Parkinson’s disease (PD), and the risk of falling increases as the disease progresses. This raises the possibility that clinical disease severity might mediate the relationship between stride length and speed and the risk of falling in patients with PD. Sixty-one patients with PD patients underwent the clinical scores as well as quantitative biomechanical measures during walking cycles before and after dopamine replacement therapy. Mediation analysis tests whether the direct effect of an independent variable (stride length and speed) on a dependent variable (three-step fall prediction model score) can be explained by the indirect influence of the mediating variable (Unified Parkinson’s Disease Rating Scale (UPDRS) total scores). The results demonstrate that decreased stride length, straight walking speed, and turning speed is associated with increased three-step fall prediction model score (r = −0.583, p < 0.0001, r = −0.519, p < 0.0001, and r = −0.462, p < 0.0001, respectively). We further discovered that UPDRS total scores value is negatively correlated with stride length, straight walking, and turning speed (r = −0.651, p < 0.0001, r = −0.555, p < 0.0001, and r = −0.372, p = 0.005, respectively) but positively correlated with the fall prediction model score value (r = 0.527, p < 0.0001). Further mediation analysis shows that the UPDRS total score values serve as mediators between lower stride length, straight walking, and turning speed and higher fall prediction model score values. Our results highlighted the relationship among stride length and speed, clinical disease severity, and risk of falling. As decreased stride length and speed are hallmarks of falls, monitoring the changes of quantitative biomechanical measures along with the use of wearable technology in a longitudinal study can provide a scientific basis for pharmacology, rehabilitation programs, and selecting high-risk candidates for surgical treatment to reduce future fall risk.

Dopaminergic but not cholinergic neurodegeneration is correlated with gait disturbances in PINK1 knockout rats

Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by gait dysfunction in later stages of the disease. PD hallmarks include a decrease in stride length, run speed, and swing time; an increase in stride time, stance time, and base of support; dopaminergic degeneration in the basal ganglia; and cholinergic degeneration in the pedunculopontine nucleus (PPN). A progressive animal model of PD is needed to identify treatments for gait dysfunction. The goal of this study was to quantify progressive gait degeneration in PTEN-induced putative kinase 1 knockout (P1KO) rats and investigate neurodegeneration as potential underlying mechanisms. Gait analysis was performed in male P1KO and wild-type rats at 5 and 8 months of age and immunohistochemical analysis at 8 months. Multiple parameters of volitional gait were measured using a runway system. P1KO rats exhibited significant gait deficits at 5 months, but not 8 months. Gait abnormalities improved over time suggesting compensation during behavioral testing. At 8 months a 15% loss of tyrosine hydroxylase (TH) in the striatum, a 27% loss of TH-positive cells in the substantia nigra pars compacta, and no significant loss of choline acetyltransferase-positive cells in the PPN was found. Dopaminergic cell loss may contribute to gait deficits in the P1KO model, but not cholinergic cell loss. The P1KO rat with the greatest dopamine loss exhibited the most pronounced PD-like gait deficits, highlighting variability within the model. Further analysis is required to determine the suitability of the P1KO rat as a progressive model of gait abnormalities in PD.

Relationship Between Age And Spatiotemporal Parameters Of Running In Female Runners

PURPOSE: Aging runners demonstrate marked differences in running biomechanics. Few studies have considered age as a continuous variable when assessing running biomechanics. Females demonstrate a more rapid decline in physical function than males in middle age, therefore it is important to consider separate-sex analyses. The purpose of this study was to determine the relationship between age and velocity, stride length, and stride rate specifically in female runners at jogging (JOG) and maximum (MAX) speeds. Running studies typically include a self-selected or controlled pace, but maximum running speed is rarely considered. METHODS: 46 female participants (ages 18-65) ran at their self-selected JOG (long distance) and MAX (maximal running) pace on a treadmill. Running velocity was recorded and stride length and rate were measured. Simple linear regression was used to assess the relationship between age and each variable for both JOG and MAX speeds. RESULTS: For the JOG condition, there was a significant negative correlation between age and stride length, but not for age with velocity or stride rate (Figure 1). For the MAX condition, there were significant negative correlations of age with velocity and stride length, but not stride rate. Youngest runners ran significantly faster (ages 18-28, n = 13) at JOG (p = .037) and MAX speeds (p < .001), and had longer stride lengths (JOG: p = .037, MAX = p < .001) than the oldest runners (ages 50-65, n = 11). CONCLUSIONS: Female runners demonstrate decreased maximum running speed with age, primarily as a result of decreased stride length. In the literature, decreased stride length and running velocity have been associated with decreased horizontal propulsive effort and decreased ankle muscle function in the aging runner. Including maximum running speeds in analyses may be important, as this appears to be a more sensitive measure of the changes in spatiotemporal variables associated with age.

Early manifestation of gait alterations in the Tg2576 mouse model of Alzheimer's disease.

There is strong clinical evidence that multifaceted gait abnormalities may be manifested at early stages of Alzheimer's disease (AD), are related to cognitive decline, and can be used as an early biomarker to identify patients at risk of progressing to full-blown dementia. Despite their importance, gait abnormalities have not been investigated in mouse models of AD, which replicate important aspects of the human disease. The Tg2576 is frequently used in AD research to test therapeutic interventions targeting cellular mechanisms contributing to the genesis of AD. This transgenic mouse strain overexpresses a mutant form of the 695 amino acid isoform of human amyloid precursor protein with K670N and M671L mutations (APPK670/671L) linked to early-onset familial AD. Tg2576 mice exhibit impaired cognitive functions and increased cortical and hippocampal soluble β-amyloid levels starting from 5months of age and increased insoluble β-amyloid levels and amyloid plaques that resemble senile plaques associated with human AD by 13months of age. To demonstrate early manifestations of gait dysfunction in this relevant preclinical model, we characterized gait and motor performance in 10-month-old Tg2576 mice and age-matched littermate controls using the semi-automated, highly sensitive, Catwalk XT system. We found that Tg2576 mice at the pre-plaque stage exhibited significantly altered duty cycle and step patterns and decreased stride length and stride time. Base-of-support, stride time variability, stride length variability, cadence, phase dispersions and gait symmetry indices were unaltered. The presence of measurable early gait abnormalities during the pre-plaque stages of AD in this relevant preclinical mouse model has direct translational relevance and supports the view that longitudinal monitoring of gait performance could be used in addition to behavioral testing to evaluate progression of the disease and to assess treatment efficacy.

Inertial sensing of step kinematics in ambulatory patients with ALS and related motor neuron diseases

Amyotrophic lateral sclerosis (ALS) is a progressive disorder which impairs gait and elevates the risk for falls. Current methods of assessing gait in these patients are infrequent and subjective. The goal of this study was to evaluate wearable-based methods for assessing gait to facilitating better monitoring of ambulatory health and ultimately lessen fall risk. Thirty ambulatory patients seen in ALS clinic were guided by a physical therapist on a short walk, during which inertial sensors recorded their movement. Two methods, utilising sensors at the waist or foot, were used independently to estimate gait parameters. Decreased stride length, increased stride duration and decreased walking speed were associated with lower functional walking scores, and the presence of a cane or walker. Overall, there was no group-wide mean walking speed differences between methods, though the waist method overestimated stride length and walking speed in those with more significant gait dysfunction compared to the foot method. Reconstruction of movement using the foot-based sensor resulted in route segments that were 94 ± 1% standard error of the mean (SEM) the length of a centre-to-centre hallway reference vector, with an angular error of 0.66 ± 0.28° SEM.

Testing of path-based visual cues on patterned carpet to assist older adults' gait in a continuing care retirement community

Fall accidents lead to hospitalization and medical costs among all age groups, especially severe for older adults. Both intrinsic (e.g., visual impairment, fear of falling) and extrinsic (e.g., inappropriate carpet design, poor lighting) factors contribute to fall accidents. Older adults increasingly rely on visual perception to maintain balance as their health conditions decline. Patterned carpet is common in the built environment, which is one of the factors contributing to fall accidents among older adults. This study examined the role of path-based visual cues (provide visual guidance while walking along the patterned carpet) in helping older adults maintain safe movement and overcome the fear of falling. The experimental field study was conducted at a Continuing Care Retirement Community. Thirty-two residents were recruited. Within-subjects design was employed to examine the effects of path-based visual cues (light color and brightness) on the gait characteristics of older adults with and without visual impairment while walking on patterned carpet. Wearable sensors collected older adults' gait characteristics and questionnaires were used to evaluate their perceptions of confidence and safety with different visual cues provided. Individual repeated measures analysis results indicated that older adults significantly decreased stride length and stride velocity under 8.3fc white and 7.3fc blue lighting conditions compared to the baseline condition. In addition, the principal component analysis also indicated significant differences in gait performance among lighting colors and lighting brightness. The subjective responses indicated that the path-based visual cues were helpful in improving walking confidence, particularly for older adults with visual impairment.

Gait Analysis of Old Individuals with Mild Parkinsonian Signs and Those Individuals' Gait Performance Benefits Little from Levodopa.

Background and PurposeGait analysis and the effects of levodopa on the gait characteristics in Mild parkinsonian signs (MPS) are rarely published. The present research aimed to (1) analyze the gait characteristics in MPS; (2) explore the effects of levodopa on the gait performance of MPS.MethodsWe enrolled 22 inpatients with MPS and 20 healthy control subjects (HC) from Nanjing Brain Hospital. The Unified Parkinson’s Disease Rating Scale was used to evaluate motor symptoms. Acute levodopa challenge test was performed to explore the effects of levodopa on the gait performance of MPS. The instrumented stand and walk test was conducted for each participant and the JiBuEn gait analysis system was used to collect gait data.ResultsFor spatiotemporal parameters: Compared with HC, the state before taking levodopa/benserazide in MPS group (meds-off) demonstrated a decrease in stride length (SL) (p≤0.001), an increase in SL variability (p≤0.001), and swing phase time variability (p=0.016). Compared with meds-off, the state after 1 hour of taking levodopa/benserazide in MPS group (meds-on) exhibited an increase in SL (p≤0.001), a decrease in SL variability (p≤0.001). For kinematic parameters: Compared with HC, meds-off demonstrated a decrease in heel strike angle (p=0.008), range of motion (ROM) of knee joint (p=0.011) and ROM of hip joint (p=0.007). Compared with meds-off, meds-on exhibited an increase in HS (p≤0.001). Bradykinesia and rigidity scores were significantly correlated with gait parameters.ConclusionAlthough the clinical symptoms of the MPS group are mild, their gait damage is obvious and they exhibited a decreased SL and joints movement, and a more variable gait pattern. Levodopa had little effect on the gait performance of those individuals.

Upper and Lower Limb Movement Kinematics in Aging FMR1 Gene Premutation Carriers.

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder associated with a premutation cytosine-guanine-guanine (CGG) trinucleotide repeat expansion of the FMR1 gene. FXTAS is estimated to be the most common single-gene form of ataxia in the aging population. Gait ataxia and intention tremor are the primary behavioral symptoms of FXTAS, though clinical evaluation of these symptoms often is subjective, contributing to difficulties in reliably differentiating individuals with FXTAS and asymptomatic premutation carriers. This study aimed to clarify the extent to which quantitative measures of gait and upper limb kinematics may serve as biobehavioral markers of FXTAS degeneration. Nineteen premutation carriers (aged 46–77 years), including 9 with possible, probable, or definite FXTAS and 16 sex- and IQ-matched healthy controls, completed tests of non-constrained walking and reaching while both standing (static reaching) and walking (dynamic reaching) to quantify gait and upper limb control, respectively. For the non-constrained walking task, participants wore reflective markers and walked at their preferred speed on a walkway. During the static reaching task, participants reached and lifted boxes of different sizes while standing. During the dynamic reaching task, participants walked to reach and lift the boxes. Movement kinematics were examined in relation to clinical ratings of neuromotor impairments and CGG repeat length. During non-constrained walking, individuals with FXTAS showed decreased stride lengths and stride velocities, increased percentages of double support time, and increased variabilities of cadence and center of mass relative to both asymptomatic premutation carriers and controls. While individuals with FXTAS did not show any static reaching differences relative to the other two groups, they showed multiple differences during dynamic reaching trials, including reduced maximum reaching velocity, prolonged acceleration time, and jerkier movement of the shoulder, elbow, and hand. Gait differences during non-constrained walking were associated with more severe clinically rated posture and gait symptoms. Reduced maximum reaching velocity and increased jerkiness during dynamic reaching were each related to more severe clinically rated kinetic dysfunction and overall neuromotor symptoms in FMR1 premutation carriers. Our findings suggest kinematic alterations consistent with gait ataxia and upper limb bradykinesia are each selectively present in individuals with FXTAS, but not asymptomatic aging premutation carriers. Consistent with neuropathological and magnetic resonance imaging (MRI) studies of FXTAS, these findings implicate cerebellar and basal ganglia degeneration associated with neuromotor decline. Our results showing associations between quantitative kinematic differences in FXTAS and clinical ratings suggest that objective assessments of gait and reaching behaviors may serve as critical and reliable targets for detecting FXTAS risk and monitoring progression.

Effects of Auditory Cueing on Cadence and Gait Pattern

A large portion of the population participate in gait rehabilitation, especially those with conditions such as increased fall risk such as stroke, or Parkinson’s Disease. Some studies have shown that auditory cues help improve gait and reduce fall risk, but relationship with gait patterns is missing. In this study, eight participants walked at their preferred cadence and at increased and reduced cadence by 20%. We found that step length and step width were not significantly different in all walking conditions. Decreased cadence resulted in an increase of swing time, stance time, stride time, and stance to swing ratio, and a decrease in stride length. Increased cadence resulted in a decrease in stance time, stride time, swing time, and stance to swing ratio, and an increase in stride length. The results suggest there is a strong correlation between auditory cues and gait patterns that can improve rehabilitative processes in the future.

Increased Contact Time and Strength Deficits in Runners With Exercise-Related Lower Leg Pain.

Exercise-related lower leg pain (ERLLP) is common in runners. To compare biomechanical (kinematic, kinetic, and spatiotemporal) measures obtained from wearable sensors as well as lower extremity alignment, range of motion, and strength during running between runners with and those without ERLLP. Case-control study. Field and laboratory. Of 32 young adults who had been running regularly (>10 mi [16 km] per week) for ≥3 months, 16 had ERLLP for ≥2 weeks and 16 were healthy control participants. Both field and laboratory measures were collected at the initial visit. The laboratory measures consisted of alignment (arch height index, foot posture index, navicular drop, tibial torsion, Q-angle, and hip anteversion), range of motion (great toe, ankle, knee, and hip), and strength. Participants then completed a 1.67-mi (2.69-km) run along a predetermined route to calibrate the RunScribe devices. The RunScribe wearable sensors collected kinematic (pronation excursion and maximum pronation velocity), kinetic (impact g and braking g), and spatiotemporal (stride length, step length, contact time, stride pace, and flight ratio) measures. Participants then wore the sensors during at least 3 training runs in the next week. The ERLLP group had a slower stride pace than the healthy group, which was accounted for as a covariate in subsequent analyses. The ERLLP group had a longer contact time during the stance phase of running (mean difference [MD] = 18.00 ± 8.27 milliseconds) and decreased stride length (MD = -0.11 ± 0.05 m) than the control group. For the clinical measures, the ERLLP group demonstrated increased range of motion for great-toe flexion (MD = 13.9 ± 4.6°) and ankle eversion (MD = 6.3 ± 2.7°) and decreased strength for ankle inversion (MD = -0.49 ± 0.23 N/kg), ankle eversion (MD = -0.57 ± 0.27 N/kg), and hip flexion (MD = -0.99 ± 0.39 N/kg). The ERLLP group exhibited a longer contact time and decreased stride length during running as well as strength deficits at the ankle and hip. Gait retraining and lower extremity strengthening may be warranted as clinical interventions in runners with ERLLP.

Gait characteristics in patients with ankylosing spondylitis: a systematic review.

Ankylosing spondylitis (AS) is a chronic rheumatic disease which affects the axial skeleton and sacroiliac joints. By impacting spinal mobility and physical functions, AS could also potentially impair gait. However, while published data are rather sparse, it appears that discrepancies exist regarding AS consequences on gait characteristics, tasks and analysis techniques used to assess gait ability of patients with AS. The review questions are twofold: (1) How is gait assessed in patients with AS? and (2) What are the consequences of AS on gait? Databases were systematically searched to identify studies satisfying the search criteria, using the synonyms of ankylosing spondylitis and gait. Two reviewers extracted from the articles study characteristics, methods and main results in relation to gait. 192 titles were extracted from databases and 21 studies were included in the review. 16 studies (76%) used clinical gait measurements and 5 (23%) used laboratory gait measurements. Only 7 involved a healthy control group. Studies used various protocols, instructions and parameters when assessing gait. Gait of patients with AS was associated with decreased stride length, pelvic movements and lower limbs angles in the sagittal plane, and increased hip abduction and external rotation compared to healthy controls. Only few studies have assessed gait characteristics in patients with AS and published data evidence that kinematic parameters of gait is altered, but no consensus exists regarding gait analysis methods for patients with AS. Guidelines are provided to improve the design and methodology for future studies on gait and AS.

Characterization of idiopathic Parkinson’s disease subgroups using quantitative gait analysis and corresponding subregional striatal uptake visualized using 18F-FP-CIT positron emission tomography

BackgroundGait disturbance is one of the most common symptoms among patients with idiopathic Parkinson’s disease (IPD). Nevertheless, Parkinson’s disease subtype clustering according to gait characteristics has not been thoroughly investigated. Research questionThe aim of this study was to identify subgroups according to gait pattern among patients with IPD. MethodsThis study included 88 patients with IPD who underwent 18F-fluorinated-N-3-fluoropropyl-2-β-carboxymethoxy-3-β-4-iodophenyl-nortropane positron emission tomography (18F-FP-CIT PET) and three-dimensional gait analysis (3DGA) between January 1, 2014 and December 31, 2016. We performed cluster analysis using temporal-spatial gait variables (gait speed, stride length, cadence, and step width) and divided patients into four subgroups. The kinematic and kinetic gait variables in 3DGA were compared among the four subgroups. Furthermore, we compared the uptake patterns of striatum among the four subgroups using 18F-FP-CIT PET. ResultsThe patients were clustered into subgroups based on gait hypokinesia and cadence compensation. Group 1 had decreased stride length compensating with increased cadence. Group 2 had decreased stride length without cadence compensation and wider step width. Group 3 had relatively spared stride length with decreased cadence. Group 4 had spared stride length and cadence. The uptake of posterior putamen was significantly decreased in Group 3 compared with Group 4. SignificanceGait hypokinesia and cadence can help to classify gait patterns in IPD patients. Our subgroups may reflect the different gait patterns in IPD patients.

The Biomechanics of Pregnancy: A Systematic Review.

During pregnancy, a number of biomechanical and hormonal changes occur that can alter spinal curvature, balance, and gait patterns by affecting key areas of the human body. This can greatly impact quality of life (QOL) by increasing back pain and the risk of falls. These effects are likely to be the ultimate result of a number of hormonal and biomechanical changes that occur during pregnancy. Research Question and Methodology: Using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, this systematic review sets out to analyse all available literature relating to the biomechanics factors caused by pregnancy and assess how this might reduce QOL. Fifty papers were deemed eligible for inclusion in this review based on the PUBMED and SCOPUS databases. Results: Angles of lordosis and kyphosis of the spine are significantly increased by pregnancy, but not consistently across all studies. Back pain is significantly increased in pregnant women, although this is not significantly correlated with spinal changes. Increased movements of centre of pressure (COP) and increased stability indexes indicate postural control is reduced in pregnancy. Trunk range of motion, hip flexion, and extension are reduced, as well as decreased stride length, decreased gait velocity, and increased step width; again, not consistently. It is likely that each woman adopts unique techniques to minimise the effects, for example increasing step width to improve balance. Further research should focus on how altered limb kinematics during gait might affect QOL by influencing the human body, as well as assessing parameters in all planes to develop a wider understanding of pregnant biomechanical alterations.

Computer interactions during walking workstation use moderately affects spatial-temporal gait characteristics

BackgroundDue to increased sedentary workstyles, active workstations have shown the ability to increase activity while only moderately affecting work ability. However, previous examinations have not examine fine motor mousing tasks on tripping descriptors. Research QuestionWhat affect do mousing tasks of varying target size have on tripping descriptors during walking workstation use? MethodsThree-dimensional kinematic data were collected while participants used a walking workstation completing one baseline and three mousing conditions of varying target sizes. ResultsTarget size main effects (p < 0.001) detected decreased stride length in all experimental conditions, which were supported by moderate effect sizes, and decreased stance width and time in double limb support (p < 0.001 for both comparisons). Stance width differences resulted in large effect sizes between baseline and all conditions, while only moderate effect sizes were observed between time in double limb support in baseline compared to all conditions. No changes in knee flexion range of motion were observed in response to target size (p = 0.278). SignificanceThese results indicate that walking workstation users shorten their stride length and decrease their base of support while completing mousing tasks. The placement of the upper extremities on the workstation desk likely acted as the primary mechanism to increase stability. It is concluded that performing mousing tasks of varying target size using a walking workstation does not pose greater risk for adverse gait events.

Effects of Cycling on Subsequent Running Performance, Stride Length, and Muscle Oxygen Saturation in Triathletes.

Running performance is a determinant factor for victory in Sprint and Olympic distance triathlon. Previous cycling may impair running performance in triathlons, so brick training becomes an important part of training. Wearable technology that is used by triathletes can offer several metrics for optimising training in real-time. The aim of this study was to analyse the effect of previous cycling on subsequent running performance in a field test, while using kinematics metrics and SmO2 provided by wearable devices that are potentially used by triathletes. Ten trained triathletes participated in a randomised crossover study, performing two trial sessions that were separated by seven days: the isolated run trial (IRT) and the bike-run trial (BRT). Running kinematics, physiological outcomes, and perceptual parameters were assessed before and after each running test. The running distance was significantly lower in the BRT when compared to the IRT, with a decrease in stride length of 0.1 m (p = 0.00) and higher %SmO2 (p = 0.00) in spite of the maximal intensity of exercise. No effects were reported in vertical oscillation, ground contact time, running cadence, and average heart rate. These findings may only be relevant to ‘moderate level’ triathletes, but not to ‘elite’ ones. Triathletes might monitor their %SmO2 and stride length during brick training and then compare it with isolated running to evaluate performance changes. Using wearable technology (near-infrared spectroscopy, accelerometry) for specific brick training may be a good option for triathletes.

Parameters for gait rehabilitation in Tropical Spastic Paraparesis: cross sectional study

INTRODUCTION: The gait in people with HTLV-1 associated myelopathy or tropical spastic paraparesis (HAM / TSP) is little known. OBJECTIVE: To evaluate the kinematic profile of gait in people with HAM/TSP. METHODS: A cross-sectional study with 25 people with HAM/TSP and 25 healthy participants. Spatiotemporal and angular data from filming of gait were submitted to kinematic analysis using CVMob software. The gait of partipants with HAM/TSP was analized quantitatively through t Student test (alpha 5% and Power of 80%). The project was approved by Ethical Committee of the Bahiana School of Medicine and Public Health with CAAE 13568213.8.0000.5544. RESULTS: The HAM/TSP group showed significant changes in two different domains of biomechanical gait analysis when compared to healthy controls. The angular variables showed increased trunk inclination, flexion and extension (p&lt;0.05); increased hip flexion and decreased hip extension (p&lt;0.05); decreased knee flexion and extension (p&lt;0.05); decreased ankle dorsi and plantar flexion (p&lt;0.05). Range of Motion was also reduced in all those joints. The spatiotemporal variables showed decreased stride length and increased stride time and speed gait cycle (p&lt;0.001). Those changes point out to reduction in joint amplitudes of hip, knee and ankle, changes in support base and double support time asymmetry between right and left sides, reduction of pre-swing time, hip lift in the mid-swing, and foot drop throughout the swing. CONCLUSION: People with HAM/TSP have gait characterized by reduction in joint amplitudes of hip, knee and ankle, asymmetry between right and left sides and reduction of pre-swing time, hip lift in the mid-swing, and foot drop throughout the swing.

Associations Between Self-Reported Symptoms and Gait Parameters Using In-Home Sensors in Persons With Multiple Sclerosis.

Multiple sclerosis (MS) is a progressive neurological disorder, characterized by exacerbations and remissions, often resulting in disability affecting multiple neurological functions. The purpose of this article was (1) to describe the frequencies of self-reported symptoms in a natural environment and (2) to determine characteristics and associations between self-reported symptoms and home gait parameters (speed, stride time, and stride length) at baseline and at 3 months in patients with MS. Participants completed the self-report MS-Related Symptom Scale to measure symptoms. A three-dimensional depth imaging system (Foresite Healthcare) was used to measure gait parameters in the home environment. These data show significant correlations between the following symptoms: knee locking or collapsing, difficulty sleeping, depression, and anxiety with decreased number of average walks per day; however, the symptoms including trouble-making toilet: day and difficulty in starting urine were positively correlated with average walks per day. The symptom numbness was significantly correlated with decreased speed and decreased stride length. Our findings suggest that certain groups of symptoms were more frequently reported with certain gait parameters (stride time/speed) in persons with MS. Rehabilitation nurses can provide optimal care to prevent future decline in symptoms and gait.

A kinematic and kinetic analysis of the hip and knee joints in patients with posterior tibialis tendon dysfunction; comparison with healthy age-matched controls

BackgroundThe biomechanical abnormalities in patients with posterior tibial tendon dysfunction (PTTD) have been described, but few studies have investigated biomechanical chains of adjacent joints. Therefore, we examined the gait pattern of the lower extremity in subjects with PTTD, focusing on the hip and knee joints. MethodsWe compared 19 PTTD patients (average age: 67.1) with 30 age-matched control subjects (average age: 65.1). Gait analysis was performed with a nine-camera motion-capture system and four force plates, using the Vicon Plug-In-Gait and Vicon Nexus software. Temporal-spatial parameters were compared between PTTD and control subjects, and motion and ground reaction force data were compared between the affected limb, the contralateral limb, and the right limb in control subjects. ResultsSubjects with PTTD had increased stance phase ratio and decreased stride length, cadence, and gait speed. The limbs of subjects with PTTD showed increased knee internal rotation at lording response, which was biased to abduction in the knee joint during the gait cycle, and irregular hip flexion and knee extension moment in the terminal stance, even under control of gait speed. SignificanceWe believe that the subjects with PTTD have an increased risk of knee osteoarthritis in both the affected and contralateral limbs.