The availability of age-matched normative data is an essential component of clinical gait analyses. Comparison of normative gait databases is difficult due to the high-dimensionality and temporal nature of the various gait waveforms. The purpose of this study was to provide a method of comparing the sagittal joint angle data between two normative databases. We compared a modern gait database to the historical San Diego database using statistical classifiers developed by Tingley et al. (2002). Gait data were recorded from 60 children aged 1–13 years. A six-camera Vicon 512 motion analysis system and two force plates were utilized to obtain temporal-spatial, kinematic, and kinetic parameters during walking. Differences between the two normative data sets were explored using the classifier index scores, and the mean and covariance structure of the joint angle data from each lab. Significant differences in sagittal angle data between the two databases were identified and attributed to technological advances and data processing techniques (data smoothing, sampling, and joint angle approximations). This work provides a simple method of database comparison using trainable statistical classifiers.
We present a 3-dimensional biomechanical model of the upper extremities to characterize joint dynamics during 2 patterns of Lofstrand crutch-assisted gait in children with myelomeningocele. The upper extremity model incorporates recommendations by the International Society of Biomechanics.
A Vicon motion analysis system (14 cameras) captured the marker patterns. Instrumented crutches measured reaction forces. Five subjects with L3 or L4 level myelodysplasia (aged 9.8 ± 1.6 years) were analyzed during reciprocal and swing-through Lofstrand crutch-assisted gait.
The mean walking speed, cadence, and stride length were greatest during swing-through gait. Although the gait patterns had different morphologies, the thorax and elbows remained in flexion, the wrists remained in extension, and the shoulders demonstrated both flexion and extension throughout the gait cycles. Swing-through gait showed larger ranges of motion for all joints than reciprocal gait. Peak crutch forces were highest during swing-through gait. The model was effective in detecting significant differences in upper extremity joint dynamics between reciprocal and swing-through crutch-assisted gait in children with myelomeningocele.
Results support continued testing. Future work should include clinical and functional assessment in a correlated study of dynamics and function. Knowledge from the study may be useful in treatment planning and intervention.
Crutch-assisted gait; Myelomeningocele; Motion analysis; Upper extremity modeling; Biomechanics
Central cord syndrome (CCS) is considered the most common incomplete spinal cord injury (SCI). Independent ambulation was achieved in 87-97% in young patients with CCS but no gait analysis studies have been reported before in such pathology. The aim of this study was to analyze the gait characteristics of subjects with CCS and to compare the findings with a healthy age, sex and anthropomorphically matched control group (CG), walking both at a self-selected speed and at the same speed.
Twelve CCS patients and a CG of twenty subjects were analyzed. Kinematic data were obtained using a three-dimensional motion analysis system with two scanner units. The CG were asked to walk at two different speeds, at a self-selected speed and at a slower one, similar to the mean gait speed previously registered in the CCS patient group. Temporal, spatial variables and kinematic variables (maximum and minimum lower limb joint angles throughout the gait cycle in each plane, along with the gait cycle instants of occurrence and the joint range of motion - ROM) were compared between the two groups walking at similar speeds.
The kinematic parameters were compared when both groups walked at a similar speed, given that there was a significant difference in the self-selected speeds (p < 0.05). Hip abduction and knee flexion at initial contact, as well as minimal knee flexion at stance, were larger in the CCS group (p < 0.05). However, the range of knee and ankle motion in the sagittal plane was greater in the CG group (p < 0.05). The maximal ankle plantar-flexion values in stance phase and at toe off were larger in the CG (p < 0.05).
The gait pattern of CCS patients showed a decrease of knee and ankle sagittal ROM during level walking and an increase in hip abduction to increase base of support. The findings of this study help to improve the understanding how CCS affects gait changes in the lower limbs.
The later stages of Parkinson's disease (PD) are characterized by altered gait patterns. Although decreased arm swing during gait is the most frequently reported motor dysfunction in individuals with PD, quantitative descriptions of gait in early PD have largely ignored upper extremity movements. This study was designed to perform a quantitative analysis of arm swing magnitude and asymmetry that might be useful in the assessment of early PD. Twelve individuals with early PD (in “off” state) and eight controls underwent gait analysis using an optically-based motion capture system. Participants were instructed to walk at normal and fast velocities, and then on heels (to minimize push-off). Arm swing was measured as the excursion of the wrist with respect to the pelvis. Arm swing magnitude for each arm, and inter-arm asymmetry, were compared between groups. Both groups had comparable gait velocities (p=0.61), and there was no significant difference between the groups in the magnitude of arm swing in all walking conditions for the arm that swung more (p=0.907) or less (p=0.080). Strikingly, the PD group showed significantly greater arm swing asymmetry (asymmetry angle: 13.9±7.9%) compared to the control group (asymmetry angle: 5.1±4.0%; p=0.003). Unlike arm swing magnitude, arm swing asymmetry unequivocally differs between people with early PD and controls. Such quantitative evaluation of arm swing, especially its asymmetry, may have utility for early and differential diagnosis, and for tracking disease progression in patients with later PD.
Parkinson's Disease; gait; biomechanics; arm swing; arm swing asymmetry
Gait abnormalities have been reported in individuals with Chronic Fatigue Syndrome (CFS) however no studies exist to date investigating the kinematics of individuals with CFS in over-ground gait. The aim of this study was to compare the over-ground gait pattern (sagittal kinematics and temporal and spatial) of individuals with CFS and control subjects at their self-selected and at matched velocities.
Twelve individuals with CFS and 12 matched controls participated in the study. Each subject walked along a 7.2 m walkway three times at each of three velocities: self-selected, relatively slow (0.45 ms-1) and a relatively fast (1.34 ms-1). A motion analysis system was used to investigate the sagittal plane joint kinematics and temporal spatial parameters of gait.
At self-selected velocity there were significant differences between the two groups for all the temporal and spatial parameters measured, including gait velocity (P = 0.002). For the kinematic variables the significant differences were related to both ankles during swing and the right ankle during stance. At the relatively slower velocity the kinematic differences were replicated. However, the step distances decreased in the CFS population for the temporal and spatial parameters. When the gait pattern of the individuals with CFS at the relatively fast walking velocity (1.30 ± 0.24 ms-1) was compared to the control subjects at their self-selected velocity (1.32 ± 0.15 ms-1) the gait pattern of the two groups was very similar, with the exception of both ankles during swing.
The self-selected gait velocity and/or pattern of individuals with CFS may be used to monitor the disease process or evaluate therapeutic intervention. These differences may be a reflection of the relatively low self-selected gait velocity of individuals with CFS rather than a manifestation of the condition itself.
For many years, mainly to simplify data analysis, scientists assumed that during a gait, the lower limbs moved symmetrically. However, even a cursory survey of the more recent literature reveals that the human walk is symmetrical only in some aspects. That is why the presence of asymmetry should be considered in all studies of locomotion. The gait data were collected using the 3D motion analysis system Vicon. The inclusion criteria allowed the researchers to analyze a very homogenous group, which consisted of 54 subjects (27 women and 27 men). Every selected participant moved at a similar velocity: approximately 1,55 m/s. The analysis included kinematic parameters defining spatio-temporal structure of locomotion, as well as angular changes of the main joints of the lower extremities (ankle, knee and hip) in the sagittal plane. The values of those variables were calculated separately for the left and for the right leg in women and men. This approach allowed us to determine the size of the differences, and was the basis for assessing gait asymmetry using a relative asymmetry index, which was constructed by the authors. Analysis of the results demonstrates no differences in the temporal and phasic variables of movements of the right and left lower limb. However, different profiles of angular changes in the sagittal plane were observed, measured bilaterally for the ankle joint.
angular changes; relative asymmetry index; bilateral data; Vicon
This study aimed at identifying measurable asymmetries during gait and relating them to the spinal deformity in subjects with idiopathic scoliosis. We investigated 21 patients aged between 10 and 26 years for gait asymmetries using force plates. All subjects completed five walking cycles over two force plates measuring vertical ground reaction forces. Among the parameters measured were contact time and magnitude of the two peaks of the vertical forces as well as the rate of application of those forces. Published gait data on normal subjects were used as a control group. In 20 subjects an asymmetry of at least one gait parameter was noted. Multiple regression analysis showed, however, that there was no relation between the noted gait asymmetry and the curve direction, curve magnitude or vertebral rotation. This suggests that although functional asymmetries of the central nervous system have been described in patients with idiopathic scoliosis, they do not appear to have a reproducible effect on gait.
Key words Scoliosis; Gait; Nervous system
Several gait impairments have been associated with freezing of gait (FOG) in patients with Parkinson's disease (PD). These include deteriorations in rhythm control, gait symmetry, bilateral coordination of gait, dynamic postural control and step scaling. We suggest that these seemingly independent gait features may have mutual interactions which, during certain circumstances, jointly drive the predisposed locomotion system into a FOG episode. This new theoretical framework is illustrated by the evaluation of the potential relationships between the so-called “sequence effect”, that is, impairments in step scaling, and gait asymmetry just prior to FOG. We further discuss what factors influence gait control to maintain functional gait. “Triggers”, for example, such as attention shifts or trajectory transitions, may precede FOG. We propose distinct categories of interventions and describe examples of existing work that support this idea: (a) interventions which aim to maintain a good level of locomotion control especially with respect to aspects related to FOG; (b) those that aim at avoiding FOG “triggers”; and (c) those that merely aim to escape from FOG once it occurs. The proposed theoretical framework sets the stage for testable hypotheses regarding the mechanisms that lead to FOG and may also lead to new treatment ideas.
The goal of this study was to observe scoliotic subjects during level walking to identify asymmetries—which may be related to a neurological dysfunction or the spinal deformity itself—and to correlate these to the severity of the scoliotic curve.
We assessed the gait pattern of ten females (median age 14.4) with idiopathic scoliosis characterised by a left-lumbar and a right-thoracic curve component. Gait analysis consisted of 3D kinematic (VICON) and kinetic (Kistler force plates) measurements. The 3D-segment positions of the head, trunk and pelvis, as well as the individual joint angles of the upper and lower extremities, were computed during walking and static standing. Calculation of pertinent kinetic and kinematic parameters allowed statistical comparison.
All subjects walked at a normal velocity (median: 1.22 m/s; range:1.08–1.30 m/s; height-adjusted velocity: 0.75 m/s; range: 0.62–0.88 m/s). The timing of the individual gait phases was normal and symmetrical for the whole group. Sagittal plane hip, knee and ankle motion followed a physiological pattern. Significant asymmetry was observed in the trunk’s rotational behaviour in the transverse plane. During gait, the pelvis and the head rotated symmetrically to the line of progression, whereas trunk rotation was asymmetric, with increased relative forward rotation of the right upper body in relation to the pelvis. This produced a torsional offset to the line of progression. Minimal torsion (at right heel strike) measured: median 1.0° (range: 5.1°–8.3°), and maximal torsion (at left heel strike) measured 11.4° (range 6.9°–17.9°). The magnitude of the torsional offset during gait correlated to the severity of the thoracic deformity and to the standing posture, whereas the range of the rotational movement was not affected by the severity of the deformity. The ground reaction forces revealed a significant asymmetry of [Msz], the free rotational moment around the vertical axis going through the point of equivalent force application. On the right side, the initial endo-rotational moment was lower, followed by a higher exo-rotational moment than on the left. All the other force parameters (vertical, medio–lateral, anterior–posterior), did not show a significant side difference for the whole group. The use of a brace stiffened torsional motion. However the torsional offset and the asymmetry of the free rotational moment remained unchanged.
The most significant and marked asymmetry was seen in the transverse plane, denoted as a torsional offset of the upper trunk in relation to the symmetrically rotating pelvis. This motion pattern was reflected by a ground-reaction-force asymmetry of the free rotational moment. Further studies are needed to investigate whether this behaviour is solely an expression of the structural deformity or whether it could enhance the progression of the torsional deformity.
Idiopathic scoliosis; Gait analysis; Biomechanics; Asymmetry
Gait variability, that is, fluctuations in movement during walking, is an indicator of walking function and has been associated with various adverse outcomes such as falls. In this paper, current research concerning gait variability in persons with multiple sclerosis (MS) is discussed. It is well established that persons with MS have greater gait variability compared to age and gender matched controls without MS. The reasons for the increase in gait variability are not completely understood. Evidence indicates that disability level, assistive device use, attentional requirement, and fatigue are related to gait variability in persons with MS. Future research should address the time-evolving structure (i.e., temporal characteristics) of gait variability, the clinical importance of gait variability, and underlying mechanisms that drive gait variability in individuals with MS.
Leg length discrepancy is common both in healthy subjects and after total hip arthroplasty (THA). Studies that evaluated leg length following THA have demonstrated a notable inconsistency in restoring leg length. The effects concerning joint load during gait is however not well known. The purpose of this study was to use three-dimensional (3D) gait analysis to evaluate joint load during gait with a simulated leg length discrepancy of 2 and 4 cm. Nine healthy subjects without any history of hip injury participated.
A 3D gait analysis (Vicon, Motion System, Oxford, England) was performed with 6 cameras and 2 force palates using a standard biomechanical gait model. Hip joint moments of force were calculated for all three degrees of motion freedom. ANOVA for repeated measurements was used for statistical calculations.
Abduction peak moment was significantly increased at the short side (P < 0.05) but unaffected on the long side. The adduction moment decreased on the long side between 0 and 4 cm (P < 0.01) but was unaffected on the short side. The internal hip rotation moments were unchanged for both the long and the short side. The external rotation moment was unchanged on the short side and decreased between bare foot and 4 cm on the long side (P < 0.05).
A leg length discrepancy of 2 cm or more creates biomechanical changes concerning hip joint load both on the long and the short side and that the effects are larger on the short side. The increased stress may cause problems in the long run.
gait analyses; leg length discrepancy; hip; biomechanics
It is well documented that individuals with chronic stroke often exhibit considerable gait impairments that significantly impact their quality of life. While stroke subjects often walk asymmetrically, we sought to investigate whether prescribing near normal physiological gait patterns with the use of the Lokomat robotic gait-orthosis could help ameliorate asymmetries in gait, specifically, promote similar ankle, knee, and hip joint torques in both lower extremities. We hypothesized that hemiparetic stroke subjects would demonstrate significant differences in total joint torques in both the frontal and sagittal planes compared to non-disabled subjects despite walking under normal gait kinematic trajectories.
A motion analysis system was used to track the kinematic patterns of the pelvis and legs of 10 chronic hemiparetic stroke subjects and 5 age matched controls as they walked in the Lokomat. The subject's legs were attached to the Lokomat using instrumented shank and thigh cuffs while instrumented footlifters were applied to the impaired foot of stroke subjects to aid with foot clearance during swing. With minimal body-weight support, subjects walked at 2.5 km/hr on an instrumented treadmill capable of measuring ground reaction forces. Through a custom inverse dynamics model, the ankle, knee, and hip joint torques were calculated in both the frontal and sagittal planes. A single factor ANOVA was used to investigate differences in joint torques between control, unimpaired, and impaired legs at various points in the gait cycle.
While the kinematic patterns of the stroke subjects were quite similar to those of the control subjects, the kinetic patterns were very different. During stance phase, the unimpaired limb of stroke subjects produced greater hip extension and knee flexion torques than the control group. At pre-swing, stroke subjects inappropriately extended their impaired knee, while during swing they tended to abduct their impaired leg, both being typical abnormal torque synergy patterns common to stroke gait.
Despite the Lokomat guiding stroke subjects through physiologically symmetric kinematic gait patterns, abnormal asymmetric joint torque patterns are still generated. These differences from the control group are characteristic of the hip hike and circumduction strategy employed by stroke subjects.
Our goal was to examine the gait patterns of older adults with Down syndrome (DS) for precocious stabilizing adaptations during comfortable over-ground walking and in more challenging conditions. Twelve participants with DS and 12 with typical development (TD) were matched for height, weight and age (range 35 to 62 years). We used a 6-camera motion capture system to assess foot trajectories over obstacles. Participants first walked at their preferred speed over a 5.3 m instrumented gait mat (unperturbed condition). Subsequent walking trials included perturbations mid-walkway: a) minimal obstacle to step over (12 cm high), b) moderate obstacle to step onto with both feet and then off (standard step), c) maximum obstacle to step onto with only one foot and over with the other (standard step).
Adults with DS walked slower with shorter, wider strides while spending more time in both stance and double support. These adaptations increased during the moderate and maximal perturbations. They stepped with the minimal perturbation obstacle further forward in their crossing step and produced a lower, flatter trajectory of the lead foot, with less dorsiflexion at crossing. This strategy decreased trailing toe clearance but did not alter leading heel clearance.
The combined effects of ligamentous laxity, low tone, obesity, inactivity and physiological decrements associated with aging lead to these stability-enhancing adaptations at a younger chronological age in adults with DS. We believe intervention to increase overall stability will be beneficial in helping adults with DS maintain optimal functional mobility and health.
This paper presents the development of a wearable accelerometry system for real-time gait cycle parameter recognition. Using a tri-axial accelerometer, the wearable motion detector is a single waist-mounted device to measure trunk accelerations during walking. Several gait cycle parameters, including cadence, step regularity, stride regularity and step symmetry can be estimated in real-time by using autocorrelation procedure. For validation purposes, five Parkinson’s disease (PD) patients and five young healthy adults were recruited in an experiment. The gait cycle parameters among the two subject groups of different mobility can be quantified and distinguished by the system. Practical considerations and limitations for implementing the autocorrelation procedure in such a real-time system are also discussed. This study can be extended to the future attempts in real-time detection of disabling gaits, such as festinating or freezing of gait in PD patients. Ambulatory rehabilitation, gait assessment and personal telecare for people with gait disorders are also possible applications.
accelerometry; accelerometer; Parkinson’s disease; gait; mobility
The presence of measles virus (MV) RNA in bowel tissue from children with autism spectrum disorders (ASD) and gastrointestinal (GI) disturbances was reported in 1998. Subsequent investigations found no associations between MV exposure and ASD but did not test for the presence of MV RNA in bowel or focus on children with ASD and GI disturbances. Failure to replicate the original study design may contribute to continued public concern with respect to the safety of the measles, mumps, and rubella (MMR) vaccine.
The objective of this case-control study was to determine whether children with GI disturbances and autism are more likely than children with GI disturbances alone to have MV RNA and/or inflammation in bowel tissues and if autism and/or GI episode onset relate temporally to receipt of MMR. The sample was an age-matched group of US children undergoing clinically-indicated ileocolonoscopy. Ileal and cecal tissues from 25 children with autism and GI disturbances and 13 children with GI disturbances alone (controls) were evaluated by real-time reverse transcription (RT)-PCR for presence of MV RNA in three laboratories blinded to diagnosis, including one wherein the original findings suggesting a link between MV and ASD were reported. The temporal order of onset of GI episodes and autism relative to timing of MMR administration was examined. We found no differences between case and control groups in the presence of MV RNA in ileum and cecum. Results were consistent across the three laboratory sites. GI symptom and autism onset were unrelated to MMR timing. Eighty-eight percent of ASD cases had behavioral regression.
This study provides strong evidence against association of autism with persistent MV RNA in the GI tract or MMR exposure. Autism with GI disturbances is associated with elevated rates of regression in language or other skills and may represent an endophenotype distinct from other ASD.
This is the first time that gait characteristics of broiler (meat) chickens have been compared with their progenitor, jungle fowl, and the first kinematic study to report a link between broiler gait parameters and defined lameness scores. A commercial motion-capturing system recorded three-dimensional temporospatial information during walking. The hypothesis was that the gait characteristics of non-lame broilers (n = 10) would be intermediate to those of lame broilers (n = 12) and jungle fowl (n = 10, tested at two ages: immature and adult). Data analysed using multi-level models, to define an extensive range of baseline gait parameters, revealed inter-group similarities and differences. Natural selection is likely to have made jungle fowl walking gait highly efficient. Modern broiler chickens possess an unbalanced body conformation due to intense genetic selection for additional breast muscle (pectoral hypertrophy) and whole body mass. Together with rapid growth, this promotes compensatory gait adaptations to minimise energy expenditure and triggers high lameness prevalence within commercial flocks; lameness creating further disruption to the gait cycle and being an important welfare issue. Clear differences were observed between the two lines (short stance phase, little double-support, low leg lift, and little back displacement in adult jungle fowl; much double-support, high leg lift, and substantial vertical back movement in sound broilers) presumably related to mass and body conformation. Similarities included stride length and duration. Additional modifications were also identified in lame broilers (short stride length and duration, substantial lateral back movement, reduced velocity) presumably linked to musculo-skeletal abnormalities. Reduced walking velocity suggests an attempt to minimise skeletal stress and/or discomfort, while a shorter stride length and time, together with longer stance and double-support phases, are associated with instability. We envisage a key future role for this highly quantitative methodology in pain assessment (associated with broiler lameness) including experimental examination of therapeutic agent efficacy.
Crouch gait, one of the most prevalent movement abnormalities among children with cerebral palsy, is frequently treated with surgical lengthening of the hamstrings. To assist in surgical planning many clinical centers use musculoskeletal modeling to help determine if a patient's hamstrings are shorter or lengthen more slowly than during unimpaired gait. However, some subjects with crouch gait walk slowly, and gait speed may affect peak hamstring lengths and lengthening velocities. The purpose of this study was to evaluate the effects of walking speed on hamstrings lengths and velocities in a group of unimpaired subjects over a large range of speeds and to determine if evaluating subjects with crouch gait using speed matched controls alters subjects' characterization as having “short” or “slow” hamstrings. We examined 39 unimpaired subjects who walked at five different speeds. These subjects served as speed-matched controls for comparison to 74 subjects with cerebral palsy who walked in crouch gait. Our analysis revealed that peak hamstrings length and peak lengthening velocity in unimpaired subjects increased significantly with increasing walking speed. Fewer subjects with cerebral palsy were categorized as having hamstrings that were “short” (31/74) or “slow” (38/74) using a speed-matched control protocol compared to a non-speed-matched protocol (35/74 “short”, 47/74 “slow”). Evaluation of patients with cerebral palsy using speed-matched controls alters and may improve selection of patients for hamstrings lengthening procedures.
Post-stroke gait impairments are common and result in slowed walking speeds and decreased community participation post-stroke. Treadmill training has recently emerged as an effective gait rehabilitation intervention. Furthermore, kinematic and kinetic data collected during treadmill walking are commonly used for assessing gait performance. The minimal detectable change (MDC) for gait variables provides a useful index to determine whether the magnitude of change in gait produced after an intervention is greater than the amount of change attributable to day-to-day variability in gait or test–retest measurement errors. The MDC values for kinematic, ground reaction force (GRF), spatial, and temporal variables collected during treadmill walking post-stroke have not been previously reported. The objective of this study was, therefore, to compute MDCs for post-stroke gait kinematics, GRF indices, temporal, and spatial measures during treadmill walking. Nineteen individuals with chronic post-stroke hemiparesis (12 males; age = 47–75 years; 72.6 ± 63.4 months since stroke) participated in 2 testing sessions separated by 20.7 ± 26.8 days. Our results showed that test–retest reliability was excellent for all gait variables tested (intraclass correlation coefficients = 0.799–0.986). MDCs were reported for hip, knee, and ankle joint angles (range 3.8° for trailing limb angles to 11.5° for hip extension), peak anterior GRF (2.85% body weight), mean vertical GRF (4.65% body weight), all temporal variables (range 3.2–4.2% gait cycle), and paretic step length (6.7 cm). These MDCs provide a useful reference to help interpret the magnitudes of changes in post-stroke gait variables.
Hemiparesis; Stroke; Treadmill; Gait; Reliability; Minimal detectable change
A clinical memory test was administered to 38 high-functioning children with autism and 38 individually matched normal controls, 8–16 years of age. The resulting profile of memory abilities in the children with autism was characterized by relatively poor memory for complex visual and verbal information and spatial working memory with relatively intact associative learning ability, verbal working memory, and recognition memory. A stepwise discriminant function analysis of the subtests found that the Finger Windows subtest, a measure of spatial working memory, discriminated most accurately between the autism and normal control groups. A principal components analysis indicated that the factor structure of the subtests differed substantially between the children with autism and controls, suggesting differing organizations of memory ability.
autism; memory assessment; discriminant analysis; principal components analysis
Amputees walk with an asymmetrical gait, which may lead to future musculoskeletal degenerative changes. The purpose of this study was to compare the gait asymmetry of active transfemoral amputees while using a passive mechanical knee joint or a microprocessor-controlled knee joint.
Objective 3D gait measurements were obtained in 15 subjects (12 men and 3 women; age 42, range 26–57). Research participants were longtime users of a mechanical prosthesis (mean 20 years, range 3–36 years). Joint symmetry was calculated using a novel method that includes the entire waveform throughout the gait cycle.
There was no significant difference in hip, knee and ankle kinematics symmetry when using the different knee prostheses. In contrast, the results demonstrated a significant improvement in lower extremity joint kinetics symmetry when using the microprocessor-controlled knee.
Use of the microprocessor-controlled knee joint resulted in improved gait symmetry. These improvements may lead to a reduction in the degenerative musculoskeletal changes often experienced by amputees.
amputee; artificial limbs; gait; knee; microprocessor
Investigating gait characteristics during the early stages of walking in CP may contribute to the understanding of the development of impaired gait. The objective of this study was to investigate differences in the variability and symmetry of spatiotemporal gait characteristics during the early years of walking in children with bilateral spastic CP compared to children with similar amounts of walking experience and typical development (TD).
The spatiotemporal gait parameters of 31 children (15 with spastic CP, 16 with TD) who had an average of 28.5 (18.1 SD) months of walking experience were collected using an instrumented walkway.
All primary spatiotemporal parameters were reduced in the CP group, who also demonstrated greater stride-to-stride variability, compared to the TD group. There were no statistically significant differences in side-to-side symmetry between groups. Ankle dorsiflexion range of motion was related to several of the gait measures.
Clinical trials investigating gait interventions during the early years of walking in children with CP should be conducted to determine if treatment can reduce the functional limitations that are present during the emergence of walking skills. Further investigation should examine variability and symmetry in the kinematics, kinetics, and muscle activity patterns of early walkers with CP, and the effect of treatment on the variability and symmetry of walking characteristics.
cerebral palsy; gait; variability; symmetry; early walking
To assay if plasma antibody levels in children with autism or developmental delays (DD) differ from those with typical development as an indicator of immune function and to correlate antibody levels with severity of behavioral symptoms.
Plasma was collected from children with autistic disorder (AU; n=116), DD but not autism (n=32), autism spectrum disorder but not full autism (n=27), and age-matched typically developing (TD) controls (n=96). Samples were assayed for systemic levels of immunoglobulin (IgG, IgM, IgA, and IgE) by enzyme-linked immunosorbent assay. Subjects with autism were evaluated using the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview—Revised, and all subjects were scored on the Aberrant Behavior Checklist (ABC) by the parents. Numerical scores for each of the ABC subscales as well as the total scores were then correlated with Ig levels.
Children with AU have a significantly reduced level of plasma IgG (5.39±0.29 mg/mL) compared to the TD (7.72±0.28 mg/mL; P<0.001) and DD children (8.23±0.49 mg/mL; P<0.001). Children with autism also had a reduced level of plasma IgM (0.670.06mg/mL) compared to TD (0.79±0.05 mg/mL; P<0.05). Ig levels were negatively correlated with ABC scores for all children (IgG: r=−0.334, P<0.0001; IgM: r=−0.167, P=0.0285).
Children with AU have significantly reduced levels of plasma IgG and IgM compared to both DD and TD controls, suggesting an underlying defect in immune function. This reduction in specific Ig levels correlates with behavioral severity, where those patients with the highest scores in the behavioral battery have the most reduced levels of IgG and IgM.
Autism; immunoglobulin; behavior; IgG
The purpose of this study was to examine the differences in gait profile between patients with knee osteoarthritis (OA) and healthy control and to create motion characteristics that will differentiate between them.
Twenty three patients diagnosed with knee OA and 21 healthy matched controls underwent a gait test using a sensor system (gaitWALK). Gait parameters evaluated were: stride duration, knee flexion range of motion (ROM) in swing and stance. T-Test was used to evaluate significant differences between groups (P < 0.05).
Patients with knee OA had significant lower knee flexion ROM (10.3° ± 4.0°) during stance than matched controls (18.0° ± 4.0°) (p < 0.001). Patients with knee OA had significant lower knee flexion ROM (54.8° ± 5.5°) during swing than matched controls (61.2° ± 6.1) (p = 0.003). Patients with knee OA also had longer stride duration (1.12 s ± 0.09 s) than matched controls (1.06 s ± 0.11 s), but this was not statistically significant (p = 0.073). Motion characteristics differentiate between a patient with knee OA and a healthy one with a sensitivity of 0.952 and a specificity of 0.783.
Significant differences were found in the gait profile of patients with knee OA compared to matched control and motion characteristics were identified. This test might help clinicians identify and evaluate a knee problem in a simple gait test.
Osteoarthritis; Gait; Electronic measurement systems
We determined the effect of claudication pain on temporal and spatial gait characteristics, and on ambulatory symmetry at preferred and rapid self-selected walking paces in patients with unilateral peripheral arterial disease (PAD).
Twenty-eight patients with PAD limited by intermittent claudication were studied. Patients ambulated at their preferred and rapid paces over a 24-foot portable gait mat system while they were pain-free and after experiencing claudication pain. The order of the pain-free and painful walking trials was randomized, and the following gait parameters were obtained: velocity, cadence, stride length, swing time, stance time, single-support time, and double-support time.
During the self-selected rapid pace, patients walked 3% slower (p = 0.020) while in pain due to a 3% shorter stride length (p < 0.001), and they were in double stance longer (p = 0.024). Claudication pain in the symptomatic leg resulted in an increase in single-stance (p = 0.007). Furthermore, gait became asymmetrical with pain, as the symptomatic leg spent a higher percentage of the gait cycle in the swing phase (p < 0.01), and lower percentages in stance (p < 0.01) and single-stance (p < 0.01) than the asymptomatic leg. Ambulation was symmetrical for all measures during the pain-free trial.
Claudication pain slows ambulatory velocity at preferred and rapid paces, and increases asymmetry when ambulatory function is challenged with rapid walking. The reduced ambulatory speed with the development of claudication pain may be an adaptation to elicit a safer and less destabilizing gait pattern.
The authors examined the changes in bipedal gait of toddlers in the anteroposterior (AP) and mediolateral (ML) directions, as a set, at the onset of independent gait and 1 month after onset. Two groups with distinctly different dynamic resources were studied: 8 toddlers with typical development (TD) and 8 toddlers with Down syndrome (DS). Three-dimensional kinematic data were collected, and gait parameters, such as walking speed, stride length, and stride frequency, as well as the ratio of exchange between potential energy and kinetic energy of the center of mass (COM), were calculated. Displacement of the COM in the AP and ML directions were also analyzed. For some gait variables, toddlers with DS seemed to show more mature values at walking onset than their peers with TD. Those group differences reversed and increased by Visit 2. When the authors considered the motion of the COM of the system, it became clear that the qualitative differences between those groups were characterized primarily by constraints in the ML direction. The authors propose that establishment of coupling between AP and ML oscillations is a key component for the emergence of independent bipedal walking for both populations.
dynamic strategies; mediolateral control; stability constraints; walking onset