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Burrows are used by many mammals to escape predation, cache food and for parturition. Although the construction of burrows has been studied in some taxa, the locomotion while inside of them has received scant attention. In this study we collected simultaneous video and force data to characterize gaits, kinematics, peak ground reaction forces (GRFs) and external mechanical energy profiles in the domestic ferret, an animal that displays the typical morphology and behaviors associated with subterranean adaptations in mustelines. We compared kinematics and kinetics between locomotion in two experimental conditions: subterranean, simulated by a Plexiglass tunnel designed such that the ferrets' peak back height was reduced by 40% and hip height by 25%, and epigean, or unconstrained overground. Despite the large change in posture, a striking number of gait and force variables were not statistically different between experimental conditions. In both subterranean and epigean conditions, the ferrets in our study traveled at similar average velocities (approximately 0.8 m s(-1)), preferred to use a lateral-sequence diagonal-couplet gait, and were more likely to demonstrate the in-phase fluctuations of external mechanical energy indicative of running mechanics (68% of all trials). The ferrets conformed to gait and mechanical patterns seen in a variety of other small (

OBJECTIVES: To evaluate the usual gait speed of asymptomatic adult and elderly Brazilians with a 10-meter walk test and to compare the results with foreign reference values. METHODS: Seventy-nine asymptomatic volunteers >40 years old of both genders were assessed. After anamnesis, anthropometry and the application of a habitual physical activity questionnaire, the volunteers were submitted to a 10-meter walk test at usual speed by means of which gait speed, the number of steps and length of stride were calculated. RESULTS: Except for age, all study variables were significantly lower in women. Subjects >70 years old presented a significantly lower gait speed than subjects between 40 and 49 years old and between 50 and 59 in both men (1.09±0.18 m/s, 1.35±0.11 m/s and 1.34±0.22 m/s, respectively) and women (1.02±0,10 m/s, 1.27±0.20 m/s and 1.27±0,15 m/s), respectively). Gait speed showed moderate correlations with age (r=-0.41, p

Objective: The purpose of this study is to constitute a normative walking kinematic database and to investigate the differences between 7-11 aged children and between the left and right sides of those age groups. Materials and Methods: Fifty children between the 7 and 11 years old (10 from each age group) participated in this study. The measurements were made with Zebris© CMS 70 P 3D motion analysis system. Flexion- extension, abduction-adduction angles of the hip joint, the fl exion-extension of the knee and ankle joints and foot rotations for each age group for both sides were recorded. Results: Even all the groups’ gait patterns were similar with the literature, 9 years old group has lower knee fl exion and higher ankle extensions (p

Older adults look at the ground more while they are walking than younger adults do. In the present study, the effect of blocking that exproprioceptive visual information on the walking pattern of older adults was investigated. The first 0.75 m of the floor in front of healthy young adults (n = 10, mean age = 26.0 years) and 2 groups of older adults (n = 10, mean age 65.7 years; and n = 9, mean age = 75.9 years) was occluded. The dependent variables were step velocity, step length, and step frequency. The effect of the manipulation on those kinematic variables increased with age. The older adults had a significant increase in velocity and step length. The possible use of optic flow information from the ground to regulate the velocity of self-motion is discussed.

We propose a two-layer gait modeling framework for estimating unknown gait kinematics from a monocular camera. Dual gait generative models are introduced to represent a human gait both visually and kinematically via a few latent variables. A new manifold learning method is developed to create two sets of gait manifolds that capture the gait variability among different individuals at both whole and part levels and by which the two generative models can be integrated together for video-based gait estimation. A two-stage statistical inference algorithm is employed for whole-part gait estimation. The proposed algorithm was trained on the CMU Mocap data and tested on the HumanEva data, and the experiments show very promising results on estimating the kinematics of unknown gaits.

Footswitches, instrumented insoles, and forceplates are commonly used for detecting footfall instants during treadmill walking. This study aimed to explore the feasibility of using an optoelectronic light curtain for detecting initial foot contact (FC) and toe-off (TO) instants during treadmill walking. A commercial light curtain comprised of an array of parallel infrared light beams was installed 5 mm above the treadmill belt. Ten subjects walked on the treadmill at 0.5, 1.0 and 1.4 m/s and their gait was captured using seven optoelectronic cameras. Footswitches were secured over the heel and big toe of the right foot and the corresponding areas of the shoe. Footfall instants from the light curtain, markers, and foot footswitches were compared with the shoe footswitches serving as a criterion. The respective time differences were computed for each step and used to evaluate the agreement with the criterion and variability across subjects. FC instants from foot footswitches were on average within 10 ms of the criterion. Both video and light curtain FC instants were detected at least 30 ms before the criterion. For TO, both the foot footswitches and video instants preceded the criterion. In contrast, the TO from the light curtain occurred >110 ms after the criterion but the variability was the smallest. The results indicated that using a light curtain for detecting footfall instants is feasible. The advantages of light curtain are relatively low cost, no subject preparations, and real-time signals. Greater accuracy is expected with further optimization of the setup.

Physical rehabilitation is critical in optimizing the functional abilities of persons following a lower extremity amputation. Unfortunately, limitations in gait performance are common even in those persons who are considered to be highly functional. The purpose of this case report is to describe changes in gait kinematics and physiologic energy cost resulting from a virtual reality based gait training program that capitalizes on real-time feedback to facilitate improvement in walking ability.

Context: Lower extremity alignment, range of motion (ROM), gait kinematics, and strength has been reported to be predisposed condition of Medial Tibial Stress Syndrome (MTSS). However, foot related measures were selectively assessed to examine the characteristics of MTSS. Moreover, previous studies examined only direct effect of potential risk factors on MTSS, however, there should be indirect effect of lower extremity alignment on MTSS by altering lower extremity gait biomechanics during running. Objectives: The purposes of this study are: 1) to investigate the characteristics of lower extremity static alignment, ROM, and strength, and gait kinematic measures among those with MTSS; and second, to identify the strongest factors that account for MTSS status in runners; 2) to investigate the direct and indirect effects of lower extremity alignment and gait kinematic measures on MTSS status, while relevant extrinsic factors are controlled, 3) to classify measures of static proximal and distal alignment and gait kinematics that are highly correlated to each other in order to develop latent variables (factors) that reduce the dimensionality of potential predictor measures. Design: A case control design. Setting: Laboratory Patients or other participant: A total of 74 recreational and competitive runners (37 normal, 37 MTSS injured) were recruited. Intervention: The independent variable was MTSS status. Main Outcome Measures: The dependent variables include 13 lower extremity alignment, 10 lower extremity (ROM), 7 strength, 20 maximum joint kinematics, and 10 total excursion measures during running (2.6m/s). All the measurements were performed three times by a single examiner who established intersession intra-tester reliability of at least ICC=.80 for each alignment measures. The difference between the MTSS and the control in all measures 111 was analyzed via independent T-test analysis. Those measures identified as being statistically significant (P

A number of in vitro, invasive in vivo, and non-invasive marker based multi-segment foot models (MSFMs) have reported significant motion in the articulations distal to the calcaneus during gait. Few studies, however, have applied a MSFM to the investigation of the effect of foot posture on gait kinematics. Differences in stance phase kinematics between participants with low-mobile (LMF) (n = 11) versus ‘‘typical’’ (TYPF) (n = 11) foot postures were investigated using a multi-segment medial foot model. Three-dimensional position and stance phase excursions of four functional articulations (rearfoot complex [RC], calcaneonavicular complex [CNC], medial forefoot, first metatarsophalangeal complex) were quantified using an eight optical camera motion analysis system (Vicon Motus, Vicon Motions Systems, Centennial, CO) and a custom written software program (Matlab 7.0.1, The MathWorks, Natick, MA), respectively. Excursions during four subphases of stance phase (loading response, midstance, terminal stance, pre-swing) at each of the functional articulations were compared using multivariate analyses of variance ( a 0.05). Results revealed significantly decreased LMF group CNC abduction excursion (p = 0.047) during midstance. During pre-swing, LMF group RC inversion excursion was significantly increased (p = 0.032) and eversion excursion was significantly decreased (p = 0.003) compared to the TYPF group. When these differences are considered in conjunction with the kinematic patterns of other foot/leg segments and functional articulations, the changes may suggest dysfunction of normal leg-calcaneus coupling and the constrained tarsal mechanism associated with low-mobile foot postures.

The current method for fabricating prosthetic sockets is to modify a positive mold to account for the non-homogeneity of the residual limb to tolerate load (i.e., rectified socket). We tested unrectified sockets by retaining the shape of the residual limb, except for a distal end pad, using an alginate gel process instead of casting. This investigation compared rectified and unrectified sockets. Forty-three adults with unilateral transtibial amputations were tested after randomly wearing both rectified and unrectified sockets for at least 4 weeks. Testing included a gait analysis, energy expenditure and Prosthesis Evaluation Questionnaire (PEQ). Results indicated no differences between sockets for gait speed and timing, gait kinematics and kinetics, and gait energy expenditure. There were also no differences in the Prosthetic Evaluation Questionnaire and 16 subjects selected the rectified socket, 25 selected the unrectified socket, and 2 subjects selected to use both sockets as their exit socket. Results seemed to indicate that more than one paradigm exists for shaping prosthetic sockets, and this paradigm may be helpful in understanding the mechanisms of socket fit. The alginate gel fabrication method was simpler than the traditional method. The method could be helpful in other countries where prosthetic care is lacking, may be helpful with new amputees, and may be helpful in typical clinics to reduce costs and free the prosthetist to focus more time on patient needs.

In the study, the influence of different boot prototype stiffness on gait kinematics and kinetics was investigated. The boot stiffness was determined by force-deformation measurement while pressing the foot model inserted into the boot by a custom-made robot. Gait analysis was carried out in nine neurologically intact subjects during walking while wearing two different boots with and without carrying a backpack, and differences were statistically tested using ANOVA. The results indicated distinctions in the boot shaft and vamp stiffness. The boot with a softer boot shaft enabled a wider range of motion in the ankle joint leading to more power generation in the ankle joint during the push-off, increased step length and gait velocity. The backpack mostly influenced the pelvis and trunk kinematics. The study has demonstrated the influence of boot shaft stiffness on biomechanical gait parameters and its importance for push-off that manufacturers should take into consideration when optimizing the footwear performance.

Three-dimensional gait analysis data from 134 patients attending routine 10-year post-operative review clinics is presented. Patients were divided into five age groups-54-64 years, 65-69 years, 70-74 years, 75-79 years and over 80 years. A group of 10 normal elderly subjects was also tested. All age groups displayed reduced range of hip flexion/extension, range of knee flexion extension, maximum hip extension and range of hip abduction/adduction and reduced velocity and step length compared to the normal elderly group. However, there was no difference in gait kinematics between the age groups. Patients over 80 years of age displayed significantly reduced range of sagittal plane ankle motion, but this is unlikely to be secondary to hip joint restriction and more likely due to reduced walking speed associated with very elderly subjects. This study reveals that even the youngest hip replacement patients do not attain normal gait kinematics 10-year post-operatively and that muscle atrophy and residual stiffness may influence patient kinematics many years post-operation.

Human movement and its measurement have been of general interest since classical times. Gait analysis is the quantified measurement of movement patterns and forces during walking, which comprise kinematics and kinetics. The actual process of performing such an analysis involves measurement (kinematic and kinetic), storage, retrieval, processing, analysis and presentation. The practical measurement of gait kinematics was not possible until optical technology evolved to facilitate easy and repeatable recording of motion. The kinematic and kinetic measurements allow definition of normal patterns and several key variables have been identified which are thought to characterize gait. This chapter discusses the basics of gait analysis and the progression of the technology.

The paper proposed to analyze the gait kinematics of different physical activity levels. A cross-sectional study, with 60 seniors, divided according to level of physical activity into groups of active, insufficiently active and inactive seniors. The kinematic parameters investigated in gait were stride length, gait speed, distance between the ground and the hallux and the angles of the hip, knee and ankle. Kinovea 0.8 and ImageJ were used for photogrammetric data analysis and STATA 9.2 was used for statistical analysis. Average stride length, gait speed and distance between the hallux and the ground were significantly higher among physically active seniors. As for the ankle joint angle, during the gait phase referred to as toe-off, the angle was greater in the active group (82.98, SD 5.96) compared with the inactive group (86.05, SD 5.44) (p=0.025). Average knee joint angles in degrees during the toe-off phase were 151.02 (SD 10.03) in the active group, 151.12 (SD 7.79) in the insufficiently active and 143.35 (SD 7.08) (p= 0.006) in inactive group. In the acceleration phase the results were 126.81 (SD 7.26), 123.81 (6.60) and 130.4 (6.94) in each group (p=0.015), respectively. Our findings demonstrated that physical activity is important to reduce changes to gait caused by the natural aging process. Physical activity should therefore be widely encouraged among the elderly as a preventive and health promotion in measure this population.

The use of footwear with contoured soles is common in treatment and care of patients with diabetes; these rocker sole shoes are designed to alleviate loading in key areas on the plantar surface of the foot, reducing pressure in key areas and alleviating pain, and potential soft tissue damage. While investigations of pressure changes have been conducted, no quantitative study to date has addressed the three-dimensional (3D) kinematic and kinetic changes that result from using these shoes. Forty subjects were tested wearing both unmodified and double rocker sole shoes, and the resulting motion patterns were compared to assess change caused by the rocker sole. Overall walking speed remained unchanged throughout testing; slightly increased flexion (5 degrees ) was apparent at the hip, knee, and ankle during early and mid-stance. These results demonstrate the maintenance of gait function with minimal kinematic changes when using the rocker sole shoe. Investigations of multisegmental foot motion may reveal additional information about the contour effects; analysis of contour variations may also be warranted to investigate the possibility of controlling motion based on rocker sole parameters.

The purpose of this study was to determine if sagittal plane gait kinematics and kinetics of 7-year-old children differed from those of adults when age-specific anthropometrics were used in the calculations. Joint angles, moments, and power obtained during level walking in 7-year-old children (n=15) were compared to data from adults (n=15). Calculations were performed using age-specific anthropometric data obtained from dual energy X-ray absorptiometry. For most of the variables examined, 7-year-olds were similar to adults, however children demonstrated a diminished peak plantar flexor moment and less peak power absorption and generation at the ankle during late stance. These results provide support for the hypothesis that children lack the neuromuscular maturity, especially at the ankle, to produce an adult-like gait pattern.

Minimally invasive (MI) total hip replacement (THR) supposedly provides improved ambulation in the immediate post-operative period. This study used a prospective blinded design to analyse early post-operative walking ability using gait analysis. Seventeen patients were available for full analysis with nine having had the MI technique and eight having the standard incision (SI) technique. Patients were blinded as to the incision used, as were all physiotherapists and assessors. Differences in temporal-spatial variables and joint kinematics measured 1 day pre-operatively, 2 days post-operatively and 42 days (6 weeks) post-operatively were compared between groups. There was no significant difference in velocity, step length of the affected or unaffected leg, stride length or stance phase duration between the MI and SI groups between any of the timepoints tested. There was no significant improvement in the gait kinematics of the MI group compared to the SI group either 2 days post-operatively or 6 weeks post-operatively. Contrary to previous studies, there was no improvement in early post-operative gait for those patients who received THR using the minimally invasive technique.

Sagittal plane gait analysis was performed on 6 normal children (mean age 7.5/spl plusmn/1.2) and on 4 children (mean age 8.3/spl plusmn/1.2) with myelomeningocele (ML) at the low lumbo-sacral level (L5-S2). Temporal distance parameters and kinematics variables were calculated after digitized video recordings of the subjects. Children with ML show stance phase and double limb support greater than normal. Angles values for the lower limb segments confirm the weakness of triceps and quadriceps muscles for myelomeningocele.

The gait transition models of a quadruped are studied based on gait kinematics and CMAC neural networks are applied to learn and generalize these gait transition models. Three gait transition cases are studied: from wave gait to continuous follow-the-leader gait, from walk to trot, and from trot to gallop. Four solution methods are proposed for solving the gait transition models. Computer simulations are then conducted to evaluate and display the gait transition model. The good transition gaits are then selected to train CMAC neural network gait transition models. The performance of the CMAC gait transition models are evaluated and found to be satisfactory.

A four-segment rigid body model of the foot and ankle has been previously developed by the authors' group which is capable of describing gait kinematics (S.M. Kidder et al., Proc. IEEE EMBS, San Diego, CA, USA, 15(3), p. 1065-6, 1993). A kinetic model for use with that system is described in this study. The kinetic model allows independent foot articulations at the first metatarsophalangeal, talo-navicular, subtalar and talocrural joints. Forces and moments resulting at these joints during the stance phase of gait are described.

Discussion and conclusions: The hypothesis that gait kinematics change in children with CP while walking over a long distance could not be confirmed. A possible explanation for the lack of changes could be that the exercise was not demanding enough, or that the changes only appeared on muscular and/or cardiorespiratory level. In this pilot study fatigue was not directly measured. Further research should explore the relation between fatigue (evaluated by Visual Analogue Scale) and muscle activity (i.e. co-contractions and EMG frequency) but also between fatigue and cardiorespiratory limitations.

Introduction: Slipped upper femoral epiphysis (SUFE) results in hip deformity and femoro-acetabular impingement (FAI). FAI affects hip motion and impacts on gait. The purpose of this study was to quantify the effects of moderate to severe SUFE on 3D gait kinematics and to determine if there were correlations between gait deviations and slip severity. Patients/materials andmethods: Patients referred to the Royal Children’s Hospital for a 3D gait analysis (3DGA) between 2000 and 2009 after pinning in situ of a stable SUFE were studied retrospectively. Inclusion criteria were unilateral SUFE, Southwick Lateral Slip Angle (LSA)≥30◦, [1], no surgical complications, appropriate hip and pelvis radiology and 3DGA. 3DGA was performed with a Vicon motion system (OMG, UK) and followed the Plug in Gait (VICON, UK) protocol. Gait variable score (GVS) and Gait profile score (GPS) [2], were calculated on the study cohort for both the sound and slipped side, compared to 38 paediatric subjects with no gait pathology (NGP), using t-test with unequal variances ( =0.05) in Minitab (Minitab, Inc., USA). Results:30Patients (17Male, 13 Female),with an average age at pinning of 13.3 years (±1.9 years) were included. The average LSA, Klein’s line offset and alpha angle of Noztli were 45.3◦ (±13.0◦), −6.4mm (±8.0mm) and 113.6◦(±13.1◦) respectively. The GPS and all GVS, except pelvic tilt (sound and slip side) and foot progression (sound side), were significantly different compared to the NGP group. Hip rotation and foot progression GVSs as well as GPS were significantly different between the slipped and sound sides. However, no significant correlations were found between GVSs and the radiological measurements.

BACKGROUND Aging is associated with a reduction in gait velocity, which is due to a shortened step length. This study investigated the relationship between joint kinetics and step length. METHODS Three-dimensional gait kinematics and kinetics were measured during usual pace gait in 26 older subjects (average age 79) and in 32 young subjects (average age 26). Gait measures were obtained at maximal velocity in five older subjects. Lower extremity strength was measured in the older subjects on an isokinetic dynamometer. RESULTS Older persons had a 10% shorter step length during usual gait, when corrected for leg length (.65 +/- .07, .74 +/- .04/leg length, respectively, p < .001). Older persons had reduced ankle plantarflexion during late stance (13 +/- 5 degrees, 17 +/- 5 degrees, p = .02) and lower ankle plantarflexor power (2.9 +/- 0.9 W kg-1, 3.5 +/- 0.9 W kg-1, respectively, p = .007). Ankle strength was associated with plantarflexor power developed during late stance (r = .49, p < .001). When gait kinetics were corrected for step length, the older subjects developed 16% greater hip flexor power during late stance than younger subjects (estimate of effect: .15 W kg-1, p = .002). Older subjects were unable to increase ankle plantarflexor power at maximal pace, but increased hip flexor power 72% (1.1 +/- 0.3 W kg-1 to 1.9 +/- 1.0 W kg-1, p = .02). CONCLUSIONS Older subjects had lower ankle plantarflexor power during the late stance phase of gait and appeared to compensate for reductions in plantarflexor power by increasing hip flexor power. Appropriate training of ankle plantarflexor muscles may be important in maintaining step length in advanced age.