Gait Frequency Research Articles

Is primate-like quadrupedalism necessary for fine-branch locomotion? A test using sugar gliders ( Petaurus breviceps)

Locomotor features shared by arboreal marsupials and primates are frequently cited as a functional complex that evolved in the context of a “fine branch niche.” Adaptation to a fine branch niche cannot be understood without considering that small and large arboreal mammals may differ in their biomechanical response to a given branch size. We tested the effects of substrate diameter and orientation on quadrupedal kinematics in a small arboreal marsupial (the sugar glider, Petaurus breviceps). P. breviceps individuals were filmed moving across a flat horizontal surface and on horizontal, inclining and declining poles of diameter 2.5, 1.0, and 0.5 cm. Gait frequencies, limb phases, speeds and duty factors were compared across substrate conditions. P. breviceps had a clear preference for lateral sequence/diagonal couplets gaits, regardless of substrate type, diameter or orientation. Limb phase was significantly influenced by substrate type (higher limb phases on poles vs. the flat surface) and by orientation (higher limb phases on inclined vs. horizontal poles), but was not influenced by pole diameter. Speed was lowest on declines, and duty factors (at a given speed) were highest on the flat board, smallest pole, and on declines. P. breviceps exhibited some parallels, but also some departures from the characteristic patterns of other arboreal marsupials and primates. Notably, limb phase values, on average, remained lower in P. breviceps than those recorded for primates or other arboreal marsupials. We suggest that arboreal mammals of different body sizes may use dissimilar, but apparently equally successful strategies for navigating a “fine branch niche.”

Effects of Motor Control Intervention for Children With Idiopathic Toe Walking

To describe and evaluate the effects of motor control intervention in young children diagnosed with idiopathic toe walking. Five children received motor control intervention in a multiple-case series design using a nonconcurrent, variable baseline. Multiple gait measures were taken before and during the intervention phase. Pre- and posttreatment measures of gross motor development and ankle dorsiflexion range of motion were compared. During the intervention phase, heel strike frequency showed an upward slope for 1 participant, slight upward trends for 3 participants, and no change for 1 participant. Parents indicated minimal gait change within the children's regular environments. Gross motor skill scores increased but were not statistically significant. Passive ankle range of motion improved and was maintained (P = .002). Presentation of children with idiopathic toe walking varies and refinement is needed for gait measures and assessment methods. Intervention improved ankle mobility, but additional components appear necessary to attain spontaneous heel-toe gait.

Predicting Falls Among Psychiatric Inpatients: A Case-Control Study at a State Psychiatric Facility

Predicting Falls Among Psychiatric Inpatients: A Case-Control Study at a State Psychiatric Facility

Three-D gait patterns before and after total hip arthroplasty

To determine how selected gait parameters may change as a result of total hip arthroplasty (THA). From February 2006 to February 2007 the study was performed on 53 osteonecrosis of femoral head subjects prior to and 6 weeks, 3, 6 and 12 months after total hip arthroplasty surgery. Gait analysis was performed using the three-dimensional Infrared-based system (Dalian Dong Fang Xin Rui Company, China). Kinematic data were recorded for the lower limb. The results obtained from the osteonecrosis of femoral head subjects were compared with those of 40 individuals without osteonecrosis. Using a three-dimensional motion analyzer, the following were measured: (1) gait speed, stride length, cadence; (2) step length, stride width; (3) standing phase time, walking phase time; (4) gait cycle time, Joint movement angular. Compared with persons before total hip arthroplasty, THA patients showed significantly increased gait speed, gait frequency, step length and affected limb stand phase (P < 0.01). Angle timetable: preoperative hip-maximum flexion was 15 degrees, post-extension was 8 degrees, knee-maximum flexion was 70 degrees, ankle-maximum flexion was 15 degrees. Postop hip-maximum flexion was 27, post-extension was 17 degrees, knee-maximum flexion was 50 degrees, ankle-maximum flexion was 14 degrees; parameters of hip, knee between preoperative and postoperative was significance (P < 0.01). These results suggest that 3-D gait analysis before and after total hip arthroplasty can evaluate precisely hip vitodynamics variation.

Simulating the Hip and Knee Behavior of a Biped by Means of Nonlinear Oscillators

Nervous networks in the spinal marrow are capable to produce rhythmic movements, such as: swimming, jumping, and walking. These specialised nervous systems are known as central pattern generators (CPGs). Nonlinear os- cillators can be used in control systems of locomotion as pattern generators similar to the pattern of human gait, providing the approach trajectories of the legs. The objective of this work is to present the simulation of the biped gait using a cen- tral pattern generator formed by coupled nonlinear oscillators. Using nonlinear oscillators with integer relation of fre- quency, the transient motion and stable limit cycles of the network formed by oscillators were determined, showing the behavior of the hip and knee angles. Modification of the step length and gait frequency can be obtained by means of the change of few parameters in the oscillators.

Movement disorders in Rett syndrome: An analysis of 60 patients with detected MECP2 mutation and correlation with mutation type

Rett syndrome (RS) is one of the best human models to study movement disorders. Patients evolve from a hyperkinetic to a hypokinetic state, and a large series of abnormal movements may be observed along their lives such as stereotypies, tremor, chorea, myoclonus, ataxia, dystonia, and rigidity. The aim of this work was to analyze movement disorders in RS patients with a detected MECP2 mutation, as well as their correlation with genotype, in a clinically and genetically well-characterized sample of patients, and thus contribute to redefine the clinical profile of this disease. In this study, we included 60 patients with detected MECP2 mutations. These were categorized and grouped for analysis, according to (1) type of change (missense or truncating, including nonsense and frameshift but also large deletions) and (2) location of the mutation. Differences were found concerning the frequency of independent gait, dystonia, type of tremor, and global score severity when comparing the group of patients with missense and truncating mutations. We also found differences in the presence, distribution, severity, or type of movement disorders in the two groups of patients according to the median duration of the disease (less than 60 months; 60 months or more). We conclude that movement disorders seem to reflect the severity and rate of progression of Rett disorder, patients with truncating mutations presenting a higher rate and more severe dystonia and rigid-akinetic syndrome, when comparing groups with similar time of disease evolution.

Pedestrian-induced vibrations on footbridges: advanced response analysis

Pedestrian-induced vibrations (PIV) on footbridges, overpasses, and floors are attracting more attention by designers and are becoming as important to dynamic excitation to consider as wind and earthquakes. A key reason for this trend is the public awareness and higher performance standards set on new projects where better comfort is sought and lively structures are less tolerated. At the same time, more efficient material utilization and new construction methods are producing more efficient structures with less capability to dissipate the energy input (low damping) and, as a result, are more sensitive to dynamic excitations. In addition, recent research has led to an improved understanding of the pedestrian vibration problem, and with the advances in both practical and refined analytical methods, designers may better determine what vibration control measures are appropriate for an optimized design. This paper presents the basics of the PIV problem and a new method for direct time domain simulations of PIVs allowing or realistic evaluation of a bridge's dynamic performance and evaluation of comfort to its users. Based on statistical distributions of key parameters such as gait frequency, phase and length, personal weight, and type of activity, a wide variety of loading scenarios may be readily evaluated. Most importantly, the hypothesis of 'lock-in' can be verified, which allows less conservative response estimates derived from methods based on formulae that assume post lock-in conditions. A brief discussion on vibration control is also included.

Gait and posture impairment, parkinsonism and cognitive decline in older people

Our objective was to examine the frequency of gait and posture impairment and parkinsonism in 3 waves of the Canadians Study of Health and Aging (CSHA) and to determine their relationship to the development of cognitive impairment-not dementia (CIND) and dementia. A secondary analysis of a Canadian population-based cohort study was performed. People 65 years of age and older without cognitive impairment or dementia underwent examination for the presence of gait or posture impairment (GPI) or parkinsonism (based on the presence of 2/3 signs among resting tremor, rigidity or bradykinesia), both defined by a clinical examination. Risk for development of cognitive impairment or dementia was examined at 5 and 10 year follow up in pre-specified logistic regression models adjusted for age, sex, education and in separate models, frailty. The frequency of GPI ranged from 25 to 30% in cognitively unimpaired to 46-53% in CIND and demented subjects. Parkinsonism was more common with increasing cognitive impairment at each wave of the CSHA. Both GPI and parkinsonism predicted cognitive decline. Frailty reduced, but did not eliminate the impact of these motor measures and was itself a significant predictor of cognitive decline. In conclusion, motor impairment and frailty are common in older people and are associated with an increased risk of cognitive decline and dementia. GPI is common in CIND, while GPI and parkinsonism are both common in dementia.

Mechanosensation and mechanical load modulate the locomotory gait of swimmingC. elegans

Animals move through their environments by selecting gaits that are adapted to the physical nature of their surroundings. The nematode Caenorhabditis elegans swims through fluids or crawls on surfaces by propagating flexural waves along its slender body and offers a unique opportunity for detailed analysis of locomotory gait at multiple levels including kinematics, biomechanics and the molecular and physiological operation of sensory and motor systems. Here, we study the swimming gait of C. elegans in viscous fluids in the range 0.05-50 Pa s. We find that the spatial form of the swimming gait does not vary across this range of viscosities and that the temporal frequency of the swimming gait only decreases by about 20% with every 10-fold increase in viscosity. Thus, C. elegans swims in low gear, such that its musculature can deliver mechanical force and power nearly 1000-fold higher than it delivers when swimming in water. We find that mutations that disrupt mechanosensation, or the laser killing of specific touch receptor neurons, increase the temporal frequency of the undulating gait, revealing a novel effect of mechanosensory input in regulating the putative central pattern generator that produces locomotion. The adaptability of locomotory gait in C. elegans may be encoded in sensory and motor systems that allow the worm to respond to its own movement in different physical surroundings.

Kinematic cues for person identification from biological motion

We examined the role of kinematic information for person identification. Observers learned to name seven walkers shown as point-light displays that were normalized by their size, shape, and gait frequency under a frontal, half-profile, or profile view. In two experiments, we analyzed the impact of individual harmonics as created by a Fourier analysis of a walking pattern, as well as the relative importance of the amplitude and the phase spectra in walkers shown from different viewpoints. The first harmonic contained most of the individual information, but performance was also above chance level when only the second harmonic was available. Normalization of the amplitude of a walking pattern resulted in a severe deterioration of performance, whereas the relative phase of the point lights was only used from a frontal viewpoint. No overall advantage for a single learning viewpoint was found, and there is considerable generalization to novel testing viewpoints.

Equine locomotor analysis on vet‐gates in endurance events

Fatigue during endurance rides might induce changes in gait pattern that could be difficult to distinguish from subtle lameness. To assess changes in gait pattern en route, in fore(FL) and hindlimbs (HL) and establish differences between excellent (EP) and good performers (GP). Seventy-five sound and fit horses that completed endurance rides of 80 km were filmed at trot in the vet-gates (VGs) prior to competitions (VGO), and at 29 km (VG1), 59 km (VG2) and 80 km (VG3). Mean gait velocity (V), stride length (SL), duration (SD) and frequency (SF) were measured. Also, stance (StD), swing (SwD), braking (BrD) and propulsion (PrD) durations were determined in the 4 limbs and expressed as % of SD. Horses trotted with a significant lower V at VG3 in comparison to VG0 (mean +/- s.d. 2.3 +/- 0.6 m/sec, 3.3 +/- 0.6 m/sec) and showed a shorter SL (1.5 +/- 0.4 m and 2.2 +/- 0.3 m in VG0 and VG3). Regression analysis confirmed that the reduced SL at VG3 was due to the lower V. Horses in VG3 presented longer FL-StD (46.2 +/- 4.7%, 38.1 +/- 4.6%), BrD (22.0 +/- 2.5%, 16.9 +/- 2.5%) and PrD (24.1 +/- 21%, 21.5 +/- 2.47%) compared to VG0. In VG0, HL-PrD (23.0 +/- 3.0%) and HL-BrD (18.7 +/- 1.8%) were longer than FL-PrD (21.5 +/- 2.47%) and FL-BrD (16.9 +/- 2.5%). EP showed fastest V and longer SL at VG0, and VG3 than GP (P<0.05). Sound endurance horses undergo changes in gait pattern during competition, mainly due to reduction of V. Some differences exist between FL and HL, and EP show higher V and SL in the VGs. Understanding of the locomotor effect of fatigue will provide an objective basis for the assessment of soundness during endurance events.

The status of gait assessment among physiotherapists in the United Kingdom

Toro B, Nester CJ, Farren PC. The status of gait assessment among physiotherapists in the United Kingdom. Arch Phys Med Rehabil 2003;84:1878–84. Objectives To evaluate how physiotherapists are trained in and use clinically orientated gait assessment tools and instrumented gait analysis, and to identify if a need exists for a standardized methology. Design Survey. Setting UK National Health Service. Participants Physiotherapists working with a variety of patient groups in 210 randomly selected Health Care Trusts. Interventions Not applicable. Main outcome measures Amount of gait assessment training, frequency of gait laboratory use, types and frequency of standardized gait assessment tools used, and expressed need for a gait assessment tool in clinical practice. Results A total of 1826 (43.5%) physiotherapists responded. Management of abnormal gait constituted a major aspect of physiotherapy practice; yet, there was no systematic use of standardized gait assessment tools. Gait video images were typically collected and analyzed without the use of standardized protocols. Only 23.1% of all respondents had a patient assessed in a gait laboratory. Clinicians indicated that they need training in gait assessment (66.4%) and desire guidance at a national level. Exactly 91.8% of physiotherapists requested a new gait assessment tool that can be used easily and quickly within a busy schedule without compromising reliability and validity. Conclusions Gait assessment plays a pivotal role for physiotherapists managing gait problems. The challenge for developers of gait assessment tools is to find a balance between the practicalities of use and scientific merit.

Differential Method of Characterizing Gait Strategies From Step Lengths and Frequencies: Strategy of Velocity Modulation

The differential method consists of the analysis of the variation of gait parameters length, frequency, and velocity with respect to their mean values, respectively, ΔL = L — Lm , Δf = f — fm , and Δv = v – vm , where Lm , fm , and vm represent the mean values of those parameters. Assuming that the strategy of modulation of velocity implies that L and f are functions of v and that statistical analyses of ratios ΔL/Δv and Δf/Δv have established that there is a very significant linear correlation, close to 1, between those ratios, the mathematical procedure allows one to determine the equation of step length, L = a · f + b · v + K, where a and b are the slope and the intercept of the linear regression and K is close to Lm . The equation was experimentally tested on 140 gait sequences performed by 6 participants and for gait velocities ranging from 0.6 to 2.2 m/s and was found to be very representative of all individual values. The differential method provides another way of using the derivative of velocity, v = L·f, to characterize the strategy of velocity modulation, which then permits one to determine the linear equation of velocity, v = f · Lm + L · fm — Lm · fm , and to show that the respective parts played by each parameter in the progression velocity are approximately equal. The author establishes the uniqueness of the different linear adjustments and discusses the differential method's own modes of use, that is, interindividually or globally.

Investigations into the role of the thyrohyoid muscles in the pathogenesis of dorsal displacement of the soft palate in horses.

Contributes to the understanding of the pathogenesis of dorsal displacement of the soft palate during exercise so that management of this condition could be enhanced. That the thyrohyoid muscles play an important role in the stability of the laryngo-palatal relationship and that dysfunction of these muscles leads to dorsal displacement of the soft palate (DDSP) during exercise. Ten horses were exercised on a high-speed treadmill under 4 different treatment conditions: control conditions (n = 10), after resection of thyrohyoid muscles (TH, n = 10), after sham-treatment (n = 5), or after restoration of function of the thyrohyoid muscles with surgical sutures (prosthesis-treatment, n = 6). During trials, the following determinations were made: videoendoscopy of the upper airway, gait frequency and pharyngeal and tracheal static pressures. None of the 10 horses developed DDSP during 2 separate treadmill-exercise trials under the control conditions. Seven of the 10 horses developed DDSP after resection of the TH muscles, 4 of 5 of these horses still experienced DDSP after sham-treatment, but 5 of 6 horses no longer experienced DDSP at exercise after the prosthesis-treatment. There were significant anomalies in airway pressures, respiratory frequency, and occurrence of DDSP in both the TH resection and sham-treatment conditions compared to control conditions. In contrast, no statistical differences were noted in any of the parameters measured between the prosthesis-treatment and control conditions. That the function of the TH muscles is important to the stability of the laryngo-palatal relationship and plays a role in the pathophysiology of exercise-induced DDSP. Management of horses with DDSP could be enhanced by restoring the function of the TH muscles.

A point-mass model of gibbon locomotion

In brachiation, an animal uses alternating bimanual support to move beneath an overhead support. Past brachiation models have been based on the oscillations of a simple pendulum over half of a full cycle of oscillation. These models have been unsatisfying because the natural behavior of gibbons and siamangs appears to be far less restricted than so predicted. Cursorial mammals use an inverted pendulum-like energy exchange in walking, but switch to a spring-based energy exchange in running as velocity increases. Brachiating apes do not possess the anatomical springs characteristic of the limbs of terrestrial runners and do not appear to be using a spring-based gait. How do these animals move so easily within the branches of the forest canopy? Are there fundamental mechanical factors responsible for the transition from a continuous-contact gait where at least one hand is on a hand hold at a time, to a ricochetal gait where the animal vaults between hand holds? We present a simple model of ricochetal locomotion based on a combination of parabolic free flight and simple circular pendulum motion of a single point mass on a massless arm. In this simple brachiation model, energy losses due to inelastic collisions of the animal with the support are avoided, either because the collisions occur at zero velocity (continuous-contact brachiation) or by a smooth matching of the circular and parabolic trajectories at the point of contact (ricochetal brachiation). This model predicts that brachiation is possible over a large range of speeds, handhold spacings and gait frequencies with (theoretically) no mechanical energy cost. We then add the further assumption that a brachiator minimizes either its total energy or, equivalently, its peak arm tension, or a peak tension-related measure of muscle contraction metabolic cost. However, near the optimum the model is still rather unrestrictive. We present some comparisons with gibbon brachiation showing that the simple dynamic model presented has predictive value. However, natural gibbon motion is even smoother than the smoothest motions predicted by this primitive model.

Pectoral fin locomotion in the striped surfperch. I. Kinematic effects of swimming speed and body size

Swimming trials at increasing velocity were used to determine the effects of steady swimming speed on pectoral fin kinematics for an ontogenetic series of striped surfperch Embiotoca lateralis, ranging from 6 to 23 cm in standard length (SL). The fin stroke cycle consisted of a propulsive period, the duration of fin abduction and adduction, and a 'refractory' period, during which the fin remained adducted against the body. Pectoral fin-beat frequency (fp) measured as the inverse of the entire stride period, as in past studies, increased curvilinearly with speed. Frequency, calculated as the reciprocal of the propulsive period alone, increased linearly with speed, as shown previously for tail-beat frequency of fishes employing axial undulation. Fin-beat amplitude, measured as the vertical excursion of the pectoral fin tip during abduction, increased over a limited range of low speeds before reaching a plateau at 0.35&shy;0.40 SL. Pectoral fin locomotion was supplemented by intermittent caudal fin undulation as swimming speed increased. At the pectoral&shy;caudal gait transition speed (Up-c), frequency and amplitude attained maxima, suggesting that the fin musculature reached a physiological limit. The effects of body size on swimming kinematics differed according to the method used for expressing speed. At a given absolute speed, small fish used higher stride frequencies and increased frequency at a faster rate than large fish. In contrast, the relationship between fp and length-specific speed (SL s-1) had a greater slope for large fish and crossed that for small fish at high speeds. We recommend that comparisons across size be made using speeds expressed as a percentage of Up-c, at which kinematic variables influencing thrust are size-independent.

Effects of withdrawal of antiparkinson medication on gait and clinical score in the Parkinson patient

Objective testing of medication is needed in Parkinson's disease. Gait analysis and clinical evaluation were done before and after a 24-h withdrawal of Parkinson medication. Twelve patients with stable, mild to moderate idiopathic parkinsonism (Hoehn and Yahr 1-3; seven men and five women mean age 59.9 years, mean duration of disease 6 years) were tested with gait analysis walking in five different paces. Velocity of gait, stride length and stride frequency, as well as stride length at constant velocity were calculated. Regression coefficients for the relation between stride length and stride frequency were also calculated. Clinical scoring according to the Webster rating scale and Hoehn and Yahr were performed for each test. Clinical functional assessment with a specially designed rise and gait test, an arm cycle test and the wooden rods test were done. Evaluated clinical score increased significantly (p less than 0.05) using both clinical tests. Maximum gait velocity (p less than 0.01), stride length at max. velocity (p less than 0.01), and stride length at constant velocity (p less than 0.03) were significantly decreased without medication. Stride frequency did not change. In the functional assessment tests only performance on the arm cycle test (p less than 0.03) was less well performed without medication. There was correlation between clinical score, gait and clinical functional assessment. The methods used detected significant changes in variables of gait as well as clinical scoring and some of the clinical functional assessments when medication was withdrawn for a 24-h period. The methods were useful in evaluation of pharmacological treatment.

Do cardiorespiratory frequencies show entrainment with hopping in the tammar wallaby?

Breathing, heart and gait frequencies, tidal volume, cardiac output, and rates of oxygen consumption were measured in tammar wallabies (Macropus eugenii Desmarest) hopping on a treadmill. At speeds greater than 1.6 ms-1 the rate of metabolic power consumption was independent of hopping speeds. Blood lactate levels within the speed range where VO2 was independent of speed showed a mean increase of 4.8 mmol l-1. During bipedal hopping, the frequencies of breathing and limb movement are phase-locked in the ratio of 1:1. Inspiration begins as the animal leaves the ground and may be a passive process driven by a visceral piston. A relatively large central tendon in the diaphragm may correlate this function. Unlike breathing frequencies, cardiac frequencies show no entrainment with hopping. The site of dissipation of the presumed large arterial pressure excursion is unknown.

When and how does steady state gait movement induced from upright posture begin?

The aim of this research was to study when and how the stationary process of gait begins when walking starts from upright posture. The subject initially stood up on a large force plate, then walked. Three conditions of speed (slow, normal, fast) were examined. Five subjects participated in the experiment. A total of 105 trials were performed. The results show that, at the end of the first step, the progression velocity of the center of gravity is not significantly different from the mean progression velocity of gait during the second step of gait and that the time necessary to reach steady state gait from initial posture phase is constant. Furthermore, the frequency of the first step, when compared to published values of the steady state gait frequency, is not significantly different from these frequencies. It can be concluded that the aim of the gait initiation process is to place the subject in steady-state gait within the first step, in an invariant time which is dependent only on the body segment parameters of each subject.