Gait patterns of young Japanese women.

Gait patterns of 440 young Japanese women walking along a sidewalk were observed in September. Walking speed, step length and cadence were significantly greater in single walking than in group walking. Time of day, walking direction and clothes did not influence the walking patterns. Step length in heeled shoes was shorter than that in sneakers and flat shoes.     

Sex difference in the pattern of lower limb movement during treadmill walking

To evaluate the characteristics of stereo-typed movement of the lower limb during treadmill walking, the step length and duration of 200 steps were monitored consecutively and calculated by means of a computerized system, consisting of a position sensor, shoes with foot switches and a minicomputer. Eleven male and 10 female subjects walked at various constant speeds ranging from 60-130 m.min-1. Mean, standard deviation (SD) and coefficient of variation (CV) of the time-distance component at each speed were utilized for the assessment of stereotyped movement. When compared with males, females had a tendency to increase their speed by increasing their cadence. The difference of the walking pattern was specifically related to their height. The SD and CV of the time-distance component at a given speed were significantly greater in females than in males. Regression analyses revealed that in the relationship between the walking speeds and the SDs or CVs of the time-distance component, the significant quadratic equations could be fitted. The speed, at which the SD of step length was minimum, was estimated to be about 90 m.min-1 in both males and females. This was regarded as the free walking speed or as the walking speed resulting from a mechanically efficient step length which suited the subject's body size.     

Walking at moderate speed with heel-less shoes increases calf blood flow

This study was designed to examine the physiological and biochemical effects of wearing heel-less shoes over a wide range of walking speeds. Six male students wearing alternately regular shoes and heel-less shoes walked at the constant speeds of 60, 80, 100 and 120 m/min for 10 min on a treadmill at 0% grade. The average heart rate was higher during heel-less shoe trials than when subjects walked in regular shoes at each speed, but differences were not significant. The calf blood flow showed its highest mean value at 80 m/min when subjects walked in heel-less shoes, and at 100 m/min when they walked in regular shoes. However, at walking speeds higher than these, calf blood flow decreased for wearers of both types of shoes. The calf blood flow after 80 m/min was higher when walking in heel-less rather than regular shoes. Blood lactate concentration after walking in heel-less shoes at 120 m/min was significantly higher than basal level, but after walking in regular shoes it was unchanged from the level before walking. Noradrenaline concentration at 120 m/min while walking in heel-less shoes was significantly higher than while walking in regular shoes. In conclusion, walking exercise in heel-less shoes induced an increase of the calf blood flow at a moderate speed, and increased glycogen metabolism and noradrenaline secretion at a faster speed.     

Sex-specific differences in gait patterns of healthy older adults: results from the Baltimore Longitudinal Study of Aging

The effects of normal aging and orthopedic conditions on gait patterns during customary walking have been extensively investigated. Empirical evidence supports the notion that sex differences exist in the gait patterns of young adults but it is unclear as to whether sex differences exist in older adults. The aim of this study was to investigate sex-specific differences in gait among older adults. Study participants were 336 adults (50-96 years; 162 women) enrolled in the Baltimore Longitudinal Study of Aging (BLSA) who completed walking tasks at self-selected speed without assistance. After adjusting for significant covariates, women walked with higher cadence (p=0.01) and shorter stride length (p=0.006) compared to men, while gait speed was not significantly related to sex. Women also had less hip range of motion (ROM; p=0.004) and greater ankle ROM (p<0.001) in the sagittal-plane, and greater hip ROM (p=0.004) in the frontal-plane. Hip absorptive mechanical work expenditure (MWE) of the women was greater in the sagittal-plane (p<0.001) and lower in the frontal-plane (p<0.001), compared to men. In summary, women's gait is characterized by greater ankle ROM than men while men tend to have greater hip ROM than women. Characterizing unique gait patterns of women and men with aging may be beneficial for detecting the early stages of gait abnormalities that may lead to pathology.     

Walking on high heels changes muscle activity and the dynamics of human walking significantly

The aim of the study was to investigate the distribution of net joint moments in the lower extremities during walking on high-heeled shoes compared with barefooted walking at identical speed. Fourteen female subjects walked at 4 km/h across three force platforms while they were filmed by five digital video cameras operating at 50 frames/second. Both barefooted walking and walking on high-heeled shoes (heel height: 9 cm) were recorded. Net joint moments were calculated by 3D inverse dynamics. EMG was recorded from eight leg muscles. The knee extensor moment peak in the first half of the stance phase was doubled when walking on high heels. The knee joint angle showed that high-heeled walking caused the subjects to flex the knee joint significantly more in the first half of the stance phase. In the frontal plane a significant increase was observed in the knee joint abductor moment and the hip joint abductor moment. Several EMG parameters increased significantly when walking on high-heels. The results indicate a large increase in bone-on-bone forces in the knee joint directly caused by the increased knee joint extensor moment during high-heeled walking, which may explain the observed higher incidence of osteoarthritis in the knee joint in women as compared with men.     

Contribution of Step Length to Increase Walking and Turning Speed as a Marker of Parkinson’s Disease Progression

When increasing ambulation speed in Parkinson’s disease, step cadence increases more than stride length, indicating movement scaling difficulties that affect step generation in particular. We investigated whether step length variation when increasing ambulation speed was related to disease progression. Patients with Parkinson’s disease (N = 39) and controls (N = 152) performed two timed ambulation tasks: at a ''free'' (self-selected) pace and then at ''maximal'' speed. The total number of steps (including during turns) and time to complete the task were clinically measured. The relative contribution of step length and cadence to increased ambulation speed was determined using two methods: the ratios of change in step length or in cadence to the change in ambulation speed, and the step length index. While the relative contribution of step length and cadence to increased ambulation speed was independent of age in both control and patient groups, in Parkinson’s disease there was a negative correlation between time from diagnosis and the ratio of change in step length to change in ambulation speed (R = 0.54; p = 0.0004) and the step length index (R = 0.56, p = 0.0002). In parallel, there was a positive correlation between time since diagnosis and the ratio of change in cadence to change in ambulation speed (R = 0.57; p = 0.0002). The relative contribution of step length and cadence to increased ambulation speed is age invariant but a marker of Parkinson''s disease advancement, and can be easily determined in the clinical setting.     

Older Adults Show Preserved Equilibrium but Impaired Step Length Control in Motor-Equivalent Stabilization of Gait

Stable walking depends on the coordination of multiple biomechanical degrees of freedom to ensure the dynamic maintenance of whole-body equilibrium as well as continuous forward progression. We investigated adult age-related differences in whole-body coordination underlying stabilization of center of mass (CoM) position and step pattern during locomotion. Sixteen younger (20-30 years) and 16 healthy older men (65–80 years) walked on a motorized treadmill at 80%, 100% and 120% of their self-selected preferred speed. Preferred speeds did not differ between the age groups. Motor-equivalent stabilization of step parameters (step length and width) and CoM position relative to the support (back and front foot) was examined using a generalized covariation analysis. Across age groups, covariation indices were highest for CoM position relative to the front foot, the measure most directly related to body equilibrium. Compared to younger adults, older adults showed lower covariation indices with respect to step length, extending previous findings of age-related differences in motor-equivalent coordination. In contrast, no reliable age differences were found regarding stabilization of step width or any of the CoM parameters. The observed pattern of results may reflect robust prioritization of balance over step pattern regularity, which may be adaptive in the face of age-associated sensorimotor losses and decline of coordinative capacities.     

Effects of walking speed, strength and range of motion on gait stability in healthy older adults

Falls pose a tremendous risk to those over 65 and most falls occur during locomotion. Older adults commonly walk slower, which many believe helps improve walking stability. While increased gait variability predicts future fall risk, increased variability is also caused by walking slower. Thus, we need to better understand how differences in age and walking speed independently affect dynamic stability during walking. We investigated if older adults improved their dynamic stability by walking slower, and how leg strength and flexibility (passive range of motion (ROM)) affected this relationship. Eighteen active healthy older and 17 healthy younger adults walked on a treadmill for 5min each at each of 5 speeds (80-120% of preferred). Local divergence exponents and maximum Floquet multipliers (FM) were calculated to quantify each subject's inherent local dynamic stability. The older subjects walked with the same preferred walking speeds as the younger subjects (p=0.860). However, these older adults still exhibited greater local divergence exponents (p<0.0001) and higher maximum FM (p<0.007) than the younger adults at all walking speeds. These older adults remained more locally unstable (p<0.04) even after adjusting for declines in both strength and ROM. In both age groups, local divergence exponents decreased at slower speeds and increased at faster speeds (p<0.0001). Maximum FM showed similar changes with speed (p<0.02). Both younger and older adults exhibited decreased instability by walking slower, in spite of increased variability. These increases in dynamic instability might be more sensitive indicators of future fall risk than changes in gait variability.     

Normal gait characteristics under temporal and distance constraints

Walking patterns of 53 males and 39 females, all in good health, were studied at slow, free, and fast speeds using a walkway system developed by the author. Three males and three females, also in good health, were then studied under constrained walking conditions such as rhythm constraint, speed coupled with constraint, walking up or down a slope, line stepping contraint, stepping onto a marked square, and starting/stopping of walking. In the first set of experiments, the following results were obtained. When increasing speed, the male had a tendency to increase step length and the female had a tendency to increase cadence. The relationships between the speed and the statistics of gait parameters, i.e. the coefficient of variation and the symmetry were examined. The data in this experiment were also applied to Grieve's gait equations which formulated the relationships between step frequency and speed, or between swing time and cycle time.In the second set of experiments the following results were obtained. Although rhythm constraint (induced by a metronome) resulted in no difference of gait between males and females, a difference did appear in the case of speed coupled with constraint. When walking up and down a slope, the ascent case showed a longer step length and a lower cadence compared with the descent. The idea of functional asymmetry, a supporting function of the left leg and a moving function of the right leg, is well accepted. However, in this study of the effect of line stepping constraints predominant right-left functional differences were found. The perturbation of gait when the subjects stepped onto a marked square resembling a force-plate was recorded quantitatively. With regard to the starting and stopping characteristics of walking, it was concluded that the two steps from starting and the three steps before stopping should be excluded from ordinary data due to their acceleration and deceleration properties.     

Effects of obesity and sex on the energetic cost and preferred speed of walking.

The metabolic energy cost of walking is determined, to a large degree, by body mass, but it is not clear how body composition and mass distribution influence this cost. We tested the hypothesis that walking would be most expensive for obese women compared with obese men and normal-weight women and men. Furthermore, we hypothesized that for all groups, preferred walking speed would correspond to the speed that minimized the gross energy cost per distance. We measured body composition, maximal oxygen consumption, and preferred walking speed of 39 (19 class II obese, 20 normal weight) women and men. We also measured oxygen consumption and carbon dioxide production while the subjects walked on a level treadmill at six speeds (0.50-1.75 m/s). Both obesity and sex affected the net metabolic rate (W/kg) of walking. Net metabolic rates of obese subjects were only approximately 10% greater (per kg) than for normal-weight subjects, and net metabolic rates for women were approximately 10% greater than for men. The increase in net metabolic rate at faster walking speeds was greatest in obese women compared with the other groups. Preferred walking speed was not different across groups (1.42 m/s) and was near the speed that minimized gross energy cost per distance. Surprisingly, mass distribution (thigh mass/body mass) was not related to net metabolic rate, but body composition (% fat) was (r2= 0.43). Detailed biomechanical studies of walking are needed to investigate whether obese individuals adopt novel energy saving mechanisms during walking.     

Biomechanical characteristics of elderly individuals walking on land and in water

In this study, we examined Spatial–temporal gait stride parameters, lower extremity joint angles, ground reaction forces (GRF) components, and electromyographic activation patterns of 10 healthy elderly individuals (70 ± 6 years) walking in water and on land and compared them to a reference group of 10 younger adults (29 ± 6 years). They all walked at self-selected comfortable speeds both on land and while immersed in water at the Xiphoid process level. Concerning the elderly individuals, the main significant differences observed were that they presented shorter stride length, slower speed, lower GRF values, higher horizontal impulses, smaller knee range of motion, lower ankle dorsiflexion, and more knee flexion at the stride’s initial contact in water than on land. Concerning the comparison between elderly individuals and adults, elderly individuals walked significantly slower on land than adults but both groups presented the same speed walking in water. In water, elderly individuals presented significantly shorter stride length, lower stride duration, and higher stance period duration than younger adults. That is, elderly individuals’ adaptations to walking in water differ from those in the younger age group. This fact should be considered when prescribing rehabilitation or fitness programs for these populations.     

Walking fast-ranking high: A sociobiological perspective on pace

Sexual selection theory says that because females are the limiting factor in reproduction, males have to compete for them. Females in turn choose among males. In humans, socioeconomic status is a much more important mate choice criterion of women than of men. Thus, striving for status and signaling status is more important for men. We chose walking to test this sex difference because upright posture and walking probably were under sexual selection pressure for a long time. The latter is illustrated by upright threat displaying, quite common in male primates; for example, men may walk stiff and erect and accelerate to vigorous striding, both to impress women and to threaten rivals (in which case they may also raise their arms). Moreover, gathering and hunting, the condition of all modern humans until about 15,000 years ago, implies a division of labor, with men playing the more mobile hunter part. In view of the outstanding importance of food for female reproduction, women probably highly valued men's hunting capabilities, among which are locomotory speed and perseverance. Long-standing quantitative data on walking speed also suggest a sex-specific association between pace and status. We hypothesized that habitual fast walking might be a means to acquire and/or to display status, and predicted a positive correlation between walking speed and socioeconomic status in men, not in women. We found that men walked faster, the higher their status, whereas the pace of women was independent of their status. This result held when proximate factors like age, body height, next destination, and number of dates were controlled for.     

Older adults have unstable gait kinematics during weight transfer

The present article investigates gait stability of healthy older persons during weight transfer. Ten healthy older persons and ten younger persons walked 10 min each on a treadmill at 3 different gait speeds. The intra-stride change in gait stability was defined by the local divergence exponent λ(t) estimated by a newly developed method. The intra-stride changes in λ(t) during weight transfer were identified by separating each stride into a single and double support phase. The intra-stride changes in λ(t) were also compared to changes in the variation of the gait kinematics, i.e., SD(t). The healthy older persons walked at the same preferred walking speed as the younger persons. However, they exhibited significantly larger λ(t) (p<0.001) during weight transfer in the double support phase. Local divergence was closely related to intra-stride changes in SD(t) of the feet in the anterior-posterior direction. Furthermore, a high correlation was found between local divergence and the variation in step length and step width for both older (R>0.67, p<0.05) and younger persons (R>0.67, p<0.05). The present results indicate that the gait kinematics of older adults are more dynamical unstable during the weight transfer compared to younger persons. Furthermore, a close relationship exists between intra-stride changes in dynamical stability and variation in step length and step width. Further work will validate the results of the present study using real-life perturbations of the gait kinematics of both younger and older adults.     

The analysis of walk cycle in patients with spastic cerebral palsy after surgical management on the lower extremity

Gait pattern is a frequent problem in cerebral palsy. The aim of the investigation is the evaluation of proximal femur normalization and/or pelvis normalization after surgical correction and simultaneous operations on soft tissues of lower limbs, as well as walk analysis. From 1980. to 2000. were operated 856 patients, 476 male and 380 female, between 1-51 years. Basic walk parameters were analyzed: step length, speed and the number of steps in one minute (cadence). 75.25% of patients had good results with improved of centrum collum diaphysis (CCD) and angle of anteversion (AV) or antetorsion (AT) for 70%, and more independent walking with contracture corrections and decreased spasticism. The best results were achieved with simultaneous two-side operations, with patients' age between 1 and 3, achieving independent walking. More operations at the same time significantly reduce spasticism--one anesthesia, one immobilization, and later same time post-operative physical therapy and satisfactory better results.     

Effects of worn-out soles on lower limb stability, shock absorption and energy cost during prolonged walking

This study investigated the effects of worn-out shoes on lower leg stability, shock absorption and energy cost during prolonged walking. Seven male subjects (23.4 +/- 0.5 yr) walked at 4.8 km/h for 60 minutes wearing three different pairs of shoes: two of these pairs had severely and moderately worn soles (EASC: Excessive Attrite Shoe Condition and MASC: Moderate Attrite Shoe Condition, respectively) and the other pair had no wear (NASC: No Attrite Shoe Condition). Impact acceleration at the subtalar at heel strike, rearfoot angles (the subtalar joint and the lower leg) during stance phase, and oxygen uptake (VO2) were measured throughout the 60-minute walk. At the 10th minute of walking, worn-out shoes increased the supination of the subtalar joint and extortion of the lower leg. In addition, VO2 was significant larger in EASC (808.3 ml x min(-1)) than in NASC (749.5 ml x min(-1)). During the 60-minute walk, however, there were no time effects of shoe condition on the rearfoot angles and on VO2. In contrast, impact acceleration at the subtalar joint in EASC remained almost constant until the 30th minute of walking, and then began to elevate. In conclusion, worn-out shoes increased the energy cost and reduced lower leg stability during walking, although these changes were not influenced by walking duration within 60 minutes. However, prolonged walking showed the potential negative effect of worn-out shoe on shock absorption.     

Effects of age and physical activity status on the speed-aerobic demand relationship of walking.

Older adults tend to show lower preferred walking speeds and higher aerobic demands per distance walked than young adults. It has been suggested that a more sedentary life-style contributes to diminished musculoskeletal functioning, which in turn contributes to poorer economy of motion in the aged and sedentary adults. The purpose of this study was to quantify the speed-aerobic demand relationship during walking for old (greater than 65 yr of age) and young adults and to determine whether physical activity status affects this relationship. Aerobic demands for 30 young and 30 old individuals representing sedentary and physically active groups were measured as the subjects performed treadmill walking at seven speeds ranging from 0.67 to 2.01 m/s. All four age/physical activity groups displayed U-shaped speed-aerobic demand curves with minimum gross oxygen consumption per unit distance walked (ml.kg-1.km-1) at 1.34 m/s. A statistically significant age effect on walking aerobic demand was observed, with old subjects showing an 8% higher mean aerobic demand than the young subjects. This age-related effect was not associated with shifts in the speed at which aerobic demand was minimized or with the preferred walking speed of older individuals falling on a less economical portion of the speed-aerobic demand curve. Rather, it was speculated that declines in force-generating capacity of muscle in the aged may require recruitment of additional motor units and perhaps an additional proportion of less economical fast twitch muscle fibers to generate necessary forces. Physical activity status had no significant effect on walking aerobic demand.(ABSTRACT TRUNCATED AT 250 WORDS)     

IMU-based ambulatory walking speed estimation in constrained treadmill and overground walking

This study evaluated the performance of a walking speed estimation system based on using an inertial measurement unit (IMU), a combination of accelerometers and gyroscopes. The walking speed estimation algorithm segments the walking sequence into individual stride cycles (two steps) based on the inverted pendulum-like behaviour of the stance leg during walking and it integrates the angular velocity and linear accelerations of the shank to determine the displacement of each stride. The evaluation was performed in both treadmill and overground walking experiments with various constraints on walking speed, step length and step frequency to provide a relatively comprehensive assessment of the system. Promising results were obtained in providing accurate and consistent walking speed/step length estimation in different walking conditions. An overall percentage root mean squared error (%RMSE) of 4.2 and 4.0% was achieved in treadmill and overground walking experiments, respectively. With an increasing interest in understanding human walking biomechanics, the IMU-based ambulatory system could provide a useful walking speed/step length measurement/control tool for constrained walking studies.     

IMU-based ambulatory walking speed estimation in constrained treadmill and overground walking

This study evaluated the performance of a walking speed estimation system based on using an inertial measurement unit (IMU), a combination of accelerometers and gyroscopes. The walking speed estimation algorithm segments the walking sequence into individual stride cycles (two steps) based on the inverted pendulum-like behaviour of the stance leg during walking and it integrates the angular velocity and linear accelerations of the shank to determine the displacement of each stride. The evaluation was performed in both treadmill and overground walking experiments with various constraints on walking speed, step length and step frequency to provide a relatively comprehensive assessment of the system. Promising results were obtained in providing accurate and consistent walking speed/step length estimation in different walking conditions. An overall percentage root mean squared error (%RMSE) of 4.2 and 4.0% was achieved in treadmill and overground walking experiments, respectively. With an increasing interest in understanding human walking biomechanics, the IMU-based ambulatory system could provide a useful walking speed/step length measurement/control tool for constrained walking studies.