Mechanics of Normal and Pathological Locomotion in Man

Steindler, Arthur; Keene, Charles H.

doi:10.1111/j.1746-1561.1936.tb08846.x

Cited by 29 publications

(9 citation statements)

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“…Carlsoo (1972) and others (Farber, 1969, pp. 103-113;Napier, 1967;Steindler, 1935) provide an informative description of human gait. It is a modification of the Philippson step cycle used in the analysis of animal gait (see Grillner, 1975).…”

Section: Results Anddiscussionmentioning

confidence: 99%

Temporal and spatial factors in gait perception that influence gender recognition

Barclay

Cutting

Kozlowski

1978

Perception & Psychophysics

346

273

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Several temporal and spatial factors affect gender recognition of a walker when portrayed, without familiarity cues, as a dynamic point-light display. We demonstrate that, among temporal parameters, the duration of the dynamic stimulus. must be longer than 1.6 sec, but that 2.7 sec is fully adequate. Given the speed of our walkers, the recognition threshold appears to be roughly two step cycles. In addition, presentation rate of the stimulus must be near to normal, perhaps because nonnormal rates alter apparent gravity and obscure the normal relationship between output and conservation of energy. We demonstrate that, among spatial factors, the discreteness of the joint information must be maintained for accurate recognition. We go on to argue that it is the information about the shoulder and the hip of a walker that is of primary importance. Finally, inversion of the stimulus display produces the unexpected effect of reversing the apparent sex of most walkers. That is, when presented upside down, male walkers appear female and female walkers appear male.If one removes familiarity cues from a dynamic display, nothing is left for the viewer to perceive except formless relations projected over time. Yet these formless relations can yield rich and vivid percepts. This fact proves embarrassing for any view of form perception that relies exclusively on superficial features such as lines and angles. The present studies explore how formless relations that afford gender recognition in human walkers survive temporal and spatial distortion. Our goal is that through this type of study we can learn more about the nature of those relations and how they are perceived.For nearly a century researchers have attached points of light that glow in the dark to the limbs of walkers for the purposes of studying gait (see Bernstein, 1967). In fact, through this technique and others, human gait may be the most studied of all biological movement. Nevertheless, nearly all of this work has focused on how the movement is produced. Until the work of Johansson (1973Johansson ( , 1975Johansson ( , 1976, few have studied how that movement is perceived.Using a point-light technique developed by Johansson, we have begun to study various aspects of gait recognition. Previously, we had found that individuals can recognize themselves and others without familiarity cues from such a dynamic display (Cutting & Kozlowski, 1977). Next, we (Kozlowski & Cutting, 1977) determined that viewers could idenThis paper is based on the Master's thesis of the first author. This research was supported by a small research grant from Wesleyan University to each of the authors. We thank Robert J. White for his continued help, and Carol Fowler, Dennis Proffitt, and David Stier for instructive comments. Reprint requests should be sent to J. Cutting or L. Kozlowski, Department of Psychology, Wesleyan University, Middletown, Connecticut 06457.tify the gender of a walker from that display, but not from static tokens taken out of the dynamic sequences. Variations in walking s...

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Section: Results Anddiscussionmentioning

confidence: 99%

Temporal and spatial factors in gait perception that influence gender recognition

Barclay

Cutting

Kozlowski

1978

Perception & Psychophysics

346

273

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“…Step Cycle Carlsoo (1972), among others (see Inman, 1966;Murray, 1967;Napier, 1967;Steindler, 1935), provided a useful description of human gait as a modification of the Philippson step cycle (see Grillner, 1975;Sukhanov, 1974). A stride begins when the body sways slightly forward placing the center of gravity in front of the feet.…”

Section: Thementioning

confidence: 99%

A biomechanical invariant for gait perception.

Cutting¹,

Proffítt²,

Kozlowski³

1978

Journal of Experimental Psychology: Human Perception and Perfor

199

176

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Viewers can determine the gender of a walker from sagittally projected, dynamic displays of point-lights attached to prominent joints. This article explores three interrelated approaches in search of a biomechanical invariant that viewers might use. The first, an index of torso structure, accounts for the data handsomely but seems inappropriate because it is not directly revealed in the dynamic stimuli. The second, a dynamic index of visible torsion in the trunk of a walker, also fits the data well but seems to have a logical problem and a difficulty in accounting for performance in certain conditions of several previous studies. The third has the strengths of the first two indices, and it can account for some other data as well. It is the center of moment and is a "deeper," more general description of the invariant. This center is a point around which all movement occurs. It can be thought of as one specification of the gestalt law of common fate and may be helpful for the study of movement perception in general.We are continually impressed by the fact that one can identify a friend at great distance. Across a broad field, for example, individuals are incredibly small-subtending less than 1 ° of visual angle-yet their recognition is easily obtained. Since differences in clothing and hairstyle are obscured at such distances, one suspects that it must be the friend's pattern of gait that provides the critical information. Recently, this suspicion was confirmed with a technique whose antecedents are quite old.For over a century human gait has been studied by using strips or points of light that glow in the dark. Marey (1895Marey ( /1972, for example, attached white tape to the limbs of a walker dressed in a black body stocking. He then observed the systematic traces left with stroboscopic photography as the walker moved laterally in front of a camera. Later, This research was sponsored by small research grants from Wesleyan University to the authors. We thank Catharine D. Barclay and David M. Stier for their help.Requests for reprints should be sent to J. Cutting, Department of Psychology, Wesleyan University, Middletown, Connecticut 06457.other researchers used small incandescent bulbs attached to the joints to gain the same effect (for a review, see Bernstein, 1967, p. 3ff). This technique, called cydography, yields planar projections of the cycles of movement displayed over time. With this technique and others, human gait became one of the most studied of all complex, cyclical movements. Most of this research, however, focused on how the movement is produced. Following Johansson (1973Johansson ( , 1975Johansson ( , 1976, we have chosen a variant of the cyclographic technique to study how gait is perceived.Glass-bead retroflectant bicycle tape is wrapped around walkers' joints, and bright lights focused on them as they walk in front of a television camera connected to videorecording apparatus. With contrast on the television monitor turned to maximum and with brightness to near minimum, only patches of light c...

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“…We assume that the same principles hold for each agonist/antagonist pair involved, and thus the discussion represents an average behavior of all pairs contributing to the actual limb motion. The human locomotor system is equipped with an abundance of two joint muscles; however, Steindler [4], Eberhart et al [ 10] have shown how two joint muscles can be functionally decomposed into the one joint variety, b. Derivation.…”

Section: Discussionmentioning

confidence: 99%

“…The remaining 40% is swing motion. The deploy (or restraint) portion in stance takes 10 to 1 5% of a double-step period [4,19].…”

Section: Quantitative Features Of the Biped Gaitmentioning

confidence: 99%

“…This performance criterion is meaningful in that it is shown to be proportional to the mechanical work done during normal Piecewise Approximation of Characteristic Surface (Houk [42], Stark [41], Galiana [33]) 49 The modern study of human locomotion began in the 1930's and has drawn greater attention since then. Significant contributions during this time include the works of Fenn [2,3], Steindler [4], Elftman [5][6][7][8],…”

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Studies of Human Locomotion via Optimal Programming

Chow¹,

Jacobson²

1970

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Research to-date towards an understanding of human biped locomotion has been primarily experimental in nature, largely due to the complexity of the process. In view of the new, exciting possibilities of programmed electro-stimulation of paralyzed extremities to restore locomotion, a critical study at the theoretical level is greatly warranted.Optimal programming and modern control theory offer a new approach to the study. First, it is proposed that normal walking obeys a certain "principle of optimality". Next, at the dynamic level, modern control theory is used to derive the optimal moment profiles which actuate the locomotor elements to synthesize the observed patterns of the normal gait.Development of the problem structure relies closely on the functional characteristics of the biped gait, particularly the ideas of distinct phasic activities and the associated temporal patterns of a walking cycle.The result is a multi-arc programming problem with three stages. by equality constraints on the "states" while the swing phase is characterized by inequality state constraints. A novelty of the approach is that the theory could be used to study walking behavior under different environmental conditions, such as walking up-stairs or over a hole.Joining of the arcs is arranged in such a way as to maintain continuity of certain trajectories as well as repeatability of motion.A distinct feature of the present approach which differs from other studies is the presence of a minimizing performance criterion.Based on external characteristics of muscles and certain assumptions regarding normal locomotion, a simple quadratic type of performance index is proposed. This performance criterion is meaningful in that it is shown to be proportional to the mechanical work done during normal

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Mechanics of Normal and Pathological Locomotion in Man

Cited by 29 publications

References 0 publications

Temporal and spatial factors in gait perception that influence gender recognition

Temporal and spatial factors in gait perception that influence gender recognition

A biomechanical invariant for gait perception.

Studies of Human Locomotion via Optimal Programming

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