Browsing by Author "Sun, JS"

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Age differences in remote pointing performance
(1997-10-01)
Hsu, SH
;
Huang, CC
;
Tsuang, YH
;
Sun, JS
;
工業工程與管理學系
The purpose of this study was to investigate age differences in remote pointing movements. The subjects were recruited from three age groups (ages 18-22 yr., 40-50 yr., and 60-70 yr., with 9 men and 9 women in each group). They were required to perform cursor-positioning tasks using a remote pointing device, in which the dependent measures were the time taken to reposition the cursor and the accuracy of subjects' movement trajectories. The movement time was further separated into two components, First Submovement duration and Adjustment Submovement duration. Analysis indicated that age groups showed reduced performance on remote pointing. Moreover, remote positioning movement for the young-adult group was mostly completed in their First Submovement phase, while the elderly subjects spent most of their movement time on the Adjustment Submovement phase. These results support the proposition that different age groups exhibit different kinds of movement patterns.
Age-related differences in remote pointing performance
(1997)
Hsu, SH
;
Huang, CC
;
Tsuang, YH
;
Sun, JS
;
交大名義發表
The present study investigated age-related differences in remote pointing performance. Three age groups (i.e., the Young adult, Middle-aged, and Elderly) performed cursor positioning tasks by using a remote pointing device. The time taken to reposition the cursor was collected. The result showed that age groups had differences in movement time. Further analysis on the submovement duration times showed that movement time for the Young-adult group was mostly travel time, while the Elderly subjects spent most of their movement time on fine adjustment. This study supports the proposition that different age groups exhibit different kinds of movement patterns.
Effects of age and gender on remote pointing performance and their design implications
(1999-03-20)
Hsu, SH
;
Huang, CC
;
Tsuang, YH
;
Sun, JS
;
工業工程與管理學系
The purpose of this research is to investigate the effects of age and sex on remote pointing movements. In addition, an attempt was made to incorporate possible age-related or sex differences into the design of a remote pointing user interface. The subjects were recruited from three age groups (elderly, middle-aged, and young) with equal number of both sexes. The participants were required to perform cursor positioning tasks using a remote pointing device. Their static hand stability and remote positioning time were recorded and analyzed. The remote positioning time was further separated into two components: initial submovement duration and adjustment submovement duration. The results reveal that age-related effects reduced the subjects' ability to perform remote pointing tasks and also maintained hand stability. However, sex differences had no significant effect on either performance. Moreover, the results also reveal that remote positioning movements for the young group were mostly completed in their initial submovement phase, while the elderly subjects spent most of their movement time on the fine adjustment phase. In light of the fact that different age groups exhibit different kinds of movement behavior patterns, suggestions for the design of signal sensitivity, target features, and display/control gain in remote pointing user interface were outlined.
Morphological changes of the triceps surae muscle-tendon unit during passive extension: an in vivo rabbit model
(1998-12-01)
Sun, JS
;
Hang, YS
;
Tsuang, YH
;
Cheng, CK
;
Tsao, KY
Objective. To elucidate the morphological and biomechanical manifestation of the triceps surae muscle-tendon unit during passive extension. Design. The instantaneous changes within the load-deformation curve of muscle-tendon unit were analyzed by an in vivo rabbit model. Background. Although muscle strains occur more frequently than complete failures, the failure mechanism of these sub-failure injuries is rarely investigated. Monitoring of the instantaneous changes in the load-deformation curve allows correlation with the morphological changes that occur during passive extension. Methods. After anesthesia, the triceps surae muscle of rabbit was dissected and then stretched to failure by a MTS Bionix 858 machine. The morphological changes in failure patterns were recorded by photographs. Results. The morphological and biomechanical manifestations of the triceps surae muscle-tendon unit was divided into five different portions: first, the viscoelastic portion with minimal morphologic change; second, the portion of micro-failure with local ecchymosis; third and fourth, the portions of macrofailure with sequential rupture of the muscle fibers; and filth, the portion of rupture and separation of muscle parenchyma. Conclusions. A threshold for stretch-induced injury does exist. The threshold of the initiation of micro-failure in this model was 16.5% of the strain, which corresponded to 16.6% of the maximal sustainable force. Relevance Elucidation of the existence of micro-failure in skeletal muscle gives a good reference point to determine the functional capabilities and limitation of muscular tissue. With this, the deleterious effect of muscle stretching can be avoided by limiting muscle stretching to below this limit. (C) 1998 Elsevier Science Ltd. All rights reserved.
The effects of cyclic stretching on tensile properties of the rabbit's skeletal muscle
(1998-01-01)
Tsuang, YH
;
Sun, JS
;
Chen, IH
;
Hsu, SH
;
Tsao, KY
Objective. To define the threshold of muscle injury with cyclic passive stretch. Design. The changes in the load-deformation curve of muscle-tendon unit were monitored until the failure point by an in vivo rabbit model. Background. Muscle injuries range in severity from a simple strain to complete rupture. Although strains occur more frequently than complete failures, only a few studies have investigated the phenomena of these sub-failure injuries. Monitoring of the continuum for stretch-induced injury allows us to define the threshold of stretch injury. Methods. Thirty rabbits' triceps surae muscle-tendon unit preparations were used. One of the pairs (control) was stretched until failure; the other (experimental) was first cyclic stretched to either 12, 20 or 25% of the initial length of the muscle-tendon unit and then stretched to failure. Comparisons were made between the load-deformation curves of the experimental and control specimens. Results. When cyclic stretched to 12 or 20%, there were no significant changes existed in the biomechanical parameters except the deformation at the peak load. In contrast, all the biomechanical parameters except the ration of the energy absorption changed significantly after 25% strain cyclic stretch. Conclusions. A threshold for stretch-induced injury does exist. This can be reproduced at the 25% strain of the triceps surae muscle-tendon unit. Relevance Muscle-tendon injuries, primarily muscle strains or tears, are extremely common in professional and amateur athletes. This experimental study with rabbits, give evidence that changes in the biomechanical properties after sub-failure injury does exist in the muscle tendon unit. More importantly, stretching before competition should not exceed 25% strain in the triceps surae muscle-tendon unit. (C) 1998 Elsevier Science Ltd. All rights reserved.