In this population-based, observational study, we document the personal burden of fracture and utilization of community and health services for women during the 12-month period following a fracture. Participants were 598 women (aged 35–92 years) with inci-dent fracture in the years 1994–1996 who were enrolled in the Geelong Osteoporosis Study. Almost all hip fracture cases and 27% of nonhip fracture cases were hospitalized. Homes were modified in 14% of cases, and 32% of the women purchased or hired equipment to
assist with activities of daily living. Three-quarters of women with hip, pelvis, or lower limb fractures were confined to the ho-me, had to walk with a walking aid, or could walk only short distances for several weeks. After a year, nearly one-half had not re-gained prefracture mobility. One-seventh of women with upper-limb fractures did not venture outside the home for at least 6 weeks. Nearly half of all fracture cases needed help with personal care and housework during the first 6 weeks. After 6 months, 3.4% of all patients and 19.6% of hip, 12.8% of humeral, and 4.7% of spine fracture patients required assistance with bathing and show-ering. After a year, more than half of the hip fracture cases remained restricted regarding housework, gardening, and transport. These findings have important implications for rehabilitation therapy. A fracture, regardless of site, had a major impact on a woman’s lifestyle and wellbeing. Most women were restricted in their activities of daily living and suffered loss of confidence and independence. Short-term morbidity was common for all fractures, with varying degrees of prolonged morbidity often extending to at least a year postfracture.

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A sit-to-stand assist device can serve the needs of people suffering from muscle weakness due to age or disabilities that make sit-to-stand a difficult functional task. The objective of this paper is to design a passive gravity-balancing assist device for sit-to-stand motion. In our study, it has been shown that the contribution to the joint torques by the gravitational torque is dominant during sit-to-stand motion. On the basis of this result, a gravity balanced assistive device is proposed. This passive device uses a hybrid method to identify the center-of-mass of the system using auxiliary parallelograms first. Next, appropriate springs are connected to the device to make the total potential energy of the system due to the gravity and the springs constant during standing up. A demonstration prototype with the underlying principles was fabricated to test the feasibility of the proposed design. The prototype showed gravity balancing and was tested by the authors. This prototype will be modified appropriately for clinical testing.

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In this paper, a wearable exoskeleton leg conceived and designed to augment human’s walking ability is proposed. The ultimate goal of this project is to provide an insight into the methodology of designing and controlling a power assist system, which integrates human’s intellect as the central control system for manipulating the wearable anthropomorphic device. The whole process of design, construction and control of a prototype experimental exoskeleton is presented; the feasibility and performance of the novel ANFIS (adaptive-network-based fuzzy inference system) based control algorithm are studied followed by the conclusion as well as an outline of anticipated future research.

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Integrating human and robot into a single system offers remarkable opportunities for creating a new generation of assistive technology. Having obvious applications in rehabilitation medicine and virtual reality simulation, such a device would benefit both the healthy and disabled population. The aim of the research is to study the kinematics and the dynamics of the human arm during daily activities in a free and unconstrained environment as part of an on-going research involved in the design of a 7 degree of freedom (DOF) powered exoskeleton for the upper limb. The kinematics of the upper limb was acquired with a motion capture system while performing a wide verity of daily activities. Utilizing a model of the human as a 7 DOF system, the equations of motion were used to calculate joint torques given the arm kinematics. During positioning tasks, higher angular velocities were observed in the gross manipulation joints (the shoulder and elbow) as compared to the fine manipulation joints (the wrist). An inverted phenomenon was observed during fine manipulation in which the angular velocities of the wrist joint exceeded the angular velocities of the shoulder and elbow joints. Analyzing the contribution of individual terms of the arm’s equations of motion indicate that the gravitational term is the most dominant term in these equations. The magnitudes of this term across the joints and the various actions is higher than the inertial, centrifugal, and Coriolis terms combined. Variation in object grasping (e.g. power grasp of a spoon) alters the overall arm kinematics in which other joints, such as the shoulder joint, compensate for lost dexterity of the wrist. The collected database along with the kinematics and dynamic analysis may provide the fundamental understanding for designing powered exoskeleton for the human arm.

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The metabolic cost of walking is determined by many mechanical tasks, but the individual contribution of each task remains un-clear. We hypothesized that the force generated to support body weight and the work performed to redirect and accelerate body mass each individually incur a significant metabolic cost during normal walking. To test our hypothesis, we measured changes in metabo-lic rate in response to combinations of simulated reduced gravity and added loading. We found that reducing body weight by simula-ting reduced gravity modestly decreased net metabolic rate. By calculating the metabolic cost per Newton of reduced body weight, we deduced that generating force to support body weight comprises
28% of the metabolic cost of normal walking. Similar to previous loading studies, we found that adding both weight and mass increased net metabolic rate in more than direct proportion to load. How-ever, when we added mass alone by using a combination of simulated reduced gravity and added load, net metabolic rate increased about one-half as much as when we added both weight and mass. By calculating the cost per kilogram of added mass, we deduced that the work performed on the center of mass comprises
45% of the metabolic cost of normal walking. Our findings support the hypothe-sis that force and work each incur a significant metabolic cost. Specifically, the cost of performing work to redirect and accele-rate the center of mass is almost twice as great as the cost of generating force to support body weight.

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