Showing papers on "Stair climbing published in 1996"

A Longitudinal Trial of Weight Training in the Elderly: Continued Improvements in Year 2

Abstract: We conducted a 2-year (42 weeks of consecutive training in each year, separated by 10 weeks of testing and vacation time) randomized, controlled trial of weight training in 142 healthy male and female subjects, aged 60 to 80 years. Measurements included dynamic strength, symptom-limited endurance in cycling, treadmill walking and stair climbing, muscle size, and bone mineral density and content of the lumbar spine and whole body. One hundred and thirteen subjects completed the study (57 exercise, 56 control), with a mean attendance of 85% among the exercisers. Muscle strength was unchanged in the control subjects but increased (collapsed across age and gender) from 32% (leg press) to 90% (military press) in the exercisers. Symptom-limited endurance in cycling, treadmill walking, and stair climbing increased in the exercisers by (mean +/- SE) 6.2 +/- 0.8%, 29.2 +/- 7.3%, and 57 +/- 12%, respectively; the only change in the controls was an unanticipated 33% increase in stair climbing performance during the first year. These values were unchanged in the controls. Cross-sectional area of the knee extensors increased by 8.7 +/- 0.9% in the trained subjects and was unchanged in controls. Measures of whole body, lumbar spine bone mineral density, and lumbar spine bone mineral content were unchanged in the exercisers, but whole body bone mineral content decreased by 1%. In contrast, there were small increases (< 4.0%) in bone mineral density among the controls. Long-term weight training proved to be a safe and well-tolerated mode of exercise for the elderly. Increased strength was associated with muscle hypertrophy in each year, and with increased endurance in cycling, walking, and stair climbing. There were no changes in bone mineral density but a small reduction in whole body bone mineral content.

Effects of 2,000 kcal per week of walking and stair climbing on physical fitness and risk factors for coronary heart disease.

Abstract: BACKGROUND: Epidemiologic evidence suggests that 8,368 kJ or 2000 kcal per week of moderate physical activity, including walking and stair climbing, can reduce risk of coronary heart disease (CHD). The goal of this study was to assess the effects of this amount of these two activities on physical fitness and risk factors for CHD. METHODS: Twenty-two healthy, slightly overweight, sedentary, normotensive, normolipemic men, age 22 to 44 years, were randomly assigned to an exercise or control group for 12 weeks followed by a 4-week washout period. The subjects then were crossed-over to the alternate group for an additional 12-week period. Exercise consisted of 5 days per week of supervised treadmill exercise plus stair climbing. Treadmill exercise consisted of walking for 45 minutes at 5.15 km per hour at 2% grade for a total of 19.3 km per week. Subjects also climbed 10 floors of stairs at a time at their own pace without prescribed target heart rates for a total of 50 floors per week. The estimated total weekly energy cost of the treadmill walking plus stair climbing was 8,368 kJ or 2,000 kcal. Mean observed heart rates were 55% and 82% of maximal heart rate during treadmill walking and stair climbing, respectively. Data from the two exercise periods and two control periods were pooled and compared by analysis of variance. RESULTS: Sixteen subjects completed all phases of the study. Maximal oxygen uptake (VO2max) by the Bruce treadmill exercise protocol with metabolic gas measurements was below average for age at baseline, and was not significantly affected by 12 weeks of training. No significant changes were noted between groups in body weight or percent body fat (hydrostatic weighing), although there was a trend for loss of weight and fat with exercise training. Mean systolic blood pressure (119 mm Hg) was unchanged in both groups. However, diastolic blood pressure (72 mm Hg and 78 mm Hg for the treatment and control groups, respectively) showed an unexpected 6 mm Hg increase during the exercise period and a 5 mm Hg decline during the control period. Mean plasma lipid and lipoprotein levels were unaffected by training, except for a 16% reduction in triglycerides (P < .05). However, a 28% increase in plasma high density lipoprotein (HDL)-cholesterol (P < .01) was noted during the initial 12-week training period, which regressed during the washout period, and was not replicated during the second 12-week exercise period. CONCLUSIONS: Twelve weeks of walking and stair climbing at a moderate pace and intensity at an energy cost of about 2,000 kcal per week failed to improve physical fitness or risk factors for CHD. A reduction in physical activities other than the prescribed exercise program, as reported by a physical activity recall questionnaire, probably contributed to an absence of an exercise response. A longer and/or a more intense activity program is apparently required to improve these modalities.

Functional Training: Muscle Structure, Function, and Performance in Older Women

Abstract: Response to physical training at the cellular and whole muscle level has been established in older adults. However, the underlying molecular mechanism responsible for change has not been described nor have the relationships between change in muscle structure and functional performance been established. The purpose of this research study is to evaluate the changes of muscle ultrastructure, muscle strength, and whole body functional performance as a result of a functionally directed exercise program (stair climbing). Women (65–83 years old) selected either the control (no exercise; N = 6) or exercise (N = 7) group. The 1-year functionally based exercise program was both aerobic (75% heart rate reserve) and resistive (weighted stair climbing). Muscle ultrastructure, determined by quantitative morphometry of the vastus lateralis tissue, and maximal step- height achieved by each subject were related to isokinetic strength and muscle morphology. Changes in myofibrillar area accounted for 48% of the variance in ...

Rate responsive cardiac pacemaker and method for discriminating stair climbing from other activities

Abstract: A method of and apparatus for pacing a patient's heart at a pacing rate dependent on patient activity and posture particularly during stair climbing. A dual chamber, rate responsive pacemaker for pacing a patient's heart includes at least one DC accelerometer mounted in the pacemaker pulse generator for implantation such that the sensitive axis of the DC accelerometer is sensitive to the effects of gravity during forward lean of the patient characteristic of stair climbing posture. The DC and AC signal outputs of the accelerometer are processed to develop a tilt signal and an activity signal. A target rate control signal is derived from the activity signal dependent on the level of activity. A stair climbing rate is selected for controlling the physiologic pacing rate between a lower and an upper pacing rate in the presence of an activity signal indicative of a patient walking rate and a tilt signal value falling within a tilt window. The target rate control signal is used to control the pacing rate if the activity signal is indicative of faster patient movement, e.g. running, or if the tilt signal is outside the tilt window indicating that the patient is either upright or prone.

Stated versus Observed Performance Levels in Patients with Chronic Low Back Pain.

Abstract: This study examined the relationship between perceived (stated) levels of function and the measured (observed) performance in squatting and stair climbing activities of 20 patients with chronic low back pain (CLBP) and 20 healthy volunteers. Subjects were asked through an interview to self-assess their ability to comfortably perform stair climbing and squatting as well as other tolerances. The subjects were then asked to perform the activities and their performance levels were recorded. Results revealed that patients' estimate of squatting and stair climbing abilities as well as their demonstrated levels were significantly lower (p < 0.001) than those of the healthy subjects. There was a significant difference between groups in terms of the time required to perform squatting but not stair climbing. Both groups underestimated their physical capabilities. Findings indicate that the use of actual performance measurement combined with self-report of functional abilities is needed when assessing performance le...

Stair climbing hand truck

Abstract: A stair climbing hand truck utilizes two pairs of wheels which are attached to a secondary frame forming a part of the hand truck and which are mounted in an overlapping relationship. The first pair of wheels is mounted exteriorly of the secondary frame so as to lie outside of the hand truck's main frame structure, and the second pair of wheels is mounted interiorly of the main frame structure wherein all wheels are of the same diameter.

Robot Design for Stair Navigation

Abstract: Among the several designs of mobile robots, the wheel design is unfavorable for navigation of stairs or over obstacles. The leg design and the creeping design demand very intricate control systems and are not efficient on flat surfaces. The caterpillar design is unreliable and unstable in stair navigation. In the arm-wheel design, the sensor which discriminates between stairs and flat surfaces and the mechanism which alternates between wheel-running and arm-creeping modes are complicated. In this paper, a new type of arm-wheel design for a mobile robot enabling it to navigate stairs is developed, which requires no sensor for discrimination between stairs and flat surfaces of stairs and no mechanism for alternating between wheel-running and arm-creeping modes. Since no sensor is required, the reliability in an extreme environment is high. Moreover, since it has no intricate discrimination mechanism, it can also be applied to a wheelchair, for example, which is not powered. The author has confirmed through experiments using a stair-navigating robot prototype that the mechanism developed here functions as intended.

Physical modelling of hip joint forces in stair climbing

Abstract: A test device has been developed and validated to simulate physiologic loading of the hip during stair climbing. Forces about the hip joint were measured in static simulations of stair climbing using simulated extensor, abductor and adductor muscle groups to support the joint. Femoral flexion angle (to model step length and height) and applied hip flexion moment (to model trunk lean) were varied to examine the effects of different loading conditions on the hip. In stair climbing the maximum total joint force was six times body weight at 34 degrees of femoral flexion and 60 N m of hip flexion moment. Joint forces increased with hip flexion moment and varied little with femoral flexion angle, except for the posteriorly directed force. This component, which twists implants about the femoral shaft, increased with femoral flexion angle but changed little with hip flexion moment.

Rate responsive cardiac pacemaker for discriminating stair climbing from other activities

Abstract: A method of and apparatus for pacing a patient's heart at a pacing rate dependent on patient activity and posture particularly during stair climbing. A dual chamber, rate responsive pacemaker for pacing a patient's heart includes at least one DC accelerometer mounted in the pacemaker pulse generator for implantation such that the sensitive axis of the DC accelerometer is sensitive to the effects of gravity during forward lean of the patient characteristic of stair climbing posture. The DC and AC signal outputs of the accelerometer are processed to develop a tilt signal and an activity signal. A target rate control signal is derived from the activity signal dependent on the level of activity. A stair climbing rate is selected for controlling the physiologic pacing rate between a lower and an upper pacing rate in the presence of an activity signal indicative of a patient walking rate and a tilt signal value falling within a tilt window. The target rate control signal is used to control the pacing rate if the activity signal is indicative of faster patient movement, e.g. running, or if the tilt signal is outside the tilt window indicating that the patient is either upright or prone.

Effect of speed and experience on kinetic and kinematic factors during exercise on a stair-climbing machine

Abstract: The purpose of this project was to explore the interaction between kinematic and kinetic factors and to investigate whether this relationship was affected by different speed conditions when subjects exercised on stair-climbing machines A secondary purpose was to determine if there were any differences in kinematic and kinetic factors between experienced and inexperienced subjects The kinematic parameters included hip angle, knee angle, and pedal angle The kinetic parameters were maximum force applied on the pedals, maximum force applied on the handrails, maximum hip moment, and maximum knee moment Data from a two-way (Speed × Experience) analysis of variance suggested that there were significant differences in maximum force applied on the pedal maximum force applied on the handrail and maximum hip moment across the speed and experience conditions. In all the testing conditions, using a stair-climbing machine had a smaller impact force on the feet than was found in a previous study that examined impact for...

Function, Functional Training: Muscle Structure, and ~erhrmance in Older Women

Abstract: S pecificity of training is a well-recognized principle of exercise physiology. Muscles adapt to the specific training stimulus imposed upon them: swimmers train by swimming, weight lifters train by lifting weights, football players train by running and throwing. These strategies have proven effective for athletes; however, they have not been applied to exercise regimes aimed at improving daily activities in older adults. Traditional exercise programs use endurance training, single joint strength training, or a combination of the two, but often they do not produce an improvement in functional measures (3). This traditional a p proach to exercise is prescribed for the general public with the intention of improving activities of daily living, yet they do not incorporate these activities into the training. Although resistance training using machines strengthens each muscle in isolation, these programs do not incorporate integrated performance into the training regime. Functional performance requires the integration of multiple joints and several muscle groups. In an activity such as stair climbing, the integrated strength of the quadriceps, hamstrings, hip flexors and extensors, and plantar flexors is involved. Merely strengthening each muscle in isolation does not train the muscles to work in a coordiResponse to physical training at the cellular and whole muscle level has been established in older adults. However, the underlying molecular mechanism responsible for change has not been described nor have the relationships behveen change in muscle structure and functional performance been established. The purpose of this research study is to evaluate the changes of muscle ultrastructure, muscle strength, and whole body functional performance as a result of a functionally directed exercise program (stair climbing). Women (65-83 years old) selected either the control (no exercise; N = 6) or exercise (N = 7) group. The I-year functionally based exercise program was both aerobic (75% heart rate reserve) and resistive (weighted stair climbing). Muscle ultrastructure, determined by quantitative morphometry of the vastus lateralis tissue, and maximal stepheight achieved by each subject were related to isokinetic strength and muscle morphology. Changes in myofibrillar area accounted for 48% of the variance in muscle strength changes. Change in muscle contractile protein was the underlying basis for change in thigh strength which, in turn, was the basis for functional performance. These data provide evidence that, in older women, a mild functionally based training program results in improved muscle structure and performance of the lower body.