Biomedical subjects

T Furuna

Publications and source records attributed to T Furuna.

8 recordsLinked to original sources

PubMed1999

[Association of physical performance and falls among the community elderly in Japan in a five year follow-up study].

Since falling is one of the main causes of morbidity and mortality among the elderly, attention should be paid to prevention. The purpose of the present study was to investigate the risk factors for falls among the elderly by a 5-year longitudinal observation. The subjects were the elderly aged 65 years and over living in a rural community in the eastern part of Honshu, Japan. Of the 852 eligible subjects, 685 persons (278 males and 407 females) received the multidimensional medical examination including physical performance as the baseline of TMIG-LISA (Tokyo Metropolitan Institute of Gerontology, Longitudinal and Interdisciplinary Study on Aging) in 1992. From baseline medical examinations, the following variables were adopted to investigate risk factors for falls (2 or more times during the 5-year follow-up): self-rated health, experience of falling, TMIG-index of competence, visual deficit, anthropometric measurements (height, weight, BML total skinfold thickness), lumbar bone mineral density, and physical performance tests (grip strength, finger-tapping rate, one leg standing time with eyes open or closed, preferred and maximum speed walking for 5 meters). A total of 108 subjects experienced falls two or more times during the 5-year follow-up period (43 men and 65 women). There were significant differences in grip strength, preferred and maximum walking speeds between those who fell and those who did not. Multiple logistic regression analysis controlled for age, sex and other variables adopted in this study revealed the following variables were significantly and independently related to falling: experience of falling within one year preceding the baseline survey (directly, p < 0.0001), preferred walking speed (inversely, p < 0.005) and total skinfold thickness (inversely, p < 0.01). These results suggest that the walking test as well as the experience of falling have discriminant and predictive validity for assessing the future occurrence of falls among the elderly.

Accidental Falls↗

PubMed1997

Optimal walking in terms of variability in step length.

The optimal condition in speed, step rate, and step length of human walking has been reported in terms of temporal consistency, energy cost, and attentional demand. No study, however, has been conducted on the optimal condition in terms of spatial variability of walking. This study examined whether there is an optimal walking speed with minimum intrasubject variability in step length and step width during free walk (experiment 1) and whether there is an optimal step rate with minimum step length variability during walking with imposed step rates (experiment 2). Wearing shoes with ink-applied felt squares attached to the heels, healthy students walked on a flat walkway (0.6 x 16 m) at five different speeds with a freely chosen step rate in experiment 1 and walked at three different speeds with five different step rates in experiment 2. Free walk was found to have the fewest variable errors (VEs) in step length approximately at preferred walking speed. Variable error in step width increased linearly with an increase in walking speed. Under imposed step rates, VEs in step length were the fewest when walking with step rates close to those in free walk. Our everyday walking is performed most frequently at preferred speed and/or with freely chosen step rate, thereby optimizing the consistency of gait performance. Intrasubject variability in step length may be a useful measure for evaluation of walking.

Adult↗

PubMed1996

Walking patterns and finger rhythm of older adults.

Walking patterns and rhythmic movement of the fingers were examined in a total of 1,134 male and female community residents 65 years of age and over. Walking patterns were characterized according to the ratio of step length divided by step rate (cadence), called the Walk Ratio, during level walking at preferred and maximum speeds. The walking pattern tended to change according to age; older subjects walked with shorter steps (smaller Walk Ratio). Rhythmic movement was examined using the finger-tapping test in time to the sound of a 4-Hz metronome. Hastened tapping or finger festination, in which the subject tapped faster than requested (constant error of 3 msec. and over in the intertap interval), was characteristic of aging; 16.8% of the subjects exhibited finger festination and the occurrence increased with age, especially among those in their eighties (29.3%). Finger festination was accompanied by walking patterns with an increased step rate, or a smaller Walk Ratio. These characteristics of aging were discussed as similar to extrapyramidal symptoms of walking and rhythm production in patients with Parkinson's disease.

Acceleration↗

PubMed1995

A physical fitness model of older adults.

Physical fitness for young people is viewed as a multidimensional construct, in that it consists of specific components such as strength, mobility, balance, flexibility, and stamina. This study examined whether this structure underlying physical fitness is also relevant to older adults. A 10-item performance test, which was assumed to assess six components of physical fitness, was administered to 69 healthy volunteers ranging in age from 61 to 83 years. A covariance structure model was applied to the test data: the second-order factor was Physical Fitness, and the first-order factors were Strength, Walking, Balance, Flexibility, Stamina, and Manual Speed which were assumed to be measured based on the ten observed variables. Goodness-of-fit index (GFI) of the model was acceptable (GFI = 0.93). While four factors relating to basic motor performances (Strength, Walking, Balance, and Manual Speed) had loadings more than 0.62 to Physical Fitness, Flexibility and Stamina had less than 0.35. It was suggested for elderly people that strength, mobility, balance, and speed components of physical fitness were highly correlated and explainable by a single factor, while flexibility and cardiorespiratory endurance were to be measured by use of specific measures.

Aged↗

PubMed1995

The structure underlying physical performance measures for older adults in the community.

A 6-item physical performance test assessing hand strength/speed, mobility, and balance was administered to 678 elderly people from a Japanese community (age 65-89). A second-order covariance structure model applied to the data revealed that three factors in observed variables (Hand Power, Walking, and Balance) had loadings more than 0.8 on a single higher-order factor, Basic Motor Ability (BMA). The BMA score, or "Physical Performance Age (PPA)", of the individual was calculated on the basis of this model as a unidimensional summary score of physical performances. The PPA predicted the self-reported levels of competence and physical activity with greater accuracy than age alone. The PPA also differentiated those at the high end of the functional spectrum, and thereby not identifiable by use of ordinary self-reported functional measures. The results suggest that a short physical performance battery assessing physical functioning is useful in community-based studies of aging.

Aged↗

PubMed1994

[Age-related difficulty in rhythmic movement].

In order to identify a characteristic difficulty in rhythmic movements with aging, a total of 380 healthy participants aged from 18 to 85 years (group 1), and 1,134 elderly community residents aged from 65 to 89 years (group 2), were examined using a finger-tapping test. The test requested the participant to tap in time to a periodic sound train with frequencies of 2, 3, 4, and 5 Hz (cycles/sec) for group 1, and with 4 Hz for group 2. Tapping deviated towards a faster rate from the stimulus frequency by more than 3 msec at 4 Hz and/or 5 Hz, "hastened tap" (HT), was found to be characteristic of aging. In group 1, the participants who exhibited HT increased with age and reached more than 35% in their 60s and 70s. In group 2, the percentages of participants with HT at 4 Hz were 14.6 (60s), 15.9 (70s) and 29.3 (80s), which were very close to the 16.9% of participants with HT at 4 Hz over 65 years in group 1. This figure suggested that more than 50% of participants over 80 years exhibited HT in tapping test at 2 through 5 Hz. HT in the elderly appears to be similar to hastened tapping observed typically in patients with Parkinson's disease, suggesting a parallel of extrapyramidal motor dysfunction between normal aging and parkinsonism.

Adolescent↗

PubMed1994

[Effect of aging on the aerobic capacity measured by a step-test].

The purpose of this study was to develop a step-test in order to evaluate age-related change in aerobic capacity. A total of 149 healthy men of age through 18 to 83 yrs ascended and descended a single step of 0.2 m height in time to a metronome. The step rate increased step-wise through three stages, each of 3 min duration; 15, 20 and 25 (step/min) for subjects aged 59 or less, and 10, 15, and 20 (step/min) for those age 60 and over. Using the linear relationship between load and heart rate, physical work capacity (PWC, watt/kg) was estimated as the work load with maximum heart rate predicted by age (220-age). In the elderly group (n = 34), heart rate at the end of the last stage was within 60-80% of the maximum heart rate for 25 subjects, and more than 80% for the other 9 subjects. No risky arrhythmia or significant ST change on ECG appeared in any subject. A retest of the step-test for 16 elderly subjects showed its repeatability and a linear relationship between heart rate and oxygen consumption. The results suggested that the step-test was applicable to the elderly in regard to appropriate work load and safety. The PWC significantly declined with aging (r = 0.52, p < 0.001). Relative aerobic capacity, taking that at age 20 as 100%, was 60% and 53% for subjects aged 60 and 70, respectively, which was in good agreement with available reports which measured oxygen consumption directly.

Adolescent↗

PubMed1993

Trajectory formation of vertical arm movements through a via-point: a limit of validity of the minimum-jerk model.

The minimum-jerk model predicts the smoothest trajectory for a class of human movements and so provides us with a kinematic measurement of skilled motor performance. To establish the limits of the model's validity, the predicted and experimentally defined movement trajectories and the joint coordination were compared in two-joint arm movements, bringing the hand from the initial position to the final position through a specified point (a via-point). Kinematic data of the movements were obtained through the SELSPOT system. The movement path, tangential velocity, and coordinated change in positions of the shoulder and elbow joints evidently deviated from those predicted by the model. These results suggest that the minimum-jerk model is not valid for movements under extreme conditions which are highly dependent on musculoskeletal dynamics.

Adult↗