Biomedical subjects

P Amerman

Publications and source records attributed to P Amerman.

8 recordsLinked to original sources

PubMed1996

Balance and strength training in older adults: intervention gains and Tai Chi maintenance.

OBJECTIVE: To determine the effect on balance and strength of 3 months of intensive balance and/or weight training followed by 6 months of low intensity Tai Chi training for maintenance of gains. DESIGN: Randomized control intervention. Four groups in 2 x 2 design: Control, Balance, Strength, Balance + Strength, using blinded testers. SETTING: Exercise and balance laboratory at University of Connecticut Health Center. PARTICIPANTS: Subjects were 110 healthy community dwellers (mean age 80) who were free of dementia, neurological disease, and serious cardiovascular or musculoskeletal conditions. INTERVENTIONS: Short-term training (3 months) occurred 3 times/week (45 minutes Balance and Strength, 90 minutes Balance + Strength). Balance training included equilibrium control exercises of firm and foam surfaces and center-of-pressure biofeedback. Strengthening consisted of lower extremity weight-lifting. All subjects than received long-term group Tai Chi instruction (6 months, 1 hour, 1 time/week). MEASUREMENTS: Losses of balance during Sensory Organization Testing (LOB), single stance time (SST), voluntary limits of stability (FBOS), summed isokinetic torque of eight lower extremity movements (ISOK), and usual gait velocity (GVU). RESULTS AND CONCLUSIONS: Balance training meaningfully improved all balance measures by restoring performance to a level analogous to an individual 3 to 10 years younger: LOB = -2.0 +/- 0.3 (adjusted paired differences, P < .005 ANOVA); SST = 7.0 +/- 1.2 sec; and FBOS = 9.0 +/- 2.0% of foot length (P < .05). Strengthening increased ISOK by 1.1 +/- 0.1 Nm kg-1 (P < .005). There was no interaction between balance and strength training. Significant gains persisted after 6 months of Tai Chi, although there was some decrement.

Aged↗

PubMed1994

Gender differences in the balance of healthy elderly as demonstrated by dynamic posturography.

BACKGROUND: Prior studies indicate that older women fall more often than men although there is no evidence of gender-based balance differences. Using a force platform, we measured the effects of restricted sensory input and support surface movement to detect gender differences in balance. METHODS: Healthy, elderly community dwellers (N = 234, mean age = 76 +/- 5 years, 52% female) were administered the following perturbations on the balance platform: The platform and/or visual surround were fixed or tilted proportionally to the subject's sway with the eyes open or closed, forward or backward horizontal translations, and toes-up and toes-down rotations. RESULTS: Gender-based balance differences were not present during quiet standing, or when the support surface or visual input were manipulated separately. Women swayed and lost their balance more than men when the surface was sway-referenced while vision was compromised, but by the third trial their sway control was comparable to the men. Women also initially lost their balance more frequently than men during toes-up and -down rotations, and compared to men continued to lose their balance more often during repeated toes-up rotations. Finally, women developed less angular momentum than men in response to forward platform rotations. DISCUSSION: Elderly women show impairments of balance when simultaneously deprived of visual and somatosensory inputs or during a backwards destabilization. Since there is little evidence for a CNS source for such gender differences, biomechanical origins (e.g., dorsiflexion strength and range of motion) are a more likely cause. Limited postural control of women under conditions stressing balance may explain their greater frequency of falling.

Adaptation, Physiological↗

PubMed1993

Training balance and strength in the elderly to improve function.

Short-term exposure to altered sensory input or destabilizing platform movement results in significant improvement in sway control and inhibition of inappropriate motor responses, resulting in improved balance during repetitive testing. In addition, there is recent evidence that strength and function can be increased in both active and frail elderly who participate in strength training programs. Therefore, the hypotheses to be tested are that (1) balance training alone, or (2) strength training alone will each be capable of significantly improving balance, gait, and functional mobility, and that (3) a combined program of balance and strength training will be more effective than either approach alone. These hypotheses will be tested relative to a control group, using a 2 x 2 design (30 subjects per group), in a community-dwelling elderly at least 75 years of age. Intervention sessions of at least 45 minutes will occur three times per week for 3 months, with 6 months of follow-up, home-based Tai Chi training. The primary outcome variable is a basic measure of functional balance, ie, the occurrence of loss of balance during tilts of the support and/or movement of the visual surround.

Aged↗

PubMed1992

A dynamic posturography study of balance in healthy elderly.

Using dynamic posturography, we studied the balance of 234 community-dwelling elderly subjects (mean age, 76 +/- 5 years) as well as 34 young controls (mean age, 34 +/- 12 years). Almost all measures of balance were worse in elderly subjects compared with young controls. The decrements in older persons indicate a diminished capacity to process conflicting sensory input as well as a possible narrowing of the limit of stability (or, alternatively, an increase in sway). We propose that this occurs most likely as a result of biomechanical or central processing changes as opposed to diminished sensory or vestibular input. Furthermore, with difficult tasks sequentially presented, the performance of the older subjects improved, suggesting that balance, at least in the short term, adapts to stressful conditions. In these elderly subjects screened for age-related diseases affecting balance, only small decrements of balance occurred between the ages of 70 and 85 years. This nominal decrease over a 15-year span suggests that clinically significant balance impairment is the result of age-related disease rather than an inevitable consequence of aging and is therefore potentially treatable.

Adult↗

PubMed1990

Gait assessment in the elderly: a gait abnormality rating scale and its relation to falls.

We evaluated the gait of 49 nursing home residents (27 of whom had a history of recent falls), and 22 controls. Measures consisted of stride length and walking speed, as well as a videotape-based analysis of 16 facets of gait. The study demonstrates that stride length, walking speed, and the assessment of videotaped gait correlated well with each other and were significantly impaired in fallers compared to controls. Arm swing amplitude, upper-lower extremity synchrony, and guardedness of gait were most impaired in fallers. Although subjects who fell were more often demented than controls, it is likely that this represents a selection bias in nursing homes. Visual rating of gait features in the nursing home population is a simple and useful alternative to established methods of gait analysis.

Accidental Falls↗

PubMed1989

Brain white-matter changes in the elderly prone to falling.

Falls and impaired gait are a major source of morbidity in the elderly. Why some elderly become prone to falling is often unclear. We analyzed the gait, equilibrium, and brain computed tomography results of 40 elderly subjects without evidence of neurologic disease known to be associated with falls. Twenty of these subjects were prone to falling and the remaining 20 were nonfalling controls. These two groups were comparable in terms of age and sex (mean age, 83.3 years [SE, 1.7 years]). The group of fallers had significantly worse gait and equilibrium scores and a greater degree of white-matter hypodensity on computed tomography. White-matter hypodensity correlated with impaired gait and equilibrium scores but not with impaired performance on cognitive testing. This study reveals the association of white-matter disease with gait and balance impairment leading to falls in the elderly.

Accidental Falls↗

PubMed1986

Stressing the postural response. A quantitative method for testing balance.

Using a series of graded destabilizing forces, we have developed a simple quantitative test of the postural response: the Postural Stress Test (PST). Suitable for widespread testing of elderly subjects, the test evaluates the subject's ability to avoid a fall as well as the appropriateness of the response. We have determined that by comparison with young subjects, the elderly controls have compromised although functionally effective balance. On the other hand, the balance response was severely compromised in half of the individuals with a history of falls. Experience with the Postural Stress Test suggests it will predict those elderly individuals with a tendency to fall as well as provide a simple mechanism for studying the balance response in the elderly.

Accidental Falls↗

PubMed1985

Gait and balance in the elderly. Two functional capacities that link sensory and motor ability to falls.

Neuromuscular function, which underlies efficient gait and balance, deteriorates with age and disease. A review of the literature and of data from the current study suggests the presence of poor gait and balance in elderly individuals who have a history of multiple falls. The tests of gait and balance are simple to perform and therefore may be widely applicable in evaluating individuals at risk of falls. Quantitative studies of motor and sensory function, vibratory sensation, and electrophysiologic studies of nerve integrity are discussed. Deteriorating motor and sensory control mechanisms appear to play an important role in falling.

Accidents↗