Robert Whipple

The Relationship of Knee and Ankle Weakness to Falls in Nursing Home Residents: An Isokinetic Study

The strength of the knees and ankles of a group of nursing home residents with a history of falls was compared to age‐matched controls. Peak torque (PT) and power (POW) were recorded at two limb velocities (60°/s and 220°s) on a Cybex II Isokinetic dynamometer for four muscle groups: knee extensors, knee flexors, ankle plantar flexors and ankle dorsiflexors. The PT and POW of falters were significantly decreased for all four muscle groups in comparison to controls, with the ankles showing the greatest decrements. Although POW in fullers was significantly lower at the higher velocity in both joints, the decrease was most prominent in the ankles. Dorsiflexion POW production in falters was the most affected of all the motions (7.5 times less than the control value). At the higher, more functional limb velocities, ankle weakness particularly involving the dorsiflexors appears to be an important factor underlying poor balance.

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.

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 subjects 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.

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.

Effects of Resistive and Balance Exercises on Isokinetic Strength in Older Persons

OBJECTIVE: To determine the safety and efficacy of 3 months of resistive training of multiple lower extremity muscle groups compared with balance training in persons over 75 years.

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 times 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.

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.

Lower standing systolic blood pressure as a predictor of falls in the elderly: a community-based prospective study

OBJECTIVES We investigated prospectively the relationships among falls, physical balance, and standing and supine blood pressure (BP) in elderly persons. BACKGROUND Falls occur often and adversely affect the activities of daily living in the elderly; however, their relationship to BP has not been clarified thoroughly. METHODS A total of 266 community-dwelling elderly persons age 65 years or over (123 men and 143 women, mean age of 76 years) were selected from among residents of Coop City, Bronx, New York. Balance was evaluated at baseline using computerized dynamic posturography (DPG). During a one-year follow-up, we collected information on subsequent falls on a monthly basis by postcard and telephone follow-up. RESULTS One or more falls occurred in 60 subjects (22%) during the one-year follow-up. Women fell more frequently than men (28% vs. 16%, p < 0.03), and fallers were younger than nonfallers. Fallers (n = 60) had lower systolic BP (SBP) levels when compared with nonfallers (n = 206) (128 +/- 17 vs. 137 +/- 22 mm Hg for standing, p < 0.006; 137 +/- 16 vs. 144 +/- 22 mm Hg for lying, p < 0.02), whereas diastolic BP was not related to falls. Falls occurred 2.8 times more often in the lower BP subgroup (<140 mm Hg for standing SBP) than in the higher BP subgroup (> or =140 mm Hg, p < 0.0003), and gender-related differences were observed (p = 0.006): 3.4 times for women (p < 0.0001) versus 1.9 times for men (p = 0.30). Loss of balance, as detected by DPG, did not predict future falls and was also not associated with baseline BP levels. Multiple logistic regression analysis demonstrated that female gender (relative risk [RR] = 2.1, p = 0.02), history of falls (RR = 2.5, p = 0.008) and lower standing SBP level (RR = 0.78 for 10 mm Hg increase, p = 0.005) were independent predictors of falls during one year of follow-up. CONCLUSIONS Lower standing SBP, even within normotensive ranges, was an independent predictor of falls in the community-dwelling elderly. Elderly women with a history of falls and with lower SBP levels should have more attention paid to the prevention of falls and related accidents.

Stance perturbation-evoked potentials in old people with poor gait and balance.

OBJECTIVE Cerebral cortical potentials can be evoked by stance perturbation, and there is speculation that they represent the activation of supraspinal centers in preparation for the control and coordination of motor movements that maintain balance. We sought to determine if these potentials differed in old people at risk of falls. METHODS Cortical potentials were generated by the sudden forward translation of a weight-bearing platform in 8 healthy young subjects and in 33 old subjects stratified by their functional capacity. Dependent measures were compared with non-parametric tests of significance. RESULTS Perturbing the stance of young subjects produced a biphasic scalp potential centered at the vertex with an early positive peak at 60 ms and a larger, 45 microV, negative peak at 123 ms. In old subjects the response was delayed and the vertex-negative component was smaller and bifid. The interval between the two components of the negative peak was prolonged in a subgroup of old subjects with reduced mobility. CONCLUSIONS Delays in sensory conduction may play a role in subsequent maladaptive motor responses to stance perturbation that can result in falls and injury in old people.

Review Article: Neurological Dysfunction in the Elderly Prone to Fall

While impaired joint function and general debility are relevant to function, we propose that abnormalities within the motor system controlling gait and postural reflexes are major causes of impaired mobility and falls in older individuals. Neurologic disease impairs this system at different foci, producing characteristic deficits. Thus, bilateral frontal lobe disease produces a characteristic gait and balance dysfunction along with a mild dementia and incontinence, whereas Parkinsons disease produces a different set of motor abnormalities. Other loci of involvement include spinal cord, peripheral nerve, and muscle. Recently, we observed that lesions within the subcortical white matter (presumably ischemic in origin) may be an important factor in gait and balance dysfunction in older individuals without other defined neurologic disease. Key Words: Falls—Aging—Neurologic disease—Diagnosis.