Atypical involvement of undifferentiated carcinomas of the nasopharyngeal type. Apropos of 3 cases

This study compared body sway, a measure of postural stability, between regular brisk walkers and control subjects. Furthermore, the relationship between body sway and physical activity duration in postmenopausal women was examined. Subjects were 31 healthy postmenopausal women, aged 61-71 years. They were recruited from a randomized controlled study of the influence of brisk walking on bone: 16 women had been completing 20 min d-1 brisk walking, whilst 15 controls had been completing habitual activities only. Body sway was measured using a swaymeter that measured displacement at the waist whilst subjects stood on a compliant surface, with eyes closed, for 1 min. The activity was measured using activity monitors which were worn at the waist for 3 consecutive days. Body sway (eyes closed, standing on a compliant surface) was lower in walkers than in controls: 2,958 +/- (SE) 270 versus 5,225+/-371 mm2 min-1, respectively (p < 0.05). A negative correlation was found between body sway and minutes of physical activity (r = -0.47, p < 0.01). Analysis of variance revealed that body sway differed significantly (p < 0.05) between groups of differing physical activity participation, being 4,839 +/- 499, 4,167 +/- 516, and 2,877 +/- 362 mm2 min-1, respectively, in women completing <20, 20-40, and >40 min d-1 of physical activity. Body sway was significantly lower in the most active group than in the least active (p < 0.01). These data suggest that postural stability is better in regular walkers than in control subjects. Furthermore, a dose-response relationship was observed between physical activity and postural stability in postmenopausal women. These findings provide a preliminary indication that brisk walking, a low-cost and acceptable form of physical activity for the elderly, could be incorporated into strategies for improving balance in the elderly.     

Comparison of a functional obstacle course with an index of clinical gait and balance and postural sway

BACKGROUND: Older adults commonly experience falls because of balance and mobility problems. Better assessment methods are needed to understand and correct balance and mobility disorders. METHODS: We used a low technology, functional obstacle course (FOC) to measure balance and mobility in 352 community-dwelling elderly participants. To establish concurrent validity of the FOC, we compared performance on the FOC with two established measures of balance and mobility: performance on the Tinetti Index (TI) and postural sway area measured on a force platform. RESULTS: Bivariate correlation analyses revealed significant inverse correlations between FOC completion time, the TI balance and gait subscores, and the TI total score (r = -.73 to -.78). The FOC quality scores and TI balance and subscores gait and TI total scores (r = .76 to .82) were significantly positively correlated. FOC time had significant, but small, positive correlations with sway area with eyes open (r = .18) and closed (r = .17) and nonsignificant correlation with sway area with visual feedback. FOC quality also had significant, but smaller, inverse correlations with sway area with eyes open (r = -.024) and closed (r = -.015), and nonsignificant correlation with sway area with visual feedback. Regression analysis showed that TI gait and balance measures accounted for most of the variance found in FOC performance. CONCLUSIONS: Our findings support the position that the FOC and the TI measure dynamic balance, whereas postural sway measures a different aspect of balance. Advantages of the FOC include the evaluation of environmentally influenced falls and balance problems.     

Adapting reflexes controlling the human posture

Doubt about the role of stretch reflexes in movement and posture control has remained in part because the questions of reflex "usefulness" and the postural "set" have not been adequately considered in the design of experimental paradigms. The intent of this study was to discover the stabilizing role of stretch reflexes acting upon the ankle musculature while human subjects performed stance tasks requiring several different postural "sets". Task specific differences of reflex function were investigated by experiments in which the role of stretch reflexes to stabilize sway doing stance could be altered to be useful, of no use, or inappropriate. Because the system has available a number of alternate inputs to posture (e.g., vestibular and visual), stretch reflex responses were in themselves not necessary to prevent a loss of balance. Nevertheless, 5 out of 12 subjects in this study used long-latency (120 msec) stretch reflexes to help reduce postural sway. Following an unexpected change in the usefulness of stretch reflexes, the 5 subjects progressively altered reflex gain during the succeeding 3-5 trials. Adaptive changes in gain were always in the sense to reduce sway, and therefore could be attenuating or facilitating the reflex response. Comparing subjects using the reflex with those not during so, stretch reflex control resulted in less swaying when the task conditions were unchanging. However, the 5 subjects using reflex controls oftentimes swayed more during the first 3-5 trials after a change, when inappropriate responses were elicited. Four patients with clinically diagnosed cerebellar deficits were studied briefly. Among the stance tasks, their performance was similar to normal in some and significantly poorer in others. Their most significant deficit appeared to be the inability to adapt long-latency reflex gain following changes in the stance task. The study concludes with a discussion of the role of stretch reflexes within a hierarchy of controls ranging from muscle stiffness up to centrally initiated responses.     

Oligoribonucleotides containing 8-oxo-7,8-dihydroguanosine and 8-oxo-7,8-dihydro-2''-O-methylguanosine: synthesis and base pairing properties

OBJECTIVE: To test whether a rigid or a flexible ankle orthosis affects postural sway in single-limb stance as quantified by stabilometry. DESIGN: Crossover trial. SETTING: University laboratory. PARTICIPANTS: Twenty-two athletes with functional ankle instability (consecutive sample of patients with recurrent ankle sprains but without mechanical instability) and 22 healthy athletes (control group of volunteers matched to age, height, weight, physical activity). INTERVENTIONS: Stabilometry in single-limb stance on a force platform. Participants were tested on each leg with and without a rigid or a flexible ankle orthosis. The order of test conditions was randomized. MAIN OUTCOME MEASURES: Sway velocities, sway pattern, and sway area as calculated from center of pressure movements. The two groups were compared by Mann-Whitney test, and the different orthoses within each group were compared by Wilcoxon test, paired samples (type I error 5%, Bonferroni adjustment). RESULTS: In athletes with functional ankle instability, both a rigid and a flexible ankle orthosis significantly reduced mediolateral sway velocity. A flexible ankle orthosis also changed sway pattern significantly, by reducing the percentage of linear movements of less than 5 degrees per .01 sec. CONCLUSIONS: In athletes with functional ankle instability, ankle orthoses reduce mediolateral sway velocity, possibly because of improved mediolateral proprioception.     

Children's postural sway in response to low- and high-frequency visual information for oscillation.

Two experiments examined postural responses of 3- to 6-year-old children to visual information for oscillation. In Experiment 1, children saw oscillations of the surround, with these movements ranging in frequency between 0.2 and 0.8 Hz. Analyses of anterior-posterior postural sway revealed that, similar to previous developmental investigations, the frequency of sway matched the frequency of oscillations. Analyses of sway amplitude and timing, however, revealed patterns of results more in keeping with research on adults. Experiment 2 extended these findings, presenting oscillations in which the frequency changed during the trial. Analyses of anterior-posterior sway revealed that sway frequency matched both speeds of movement. In contrast, amplitude and timing measures were again in line with adult data. These results suggest that the postural sway of children contains both adultlike and nonadultlike parameters of balance control. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Better postural balance in elderly women receiving estrogens

OBJECTIVE: The amount of bone mass and the tendency to fall are main risk factors for hip fractures and both deteriorate with advancing age. The dynamics between estrogen exposure and fracture protection seem too rapid to be explained by an effect on bone mass only. Postural balance function may be another potential mechanism for the fracture-protecting effect of estrogens. STUDY DESIGN: We examined 16 long-term users of 17 beta-estradiol implants (20 mg) (mean age 67.9 years and mean duration of treatment 17.3 years [3.3 to 34 years]) and 16 age-matched (+/-2 years) nonusers (mean age 68.3 years). Postural balance (sway velocity) was measured by static posturography before and after blindfolding and application of vibration stimulus (20 to 100 Hz) to the calf muscles to disturb the proprioception and to induce imbalance. RESULTS: Sway velocities were significantly lower in estrogen users than in nonusers (p = 0.0067) and similar to those in young premenopausal women. The differences were accentuated after provocation by blindfolding and by increasing frequencies of vibration stimulus to the calf muscle. Serum levels of estradiol and estradiol/sex hormone-binding globulin were negatively and follicle-stimulating hormone levels positively associated with sway velocity (p = 0.0194, p = 0.0036, and p = 0.0052, respectively) and independent of age (p = 0.02 to 0.005), supporting causality between estrogen exposure and postural balance. CONCLUSIONS: These data indicate that postural balance function is better preserved in long-term estrogen users than in nonusers. Effects on postural balance function may be one mechanism explaining the rapid increase in distal forearm fractures early after menopause and the rapid dynamics between estrogen exposure and hip fracture protection and may potentially reduce the fracture risk in elderly women starting estrogen replacement therapy in spite of marginal increases in bone mass.     

The effect of intraarticular anesthesia and elastic bandage on elbow proprioception

Twenty uninjured male volunteers were studied to characterize normal elbow proprioception and to investigate the effect of applying an elastic bandage to the extremity and injection of an intraarticular anesthetic. A modified Biodex dynamometer was used to study position sense and detection of motion. In part 1 of the study position sense was tested by flexing the elbow to a predetermined angle, returning to the starting position, and then asking the subject to identify that angle. In part 2 detection of motion was tested by asking the subject to disengage the apparatus by pressing a stop button when movement was detected. The testing conditions in part 1 and part 2 were repeated after the elbow was wrapped with an elastic bandage and again after an intraarticular injection of 3 cc 1% lidocaine with the bandage removed. Ten additional subjects underwent testing of both elbows to examine the effect of arm dominance. Mean position sense was within 3.3 degrees+/-1.3 degrees of the actual angle in trials without an elastic bandage or an anesthetic. A significant improvement in position sense was observed (2.2 degrees+/-1.2 degrees) after an elastic bandage was applied (P < .004). No significant difference was seen in position sense after lidocaine was injected. The mean threshold for detection of motion in trials without an elastic bandage or an anesthetic was 4.21 degrees+/-1.56 degrees. No significant differences were seen in detection of motion observed with the elastic bandage or intraarticular anesthetic. No significant differences were seen between dominant and nondominant extremities for both position sense and detection of motion. The application of an elastic bandage improved position sense, suggesting that tactile cues from cutaneous or other extraarticular receptors may play a role in elbow proprioception. Intraarticular anesthesia, however, had little effect, suggesting that intracapsular receptors play a lesser role in elbow proprioception. The determination of proprioceptive qualities for the normal elbow can aid in the understanding of elbow function and provide a basis for defining its role in elbow dysfunction.     

Peripheral neuropathy effect on ankle inversion and eversion detection thresholds

A servo-controlled foot platform was used to quantify, in upright stance, the thresholds for sensing ankle inversion and eversion movements in seven geriatric patients with peripheral neuropathy (PN) confirmed by nerve conduction studies and seven age- and gender-matched (C) controls with normal nerve conduction function. The PN group had a 4.6-fold larger (p = 0.0026) threshold (mean [SD] 1.37 [1.74]degrees) for perceiving the presence and direction of an ankle rotation at a 75% rate of success (TH75) than did the C group (0.3[0.17]degrees). Inversion acuity was approximately twice that of eversion acuity in both groups. The PN group demonstrated better proprioceptive acuity in unipedal stance than in bipedal stance, whereas no such difference was found in the C group. Semiquantitative clinical tests of PN group proprioception at the ankle performed in the seated position failed to demonstrate significant differences from controls save in one case; however, the results of such tests at the toe were abnormal in all patients. In the geriatric population, PN is associated with deficits in ankle proprioception known theoretically to hamper maintenance of unipedal balance. It is significant that these deficits are associated with a clinically demonstrable loss of position sense at the toe but not the ankle.     

Fournier''s gangrene: historic (1764-1978) versus contemporary (1979-1988) differences in etiology and clinical importance

Little objective data exist regarding the effect of the Aircast Air-Stirrup on motor performance. Thus, the effect of the Aircast on the amplitude and frequency of postural sway during unilateral stance was evaluated for 15 uninjured male subjects. Postural sway during static and dynamic tests was measured using the Chattecx Balance System. Use of the Aircast improved unilateral postural control as evidenced by decreases in some of the components of postural sway. Previously, a link was made between a large amplitude of unilateral sway and a high probability of ankle injury (14). Thus, since Aircast use was found to decrease the amplitude of unilateral sway, it may also be beneficial in reducing the probability of injury. Although the scope of this study did not allow for differentiation among the complex systems involved in postural control, the possibility of the Aircast enhancing afferent feedback was proposed. The restricted inversion-eversion range of motion associated with the Aircast, in conjunction with the present observation that unilateral stability was enhanced with its use, suggests that the Aircast may provide a valuable prophylactic role in helping to reduce the incidence of ankle injuries.     

Sensory strategies in human postural control before and after unilateral vestibular neurotomy

Vestibular inputs tonically activate the anti-gravitative leg muscles during normal standing in humans, and visual information and proprioceptive inputs from the legs are very sensitive sensory loops for body sway control. This study investigated the postural control in a homogeneous population of 50 unilateral vestibular-deficient patients (Ménière's disease patients). It analyzed the postural deficits of the patients before and after surgical treatment (unilateral vestibular neurotomy) of their diseases and it focused on the visual contribution to the fine regulation of body sway. Static posturographic recordings on a stable force-plate were done with patients with eyes open (EO) and eyes closed (EC). Body sway and visual stabilization of posture were evaluated by computing sway area with and without vision and by calculating the percentage difference of sway between EC and EO conditions. Ménière's patients were examined when asymptomatic, 1 day before unilateral vestibular neurotomy, and during the time-course of recovery (1 week, 2 weeks, 1 month, 3 months, and 1 year). Data from the patients were compared with those recorded in 26 healthy, age- and sex-matched participants. Patients before neurotomy exhibited significantly greater sway area than controls with both EO (+52%) and EC (+93%). Healthy participants and Ménière's patients, however, displayed two different behaviors with EC. In both populations, 54% of the subjects significantly increased their body sway upon eye closure, whereas 46% exhibited no change or significantly swayed less without vision. This was statistically confirmed by the cluster analysis, which clearly split the controls and the patients into two well-identified subgroups, relying heavily on vision (visual strategy, V) or not (non-visual strategy, NV). The percentage difference of sway averaged +36.7%+/-10.9% and -6.2%+/-16.5% for the V and NV controls, respectively; +45.9%+/-16.8% and -4.2%+/-14.9% for the V and NV patients, respectively. These two distinct V and NV strategies seemed consistent over time in individual subjects. Body sway area was strongly increased in all patients with EO early after neurotomy (1 and 2 weeks) and regained preoperative values later on. In contrast, sway area as well as the percentage difference of sway were differently modified in the two subgroups of patients with EC during the early stage of recovery. The NV patients swayed more, whereas the V patients swayed less without vision. This surprising finding, indicating that patients switched strategies with respect to their preoperative behavior, was consistently observed in 45 out of the 50 Ménière's patients during the whole postoperative period, up to 1 year. We concluded that there is a differential weighting of visual inputs for the fine regulation of posture in both healthy participants and Ménière's patients before surgical treatment. This differential weighting was correlated neither with age or sex factors, nor with the clinical variables at our disposal in the patients. It can be accounted for by a different selection of sensory orientation references depending on the personal experience of the subjects, leading to a more or less heavy dependence on vision. The change of sensory strategy in the patients who had undergone neurotomy might reflect a reweighting of the visual and somatosensory cues controlling balance. Switching strategy by means of a new sensory selection of orientation references may be a fast adaptive response to the lesion-induced postural instability.     

Proprioceptive capacities of patients with retropatellar knee pain with special reference to effectiveness of an elastic knee bandage

In the presented study, knee joint proprioception of 43 patients with a patellar pain syndrome of the knee joint was evaluated. In a control group, the proprioception of 30 healthy volunteers with clinical and an-amnestic inconspicous knee joints was examined. We tested the proprioceptive capability of the subjects with a passive angle reproduction test. Additionally, all knee joints were measured with and without an elastic knee bandage. The patient group showed significant deterioration of angle reproduction capability (13.2 degrees +/- 6.1 degrees) compared to the control group (7.8 degrees +/- 2.8 degrees). After applying an elastic knee bandage, the angle reproduction capability significantly improved to 9.2 degrees +/- 4.5 degrees. Proprioception of the contralateral, noninvolved knee joint in the patients (11.6 degrees +/- 6.3 degrees) was worse compared to the control group. Applying an elastic knee bandage did not significantly improve the proprioception of the uninjured knee joint.     

Peripheral neuropathy: an often-overlooked cause of falls in the elderly

Peripheral neuropathy is common in the elderly and results in impairments in distal proprioception and strength that hinder balance and predispose them to falls. The loss of heel reflexes, decreased vibratory sense that improves proximally, impaired position sense at the great toe, and inability to maintain unipedal stance for 10 seconds in three attempts all suggest functionally significant peripheral neuropathy. Physicians can help their patients with peripheral neuropathy to prevent falls by teaching them and their families about peripheral nerve dysfunction and its effects on balance and by advising patients to substitute vision for the lost somatosensory function, correctly use a cane, wear proper shoes and orthotics, and perform balance and upper extremity strengthening exercises.     

Effect of gut transposition on the expression of the endocrine gene neurotensin

PURPOSE: The purpose of this study was to evaluate joint position sense (JPS) in patients with posttraumatic glenohumeral instability. MATERIALS AND METHODS: In 28 patients with posttraumatic instability and in a matched control group of 30 subjects proprioception capability was evaluated. For documentation of proprioception an angle reproduction test (ART) was performed with which joint positions sense (JPS) was measured for abduction, flexion, and rotation in three angles each. RESULTS: In both groups there was a significant better JPS with visual control than without. In contrast to the control group the patients were not able to increase angle reproduction capability without visual control when comparing positions below shoulder level with positions at or above shoulder level. When comparing the patients to the controls there were differences in most of the ARTs with worse results in the patient group. These differences were significant in 150 degrees flexion with and without visual control, in 150 degrees abduction without and in 100 degrees abduction with visual control. For rotation there were trends for almost all joint positions, however, the differences were significant only in the -45 position. When comparing the noninjured contralateral shoulder of the patients with the control group, there still were differences. Again these were not in all joint positions significant, but significant worse JPS could be demonstrated in 150 degrees abduction without visual control, 50 degrees flexion without visual control, -45 degrees rotation without and 0 degrees rotation with visual control. CONCLUSIONS: A proprioceptive deficit can be documented in patients with posttraumatic glenohumeral instability. This may be one reason for permanent instability. The contralateral joint also shows reduction in joint position sense. For consecutive treatment as well as for rehabilitation both shoulder joint should be addressed.     

Influence of sensory manipulation on postural control in Parkinson's disease

Postural control was assessed on a tilting platform system in 20 patients with idiopathic Parkinson's disease and 20 age-matched controls. The amount of information provided by vision and lower limb proprioception was varied during the experiment to investigate the influence of changes in sensory cues on postural control. The patient group with clinical evidence of impaired postural control (Hoehn and Yahr III) had significantly higher sway scores over all sensory conditions than either the Hoehn and Yahr II group or controls. The pattern of sway scores indicated that no obvious deficit in the quality, or processing, of sensory information was responsible for the postural instability observed in this group. The patients in both Hoehn and Yahr groups were also able to respond appropriately to potentially destabilising sensory conflict situations and significantly improved their sway scores when provided with visual feedback of body sway. The results indicate that in Parkinson's disease, the main site of dysfunction in postural control is likely to be at a central motor level.     

Does ice immersion influence ankle joint position sense?

The purpose of this study was to determine whether a fifteen minute ice immersion treatment influenced the normal ankle joint position sense at 40% and 80% range of inversion and to establish the length of treatment effect through monitoring the rewarming process. Forty nine healthy volunteers between the ages of 17 and 28 were tested. Subjects were screened to exclude those with a history of ankle injuries. The subject's skin temperature over antero-lateral aspect of the ankle was measured using a thermocouple device during the fifteen minutes ice intervention and thirty minutes post-intervention. Testing of ankle joint position sense using the pedal goniometer was performed before and after a clinical application of ice immersion. The testing required the subject to actively reposition their ankle at 40% and 80% of their total range of inversion. The majority of subjects experienced numbness of the foot and ankle by the fifth or sixth minute during ice immersion. One minute after immersion skin temperatures averaged 15 degrees C + 1.7 degrees C. Skin temperature was seen to rise relatively rapidly for the first ten minutes and then slowed considerably. Subjects had not returned to the pre-test skin temperatures by thirty minutes. A significant difference in ankle joint position sense (p < 0.0499) following fifteen minutes of ice immersion was found. However, the magnitude of this difference (0.5 degree) would not be deemed significant in clinical practice. The research found no significant difference in joint position sense between 40% and 80% of the range of inversion both before and after cryotherapy. These findings suggest that the clinical application of cryotherapy is not deleterious to joint position sense and assuming normal joint integrity patients may resume exercise without increased risk of injury.     

Effect of resistance training on strength, postural control, and gait velocity among older adults

The purpose of this study was to examine the effects of a 14-week resistance training program on the ankle strength, training intensity, postural control, and gait velocity of older adults. Forty-two older adults (mean age = 72), 21 in the resistance and control groups, completed the 14-week project. The resistance training group participated in 14 weeks of resistance training three times per week using elastic bands (Theraband) for resistance. Isokinetic ankle strength, training intensity, postural stability, and gait velocity were measured prior to and following the 14-week intervention. Following the training, the resistance group exhibited improved ankle dorsiflexion, training resistances, and gait velocity, but showed no change in plantar flexion or postural control. The control group also exhibited improvements in dorsiflexion, but these gains were approximately one-half of the gains observed in the resistance training group. Finally, when adjusted for baseline differences, subjects in the resistance training group demonstrated no changes in the dependent measures over the control group.     

Can some facial rejuvenation techniques cause iatrogenia?

Previous research has shown that in healthy subjects during a quiet two-legged stance, sagittal postural sway is greater than lateral postural sway with a ratio approximating 1.5. The purpose of this study was to examine the postural sway profiles of healthy men and women, and men with mental retardation (MR). Subjects consisted of 22 men (M), 22 women (W) and 22 men with MR. Postural sway characteristics were examined using a Kistler force platform. Each subject performed six trials, three with vision and three with vision occluded. Each trial was 15sec in duration, and the subject was instructed to stand motionless on the force platform. A custom-designed computer program sampled the lateral and sagittal sway characteristics for each trial, at a sample rate of 50Hz. Results indicated that the MR group exhibited significantly more lateral sway than the other two groups, and that the sagittal/lateral sway ratio was significantly lower in this group. Moreover, the MR group showed a greater amount of sway in the no-vision condition than either the M or W groups. Using the sagittal/lateral sway ratio, discriminant analyses indicated that group membership could be predicted in 75% to 82% of the cases in the vision condition, and 64% to 73% of the cases in the no-vision condition. It is concluded that the sagittal/lateral sway ratio provides a valid and objective assessment measure to determine the postural control/balance capacities of persons with MR. In addition, it is hypothesized that this ratio may prove useful in quantifying the effectiveness of therapeutic intervention programs on balance performance.     

Regulation and function of tinman during dorsal mesoderm induction and heart specification in Drosophila

Sensory-motor control of upright human posture may be organized in a top-down fashion such that certain head-trunk coordination strategies are employed to optimize visual and/or vestibular sensory inputs. Previous quantitative models of the biomechanics of human posture control have examined the simple case of ankle sway strategy, in which an inverted pendulum model is used, and the somewhat more complicated case of hip sway strategy, in which multisegment, articulated models are used. While these models can be used to quantify the gross dynamics of posture control, they are not sufficiently detailed to analyze head-trunk coordination strategies that may be crucial to understanding its underlying mechanisms. In this paper, we present a biomechanical model of upright human posture that extends an existing four mass, sagittal plane, link-segment model to a five mass model including an independent head link. The new model was developed to analyze segmental body movements during dynamic posturography experiments in order to study head-trunk coordination strategies and their influence on sensory inputs to balance control. It was designed specifically to analyze data collected on the EquiTest (NeuroCom International, Clackamas, OR) computerized dynamic posturography system, where the task of maintaining postural equilibrium may be challenged under conditions in which the visual surround, support surface, or both are in motion. The performance of the model was tested by comparing its estimated ground reaction forces to those measured directly by support surface force transducers. We conclude that this model will be a valuable analytical tool in the search for mechanisms of balance control.     

Perception–action coupling in the development of visual control of posture.

In this investigation of developmental changes in the coordination of perceived optical flow and postural responses, 4 age groups of infants (5-, 7-, 9-, and 13-month-olds) were tested while seated on a force plate in a "moving room." During each trial the walls oscillated in an anteroposterior direction for 12 s, and the postural sway of the infant was measured. The results revealed that infants perceived the frequency and amplitude of the optical flow and scaled their postural responses to the visual information. This scaling was present even before infants could sit without support, but it showed considerable improvement during the period when infants learn to sit. Taken together, these results suggest that the visuomotor coordination necessary for controlling sitting is functional prior to the onset of independent sitting but becomes more finely tuned with experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. DESIGN: Randomized 3-month clinical trial. Subjects (n = 110, mean age 80) were randomized to 4 groups in a 2 x 2 design (control, resistive, balance, combined resistive/balance). INTERVENTIONS: Resistive training involved knee extension and flexion, hip abduction and extension, and plantar and dorsiflexion using simple resistive machines and sandbags. Balance training consisted of exercises to improve postural control. The control group attended 5 health-related discussion sessions. MEASUREMENTS: Summed isokinetic moments (N m) of 8 leg movements: hip, knee and ankle flexion/extension, and hip abduction/adduction. Secondary outcomes were gait velocity and chair rise time. MAIN RESULTS: Summed peak moment increased in both resistive exercise-trained groups (13% increase in the resistive group and 21% in the combined training group, P < 0.001). The effect of resistance training was significant (MANOVA F = 21.1, P < 0.001), but balance training did not improve strength, and there was no interaction (positive or negative) between balance and resistive training. Maximal gait velocity and chair rise time did not improve. Eleven subjects (20%) had musculoskeletal complaints related to resistive training, but all were able to complete the program with modifications. CONCLUSION: Resistive training using simple equipment is an effective and acceptable method to increase overall leg strength in older persons. Resistive or balance training did not improve maximal gait velocity or chair rise time in this sample of relatively healthy older persons.