Evaluating eye-body coordination during unrestrained functional activity in older persons.

BACKGROUND: Traditional paradigms for the study of ocular-motor control restrain subject motion and have not adequately quantified the sensorimotor strategies used by older persons to control gaze while performing activities of daily living. The purpose of our study was to describe eye-head-trunk coordination during a functional activity in freely moving community-dwelling older persons. METHODS: Thirty-five community-dwelling older persons (age range 71-92 years) participated in this study. Surface electro-oculography was used with an electromagnetic tracking device to measure vertical eye movement and linear and angular head position while each subject performed a stand-from-chair task. RESULTS: Standing from a chair involved low-frequency head motion (median z = 0.25 Hz; median pitch = 0.32 Hz). The distribution of phase for eyes versus vertical body motion were skewed toward head-trunk leading, suggesting that eye motion follows vertical body motion. Vertical gaze, however, was in phase with and moved in the same direction as head pitch. CONCLUSIONS: Gaze (eye position in space) was an active, integrated component of the standing motion. The results imply that both the oculomotor system and the head motor system in older persons are coordinated to direct gaze and, when necessary, work to suppress the vestibuloocular reflex. The interaction of eye-head-trunk motion provides a basis for understanding how a breakdown in the gaze control mechanisms in older persons might contribute to the risk of falling and fall-related injuries.

Lower extremity antagonist muscle response following standing perturbation in subjects with cerebrovascular disease.

The onset, amplitude, and relative timing of opposing muscle groups during forward and backward body sway were investigated in standing subjects with hemiplegia and a normal control group. The agonist was the first muscle stretched by platform perturbation and the antagonist was the opposing muscle passively shortened by the movement stimulus. Tibialis anterior (T), quadriceps (Q), gastrocnemius (G) and hamstrings (H) were simultaneously monitored bilaterally for burst activity. During rotational (toe up/down) and horizontal perturbations in normals, two distinct muscle responses were observed--an initial long-latency response (LLR) in the agonist and a subsequent response in the antagonist muscle group. Hemiplegics showed early activation of the antagonist response (AR) with respect to the initial LLR and frequent coactivation of synergists (T-Q or G-H). Although the AR was tightly coupled to the initial LLR in both hemiplegic lower limbs, initiation of the distal LLR-AR sequence was significantly delayed in the paretic extremity by 25-40 ms. In addition, the distal AR amplitude was suppressed in the paretic limb. The number of AR defaults in hemiplegics for all perturbation modes was significantly greater than normal. Therefore, unilateral cerebrovascular disease may reduce the occurrence of antagonist muscle activation and alter the latency, amplitude and phasing of passively shortened antagonist muscles.

Kinematic properties of voluntary postural sway in patients with unilateral primary hemispheric lesions.

The temporal and spatial characteristics of rapid voluntary body sway following unilateral cerebrovascular accident were assessed in single and combined planes of motion during a visually cued non-choice reaction time movement. Three distinct directions of intentional body sway were assessed: forward, toward the paretic, and toward the non-paretic lower extremity. Fluctuations in the center of foot pressure served as the basis for calculating body displacement and velocity by combining frontal and sagittal movement in an X-Y coordinate system (a bi-planar analysis). A linear regression analysis was used on individual force output channels to reduce the sway motion into separate component parts. The velocity profile in each direction of intended sway was calculated from the slope of the regression line (a single-plane analysis). Bi-planar velocity analysis showed that hemiplegics swayed as fast as normal subjects in any sway direction. In contrast, single plane analysis revealed a decrease in the velocity of hemiplegic sway when weight shifts were directed toward the paretic extremity. Response velocity in the non-paretic direction was similar to a comparison group of normal individuals. The apparent contradiction between single and bi-planar analyses was attributed to hemiplegic sway in extraneous planes of motion surrounding the intended sway path. During the course of body sway, hemiplegics showed a statistically larger range of extraneous movement away from the plane of intended movement. The directional deficits in sway velocity and excursion are compared to previously reported sway pathology associated with lesions of the human central nervous system.

Adapting human postural reflexes following localized cerebrovascular lesion: analysis of bilateral long latency responses.

The symmetry and adaptability of long latency stretch responses was studied in a group of 4 adult hemiplegics and 5 normals of similar age. Subjects stood on a moveable platform which directly rotated the ankles unexpectedly during a series of horizontal anterioposterior (AP) translations. When the platform was rotated toes-up, long latency discharge of gastrocnemius and hamstring muscles enhanced loss of balance by pulling the body backwards. Toes-down platform rotation elicited a reflex response from tibialis anterior and quadriceps which inappropriately pulled the body forward. Attenuation of these long latency responses was necessary to minimize functional destabilization. Normal and stroke subjects demonstrated appropriate suppression of long latency responses, but the magnitude of attenuation was not uniform in hemiplegics. Adaptation was decreased in the proximal synergists compared to normal. Latency of muscle activation in the paretic limb was prolonged, and a preference for initial non-paretic limb activation was evident. Both lower extremities in hemiplegics showed a disruption of timing between distal and proximal synergists. These results suggest that stroke victims retain or recover the ability to modulate stretch reflex activity for balance. Temporal and spatial response asymmetries surface as critical factors underlying disequilibrium associated with localized cerebrovascular lesion.

Postural supporting mechanisms during spontaneous single limb movement in the cat.

Patterns of postural adjustment accompanying spontaneous single limb movement in the cat were studied to examine qualitative and quantitative variations in support strategies. A multiple plate dynamometer and electromyograph were used to measure supporting actions during consecutive trials. Weight transfer involving primarily the forelimbs was dominant. A similar tripodal stance with increased bilateral hindlimb weight-bearing characterized a secondary support strategy. Both dominant and secondary balance behavior showed transient reversals to a bipodal postural pattern. Bipodal stance exhibited increased weight-bearing in the stabilizing forelimb and in the diagonally opposite hindlimb. Selection of different postural strategies for identical phasic limb movements could possibly result from modulation of lower level reflex inhibition.

Meta-analysis of the sensitivity and specificity of platform posturography.

OBJECTIVE: To compare the sensitivity and specificity of platform posturography with other vestibular tests for patients with peripheral vestibular deficits (PVD), Meniere's disease, benign paroxysmal positional vertigo (BPPV), and central nervous system-vestibular impairment (CNS). DATA SOURCES: A computed search was conducted using the Index Medicus database (1966-1994) and Current Contents Science Editions. STUDY SELECTION: Studies were selected for analysis if the article addressed the sensitivity and/or specificity of platform posturography, compared posturography with another objective test of vestibular function, identified the basis for abnormal test results, and reported the data with sufficient detail to calculate an effect size from a 2 x 2 contingency table. DATA EXTRACTION: A count of the normal and abnormal test results for posturography and the criterion standard were retrieved from each article, analyzed using a chi 2 statistic, and converted to an effect size. A positive effect size indicated that posturography identified abnormalities in patients who had normal tests on the criterion standard. DATA SYNTHESIS: Sensitivity and specificity of posturography were about 50%. The overall effect size was small (0.13) but positive. The diagnostic category had a significant influence on the predictive value of abnormal results (73% for Meniere's disease and BPPV, compared with 41% for PVD, and 44% for mixed CNS and PVD (F2,12 = 5.26, P = .02) and on the magnitude of the effect size (0.41 for mixed CNS and PVD compared with 0.22 for Meniere's disease and BPPV, and -0.10 for PVD (F2,12 = 13.95, P = .001). CONCLUSIONS: Platform posturography provides a measurable supplement to the standard vestibular examination. The enhancement was most notable when the target population included patients with CNS deficits.

Physical therapy for patients with TMD: a descriptive study of treatment, disability, and health status.

The purposes of this study were to compare disabilities and health status associated with temporomandibular disorders (TMD) to other musculoskeletal disorders, to describe the types of physical therapy administered to patients with TMD, and to evaluate health-related quality of life (HRQOL) as an index of clinical change following physical therapy treatment. Outcomes for 56 patients (mean age 40 years, SD 13 years; 89% female) were evaluated from a large database generated by the Focus on Therapeutic Outcomes network. A generic assessment of HRQOL--the Medical Outcomes Study (MOS) 17--was used to evaluate the physical and mental aspects of disability associated with TMD, and the results were compared descriptively to three groups of patients with different cervical pain syndromes. The results showed that patients with TMD had limitations in social function, emotional well-being, and energy level similar to patients with cervical disorders. Physical function (i.e., walking, carrying loads, or lifting), however, was much more limited in cervical disorder patients and bodily pain interfered more with daily work. Large positive effect sizes (> 0.80) in the areas of social function and bodily pain indicated clinical improvement for patients with TMD at the completion of physical therapy. The results suggest that the MOS-17 may be useful as one measure of clinical change for patients with TMD who receive physical therapy.

Sensitivity and specificity of platform posturography for identifying patients with vestibular dysfunction.

Sensitive and specific measures are needed to identify patients with vestibular impairments. The purpose of this clinical perspective is to describe the sensitivity and specificity of dynamic and static platform posturography for detecting vestibular disorders. The sensory organization test (SOT) of dynamic posturography (EquiTest), the motor "perturbation" test, and Romberg's tests on a static (fixed) force platform each had over 90% specificity. This finding means that nearly all of the subjects who should have tested negative, did test negative on each type of assessment. The sensitivity of the SOT was evaluated across five studies involving a total of 836 patients with peripheral vestibular deficits (PVDs). Abnormalities in the SOT were detected in only 40% (n = 338) of the cases. Static platform posturography sensitivity was evaluated across six studies involving a total of 571 patients with PVDs, and abnormalities were detected in 53% (n = 302) of these cases. Tests of spontaneous and positional nystagmus and the horizontal component of the vestibuloocular reflex (VOR), by comparison, detected PVDs in 48% of 798 patients with suspected vestibular impairment. For patients with vestibular deficits associated with central nervous system disease, a total of 389 cases were identified in five studies and SOT abnormalities were found in 54% (n = 209) of these cases. The motor perturbation test was abnormal in 35% (n = 41) of 119 patients with central vestibular disease. In conclusion, the sensitivity of static posturography appeared to be slightly better than that of dynamic posturography for detecting PVDs, but the level of sensitivity for each posturography test, as well as for tests of horizontal VOR function, was considered to be low. Combining either type of posturography with other tests of vestibular function, however, increased the overall sensitivity of detecting vestibular deficits to 61% to 89%. It was concluded that dynamic and static platform posturography as well as tests of VOR function lack adequate sensitivity to detect vestibular impairment when applied in isolation. Posturography appears to detect vestibular deficits in some patients who had normal VOR assessments and, therefore, provides supplemental rather than redundant information about vestibular dysfunction.

Clinical assessment of manipulation and mobilization of the lumbar spine. A critical review of the literature.

The widespread use of manual therapy techniques suggests some degree of success in their application. In this article, I review the applied clinical research on the effectiveness of using manipulation or mobilization of the lumbar spine. The literature reviewed indicates highly equivocal results when the goal of therapy was to decrease pain and increase motion. Because of a high incidence of spontaneous recovery from low back syndromes, performance measures may appear to improve significantly when proper controls are not used. Evaluation of the therapeutic effects of manual therapy is complicated by potentially confounding variables when used with other physical therapy procedures. I discuss the need for further, well-designed studies.

Manipulation of the cervical spine: risks and benefits.

Manipulation of the cervical spine (MCS) is used in the treatment of people with neck pain and muscle-tension headache. The purposes of this article are to review previously reported cases in which injuries were attributed to MCS, to identify cases of injury involving treatment by physical therapists, and to describe the risks and benefits of MCS. One hundred seventy-seven published cases of injury reported in 116 articles were reviewed. The cases were published between 1925 and 1997. The most frequently reported injuries involved arterial dissection or spasm, and lesions of the brain stem. Death occurred in 32 (18%) of the cases. Physical therapists were involved in less than 2% of the cases, and no deaths have been attributed to MCS provided by physical therapists. Although the risk of injury associated with MCS appears to be small, this type of therapy has the potential to expose patients to vertebral artery damage that can be avoided with the use of mobilization (nonthrust passive movements). The literature does not demonstrate that the benefits of MCS outweigh the risks. Several recommendations for future studies and for the practice of MCS are discussed.

Efficacy of comprehensive rehabilitation programs and back school for patients with low back pain: a meta-analysis.

BACKGROUND AND PURPOSE: The use of back school as a treatment for low back pain is widespread, but determining the efficacy of this approach is complicated by variations in back schools and study methods across clinical trials. The purpose of this study was to conduct a meta-analysis to synthesize existing evidence on the efficacy of back school as either a primary intervention or a part of a comprehensive rehabilitation program for patients with low back pain. METHODS: The results of 19 prospective randomized controlled trials were evaluated. Quantitative reviewing procedures were used to calculate the effect sizes that compared patients receiving back school with those in a control or comparison group. Effect sizes were computed for 206 hypothesis tests involving 2,373 patients. RESULTS: The average effect size for comprehensive rehabilitation programs that included back school (d = 0.28) was larger than the average effect size for programs that offered back school as the primary intervention (d = -0.14). When effect sizes were stratified by program type and outcome, the comprehensive programs were superior to primary back school programs with respect to pain reduction, increased spinal mobility, and increased strength. Both types of programs showed reasonable success with education/compliance outcomes (d = 0.27-0.28). Lower effect sizes were found among the types of programs for disability and work/vocational outcomes (d < or = 0.20). CONCLUSIONS AND DISCUSSION: Back schools were most efficacious when coupled with a comprehensive rehabilitation program. Efficacy was supported for the treatment of pain and physical impairments and for education/compliance outcomes. Work/vocational and disability outcomes, however, were not improved substantially beyond control levels in comprehensive or primary back school programs. [Di Fabio RP. Efficacy of comprehensive rehabilitation programs and back school for patients with low back pain: a meta-analysis.

Efficacy of manual therapy.

The use of manual therapy to treat somatic pain syndromes and associated disabilities is widespread. Yet, the efficacy of manual therapy has not been previously established because equivocal findings in the literature prevent definitive conclusions. The purposes of this article are (1) to establish objective criteria for judging the validity of manual therapy research, (2) to identify and discuss the results of those trials that were determined to be valid demonstrations of treatment efficacy or valid demonstrations of nonuseful therapy, and (3) to determine whether patients who benefit from manual therapy have common characteristics. The abstracts or full reports of 146 titles with appropriate key words were reviewed. Of these, 105 studies were not primary studies of manual therapy and were thus eliminated from review. In the 41 remaining studies, 18 did not utilize statistical comparisons or report blinded assessment of outcome measures. Nine controlled studies yielded negative results, but the statistical power or minimum sample size required to detect potential differences between manual therapy and control groups was not described. The 14 studies that met the efficacy criteria were categorized by the following factors: (1) the anatomical region of intervention, (2) pragmatic versus explanatory goals, and (3) primary intervention (manipulation, mobilization, combination). There was a paucity of valid explanatory research in all areas and a particular absence of controlled trials involving manual therapy applied to the peripheral joints. Manual therapy for low back pain, however, was studied extensively. The analysis of valid trials provided clear evidence that manual therapy, particularly manipulation, can be an effective modality when used to treat patients who have low back pain. A preliminary "profile" of the patient with low back pain who would likely benefit from manual therapy included acute symptom onset with less than a 1-month duration of symptoms, central or paravertebral pain distribution, no previous exposure to spinal manipulation, and no pending litigation or workers' compensation. Suggestions for future manual therapy research are discussed.

Reliability of computerized surface electromyography for determining the onset of muscle activity.

The reliability of a computerized analysis system (CAS) for determining muscle burst onset was compared with the subjective assessments of three trained examiners. A sample of 154 randomly selected, full-wave rectified and filtered electromyographic recordings was evaluated using a test-retest paradigm. Percentages of agreement, Pearson product-moment correlations, analyses of variance (ANOVAs), and intraclass correlation coefficients (ICCs) were used to measure the reliability. The between-rater agreement, which included the computerized EMG assessments, was only 23%. Within-rater agreement and Pearson correlation coefficients were perfect for CAS. The trained examiners' within-rater assessments averaged only 51% agreement, but test-retest correlations were high (r = .78 - r = .82). All ICCs were statistically significant, ranged from .46 to .60, and tended to be higher when the CAS onset determinations were deleted from the analysis. The ANOVAs revealed that trained examiners were more consistent among each other than when their assessments were compared with CAS assessments of EMG recordings. This finding, however, may be facility-specific in that any generalization to other examiners was limited. In contrast to trained examiners, the CAS was free of variations in judgment, ensured perfect reproducibility of trial assessments, and was highly useful for analyzing multi-channel EMG recordings. Although the CAS ensures perfect reliability, validity determinations require visual inspection of trial data.

Aging and the mechanisms underlying head and postural control during voluntary motion.

The quality of sensory information that is necessary for balance and postural stability will depend to a great extent on head stability as the body moves. How older persons coordinate head and body motion for balance during volitional activities is not known. The purposes of this article are to present a basis for understanding the influence of aging on head control during voluntary motion and to discuss some data that demonstrate how elderly people might control head movement to improve gaze and the quality of vestibular inputs. A "top-down" or "head-first" control scheme is proposed as the mechanism that elderly people without disabilities use to maintain head position during self-initiated motion. This type of control ensures that the angular position of the head in space remains relatively constant--through the use of a head-stabilization-in-space (HSS) strategy--regardless of the magnitude or direction of displacements in the body's center of force. The HSS strategy is thought to reduce potential ambiguities in the interpretation of sensory inputs for balance and is derived primarily from a geocentric (orientation to the vertical) frame of reference. Egocentric (orientation of the head with respect to the body) or exocentric (orientation to objects in the environment) frames of reference, however, refine the control of head stabilization. Preliminary research suggests that elderly people use the HSS strategy to control head pitch during difficult balance tasks. These findings, if supported by more definitive studies, may be useful in the treatment of patients with balance disorders. The treatment of patients with balance dysfunction is discussed within the conceptual framework of a "head-first" organization scheme.

Use of the "fast evaluation of mobility, balance, and fear" in elderly community dwellers: validity and reliability.

BACKGROUND AND PURPOSE: Identifying elderly community dwellers who are at risk for falling was assessed using a comprehensive screening tool referred to as the "Fast Evaluation of Mobility, Balance, and Fear" (FEMBAF). The purpose of this study was to evaluate the concurrent validity and reliability of scores on the FEMBAF. SUBJECTS: Thirty-five elderly persons living in the community (4 men, 31 women), with a mean age 79.9 years (SD = 8.5, range = 60-92), participated. METHODS: Subjects were tested using the FEMBAF and three other instruments-the balance subscale of the Tinetti Performance-Oriented Mobility Assessment (B-POMA), the Clinical Test of Sensory Interaction on Balance (CTSIB), and the Timed Up and Go Test. Scores on the FEMBAF were compared with scores on each the other instruments using Spearman rank-order correlation coefficients and analysis of covariance (with age as the covariate) for living status and diagnostic category. A comparison of the number of subjects classified as being at risk for falling was done descriptively for the FEMBAF, B-POMA, and CTSIB. RESULTS: Associations (r > .35) were found between the FEMBAF and each of the other instruments in the areas of FEMBAF risk-factor count, task completion, mobility, and strength. The FEMBAF classified a greater number of subjects as being at risk for falling (89%) compared with the B-POMA (43%) and the CTSIB (63%). The mean chance-corrected percentage of agreement between raters on the FEMBAF was kappa = .95 (SD = .15) for assessment of risk factors and kappa = .96 (SD = .12) for task completion. CONCLUSION AND DISCUSSION: The FEMBAF provides valid and reliable measurements of risk factors, functional performance, and factors that hinder mobility.

Evaluation of eccentric exercise in treatment of patellar tendinitis.

The purpose of this study was to analyze the effects of a quadriceps femoris muscle eccentric training program on strength gain in patients with patellar tendinitis. The effect of an eight-week eccentric exercise program on quadriceps femoris muscle work was evaluated in four groups of subjects--two groups of "normal" (healthy) subjects and two groups of patients with patellar tendinitis. All four groups participated in a home muscle stretching exercise program, but only two groups--one group of normal subjects (N-A) and one group of subjects with tendinitis (T-A)--received additional eccentric training on an eccentric isokinetic dynamometer. The eccentric quadriceps femoris muscle work ratio (involved limb/uninvolved limb x 100) was used to quantify strength in the N-A and T-A Groups. Pain ratings were recorded for subjects with tendinitis before and after the eight-week experiment and were correlated with the dependent variable using a Spearman rank-order correlation coefficient. The N-A Group performed significantly better than all subjects with tendinitis (p less than .05). Subjects in the T-A Group, however, showed a trend toward increasing eccentric quadriceps femoris muscle work capacity over the eight-week training period. As pain ratings in the T-A Group increased, work ratios decreased. We concluded that eccentric exercise may be an effective treatment for patellar tendinitis, but that knee pain may limit optimal gains in strength.

Effects of postural bias during support surface displacements and rapid arm movements.

The purpose of this study was to evaluate body-sway characteristics during anticipatory and reactive postural compensation. Mechanisms of postural control were studied during self-initiated rapid arm movements (RAMs) and unexpected support surface displacements (SSDs). Ten healthy subjects, 5 men and 5 women with a mean age of 28 years, were blindfolded and stood symmetrically on a moveable force platform or with weight shifted right (R) or left (L). Averaged electromyographs were obtained from L anterior deltoid, L ipsilateral biceps femoris (BFi), R contralateral biceps femoris (BFc), R quadriceps (Q), R medial gastrocnemius (G), and R tibialis anterior (TA) muscles. During SSD, the relative timing of distal-proximal synergists was altered during all biased postures. In L biased standing, functional pairs, TA-Q and G-BF, discharged at their shortest latencies. Anterior deltoid onset times during RAM were most preparatory during R weight shift. Sway latencies were shorter also in biased standing. Absolute sway latency, peak sway, and time-to-peak sway were significantly longer in SSD conditions in comparison with RAM. When disturbances in balance cannot be predicted, lower extremity preloading facilitates contralateral muscle-discharge patterns at shorter latencies. In some neurological conditions that result in incorrect body alignment, the mechanical effects of postural bias rather than the abnormal control mechanisms may at least contribute to alterations in the postural response. These results provide a basis for evaluating balance in patients with neurological deficit.

Relationship of sensory organization to balance function in patients with hemiplegia.

Standing balance and dynamic weight shifting were evaluated in 10 subjects with hemiplegia using a sensory organization balance test (SOT) and the Fugl-Meyer sensorimotor assessment (FMSA). The SOT is a timed balance test that evaluates somatosensory, visual, and vestibular function for maintenance of upright posture. In contrast, the FMSA is a functional status assessment that indicates the amount of assistance needed during various balance tasks and the tolerated duration of the task. The results of both clinical tests were compared to determine whether the SOT correlated with functional ability. The SOT scores were significantly correlated with the FMSA balance subscores and the FMSA total lower extremity scores. Based on the results of this preliminary study, the authors concluded that the SOT may be useful for evaluating a patient's functional status. Further implications for the evaluation and treatment of balance dysfunction in persons with hemiplegia are discussed.

Influence of cerebrovascular accident on elongated and passively shortened muscle responses after forward sway.

The purpose of this study was to examine the effects of a rapid length change in the elongated and shortened ankle muscles of subjects with hemiplegia during forward body sway. The onset and amplitude of electrical activity in the ankle muscles of four standing hemiplegic subjects with mild stretch reflex abnormalities and four healthy subjects were studied. Each subject stood on a platform controlled by a hydraulic servomechanism and experienced an unexpected posterior horizontal platform movement that induced a forward body sway. The activity of the gastrocnemius (agonist) and tibialis anterior (antagonist) muscles were monitored bilaterally using surface electromyography. In comparison with the healthy subjects, the hemiplegic subjects showed a greater disassociation between agonist and antagonist activation, a larger frequency of response defaults in the antagonist, and an increase in nonparetic (left) limb agonist amplitude during the 200-msec electromyographic integration period. We concluded that the sequelae of cerebrovascular disease may hamper the initiation of a passive shortening response in the tibialis anterior muscle during forward sway. This finding is functionally significant because the response deficit described seems to be exaggerated in some cases and reduced in others.

Influence of sensory inputs on standing balance in community-dwelling elders with a recent history of falling.

Vision and/or ankle somatosensory inputs often do not correlate with the position of the center of gravity. In this case, visual or somatosensory information may be in conflict with other sensory systems that convey a true sense of body orientation. The purpose of this study was to determine how conflicting visual and ankle somatosensory inputs influenced standing balance in elders with a history of falls. Forty-seven community-dwelling elders (8 male, 39 female), between 65 and 96 years of age (mean = 80.5, SD = 9.0), participated in this project. Subjects with two or more falls in the 6 months prior to study were assigned to a fall group (n = 16), whereas those with no history of falling during the same time interval were assigned to a no-fall group (n = 31). In order to remove any bias in the testing procedure, the tester was not aware of group assignments. Subjects were evaluated using a sensory organization test (SOT) for standing balance and a "Get Up and Go" test (GUGT) for general mobility. Analysis of covariance was used to evaluate the SOT scores (by group, vision, and surface condition) and the GUGT scores. Body sway is known to increase with the normal aging process, and for this reason, age was selected as a covariate. The association between the SOT total score and the GUGT score was evaluated using Spearman rank-order correlation coefficients. The results showed a significant interaction between group and surface conditions, which indicated a decreased stance duration for fallers on a compliant surface compared with the stance duration for nonfallers (adjusted mean faller stance duration = 53 seconds, SD = 42; mean nonfaller stance duration = 67 seconds, SD = 32). Subjects in the fall group also had significantly higher GUGT scores (which indicated poor mobility function) than did subjects in the nonfall group (adjusted mean faller GUGT score = 2.65, SD = 1.48; mean nonfaller GUGT score = 1.47, SD = 0.77). The Spearman correlation between total SOT scores and the GUGT scores was greater for fallers (r = -.67) than for nonfallers (r = -.44). Orientation input from the ankle appears to have greater importance for preventing falls compared with a visual reference. The SOT and GUGT may be useful in the field to establish criteria for screening elders in a fall-prevention program.