Does upper limb coordination predict walking speed in older adults? A cross-sectional study.

BACKGROUND AND PURPOSE: Walking speed is a measure of physical function in older adults. Older adults are sometimes nonambulatory, however, and proxy measures for walking speed may be indicated. Since limb coordination tests can be conducted in non-weight-bearing positions, they may provide that capability. The purpose of this study was to examine the relationship between timed limb coordination and preferred and maximum walking speed, controlling for other known determinants of walking speed. METHODS: A total of 84 healthy adults (60 women and 24 men) older than 60 years participated. Preferred and maximum walking speed were measured during 10-Meter Walk Tests. Upper limb coordination performance was measured during a timed 5-repetition finger-to-nose test. Other variables measured included isometric knee extension strength, cognition (Montreal Cognitive Assessment), limits of stability (Functional Reach Test), the number of comorbidities (Functional Comorbidity Index), age, height, and sex. Multiple regression and partial correlation analyses (α = .05) were used to identify which variables predicted preferred and maximum walking speed, controlling for all other variables. RESULTS: Participants' mean preferred walking speed was 129 (24) cm·s⁻¹, and mean maximum walking speed was 176 (37) cm·s⁻¹. Finger-to-nose coordination performance, 4.8 (1.3) seconds, correlated negatively with preferred (r = -0.403) and maximum (r = -0.429) walking speed. Those bivariate correlation coefficients, however, were attenuated by other variables in the regression models (partial r = -0.031, P = .786, and partial r = -0.075, P = .513, for preferred and maximum walking speed, respectively). Variance in age, comorbidities, functional reach, knee extension strength, and height accounted for 55.4% of the variance in preferred walking speed. Variance in knee extension strength, cognition, functional reach, age, and comorbidities accounted for 63.5% of the variance in maximum walking speed. After removing knee extension strength and functional reach from the models--those variables that may be difficult or contraindicated to measure in some patient populations--finger-to-nose coordination was not a statistically significant predictor of preferred walking speed. Variance in age, comorbidities, cognition, height, and finger-to-nose coordination accounted for 55.9% of the variance in maximum walking speed. The change in R² attributed to finger-to-nose coordination performance, however, was only 2.9%. DISCUSSION: While knee extension strength, functional reach, comorbidities, and age were most predictive of walking speed, after removing knee extension strength and functional reach from the regression models, finger-to-nose coordination remained a potentially modifiable marker of neuromuscular control that only weakly predicted maximum walking speed in older adults. CONCLUSIONS: The timed finger-to-nose test would not appear to be a valid proxy for walking speed when weight-bearing clinical examination procedures are contraindicated.

Timed limb coordination performance is associated with walking speed in healthy older adults: a cross-sectional exploratory study.

Walking speed reflects quality of life, health status and physical function in older adults but interpreting measures of walking speed is affected by several confounders such as gender, age and height. Additionally, walking speed is influenced by neurologic conditions that impair limb coordination. In absence of defined pathology, it is less clear how varying levels of limb coordination influence walking speed. The purpose of this study was to examine the relationship between limb coordination and walking speed in older adults, controlling for effects of gender, age and height. Sixty-nine healthy, community-dwelling individuals over the age of 60 participated in the study. Participants completed a battery of timed upper and lower limb coordination tests. Normal and fast walking speed were measured over the inner six meters of a 10 m walkway. Correlation and regression analyses were used to examine the relationship between limb coordination performance and walking speed. Controlling for gender, age and height, variance in normal walking speed was accounted for by variance in pronation-supination performance (partial r = -0.396, partial r(2) = 0.16) and variance in fast walking speed was accounted for by variance in finger-to-nose performance (partial r = -0.356, partial r(2) = 0.13). The findings support our hypothesis that limb coordination performance would correlate with walking speed in healthy older adults. Moreover, limb coordination performance attenuated the effects of gender, age and height on walking speed. Limb coordination may be a modifiable determinant of walking speed in older adults.

Coordination tests in persons with acute central nervous system pathology: assessment of interrater reliability and known-group validity.

BACKGROUND AND PURPOSE: Coordination testing is a standard part of the neurologic examination, yet the psychometric properties of many tests used by practitioners are unknown. This study investigated the interrater reliability and known-group validity of limb coordination tests in participants with acute central nervous system (CNS) pathology. METHODS: Twenty-five participants with CNS pathology completed 20 different limb coordination tests administered at bedside by a physical therapist. Examinations were videotaped and independently rated by a neurologist, a physical therapist, and a student physical therapist using a 5-point ordinal scale. Nine tests were also timed. Results were analyzed for interrater reliability and the degree to which they differed between groups categorized as having or not having coordination deficits. RESULTS: Participants were individuals who had been diagnosed with either a CNS vascular lesion or intracranial tumor. Timed test scores had higher levels of agreement (mean intraclass correlation coefficient [ICC], 0.69-0.97) than ordinal scores (mean κfree 0.56-0.91). Scores from 5 of the 9 timed measures and 8 of the 20 ordinal measures differed between groups. DISCUSSION AND CONCLUSIONS: Eleven tests were scored reliably between raters (κ > 0.60 or ICC > 0.75) and were performed differently between groups with and without coordination deficits (P ≤ 0.05). These tests are recommended for use when examining patients with acute neurologic pathology from a vascular lesion or tumor. They are simple to perform and require only a stopwatch to complete. Future studies should explore the sensitivity and specificity of these tests in disease states and their correlation with functional measures.

Gender differences in dual task gait performance in older adults.

Although attention-dividing dual tasks hinder gait performance in older persons, gender differences in gait have not been examined. The purpose of this study was to examine whether gait performance differs between older men and women during dual task walking. A total of 44 healthy adults (20 men and 24 women) aged 65 years or older participated in the study. Participants walked under normal and dual task (backward spelling) conditions at self-selected speeds. Mean gait speed and stride-to-stride variability in gait speed were quantified with GAITRite( ®) instrumentation. Whereas gait speed decreased and variability in gait speed increased in both groups during dual task walking, men walked with greater variability during dual task walking than did women. The magnitude of the increase in variability in gait speed observed in men indicates that stride-to-stride variability in gait speed during dual task walking requires more investigation as a potential risk factor for falls in older men.

Brainstem cavernous malformations: anatomical, clinical, and surgical considerations.

Symptomatic brainstem cavernous malformations carry a high risk of permanent neurological deficit related to recurrent hemorrhage, which justifies aggressive management. Detailed knowledge of the microscopic and surface anatomy is important for understanding the clinical presentation, predicting possible surgical complications, and formulating an adequate surgical plan. In this article the authors review and illustrate the surgical and microscopic anatomy of the brainstem, provide anatomoclinical correlations, and illustrate a few clinical cases of cavernous malformations in the most common brainstem areas.

Neonatal bilabyrinthectomy leads to changes in skeletal muscle fiber form and function.

Children with hypoactive semicircular canals commonly have delayed motor development. We studied ferrets whose vestibular labyrinths were removed at postnatal day 10 (P10) to evaluate 1) development of motor behavior, 2) soleus contractile characteristics, 3) muscle fiber diameter, and 4) the expression of myosin heavy chain (MHC) isoforms. At P30 labyrinthectomized (LAB) ferrets exhibited a significant delay in motor development. At P120, the LAB ferrets continued to have significantly more difficulty with dynamic balance than the SHAM ferrets. At P30, the muscle fibers were about the same diameter as those in the sham operated ferrets (SHAM) at the same age but significantly more developmental MHC isoforms were expressed in the LAB soleus muscle. At P120, both the LAB soleus and medial gastrocnemius expressed significantly more type IIX MHC. The P120 LAB soleus muscle was significantly weaker and the muscle fibers were significantly smaller. These results support the hypothesis that vestibular receptors are important to the development of upright posture and balance activities, and influence muscle fiber development and MHC expression in postural muscles.

Cerebrovascular disease and cognitive dysfunction.

As the general population ages, the progressive cognitive decline that occurs with aging and dementia is having a significant socioeconomic impact on society. Vascular dementia associated with cerebral vascular disease is now the third most common cause of dementia. Recent evidence has revealed a new and significant etiopathogenetic role of cerebrovascular pathology, as well as newly determined risk factors for the development of neurocognitive deficits and other forms of dementia including Alzheimer's disease. In this article, we summarize the experimental and clinical data linking cerebrovascular pathology to neurocognitive decline and dementia.