Spinal deformity and mobility self-confidence among women with osteoporosis and vertebral fractures.

This study evaluated the direct and indirect effects of spinal deformity on confidence in mobility among 185 older women with osteoporosis and vertebral fractures. We administered multidimensional tests of physical and psychosocial impairment and function to female residents of continuing care retirement communities, and used path analytic regression methods to delineate relationships between spinal deformity, pain, function and mobility self-confidence. No direct effect of spinal deformity on confidence in mobility was observed. However, important indirect paths mediated by functional limitations were confirmed. A pattern of indirect effects was observed for a broad array of impairment-level constructs. These results support current models of the disablement process that propose functional limitations as the major pathway to disability. However, they also suggest that the impact of impairment-level constructs might be overlooked unless we evaluate indirect, as well as direct effects, on disability.

Reliability of physical performance tests in four different randomized clinical trials.

OBJECTIVES: (1) To assess the test-retest reliability of physical performance tests in subject groups with different levels of impairment and disability, and (2) to assess the stability of these tests over different time intervals. DESIGN: Test-retest, repeated measures reliability design. SETTING: (1) A university's center for aging and research center, (2) a continuing care retirement community, and (3) an extended care and rehabilitation center at a Veterans Affairs medical center. SUBJECTS: Twenty-four community-dwelling elders, 15 community-dwelling elders with Parkinson disease, 12 older women with vertebral osteoporosis and compression fractures, and 14 elderly nursing home residents. MEASURES: Lower extremity isometric strength (ankle dorsiflexion, hip abduction), spinal configuration (thoracic kyphosis, lumbar lordosis), lumbosacral motion (flexion, extension), and timed measures of the ability to get in and to get out of bed at a usual pace. RESULTS: Most of the within-group intraclass correlation coefficients (ICCs) were good to excellent (.70 to .97). Overall, ICCs for all groups combined were between .70 and .96, and no decrement in reliability was noted after controlling for group membership. In addition, no decrement in the ICC was observed for short (1 day) vs. longer (1 week) intervals of testing. CONCLUSIONS: These performance-based measures may be used reliably across a wider range of testing environments and elderly populations than has been reported.

Impairments in arm control in subjects with left and right hemisphere stroke.

OBJECTIVES: Our purpose was to identify impairments in movement control for subjects with left and right brain lesions using a kinematic analysis of the trajectory of a stylus during an upper limb tapping task. We hypothesized that subjects with left cerebrovascular accident (LCVA) would have bilateral deficits in programming while subjects with right cerebrovascular accident (RCVA) would only have deficits in the limb contralateral to the lesion. STUDY DESIGN: Data were collected from 11 subjects with LCVA, 11 with RCVA, and 22 non-disabled subjects who were age and gender-matched to subjects with left or RCVA. Subjects were videotaped performing a Fitts tapping task on a single 3-inch target with each hand. The stylus movement was digitized at 60 Hz and data were calculated for each tap cycle and averaged across each 10-s trial. We examined differences in the kinematic variables of cycle frequency, amplitude, symmetry in up and down velocity, symmetry in timing of up and down velocity, and temporal phases of acceleration and deceleration for up and down directions of the tap cycle. Multivariate analyses were performed on four dependent kinematic variables, and univariate ANOVAs were conducted for the differences in phases between stroke and non-disabled limbs. RESULTS: Subject with LCVA showed lower frequencies, and asymmetrical velocity and timing ratio in both 'uninvolved' and 'involved' limbs compared to non-disabled subjects. Subjects with RCVA showed similar impairments for the 'involved' limb only. CONCLUSIONS: Left hemisphere lesions create bilateral impairments in programming movement reversals. Right hemisphere lesions produced deficits only for the limb contralateral to the lesion. Strategies used by the subjects with LCVA may be-related to the need for subjects to use feedback to perform this rapid continuous sequencing task. Suggestions for rehabilitation are presented.