Biomedical subjects

Sang-I Lin

Publications and source records attributed to Sang-I Lin.

9 recordsLinked to original sources

PubMed2006

Disability in patients with degenerative lumbar spinal stenosis.

OBJECTIVE: To determine factors associated with disability in patients with degenerative lumbar spinal stenosis. DESIGN: One-group cross-sectional study. SETTING: University hospital. PARTICIPANTS: One hundred eight patients with degenerative lumbar spinal stenosis. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Oswestry Disability Index and 4 categories of factors, including patient demographics (age, sex, number of comorbidities, medications), symptom-related factors (intensity, location, onset duration, neurogenic claudication), body structure and function as described in the International Classification of Functioning, Disability and Health model (muscle strength, vibration sense, spine flexibility), and stenotic condition (type and number of spinal segments involved). RESULTS: Patients with symptoms in both back and leg reported greater disability than those with symptoms only in the leg or back (P=.008). Greater disability correlated significantly with greater symptom intensity (r=.385, P<.001) and higher vibration threshold (r=.236, P=.014). While controlling the variance in patient demographics in the regression analysis, vibration sense and symptom location each added 10% of the variance in disability, and symptom intensity and strength each added 5%, with a total of 44% variance explained (P=.044). CONCLUSIONS: Symptom intensity and location, vibration sense, and muscle strength were identified as significant factors and, together with patient demographics, accounted for 44% of the variance explained in disability. Further investigations are needed to determine if causal relationships exist between these factors and disability.

Age Distribution↗

PubMed2005

Association between sensorimotor function and functional and reactive balance control in the elderly.

OBJECTIVES: Postural disturbances can arise from performing functional tasks and from external perturbations. Identification of sensorimotor factors associated with both types of balance control in the elderly can help us to understand better the balance problems facing older adults. DESIGN: Cross-sectional. SUBJECTS: Healthy young, stable older, and functionally unstable older adults with 16 participants in each group. METHODS: Clinical vibration sense and muscle strength of the lower extremity, and functional balance (FB) tests were conducted. The timing and amplitude of the reactive postural muscle responses of the leg postural muscles, recorded from standing subjects following support surface backward translation, were also examined. RESULTS: Young and older subjects differed significantly in the amplitude of their postural muscle responses, while the two older groups differed significantly in muscle strength and FB. When age was controlled, the strength of the ankle dorsi- and plantar-flexors was the only significant predictor for FB. For reactive postural muscle responses, none of the sensorimotor factors was significant. CONCLUSION: Functional and reactive balance abilities differed in their associating factors. The difference in the patterns of association for functional and reactive balance implies the need for separate assessment for these two categories of balance control clinically.

Adult↗

PubMed2005

Muscle weakness and imbalance in older dizzy patients.

BACKGROUND AND AIMS: Dizziness is common in older adults, and may be associated with limitations in physical performance. The purpose of this study was to investigate if leg muscle weakness and imbalance exist in older dizzy patients. METHODS: Twenty-three older dizzy patients and an age-matched group of 16 healthy non-dizzy older adults participated in the study. Isometric strength of leg muscles, center of pressure (COP) during quiet standing, and maximal distance of reaching forward in standing were tested. All patients answered the Dizziness Handicap Inventory (DHI). RESULTS: Most patients reported that they were handicapped by dizziness (DHI mean 31.8, SD 22.1). Compared with the healthy group, they showed significantly weaker strength in hip extension, knee extension and ankle dorsiflexion (all p < 0.000). Imbalance, indicated by greater COP trajectory (p = 0.008) and anteroposterior range of displacement (p = 0.001) during quiet standing, and a smaller forward reach distance (p < 0.000), was also found in patients. CONCLUSIONS: Leg muscle weakness and imbalance were more common in older dizzy patients than in healthy subjects. Clinical management should include assessment and therapy for these problems.

Aged↗

PubMed2005

Motor function and joint position sense in relation to gait performance in chronic stroke patients.

OBJECTIVES: To determine the association between joint position sense (JPS) and motor function of the lower extremity and gait performance of patients with chronic stroke. DESIGN: Single-group cross-sectional design. SETTING: University gait laboratory. PARTICIPANTS: Twenty-one patients with stroke onset of more than 6 months. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The isometric strength, Fugl-Meyer Assessment (FMA) motor status, and JPS of the lower extremity were tested. Spatiotemporal gait characteristics were measured using a 6-camera motion analysis system, with patients walking at their comfortable speeds while using their usual devices. RESULTS: Lower-extremity muscle strength and FMA motor score correlated significantly with the spatiotemporal characteristics of gait and contributed significantly to the variance in gait velocity, stride length, and double-stance time. The JPS was not related to gait performance, except that the ankle JPS contributed significantly to the variance in gait velocity and stride length. CONCLUSIONS: For patients with chronic stroke, motor function was significantly related to gait performance. Although the JPS was not, that of the ankle joint made a significant contribution. When enhancing gait performance is desired, improving the motor function is recommended, and the role of JPS should also be taken into consideration.

Aged↗

PubMed2005

Disability and walking capacity in patients with lumbar spinal stenosis: association with sensorimotor function, balance, and functional performance.

STUDY DESIGN: One-group, prospective, cross-sectional study. OBJECTIVES: To determine how sensorimotor function, balance, and physical performance are associated with disability and walking capacity in patients with lumbar spinal stenosis. BACKGROUND: Disability and limited walking capacity are often reported by patients with lumbar spinal stenosis. Identification of associated factors could provide information for future investigations leading to better prevention and intervention strategies. METHODS AND MEASURES: Fifty patients with lumbar spinal stenosis answered questions regarding symptom intensity, disability, and walking capacity. Muscle strength and vibration sense were assessed to represent sensorimotor function. Balance ability was measured by single-leg stance time and basic physical performance was tested by the up-and-go (UG) test. Regression analyses, entering demographics and symptom intensity as control variables, and sensory, strength, balance, and physical performance as additional independent variables, were conducted separately for disability and walking capacity. RESULTS: Symptom intensity, vibration sense at the big toe, and UG test time were significantly correlated with disability. The final regression model showed that the control variables explained 20% of the variance, while vibration sense and UG test time explained an additional 20% of the variance. Walking capacity was significantly correlated with vibration sense at the big toe and UG test time. No significant regression model emerged for walking capacity. CONCLUSIONS: A moderate amount of variance in disability could be explained by sensory function at the big toe and physical performance. These factors should be considered in future research.

Aged↗

PubMed2004

Postural response in older adults with different levels of functional balance capacity.

BACKGROUND AND AIMS: Aging is frequently accompanied by a deterioration in postural control, but it is not clear whether the primary contributor is increasing age or a progressive loss of functional balance capacity. The purpose of this study was to test the hypothesis that functional balance capacity contributes more than age to changes in postural response in the elderly. METHODS: The study considered 3 groups of healthy young, and functionally-stable and functionally-unstable older adults (N = 16 each group). Postural responses, including behavioral response patterns, joint angular displacement, displacement of the center of mass and center of pressure, and ground reaction forces, were induced and examined by submitting standing subjects to unexpected backward displacements in the surface supporting them. RESULTS: Functionally-stable older adults showed similar postural response patterns to those of young adults, whereas functionally-unstable older adults differed from young adults in the control of hip, trunk, shear force, and center of pressure trajectory during balance recovery. CONCLUSIONS: These findings support the hypothesis that changes in postural control in the elderly correlate with their functional balance capacity and are not just a matter of age.

Accidental Falls↗

PubMed2002

Postural muscle responses following changing balance threats in young, stable older, and unstable older adults.

The authors determined the postural muscle response to support surface perturbations, in relation to aging and level of stability of 16 young adults and 32 older adults who were classified into stable (SOA) and unstable (UOA) groups on the basis of their functional balance abilities. Forward and backward support surface translations of various amplitudes and velocities were used so that postural responses of the standing adults could be elicited. The thigh and leg postural muscle responses were recorded with surface electromyography (EMG). The older groups had significantly longer onset latency in the anterior postural muscles, smaller integrated EMG in the posterior muscles, and greater extent of integrated EMG attenuation over time. The UOA showed longer onset latency in the gastrocnemius following slow backward perturbation and used a greater percentage of the functional capacity of the gastrocnemius muscle than the SOA did. Those findings indicate that the SOA and UOA had limited ability to adapt to changing balance threats; the UOA were more limited than the SOA. When designing balance training programs, therefore, therapists should consider the adult's level of functional stability.

Adult↗

PubMed2002

Sensorimotor and balance function in older adults with lumbar nerve root compression.

The purpose of this study was to determine how sensorimotor status and balance control would be affected by lumbar nerve root compression in older adults. The vibration sense, joint motion sense, and strength of the lower legs of healthy older adults and older patients with lumbar nerve root compression (n = 17 each group) were tested for sensorimotor function. The motion of the center of pressure during quiet standing, center of pressure during forward reach, and the score on Berg's functional balance test were examined for static, dynamic, and functional balance control abilities, respectively. It was found that the patient group had significantly weaker strength, greater center of pressure motion during quiet stance, slower center of pressure motion, shorter distance during forward reach test, and lower functional balance ability. No significant sensory deterioration was found. Older patients with lumbar nerve root compression had weaker leg muscle strength and poorer balance control than healthy older adults. A thorough examination of strength and balance should be included in the clinical treatment for patients with lumbar nerve root compression.

Age Factors↗

PubMedDate not supplied

Perception of unsteadiness in patients with dizziness: association with handicap and imbalance.

Dizziness is a common problem in patients seeking medical help and is often associated with imbalance and handicap. This study aimed to reveal whether the perception of unsteadiness could be an indication of greater imbalance and handicap in these patients. Patients with dizziness were categorized into two groups, steady patients (n = 15) and unsteady patients (n = 23), based on the presence or absence of self-perceived unsteadiness. The level of self-perceived handicap was evaluated by the Dizziness Handicap Inventory. Static balance ability was evaluated using a force platform and the center of pressure motion was calculated during various quiet standing conditions. Dynamic balance ability was evaluated by the functional forward reach test and Dynamic Gait Index. All the patients also went through isometric strength tests of the lower extremities. It was found that all patients reported themselves to be handicapped by dizziness. Patients who perceived themselves to be unsteady had greater handicap and poorer static standing, but did not differ from the steady patients in regard to muscle strength or functional balance tests. Thus, self- perceived unsteadiness was associated with greater handicap and poorer static balance in dizzy patients. In clinical management of these patients, special attention should be paid to balance and handicap.

Adult↗