Kwok-Tak Yeung

The Relationship Between Sitting Stability and Functional Performance in Patients With Paraplegia

OBJECTIVES To compare sitting stability between patients with high and low thoracic spinal cord injury (SCI), to determine the factors that can predict sitting stability, and to examine the relationship between sitting stability and functional performance. DESIGN Cross-sectional assessment was performed on subjects with paraplegia. SETTING Rehabilitation hospital affiliated with a medical university. PARTICIPANTS Convenience sample of 30 adults with complete chronic thoracic SCI. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES (1) Postural sway during quiet sitting over 30 seconds was recorded as static sitting stability, and composite maximal weight-shift during leaning tasks over 30 seconds was measured as dynamic sitting stability; (2) age, body weight, trunk length, trunk strength, postonset duration, injury level, and presence of spasticity were examined as predictive variables for sitting stability; and (3) the time for completion of upper- and lower-body dressing and undressing and transfer was measured as functional performance. RESULTS A significant difference in composite maximal weight-shift was found between high and low thoracic SCI subjects (t=2.90, P<.01). Injury level and trunk length were 2 important predictive factors for dynamic sitting stability, and they explained 43.5% of the variance. Only the completion time of upper-body dressing and undressing correlated significantly with static (r=.465, P=.01) and dynamic (r=-.377, P<.05) sitting stability. CONCLUSIONS The subjects with low thoracic SCI showed better dynamic sitting stability than those with high thoracic SCI. Injury level and trunk length, not trunk flexion or extension strength, predicted the outcome of dynamic sitting stability. Measures were not precise enough to predict functional performance from the viewpoint of injury level and sitting stability. The underlying premise that a reduction or increase in trunk strength is indicative of poorer or better sitting stability in SCI individuals is questioned, and implications for problem identification and treatment planning are discussed.

Anterior ankle-foot orthosis effects on postural stability in hemiplegic patients

OBJECTIVES To evaluate the effects of an anterior ankle-foot orthosis (AFO) on static and dynamic postural stability in hemiplegic patients. DESIGN A cross-sectional assessment of hemiplegic subjects with and without an AFO. SETTING Outpatient department of a rehabilitation hospital. PATIENTS A convenience sample of 24 subjects who had been prescribed an anterior AFO. OUTCOME MEASURES Postural sway index and postural symmetry (body weight distribution through the affected leg) when standing were measured as static postural stability. Maximal balance range in anterior-posterior and lateral directions and the affected legs weight bearing after weight shift to affected side were measured as dynamic postural stability. RESULTS When wearing the anterior AFO, there was no significant difference and small effect size (r<0.3) in postural sway index (p = .35), postural symmetry (p = .21), and maximal balance range in anterior-posterior direction (p = .46). There was a significant improvement and large effect size (r>0.5) in lateral weight shifting (p<.01) and weight bearing through the affected leg after weight shifted to the affected side (p<.01). CONCLUSIONS The significant effects of the anterior AFO in long-term hemiplegic patients were on lateral weight shifting and weight bearing through affected leg after weight shifted to the affected side. Postural sway, postural symmetry, and anterior-posterior weight shifting were not significantly affected.

Effects of the type and direction of support surface perturbation on postural responses

BackgroundPostural control is organized around a task goal. The two most frequently used types of tasks for postural control research are translational (translation along the anterior-posterior axis) and rotational (rotation in sagittal plane) surface perturbations. These types of perturbations rotate the ankle joint, causing different magnitudes and directions of body sway. The purpose of this study was to investigate the effects of the type (translation vs. rotation) and direction (forward/toe up vs. backward/toe down) of the perturbation on postural responses.MethodNineteen healthy subjects were tested with four perturbations, i.e., forward and backward translation and toe up and toe down rotation. The onset latency and magnitude of muscle activations, angular changes, and COM displacements were measured. In addition, the kinematic data were divided into two phases. The initial phase reflected the balance disturbance induced by the platform movement, and the reversal phase reflected the balance reaction.ResultsThe results showed that, in the initial phase, rotational perturbation induced earlier ankle movement and faster and larger vertical COM displacement, while translational and forward/toe up perturbations induced larger head and trunk angular change and faster and larger horizontal COM displacement. In the reversal phase, balance reaction was attained by multi-joint movements. Translational and forward/toe up perturbations that induced larger upper body instability evoked faster muscle activation as well as faster and larger hip or knee joint movements.ConclusionsThese findings provide insights into an appropriate support surface perturbation for the evaluation and training of balance.

User Satisfaction with Orthotic Devices and Service in Taiwan

User satisfaction is afforded considerable importance as an outcome measurement in evidence-based healthcare and the client-centered approach. Several studies have investigated user satisfaction with orthoses. Few studies have investigated user satisfaction with orthoses in Taiwan. Therefore, the purpose of this study was to investigate the user satisfaction with orthotic devices and service using the Taiwanese version of Quebec User Evaluation of Satisfaction with Assistive Technology. We conducted a cross-sectional study of 280 subjects who had used orthoses and received services. The results showed that the mean satisfaction score was 3.74 for the devices and 3.56 for service. Concerning the participants, 69.1% and 59.6% were quite satisfied or very satisfied with their devices and service, respectively. The satisfaction score of orthotic service was lower than that of the devices. Regarding demographic characteristics, participants living in different areas differed only in service score (p = 0.002). The participants living in eastern area and offshore islands were the least satisfied with the orthotic service. For clinical characteristics, there was a significant difference in satisfaction scores among severity of disability (all p = 0.015), types of orthoses (all p = 0.001), and duration of usage (all p = 0.001). The participants with mild disability, wearing the pressure garment and using the orthosis for less than one year, were the most satisfied with their orthotic devices and service. There is a need for improved orthotic devices and services, especially with respect to the comfort of the devices and the provision of subsidy funding.

Effects of an Anterior Ankle-Foot Orthosis on Walking Mobility in Stroke Patients: Get Up and Go and Stair Walking

OBJECTIVE To examine the effects of an anterior ankle-foot orthosis (AAFO) on walking mobility in stroke patients. DESIGN Cross-sectional and repeated-measures study design. SETTING A universitys neurologic rehabilitation department. PARTICIPANTS Ambulant stroke patients (N=21). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Walking mobility was measured by the Timed Up and Go (TUG) test and the Timed Up and Down Stairs (TUDS) test. The paired t test was used to determine the difference between the mobility performances measured with and without the AAFO. RESULTS There were significant differences between mobility performances with and without an AAFO in the TUG test (P=.038) and the TUDS test (P=.000). CONCLUSIONS This study supports the effect of an AAFO on walking mobility in stroke patients. The findings demonstrate that stroke patients wearing an AAFO may ambulate with greater speed and safety on level surfaces and stairs.

Use of and Self-Perceived Need for Assistive Devices in Individuals with Disabilities in Taiwan

Assistive devices (ADs) can help individuals with disabilities achieve greater independence, and it can enhance the quality of their lives. This study investigated the use of and self-perceived need for ADs in individuals with disabilities, and determined the influence of gender, age as well as type and degree of disability on the use of and self-perceived need for ADs. This descriptive study utilized a cross-sectional survey design with a convenience sample of participants. A total of 1018 subjects with disabilities who visited an exhibition of assistive technology and two ADs research and development centers completed a questionnaires either by themselves or via a caregiver who completed the questionnaire on behalf of the subject or via interviewers trained specifically for this study. The Mann-Whitney U test and Kruskal-Wallis test were used to determine the influence of participant characteristics on the use of ADs. The results showed that 77.2% and 83.3% of the participants reported that they used and needed AD(s) to engage in activities of daily living. The mean quantity of the use of and self-perceived need for total types of ADs were 3.0 and 5.3, respectively. Participants with different disabilities reported different percentages of the use of various types of ADs. No difference was found between genders and among the age groups in the use of quantity of ADs. Individuals with different types and degrees of disability used different quantities of ADs. Participants with physical, visual and multiple disabilities used significantly more ADs compared to participants with intellectual disability. The total quantity of ADs used increased significantly with increased severity of disability. The mean use of assistive devices was lower compared to the mean need of individuals with disabilities. Further study is required to determine why patients feel the need for but not currently use a specific assistive device.

Effect of Anterior Ankle-Foot Orthoses on Weight Shift in Persons With Stroke

OBJECTIVE To examine the effects of an anterior ankle-foot orthosis (AAFO) on the speed and accuracy of weight shift in persons with stroke. DESIGN Cross sectional, repeated measures. SETTING Neurologic rehabilitation department. PARTICIPANTS People with stroke (N=24) who were unable to voluntarily dorsiflex the foot against gravity. INTERVENTION The weight-shift performance was measured with and without the AAFO. MAIN OUTCOME MEASURES The speed and accuracy of sustained and cyclic bilateral weight shift were measured using the computerized dynamic posturography. The movement velocity, maximum excursion, and directional control of sustained weight shift were calculated using the limits of stability test. The on-axis velocity gap, directional control, and stability of cyclic bilateral weight shift were calculated using the rhythmic weight shift test. RESULTS For sustained weight shift, the maximum excursion of weight shift to the affected side was greater with the AAFO (P=.002). For cyclic bilateral weight shift, the on-axis velocity gap in the mediolateral (ML) direction was smaller at a fast speed (P=.004). The stability of the ML and anteroposterior weight shift was higher at slow (P=.002 and P<.001, respectively) and fast (P=.001 and P<.001, respectively) speeds when wearing the AAFO. CONCLUSIONS The findings demonstrated that persons with stroke who wear an AAFO might improve the excursion of the sustained weight shift to the affected side and the speed and stability of cyclic bilateral weight shift in the ML direction.

Postural responses to yaw rotation of support surface

The purposes of this study were to investigate EMG and kinematic responses to yaw rotation of a support surface. Twenty people participated in four conditions, i.e., two velocities (240°/s, 120°/s) and two amplitudes (30°, 15°). Longer latency and smaller muscle responses were induced for yaw rotation, and distal ankle and knee muscles were activated earlier than trunk and neck muscles. Joint kinematics demonstrated larger angular displacements in axial rotation. Velocity and amplitude did not affect onset latency or magnitude of muscle activation but had significant effects on joint movements and COM displacements. Preliminary information about normative data of healthy subjects was obtained, and questions were generated about optimal velocity and amplitude test protocols that require further investigation.

A Small Sample Test of the Factor Structure of Postural Movement and Bilateral Motor Integration Using Structural Equation Modeling

The goal of this study was to examine the relationship between the validity of postural movement and bilateral motor integration in terms of sensory integration theory. Participants in this study were 61 Chinese children ages 48 to 70 months. Structural equation modeling was applied to assess the relation between measures tapping postural movement and bilateral motor integration: for postural movement, the measures involve the Monkey Task, Side-Sit Co-contraction, Prone on Elbows, Wheelbarrow Walk, Airplane, and Scooter Board Co-contraction from the DeGangi-Berk Test of Sensory Integration, and Standing Balance with Eyes Closed / Opened in Southern California Sensory Integration Tests. For bilateral motor integration, the measures chosen were the Rolling Pin Activity, Jump and Turn, Diadokokinesis, Drumming, and Upper Extremity Control from the DeGangi-Berk Test of Sensory Integration, and Cross the Midline in Southern California Sensory Integration Tests (SCSIT). Postural movement was highly correlated with the bilateral motor integration. The factor structure fit the theoretical conceptualization, classifying postural movement and bilateral motor integration together in the same category. Therapists could combine two separate objectives (postural movement and bilateral motor integration) of intervention in an activity to improve the adaptive skills based on the vestibular-proprioceptive integration.

Amputees in Taiwan, 1995 to 2000

This study evaluates details concerning amputees in Taiwan, including cause for prosthetic treatment. Data is specific to the west central region, in particular the Rehabilitation .Hospital located in Taichung City. Patient case studies cover the period from 1995 to 2000. The target group totals 499 patients (321-male; 178-female); with a mean age of 48.7 + 23.0 years. In all, 379 amputees (76.0%) had been fitted with lower limb prosthesis and 120 amputees (24.0%) had been fitted with upper limb prosthesis. Trauma was the major cause of amputation (n=241, 48.3%), followed by disease (n=220, 44.1%), congenital defect (n=29, 5.8%) and tumor (n=9, 1.8%); the ratio of trauma/disease was 0.65 (142 to 219). Data further indicates that amputations resulting from occlusive peripheral vascular disease have increased when compared with earlier survey studies, and most were due to diabetes mellitus (n=208, 95%). These findings suggest the need for aggressive treatment and a focused education program to reduce or even prevent cases of lower limb amputation. The current study provides a critical guideline for evaluating future needs in terms of personnel, facilities, programs and funding.