Kwan-Hwa Lin

Effects of Virtual Reality-Augmented Balance Training on Sensory Organization and Attentional Demand for Postural Control in People With Parkinson Disease: A Randomized Controlled Trial

Background There is a lack of studies related to virtual reality (VR)–augmented balance training on postural control in people with Parkinson disease (PD). Objective The purposes of this study were: (1) to examine the effects of VR-augmented balance training on the sensory integration of postural control under varying attentional demands and (2) to compare the results with those of a conventional balance training (CB) group and an untrained control group. Design A longitudinal, randomized controlled trial was used. Setting The intervention was conducted in the clinic, and the assessment was performed in a research laboratory. Patients Forty-two people with PD (Hoehn and Yahr stages II–III) were recruited. Intervention The VR and CB groups received a 6-week balance training program. Measurements The sensory organization tests (SOTs) of computerized posturography with single- and dual-task conditions were conducted prior to training, after training, and at follow-up. Equilibrium scores, sensory ratios, and verbal reaction times (VRTs) were recorded. Results There were no significant differences in equilibrium scores or VRTs between the VR and CB groups. However, the equilibrium scores in SOT-6 (ie, unreliable vision and somatosensation) of the VR group increased significantly more than that of the control group after training. The equilibrium scores in SOT-5 (ie, unreliable somatosensation with eyes closed) of the CB group also increased significantly more than that of the control group after training. Limitations The functional significance of the improvements in equilibrium scores in the SOTs was not known, and the sample size was small. Conclusions Both VR and CB training improved sensory integration for postural control in people with PD, especially when they were deprived of sensory redundancy. However, the attentional demand for postural control was not changed after either VR or CB training.

Physical activity is related to lower levels of pain, fatigue and depression in individuals with spinal-cord injury: a correlational study.

Study design:This was a prospective cross-sectional study for people with chronic spinal cord injury (SCI).Objectives:To (1) evaluate the intensity level and nature of physical activity in community-dwelling individuals living with SCI, and (2) explore the relation between descriptive individual variables (for example, lesion level), secondary complications and participation in physical activity.Setting:Urban community setting.Methods:A total of 49 subjects with SCI who used a manual wheelchair for primary mode of mobility (mean years since injury, 11.8; mean age, 43.7 years; 67% paraplegia) completed the physical activity recall assessment for people with SCI (PARA-SCI).Results:Approximately 50% of reported physical activity among individuals with SCI is due to activities of daily living. The amount of physical activity was not related to lesion level, age, body mass index or waistline size. Greater heavy-intensity activity was related to lower levels of pain and fatigue and higher levels of self-efficacy, whereas higher amounts of mild-intensity activity and total activity were related to less depressive symptoms.Conclusions:Activities of daily living are a large component for physical activity among individuals with SCI. It appears that greater physical activity is associated with less secondary complications (pain, fatigue and depression) in individuals with SCI.

Relationships between three potentiation effects of plyometric training and performance

This study measured the potentiation effects of plyometric training [normalized electromyography (EMG) in triceps surae, stiffness and elastic energy utilization of the Achilles tendon] and investigated the correlations between these effects and performances [voluntary electromechanical delay (EMD) and jump height]. Twenty‐one subjects were randomly assigned either to the control group (10 subjects: age 22.3±1.6 years) or to a training group (11 subjects: age 22.1±1.6 years) that performed 8 weeks of plyometric training. Results: As compared with the performances before training, normalized EMG in the soleus were significantly (P≤0.001) increased after 4 and 8 weeks of training. Tendon stiffness, elastic energy storage, release and jump height determined after training were significantly increased (P<0.05), with a concomitantly reduced voluntary EMD (P=0.01). These variables also showed significant differences vs the control group (all P<0.05). The other variables remained unchanged. Correlations were observed between tendon stiffness and either voluntary EMD (r=−0. 77, P=0.014) or jump height (r=0.54, P=0.031). Conclusions: Plyometric training specifically potentiated the normalized EMG, tendon stiffness and elastic energy utilization in the myotendinous complex of the triceps surae. Although these changes are possibly essential determinants, only increases of tendon stiffness were observed to correlate with performance improvements.

Quality of life of spinal cord injured patients in Taiwan: a subgroup study

The major purposes of this study were to assess the quality of life (QOL) of spinal cord injured patients, and to assess the possible factors affecting the QOL. The survey was conducted from 1992u2009–u20091993 by mailed questionnaires to members of Spinal Cord Injury Association of the Republic of China. There were 347 quality responses with the mean age of 37.5±10.2 years old and the mean duration of illness of 7.8±6.8 years. The questionnaire included five domains, physical mobility, environment-transportation, psychosocial adjustment, education, and economics for a total of 39 items. Each item contained a rating of `importance and `satisfaction. The quality of life index (QLI) was calculated by multiplying the satisfaction score with the importance score, then dividing by the possible highest score. The major results included: (1) the subjects had mild to moderate dissatisfaction with most items in five domains except psychosocial adjustment; (2) quality of life in those with complete tetraplegia (QLI=−0.41) and incomplete tetraplegia (QLI=−0.31) was significantly lower than that of those with complete paraplegia (QLI=−0.13) and incomplete paraplegia (QLI=−0.04); (3) both the severity of injury, and the post-injury working status were the major factors affecting the life quality of spinal cord injured patients in Taiwan.

Anaerobic threshold and maximal oxygen consumption during arm cranking exercise in paraplegia

The major purpose of this investigation was to compare the anaerobic threshold (AT) and maximal cardiopulmonary responses to arm exercise between persons with paraplegia and the able-bodied. The locomotive stress on the heart in paraplegic subjects was also examined. Thirty-nine paraplegic subjects (T1-L4 lesions) and 32 able-bodied subjects completed a continuous, progressive, resisted arm cranking exercise test. The AT was determined from the ventilatory parameters. At the AT, the mean values of Vo2/body weight (BW) for class II (T1-T5, N = 9), III (T6-T10, N = 11), and IV (T11-L4, n = 19) paraplegic subjects were 10.9, 13.2, and 13.5mL/kg/min, respectively, and only class II had significantly lower value than the able-bodied (14.4mL/kg/min). During maximal exercise, the mean values of maximal oxygen consumption per body weight (Vo2max/BW) for class II and III paraplegics were 17.4 and 17.7mL/kg/min, respectively, which were significantly lower (p < 0.05) than that of class IV (21.3mL/kg/min) and the able-bodied (28.2mL/kg/min). The heart rate (HR) during wheelchair-propelling (119bpm, n = 37) was significantly less than that at the AT (134bpm), but the HR during crutch-walking (151bpm, n = 17) was significantly higher. The results indicate that both submaximal and maximal cardiopulmonary functions in high-lesion paraplegics were less than that of the able bodied. Furthermore, the intensity of wheelchair-propelling at comfortable speed is not enough for improving the cardiopulmonary functions.

Role of the premotor cortex in leg selection and anticipatory postural adjustments associated with a rapid stepping task in patients with stroke

The premotor cortex (PMC) plays an important role in selecting and preparing for movement. This study investigates how stroke-induced PMC lesions affect stepping leg selection and anticipatory postural adjustments (APAs) preparation. Fifteen hemi-paretic patients (eight with PMC lesions (PMC(Lesion)) and seven PMC spared (PMC(Spared))) and eight age- and sex-matched healthy adults participated in the study. The subjects performed rapid forward stepping with the right or left leg under simple and choice reaction time conditions. The percentage of trials in which the subject showed the correct initial vertical ground reaction force pattern before lift-off of the stepping leg indicated the accuracy in selecting the designated stepping leg. The latency of bilateral contractions in the tibialis anterior (TA) and the reaction time (RT) of the stepping leg represented the time needed to prepare for stepping-related APAs and stepping movement, respectively. All three groups demonstrated a similar rate of accuracy of the stepping leg selection under both conditions. However, in both conditions, the PMC(Lesion) group exhibited a longer RT and TA contraction latency of the affected leg than the healthy and PMC(Spared) groups. The PMC(Lesion) group also presented a longer TA contraction latency of the unaffected leg than the healthy group in both conditions. These results suggest that the PMC is involved in APAs associated with leg stepping movement and that a PMC lesion in one hemisphere impairs APAs of both the contralateral and ipsilateral legs during stepping.

Relationship Between Chest Wall Motion and Diaphragmatic Excursion in Healthy Adults in Supine Position

BACKGROUND/PURPOSEnThere has been a lack of studies that have used both three-dimensional analysis and imaging tools concurrently to describe lung volume changes and breathing pattern in subjects in the supine position. The purpose of this study was to investigate the correlation between volume changes estimated by optoelectronic plethysmography (OEP) and diaphragmatic excursion (DE) measured by ultrasonography of healthy adults in the supine position.nnnMETHODSnTwelve healthy male subjects (age, 25.08 +/- 6.35 years) were recruited and asked to perform tidal and deep breathing in the supine position. The volume changes during chest wall motion were quantified from OEP analysis---this was done for the upper thorax (UT), lower thorax (LT), and abdominal (AB) compartment. Lung volume was measured synchronously via the mouth piece of an electrospirometer. The right diaphragmatic movement was measured by ultrasonography.nnnRESULTSnLinear regression showed that all three compartments (V UT, V LT and V AB) in the inspiratory phase were correlated highly with DE during tidal and deep breathing. However, multiple linear regression analysis showed that the VAB contributed 94-95% of the variance when performing either tidal or deep breathing. A predicted equation for diaphragmatic movement during deep breathing was DE = 0.052 + 0.294 V AB.nnnCONCLUSIONnThe movement of V AB can be used as an index of DE among the normal population in the supine position. Its application in patients requires further study.

Ventilatory and mouth occlusion pressure responses to hypercapnia in chronic tetraplegia.

OBJECTIVEnTo compare the ventilatory response to hypercapnia and the mouth occlusion pressure measured at 0.1 second following inspiration (P0.1) in hypercapnia between chronic tetraplegic and normal subjects.nnnDESIGNnA case-control study with an uneven sample size for the study of clinical disorders.nnnSETTINGnPatients were recruited from the outpatient clinic of a rehabilitation department.nnnPARTICIPANTSnSeven normal men and 9 men with tetraplegia who had cervical cord injuries (C5-C8), with a mean injury duration of 9.7 yrs.nnnINTERVENTIONSnPulmonary function tests were performed during resting, whereas minute ventilation (VE) and P0.1 were measured during CO2 rebreathing.nnnRESULTSnThe maximal voluntary ventilation (MVV), vital capacity (VC), and maximal respiratory muscle strength in the tetraplegic subjects were significantly less than in the normal subjects. Both the ventilatory and P0.1 responses to hypercapnia were significantly reduced in tetraplegic as compared with normal subjects, but the reductions were eliminated by normalizing with maximal ventilatory performance (MVV or VC) and maximal inspiratory muscle strength (PImax), respectively.nnnCONCLUSIONSnChronic tetraplegic persons have diminished ventilatory and P0.1 responses to hypercapnia. Respiratory muscle weakness may be a primary factor contributing to the diminished ventilatory response observed in these patients.

Immediate effects of therapeutic music on loaded sit-to-stand movement in children with spastic diplegia.

The effects of patterned sensory enhancement (PSE) music on muscle power and movement control in children with spastic diplegia (SD) during loaded sit-to-stand (LSTS) were investigated. Twenty-three children with SD aged 5 to 12 years were recruited. Individualized PSE was composed by a music therapist based on each subjects sit-to-stand (STS) movement with 50% 1-repetition maximum load. Each subject performed LSTS continuously for eight repetitions under randomly assigned music or no-music (Control) conditions while the kinematic and kinetic data were measured simultaneously. For the music condition, PSE music was played only during the first five repetitions (PSE condition), and the following three repetitions were referred to as the Continuation condition. Paired t- or Wilcoxon signed rank tests were used to compare the variables between the PSE and Control conditions, and between the Continuation and Control conditions. Compared to the Control condition, greater peak knee extensor power (P=0.009), greater total extensor power (P=0.015), and better center-of-mass smoothness (P=0.01), but less movement time (P=0.003) were found in the PSE condition. Significant effects of the PSE music on the above variables were also found for Continuation condition. The current results showed that individualized PSE music helped improve the performance of LSTS in children with SD. The associated biomechanical features also continued to exist in subsequent movement cycles after the music had ceased. These findings suggest that therapy using LSTS combined with PSE music may be beneficial for rehabilitating children with SD.

Abdominal weight and inspiratory resistance: their immediate effects on inspiratory muscle functions during maximal voluntary breathing in chronic tetraplegic patients

OBJECTIVEnTo study the immediate effects of maximal voluntary (MV) breathing, with and without abdominal weight (AW) or inspiratory resistance (IR), on inspiratory muscle functions in chronic tetraplegic patients.nnnDESIGNnA crossover trial design.nnnSETTINGnRehabilitation department of a university hospital.nnnPARTICIPANTSnNine tetraplegic men injured at the C4 to T1 levels, with a mean duration of injury of 72.8 months.nnnINTERVENTIONSnEach subject performed MV breathing without and with AW load (AWMV breathing) and IR load (IRMV breathing) separately.nnnMAIN OUTCOME MEASURESnElectromyographic (EMG) activity of the inspiratory muscles, mouth pressure, inspiratory flow, and inspiratory volume.nnnRESULTSnAWMV breathing evoked greater diaphragmatic EMG activity, inspiratory flow, and inspiratory volume than did IRMV breathing, although the increase of diaphragmatic EMG activity was not statistically significant. Conversely, IRMV breathing produced greater sternocleidomastoid EMG activity and negative mouth pressure than did AWMV breathing. Both AWMV and IRMV breathing evoked greater inspiratory muscle EMG activity than did MV breathing.nnnCONCLUSIONnAW and IR loads have differential immediate effects on the inspiratory muscle functions during MV breathing in patients with chronic tetraplegia, suggesting that these two breathing maneuvers may have dissimilar mechanisms of training in such patients. The muscle EMG activity evoked during MV breathing with AW or IR is greater than that without a mechanical load, implying that mechanically loaded training in tetraplegic patients results in load compensatory adjustments via their respiratory motor output to improve respiratory function.