The psychometric properties of the toe tap test in people with stroke.

Objectives: To investigate the: (i) inter-rater and test-retest reliability of the toe tap test for people with stroke, (ii) the convergent validity of toe tap test counts with stroke-specific impairments, (iii) minimum detectable change in toe tap test counts, (iv) toe tap test cutoff counts which best discriminating the performance between stroke survivors and healthy controls.Design: Cross-sectional study.Setting: University-based rehabilitation center.Participants: Thirty-seven people with stroke and 35 healthy controls.Main Outcome Measures: The toe tap test was administered along with the Fugl-Meyer lower extremity assessment, muscle strength of ankle dorsiflexors and plantarflexors, five times sit-to-stand test, Berg Balance Scale, limit of stability test, timed up and go test, and Community Integration Measures questionnaire.Results: Excellent inter-rater and test-retest reliabilities (intraclass correlation coefficient = 0.868-0.995 on the affected side) were found. A minimal detectable change of 8.7 counts and a cutoff score of 21 counts was found on the affected side, while 12.6 counts and 25 counts were found on the unaffected side, respectively. Toe tap test counts on the affected side were significantly associated with Fugl-Meyer lower extremity assessment scores, ankle muscle strength, Berg Balance Scale scores and timed up and go test times.Conclusions: Toe tap test count on the affected side is a simple and reliable tool for assessing ankle control in people with stroke.Implications for rehabilitationToe Tap Test counts have excellent intra-rater, inter-rater, and test-retest reliabilities in people with stroke.Toe Tap Test counts on the affected side were significantly associated with Fugl-Meyer Assessment of Lower Extremity scores, ankle muscle strength, Berg Balance Scale scores, and timed Up and Go test completion times.The 95% Minimal Detectable Change for the Toe Tap Test counts was 8.7 counts of the affected side and 12.6 of the unaffected side.Toe Tap Test counts of 21 on the affected side and 25 on the unaffected side (sensitivity 70.3-83.3%; specificity 71.4-85.7%) was found to be the most representative for discriminating performance of Toe Tap Test in chronic stroke survivors and healthy older adults.Toe Tap Test is a simple and reliable tool for assessing ankle control in people with stroke.

Translation of robot-assisted rehabilitation to clinical service: a comparison of the rehabilitation effectiveness of EMG-driven robot hand assisted upper limb training in practical clinical service and in clinical trial with laboratory configuration for chronic stroke.

BACKGROUND: Rehabilitation robots can provide intensive physical training after stroke. However, variations of the rehabilitation effects in translation from well-controlled research studies to clinical services have not been well evaluated yet. This study aims to compare the rehabilitation effects of the upper limb training by an electromyography (EMG)-driven robotic hand achieved in a well-controlled research environment and in a practical clinical service. METHODS: It was a non-randomized controlled trial, and thirty-two participants with chronic stroke were recruited either in the clinical service (n = 16, clinic group), or in the research setting (n = 16, lab group). Each participant received 20-session EMG-driven robotic hand assisted upper limb training. The training frequency (4 sessions/week) and the pace in a session were fixed for the lab group, while they were flexible (1-3 sessions/week) and adaptive for the clinic group. The training effects were evaluated before and after the treatment with clinical scores of the Fugl-Meyer Assessment (FMA), Action Research Arm Test (ARAT), Functional Independence Measure (FIM), and Modified Ashworth Scale (MAS). RESULTS: Significant improvements in the FMA full score, shoulder/elbow and wrist/hand (P < 0.001), ARAT (P < 0.001), and MAS elbow (P < 0.05) were observed after the training for both groups. Significant improvements in the FIM (P < 0.05), MAS wrist (P < 0.001) and MAS hand (P < 0.05) were only obtained after the training in the clinic group. Compared with the lab group, higher FIM improvement in the clinic group was observed (P < 0.05). CONCLUSIONS: The functional improvements after the robotic hand training in the clinical service were comparable to the effectiveness achieved in the research setting, through flexible training schedules even with a lower training frequency every week. Higher independence in the daily living and a more effective release in muscle tones were achieved in the clinic group than the lab group.

Ablation of Bax and Bak protects skeletal muscle against pressure-induced injury.

Pressure-induced injury (PI), such as a pressure ulcer, in patients with limited mobility is a healthcare issue worldwide. PI is an injury to skin and its underlying tissue such as skeletal muscle. Muscle compression, composed of mechanical deformation of muscle and external load, leads to localized ischemia and subsequent unloading reperfusion and, hence, a pressure ulcer in bed-bound patients. Although the gross factors involved in PI have been identified, little is known about the exact disease mechanism or its links to apoptosis, autophagy and inflammation. Here, we report that PI is mediated by intrinsic apoptosis and exacerbated by autophagy. Conditional ablation of Bax and Bak activates the Akt-mTOR pathway and Bnip3-mediated mitophagy and preserves mitochondrial contents in compressed muscle. Moreover, we find that the presence/absence of Bax and Bak alters the roles and functions of autophagy in PI. Our results suggest that manipulating apoptosis and autophagy are potential therapeutic targets for treatment and prevention of PI.

Reliability and convergent validity of the five-step test in people with chronic stroke.

OBJECTIVES: (i) To estimate the intra-rater, inter-rater and test-retest reliabilities of the Five-Step Test (FST), as well as the minimum detectable change in FST completion times in people with stroke. (ii) To estimate the convergent validity of the FST with other measures of stroke-specific impairments. (iii) To identify the best cut-off times for distinguishing FST performance in people with stroke from that of healthy older adults. DESIGN: A cross-sectional study. SETTING: University-based rehabilitation centre. PARTICIPANTS: Forty-eight people with stroke and 39 healthy controls. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The FST, along with (for the stroke survivors only) scores on the Fugl-Meyer Lower Extremity Assessment (FMA-LE), the Berg Balance Scale (BBS), Limits of Stability (LOS) tests, and Activities-specific Balance Confidence (ABC) scale were tested. RESULTS: The FST showed excellent intra-rater (intra-class correlation coefficient; ICC = 0.866-0.905), inter-rater (ICC = 0.998), and test-retest (ICC = 0.838-0.842) reliabilities. A minimum detectable change of 9.16 s was found for the FST in people with stroke. The FST correlated significantly with the FMA-LE, BBS, and LOS results in the forward and sideways directions (r = -0.411 to -0.716, p < 0.004). The FST completion time of 13.35 s was shown to discriminate reliably between people with stroke and healthy older adults. CONCLUSION: The FST is a reliable, easy-to-administer clinical test for assessing stroke survivors' ability to negotiate steps and stairs.

Sideways walk test: Reliability and association with lower limb motor function after stroke.

OBJECTIVES: To investigate (i) the intra-rater, inter-rater and test-retest reliability of sideways walk test times and counts in individuals with stroke; (ii) their correlations with stroke-specific measures of impairment; (iii) the cut-off sideways walk test times and counts between stroke survivors and healthy controls; and (iv) the minimum detectable changes in the sideways walk test times and counts. DESIGN: Cross-sectional study. SETTING: University-based rehabilitation centre. SUBJECTS: Twenty-nine older adults with stroke and 32 healthy controls. METHODS: The sideways walk test was conducted together with Fugl-Meyer motor assessments of the lower extremities, lower limb muscle strength tests, the Five-Times-Sit-To-Stand test, Berg Balance Scale, Timed Up-and-Go test, and Activity-based Confidence and Community Integration Measure questionnaires. RESULTS: The sideways walk test times and counts demonstrated good to excellent intra-rater, inter-rater, and test-retest reliabilities. The sideways walk test times and counts were significantly correlated with motor control and ankle dorsiflexor and plantarflexor strength of the affected leg, balance performance and functional mobility. The cut-off sideways walk test time and count that best discriminated between individuals with stroke and controls were 10.74 s and 8.83 steps, respectively. The minimal detectable change in the sideways walk test time in that situation was 1.85 s, and the count minimum detectable change was 1.12 steps. CONCLUSION: The sideways walk test is a reliable and easy-to-administer clinical test for assessing sideways walking ability of individuals with chronic stroke.

Effect of acceleration and deceleration distance on the walking speed of people with chronic stroke.

OBJECTIVE: To examine the effect of acceleration and deceleration distance (0, 1, 2 and 3 m) on the comfortable and maximum walking speeds in: (i) the 5-m walk test (5mWT); and (ii) the 10-m walk test (10mWT) in people with chronic stroke. DESIGN: Cross-sectional study. SETTING: University-based rehabilitation centre. SUBJECTS: Thirty individuals with chronic stroke. METHODS: Timed walking at comfortable and maximum walking speeds in the 5mWT and 10mWT with different acceleration and deceleration distances (0, 1, 2 and 3 m). RESULTS: The comfortable walking speed in the 5mWT with 0 m acceleration and deceleration distance was significantly slower than that with 1, 2 or 3 m acceleration and deceleration distances (p < 0.0083), but there was no significant difference among 1, 2 and 3 m acceleration and deceleration distances. No significant difference was found in the maximum walking speed in the 5mWT, or in the comfortable and maximum walking speeds of the 10mWT. CONCLUSION: Adoption of 1 m acceleration and deceleration distance is recommended when measuring the comfortable walking speed in the 5mWT in people with stroke. Neither acceleration nor deceleration distance is needed when measuring the maximum walking speed in the 5mWT, the comfortable walking speed or the maximum walking speed in the 10mWT.

Timed 360° Turn Test for Assessing People With Chronic Stroke.

OBJECTIVES: To investigate (1) the intrarater, interrater, and test-retest reliability of the timed 360° turn test in subjects with stroke; (2) the concurrent validity of the timed 360° turn test by exploring its correlation with other measures of stroke-specific impairments; and (3) the cutoff times that best discriminate individuals with stroke from healthy older adults. DESIGN: Cross-sectional study. SETTING: University-based rehabilitation center. PARTICIPANTS: Individuals with chronic stroke (n=72) and healthy individuals (n=35) of similar age (N=107). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The timed 360° turn test was administered along with the Fugl-Meyer assessment of the lower extremity, measurement of muscle strength of ankle dorsiflexors and plantarflexors using a handheld dynamometer, Berg Balance Scale, limit of stability test, five times sit-to-stand (FTSTS) test, 10-m walk test, and timed Up and Go (TUG) test. RESULTS: The 360° turn times showed excellent intrarater, interrater, and test-retest reliability in individuals with stroke. A minimal detectable change of .76 seconds was found for subjects turning toward the affected side and 1.22 seconds for subjects turning toward the unaffected side. The 360° turn times were found to correlate significantly with Fugl-Meyer assessment of the lower extremity scores, dosiflexor strength of the affected ankle, plantarflexor strength of both ankles, FTSTS test times, balance performance, gait speed, and TUG test times. The 360° turn times of 3.43 to 3.49 seconds were shown to discriminate reliably between individuals with stroke and healthy older adults. CONCLUSIONS: The timed 360° turn test is a reliable and an easily administered clinical tool to assess the turning ability of subjects with chronic stroke.

SIRT1-dependent myoprotective effects of resveratrol on muscle injury induced by compression.

Our current understanding on the molecular mechanisms by which sustained compression induces skeletal muscle injury is very limited. This study aimed to test the hypothesis that activation of SIRT1 by the natural antioxidant resveratrol could deactivate apoptotic and catabolic signaling in skeletal muscle exposed to moderate compression. Two cycles of 6-h constant pressure at 100 mmHg was applied to the tibialis region of right, but not left hindlimbs of Sprague Dawley rats pre-treated with DMSO (vehicle control) or resveratrol with/without sirtinol. Skeletal muscle tissues lying underneath and spatially corresponding to the compressed sites were collected for analyses. Resveratrol prevented the compression-induced manifestations of pathohistological damages including elevations of the number of interstitial nuclei and area of interstitial space and ameliorated oxidative damages measured as 4-hydroxy-2-nonenal (4HNE) and nitrotyrosine in skeletal muscle. In parallel, resveratrol augmented the expression level and activity of SIRT1 and phosphorylation levels of Foxo3a and Akt while suppressed the increases in protein abundances of p53, Bax, MAFbx, and ubiquitin, enzymatic activities of caspase 3 and 20S proteasome, and apoptotic DNA fragmentation in the compressed muscle. These favorable myoprotective effects of resveratrol were diminished upon pharmacological blockade of SIRT1 by using sirtinol. These novel data support the hypothesis that the anti-apoptotic and anti-catabolic effects of resveratrol on compression injury in skeletal muscle required the action of SIRT1.

Reliability and validity of the sideways step test and its correlation with motor function after stroke.

[Purpose] This study investigated the intra-rater, inter-rater and test-retest reliability of the sideways step test (SST), its correlation with other indicators of stroke-specific impairment, and the cut-off count best discriminating subjects with stroke from their healthy counterparts. [Subjects and Methods] Forty-three subjects with chronic stroke and 41 healthy subjects older than 50 years participated in this study. The SST was administered along with the Fugl-Meyer motor assessment for the lower extremities (FMA-LE), the five-times sit to stand (5TSTS) test, the Berg Balance Scale (BBS), the movement velocity (MVL) by the limits of stability (LOS) test, the ten-metre walk (10mW) test, the timed "Up and Go" (TUG) test and the Activities-specific Balance Confidence (ABC) scale. [Results] The SST showed good to excellent intra-rater, inter-rater and test-retest reliability. The SST counts correlated with 5TSTS times, 10mW times, TUG times, and the FMA-LE and BBS scores. SST counts of 11 for the paretic leg and 14 for the non-paretic leg were found to distinguish the healthy adults from subjects with stroke. [Conclusion] The sideways step test is a reliable clinical test, which correlates with the functional strength, gait speed, and functional balance of people with chronic stroke.

Floor transfer test for assessing people with chronic stroke.

OBJECTIVE: To investigate: (i) intra-rater, inter-rater and test-retest reliability of the Timed Floor Transfer Test (FTT); (ii) validity of FTT times with stroke-specific impairments and functional mobility; and (iii) cut-off time that best discriminates people with stroke from healthy older adults. DESIGN: Cross-sectional study. SETTING: University-based rehabilitation laboratory. SUBJECTS: Forty-seven people with stroke and 35 healthy older adults. METHODS: FTT completion times were measured along with a Fugl-Meyer assessment of the lower extremities (FMA-LE); Five Times Sit-To-Stand Test (FTSTST) completion times, Berg Balance Scale (BBS) scores; Timed "Up & Go" (TUG) test; and assessment using the Activities-specific Balance Confidence Scale (ABC). RESULTS: FTT completion times showed good to excellent intra-rater, inter-rater and test-retest reliability. The minimal detectable change of FTT completion times was 7.7 s. A cut-off time of 8.8 s was found to discriminate well between people with stroke and healthy older adults. The FTT times showed significant negative correlation with FMA-LE scores and BBS scores, and significant positive correlation with FTSTS completion times and TUG times. CONCLUSION: The FTT is a reliable clinical test for assessing the floor-transfer ability of people with chronic stroke.

Oxidative stress and DNA damage signalling in skeletal muscle in pressure-induced deep tissue injury.

The molecular mechanisms that contribute to the pathogenesis of pressure-induced deep tissue injury are largely unknown. This study tested the hypothesis that oxidative stress and DNA damage signalling mechanism in skeletal muscle are involved in deep tissue injury. Adult Sprague Dawley rats were subject to an experimental protocol to induce deep tissue injury. Two compression cycles with a static pressure of 100 mmHg was applied to an area of 1.5 cm(2) over the mid-tibialis region of right limb of the rats. The left uncompressed limb served as intra-animal control. Muscle tissues underneath compression region were collected for examination. Our analyses indicated that pathohistological characteristics including rounding contour of myofibres and extensive nuclei accumulation were apparently shown in compressed muscles. The elevation of 8OHdG immunopositively stained nuclei indicated the presence of oxidative DNA damage. Increase in oxidative stress was revealed by showing significant elevation of 4HNE and decreases in mRNA abundance of SOD1, catalase and GPx, and protein content of SOD2 in compressed muscles relative to control muscles. Increase in nitrosative stress was demonstrated by significant elevation of nitrotyrosine and NOS2 mRNA content. The activation of tumor suppressor p53 signalling was indicated by the remarkable increases in protein contents of total p53 and serine-15 phosphorylated p53. The transcript expression of the DNA-repairing enzyme, Rad23A, was significantly suppressed in compressed muscles. Our time-course study indicated that increased oxidative/nitrosative stress and proapoptotic signalling were maintained in muscles receiving increasing amount of compression cycles and post-compression time. Furthermore, resveratrol was found to attenuate the histological damage, oxidative/nitrosative stress and proapoptotic signalling in response to prolonged moderate compression. In conclusion, our findings are consistent with the hypothesis that oxidative stress and DNA damage signalling in skeletal muscle are involved in the underlying mechanisms responsible for the pathogenesis of pressure-induced deep tissue injury.

Deformation and reperfusion damages and their accumulation in subcutaneous tissues during loading and unloading: a theoretical modeling of deep tissue injuries.

Deep tissue injuries (DTI) involve damages in the subcutaneous tissues under intact skin incurred by prolonged excessive epidermal loadings. This paper presents a new theoretical model for the development of DTI, broadly based on the experimental evidence in the literatures. The model covers the loading damages implicitly inclusive of both the direct mechanical and ischemic injuries, and the additional reperfusion damages and the competing healing processes during the unloading phase. Given the damage accumulated at the end of the loading period, the relative strength of the reperfusion and the healing capacity of the involved tissues system, the model provides a description of the subsequent damage evolution during unloading. The model is used to study parametrically the scenario when reperfusion damage dominates over healing upon unloading and the opposite scenario when the loading and subsequent reperfusion damages remain small relative to the healing capacity of the tissues system. The theoretical model provides an integrated understanding of how tissue damage may further build-up paradoxically even with unloading, how long it would take for the loading and reperfusion damages in the tissues to become fully recovered, and how such loading and reperfusion damages, if not given sufficient time for recovery, may accumulate over multiple loading and unloading cycles, leading to clinical deep tissues ulceration.

Protective effect of caspase inhibition on compression-induced muscle damage.

There are currently no effective therapies for treating pressure-induced deep tissue injury. This study tested the efficacy of pharmacological inhibition of caspase in preventing muscle damage following sustained moderate compression. Adult Sprague-Dawley rats were subjected to prolonged moderate compression. Static pressure of 100 mm Hg compression was applied to an area of 1.5 cm2 in the tibialis region of the right limb of the rats for 6 h each day for two consecutive days. The left uncompressed limb served as intra-animal control. Rats were randomized to receive either vehicle (DMSO) as control treatment (n =8) or 6 mg kg⁻¹ of caspase inhibitor (z-VAD-fmk; n =8) prior to the 6 h compression on the two consecutive days.Muscle tissues directly underneath the compression region of the compressed limb and the same region of control limb were harvested after the compression procedure.Histological examination and biochemical/molecular measurement of apoptosis and autophagy were performed. Caspase inhibition was effective in alleviating the compression-induced pathohistology of muscle. The increases in caspase-3 protease activity, TUNEL index, apoptotic DNA fragmentation and pro-apoptotic factors (Bax, p53 and EndoG) and the decreases in anti-apoptotic factors (XIAP and HSP70) observed in compressed muscle of DMSO-treated animals were not found in animals treated with caspase inhibitor. The mRNA content of autophagic factors (Beclin-1, Atg5 and Atg12) and the protein content of LC3, FoxO3 and phospho-FoxO3 that were down-regulated in compressed muscle of DMSO-treated animals were all maintained at their basal level in the caspase inhibitor treated animals. Our data provide evidence that caspase inhibition attenuates compression-induced muscle apoptosis and maintains the basal autophagy level. These findings demonstrate that pharmacological inhibition of caspase/apoptosis is effective in alleviating muscle damage as induced by prolonged compression.

Proteasome inhibition alleviates prolonged moderate compression-induced muscle pathology.

BACKGROUND: The molecular mechanism initiating deep pressure ulcer remains to be elucidated. The present study tested the hypothesis that the ubiquitin proteasome system is involved in the signalling mechanism in pressure-induced deep tissue injury. METHODS: Adult Sprague Dawley rats were subjected to an experimental compression model to induce deep tissue injury. The tibialis region of the right hind limb was subjected to 100 mmHg of static pressure for six hours on each of two consecutive days. The compression pressure was continuously monitored by a three-axial force transducer within the compression indentor. The left hind limb served as the intra-animal control. Muscle tissues underneath the compressed region were collected and used for analyses. RESULTS: Our results demonstrated that the activity of 20S proteasome and the protein abundance of ubiquitin and MAFbx/atrogin-1 were elevated in conjunction with pathohistological changes in the compressed muscle, as compared to control muscle. The administration of the proteasome inhibitor MG132 was found to be effective in ameliorating the development of pathological histology in compressed muscle. Furthermore, 20S proteasome activity and protein content of ubiquitin and MAFbx/atrogin-1 showed no apparent increase in the MG132-treated muscle following compression. CONCLUSION: Our data suggest that the ubiquitin proteasome system may play a role in the pathogenesis of pressure-induced deep tissue injury.

Biomechanics of pressure ulcer in body tissues interacting with external forces during locomotion.

Forces acting on the body via various external surfaces during locomotion are needed to support the body under gravity, control posture, and overcome inertia. Examples include the forces acting on the body via the seating surfaces during wheelchair propulsion, the forces acting on the plantar foot tissues via the insole during gait, and the forces acting on the residual-limb tissues via the prosthetic socket during various movement activities. Excessive exposure to unwarranted stresses at the body-support interfaces could lead to tissue breakdowns commonly known as pressure ulcers, often presented as deep-tissue injuries around bony prominences or as surface damage on the skin. In this article, we review the literature that describes how the involved tissues respond to epidermal loading, taking into account both experimental and computational findings from in vivo and in vitro studies. In particular, we discuss related literature about internal tissue deformation and stresses, microcirculatory responses, and histological, cellular, and molecular observations.

Muscle apoptosis is induced in pressure-induced deep tissue injury.

Pressure ulcer is a complex and significant health problem. Although the factors including pressure, shear, and ischemia have been identified in the etiology of pressure ulcer, the cellular and molecular mechanisms that contribute to the development of pressure ulcer are unclear. This study tested the hypothesis that the early-onset molecular regulation of pressure ulcer involves apoptosis in muscle tissue. Adult Sprague-Dawley rats were subjected to an in vivo protocol to mimic pressure-induced deep tissue injury. Static pressure was applied to the tibialis region of the right limb of the rats for 6 h each day on two consecutive days. The compression force was continuously monitored by a three-axial force transducer equipped in the compression indentor. The contralateral uncompressed limb served as intra-animal control. Tissues underneath the compressed region were collected for histological analysis, terminal dUTP nick-end labeling (TUNEL), cell death ELISA, immunocytochemical staining, and real-time RT-PCR gene expression analysis. The compressed muscle tissue generally demonstrated degenerative characteristics. TUNEL/dystrophin labeling showed a significant increase in the apoptotic muscle-related nuclei, and cell death ELISA demonstrated a threefold elevation of apoptotic DNA fragmentation in the compressed muscle tissue relative to control. Positive immunoreactivities of cleaved caspase-3, Bax, and Bcl-2 were evident in compressed muscle. The mRNA contents of Bax, caspase-3, caspase-8, and caspase-9 were found to be higher in the compressed muscle tissue than control. These results demonstrated that apoptosis is activated in muscle tissue following prolonged moderate compression. The data are consistent with the hypothesis that muscle apoptosis is involved in the underlying mechanism of pressure-induced deep tissue injury.

Post pressure response of skin blood flowmotions in anesthetized rats with spinal cord injury.

Pressure ulcer is a common complication developed in persons with spinal cord injury (SCI) when prolonged unrelieved pressure was applied to the body/skin and underlying tissues. The objective of this study is to assess the hyperemic response of the skin blood flowmotions in anesthetized rats with spinal cord injury subjected to prolonged pressure using spectral analysis based on wavelets transform of the periodic oscillations of the cutaneous laser Doppler flowmetry (LDF) signal. A total of twenty-eight Sprague-Dawley rats were used in this study, of which 14 were normal rats and the other 14 were spinal cord injured rats with transection of the T1 spinal nerves. External pressure of 13.3 kPa (100 mmHg) was applied to the trochanter area of rats via a specifically designed indentors. The loading duration was 6 h. LDF measurement was monitored for 20 min prior to and after the prescribed compression period. Five frequency intervals were identified (0.01-0.05 Hz, 0.05-0.15 Hz, 0.15-0.4 Hz, 0.4-2 Hz and 2-5 Hz) corresponding to endothelial related metabolic, neurogenic, myogenic, respiratory and cardiac origins. The absolute amplitude of oscillations of each particular frequency interval and the normalized amplitude were calculated for quantitative assessments. Comparisons of hyperemic response were performed between SCI rats and normal ones. The results showed that the normalized amplitude in the frequency interval II (0.05-0.15 Hz) was significantly lower on SCI rats than that in normal ones (p<0.01). Also, decreased reactive hyperemic response was observed in rats suffered from spinal cord injury.

An experience on wheelchair bank management.

In this article, we described the wheelchair bank program at a local hospital and our experiences in managing the service over the past 10 years from 1996 to 2005. This article also reported statistical information related to the acquisitions of wheelchairs and adaptive components, including body support and pressure relief systems. The cost benefit of recycling seating and mobility equipments for use by children with neuromuscular diseases was revealed. With the reference of the reported data, the demands on specific types of wheelchairs and adaptive parts were disclosed to facilitate budget planning of similar services.

Wavelet analysis of the effects of static magnetic field on skin blood flowmotion: investigation using an in vivo rat model.

BACKGROUND: In the literature, various in vivo studies on animals have demonstrated that a static magnetic field (SMF) might maintain microvascular tone in the cutaneous microcirculatory system by its biphasic effects on vasomotion. Here, the effects of locally applied SMF on skin blood flowmotion within the stressed or unstressed skin in the trochanter area were evaluated using wavelet analysis of skin blood perfusion as measured by laser Doppler flowmetry (LDF) in anesthetized rats. MATERIALS AND METHODS: Forty-eight experimental trials were carried out on twelve Sprague-Dawley rats. Four experimental groups were formed at random: i) Group CNL (no loading or SMF exposure; n = 12 trials); ii) Group SMF (SMF exposure only; n = 12 trials); iii) Group L (stressed skin without SMF exposure; n = 12 trials); iv) Group L + SMF (stressed skin with SMF exposure; n = 12 trials). RESULTS: SMF significantly enhanced endothelial related metabolic activity (0.01-0.05 Hz) in the stressed skin (p = 0.03). However, SMF did not induce significant change in the flowmotion amplitude in the unstressed skin (p = 0.22). CONCLUSION: The modulating effect of SMF on skin blood flowmotion might be related to the vascular tone modified by prolonged loading.

The time effect of pressure on tissue viability: investigation using an experimental rat model.

An experimental rat model was used to investigate the time-pressure effect on tissue viability. External loading equivalent to 13.3 kPa (100 mm Hg) of pressure was applied to the greater trochanter and tibialis area of Sprague-Dawley rats using pneumatic indentors for duration of 6 hrs each day for 1 to 4 days. It was observed that postocclusive hyperemic responses were gradually increased at the trochanter throughout the 4 days of loading, whereas for the tibia there was a significant increase (P = 0.04) in postocclusive hyperemic flow between Days 2 and 3. In histologic evaluations, cutaneous tissue damage was observed at the trochanter area but not at the tibialis area after 2 consecutive days of load application. In contrast, degeneration of muscle cells characterized by numerous increases of nuclei occupying the central of the muscle fibers was observed after 2 days of load application at the tibialis. The situation was found to progress with time (P = 0.17). The presence of other histologic signs, including the internalization of peripherally located nuclei, replacement of muscle cells by fibrosis and adipose tissues, and the presence of pyknotic nuclei as well as karyorrhexis, confirmed that the affected tissues were damaged. These findings suggest that postocclusive hyperemia and the distress of tissues under loading could be closely related.