Effect of negative pressure therapy on the treatment response to scar thickness and viscoelasticity

Patients with scars face a grave threat to their mental and physical health. Negative pressure has been used for scar therapy in medical care and provides a microenvironment conducive to scar healing while stimulating cell regeneration. Negative pressure may disrupt scar tissue regeneration when the pressure is too high or too low, so finding a suitable negative pressure is important. We hypothesized that different negative pressure magnitudes would affect scar tissue properties differently. This research aimed to provide practical recommendations for scar therapy. This study used three negative pressures (-105 mmHg, -125 mmHg, and -145 mmHg) to compare scar material properties. We measured scar tissue thickness and viscoelasticity with a motor-driven ultrasound indentation system. According to the results of this study, scar thickness is most effectively reduced at a negative pressure of -105 mmHg. In comparison, scar viscoelasticity continuously increases at a negative pressure of -125 mmHg. Negative pressure therapy can be recommended to scar care clinics based on the results of this study.

Plantar pressure gradient and pressure gradient angle are affected by inner pressure of air insole

Clinically, air insoles may be applied to shoes to decrease plantar pressure gradient (PPG) and increase plantar gradient angle (PGA) to reduce foot ulcers. PPG and PGA may cause skin breakdown. The effects of different inner pressures of inflatable air insoles on dynamic PPG and PGA distributions are largely unknown in non-diabetics and people with diabetes. This study aimed to explore the impact of varying inner air insole pressures on PPG and PGA to establish early mitigation strategies for people at risk of foot ulcers. A repeated measures study design, including three air insoles (80 mmHg, 160 mmHg, and 240 mmHg) and two walking durations (10 and 20 min) for a total of six walking protocols, was tested on 13 healthy participants (height, 165.8 ± 8.4 cm; age, 27.0 ± 7.3 years; and weight, 56.0 ± 7.9 kg, BMI: 20.3 ± 1.7 kg/m^2) over three consecutive weeks. PPG, a measurement of the spatial variation in plantar pressure around the peak plantar pressure (PPP) and PGA, a variation in the gradient direction values at the three plantar regions, big toe (T1), first metatarsal head (M1), and second metatarsal head (M2), were calculated. This study indicated that PPG was lower at 80 mmHg air insoles after 20 min of walking in the M1 region (p = 0.010). The PGA in the M2 increased at an air insole of 80 mmHg compared to 240 mmHg (p = 0.015). Compared to 20 min, the 10 min walking duration at 240 mmHg of air insole had the lowest PPG in the M1 (p = 0.015) and M2 (p = 0.034) regions. The 80 mmHg air insole significantly lowered the PPG compared to a 160 mmHg and 240 mmHg air insole. Moreover, the 80 mmHg air insole significantly decreased PPP and increased PGA compared to the 160 mmHg and 240 mmHg air insole. A shorter walking period (10 min) significantly lowered PPG. The findings of this study suggest that people with a higher risk of foot ulcers should wear softer air insoles to have a lower PPG, as well as an increased PGA.

The effects of different inner pressures of air insoles and walking durations on peak plantar pressure

BACKGROUND

Exercise reduces chronic complications in individuals with diabetes and peripheral vascular diseases. In clinical practice, the use of air insole may reduce peak plantar pressure (PPP), and risk for diabetic foot ulcers (DFUs). However, there is no guideline on selecting air insole pressure for effectively reducing PPP. Therefore, this study aimed to investigate the effects of different air insole pressure on PPP at different walking durations.

METHODS

We tested 13 participants using repeated measures study design, including 3 air insole pressures (80, 160, and 240 mm Hg) and 2 walking durations (10 and 20 minutes) for 6 walking conditions. PPP values at the first toe, first metatarsal head, and second metatarsal head were calculated.

RESULTS

The one-way ANOVA showed significant pairwise differences of PPP at 20 minutes duration in the first metatarsal head between 80 and 240 mm Hg (P = .007) and between 160 and 240 mm Hg (P = .038); in the second metatarsal head between 80 and 240 mm Hg (P = .043). The paired t test confirmed that walking duration significantly has lower PPP at 10 minutes than 20 minutes with 240 mm Hg air insole in the first metatarsal head (P = .012) and the second metatarsal head (P = .027).

CONCLUSION

People at risk of foot ulcers are suggested to wear shoes with 80 mm Hg of air insole for reducing PPP in the first metatarsal head and the second metatarsal head. Moreover, people may avoid wearing the stiffer insole (240 mm Hg) for more than 20 minutes.

An approach to the diagnosis of lumbar disc herniation using deep learning models

Background: In magnetic resonance imaging (MRI), lumbar disc herniation (LDH) detection is challenging due to the various shapes, sizes, angles, and regions associated with bulges, protrusions, extrusions, and sequestrations. Lumbar abnormalities in MRI can be detected automatically by using deep learning methods. As deep learning models gain recognition, they may assist in diagnosing LDH with MRI images and provide initial interpretation in clinical settings. YOU ONLY LOOK ONCE (YOLO) model series are often used to train deep learning algorithms for real-time biomedical image detection and prediction. This study aims to confirm which YOLO models (YOLOv5, YOLOv6, and YOLOv7) perform well in detecting LDH in different regions of the lumbar intervertebral disc. Materials and methods: The methodology involves several steps, including converting DICOM images to JPEG, reviewing and selecting MRI slices for labeling and augmentation using ROBOFLOW, and constructing YOLOv5x, YOLOv6, and YOLOv7 models based on the dataset. The training dataset was combined with the radiologist's labeling and annotation, and then the deep learning models were trained using the training/validation dataset. Results: Our result showed that the 550-dataset with augmentation (AUG) or without augmentation (non-AUG) in YOLOv5x generates satisfactory training performance in LDH detection. The AUG dataset overall performance provides slightly higher accuracy than the non-AUG. YOLOv5x showed the highest performance with 89.30% mAP compared to YOLOv6, and YOLOv7. Also, YOLOv5x in non-AUG dataset showed the balance LDH region detections in L2-L3, L3-L4, L4-L5, and L5-S1 with above 90%. And this illustrates the competitiveness of using non-AUG dataset to detect LDH. Conclusion: Using YOLOv5x and the 550 augmented dataset, LDH can be detected with promising both in non-AUG and AUG dataset. By utilizing the most appropriate YOLO model, clinicians have a greater chance of diagnosing LDH early and preventing adverse effects for their patients.

Using cross-correlation analysis of multi-channel near infrared spectroscopy to assess the hemodynamic response to cupping therapy

Cupping therapy is a common intervention for the management of musculoskeletal impairment. Previous studies have demonstrated that cupping therapy can improve muscle hemodynamic responses using single-channel near-infrared spectroscopy (NIRS). However, the effects of cupping therapy on spatial hemodynamic responses as well as the correlation between oxyhemoglobin and deoxy-hemoglobin are largely unknown. The cross-correlation function (CCF) algorithm was used to determine the correlation between time-series NIRS signals from inside and outside the cup as well as time-series oxyhemoglobin and deoxy-hemoglobin under 4 cupping intensities, including -225 and -300 mmHg for 5 and 10 min. The main finding was that the maximum CCF values of oxyhemoglobin was significantly higher than those in deoxy-hemoglobin (p < 0.05). Furthermore, it was found that there was a correlation between deoxy-hemoglobin with a longer duration and a larger magnitude of negative pressure. This is the first study investigating time-series hemodynamic responses after cupping therapy using cross-correlation function analysis of multi-channel NIRS signals.

Antiviral and Immunomodulatory Activities of Clinacanthus nutans (Burm. f.) Lindau

Clinacanthus nutans (Burm. f.) Lindau has been used as a traditional herbal medicine for treating snake bites, scalds, burns, and viral and bacterial infections. It has been attracting an increasing amount of attention because of its biological activities, including its antidiabetic, antioxidant, antibacterial, anticancer, anti-inflammatory, antiviral, and immunoregulatory activities. Here, we conducted a panoramic survey of the literature regarding the immunoregulatory, anti-inflammatory, and antiviral activities of C. nutans. We discovered that C. nutans extracts have virucidal activities against herpes simplex virus types 1 and 2, varicella-zoster virus, cyprinid herpesvirus 3, porcine reproductive and respiratory syndrome virus, mosquito-borne chikungunya virus, and potentially SARS-CoV-2; such activities likely result from C. nutans interfering with the entry, penetration, infection, and replication of viruses. We also reviewed the phytochemicals in C. nutans extracts that exhibit anti-inflammatory and immunoregulatory activities. This updated review of the antiviral, anti-inflammatory, and immunoregulatory activities of C. nutans may guide future agricultural practices and reveal clinical applications of C. nutans.

Effectiveness of self-management of dry and wet cupping therapy for low back pain: A systematic review and meta-analysis

BACKGROUND

Low back pain (LBP) can significantly affect a person's quality of life. Cupping has been used to treat LBP. However, various cupping methods are typically included in evaluating the efficacy of cupping therapy. Therefore, the objectives of this study were to evaluate the evidence from the literature regarding the effects of dry and wet cupping therapy on LBP in adults. Dry and wet cupping therapy are analyzed categorically in this study.

METHODS

We searched for randomized clinical trials with cupping in LBP published between 2008 and 2022. In dry or wet cupping clinical studies, pain intensity was assessed using the Visual Analogue Scale and present pain intensity, and the quality of life intensity was measured using the Oswestry disability index.

RESULTS

The 656 studies were identified, of which 10 studies for 690 patients with LBP were included in the meta-analysis. There was a significant reduction in the pain intensity score with present pain intensity using wet cupping therapy (P < .01). In addition, both cupping therapy groups displayed significant Oswestry disability index score reduction compared to the control group (both P < .01). The patients with LBP have a substantial reduction by using wet cupping but have not shown a considerable decrease by using dry cupping (P = .19). In addition, only wet cupping therapy groups displayed a significantly improved quality of life compared to the control group. The study had a very high heterogeneity (I2 > 50%). It means there is no standardization in the treatment protocol in randomized clinical trials. In the meta-regression, there was statistically significant evidence that the number of treatment times and intercepts were related (P < .01).

CONCLUSION

The present meta-analysis shows that wet cupping therapy effectively reduces the pain intensity of LBP. Furthermore, both dry wet cupping therapy improved patients with LBP quality of life.

Effects of Walking Speeds and Durations on Peak Plantar Pressures

BACKGROUND

Walking at various speeds and durations may result in different peak plantar pressure (PPP). However, there is no study comparing the effect of walking speeds and durations on PPP. The purpose of this study was to explore whether different walking speeds and durations significantly change PPP and establish a normal response in healthy people.

METHODS

An in-shoe plantar pressure system was used to measure PPP under the first toe, first metatarsal, second metatarsal, and heel regions in 12 healthy, young people. All participants performed six walking trials at three speeds (3, 6, and 9 km/h) and for two durations (10 and 20 min). The 3 × 2 two-way analysis of variance was used to examine the main effects of speeds and durations and their interaction.

RESULTS

The results showed that walking speeds significantly affected PPP and that walking duration did not. No interaction between the walking speed and duration was observed. Peak plantar pressure values under the first toe and the first metatarsal head were significantly higher (P < .05) at 9 km/h (509.1 ± 314.2 kPa and 591.4 ± 302.4 kPa, respectively) than at 3 km/h (275.4 ± 168.7 kPa and 369.4 ± 205.4 kPa, respectively) after 10-min walking.

CONCLUSIONS

People at risk for foot ulcers may use slow and brisk walking for exercise to reduce PPP, thus reducing risk for foot ulcers. Our study demonstrated that slow running at 9 km/h significantly increases PPP.

Effects of walking speeds and durations on the plantar pressure gradient and pressure gradient angle

BACKGROUND

Walking exercise has been demonstrated to improve health in people with diabetes. However, it is largely unknown the influences of various walking intensities such as walking speeds and durations on dynamic plantar pressure distributions in non-diabetics and diabetics. Traditional methods ignoring time-series changes of plantar pressure patterns may not fully capture the effect of walking intensities on plantar tissues. The purpose of this study was to investigate the effect of various walking intensities on the dynamic plantar pressure distributions. In this study, we introduced the peak pressure gradient (PPG) and its dynamic patterns defined as the pressure gradient angle (PGA) to quantify dynamic changes of plantar pressure distributions during walking at various intensities.

METHODS

Twelve healthy participants (5 males and 7 females) were recruited in this study. The demographic data were: age, 27.1 ± 5.8 years; height, 1.7 ± 0.1 m; and weight, 63.5 ± 13.5 kg (mean ± standard deviation). An insole plantar pressure measurement system was used to measure plantar pressures during walking at three walking speeds (slow walking 1.8 mph, brisk walking 3.6 mph, and slow running 5.4 mph) for two durations (10 and 20 min). The gradient at a location is defined as the unique vector field in the two-dimensional Cartesian coordinate system with a Euclidean metric. PGA was calculated by quantifying the directional variation of the instantaneous peak gradient vector during stance phase of walking. PPG and PGA were calculated in the plantar regions of the first toe, first metatarsal head, second metatarsal head, and heel at higher risk for foot ulcers. Two-way ANOVA with Fisher's post-hoc analysis was used to examine the speed and duration factors on PPG and PGA.

RESULTS

The results showed that the walking speeds significantly affect PPG (P < 0.05) and PGA (P < 0.05), and the walking durations does not. No interaction between the walking duration and speed was observed. PPG in the first toe region after 5.4 mph for either 10 or 20 min was significantly higher than 1.8 mph. Meanwhile, after 3.6 mph for 20 min, PPG in the heel region was significantly higher than 1.8 mph. Results also indicate that PGA in the forefoot region after 3.6 mph for 20 min was significantly narrower than 1.8 mph.

CONCLUSIONS

Our findings indicate that people may walk at a slow speed at 1.8 mph for reducing PPG and preventing PGA concentrated over a small area compared to brisk walking at 3.6 mph and slow running at 5.4 mph.

Advanced Cross-Correlation Function Application to Identify Arterial Baroreflex Sensitivity Variations From Healthy to Diabetes Mellitus

Diabetes mellitus (DM) is a chronic disease characterized by elevated blood glucose levels, which leads over time to serious damage to the heart, blood vessels, eyes, kidneys, and nerves. DM is of two types–types 1 or 2. In type 1, there is a problem with insulin secretion, and in type 2–insulin resistance. About 463 million people worldwide have diabetes, and 80% of the majority live in low- and middle-income countries, and 1.5 million deaths are directly attributed to diabetes each year. Autonomic neuropathy (AN) is one of the common diabetic complications, leading to failure in blood pressure (BP) control and causing cardiovascular disease. Therefore, early detection of AN becomes crucial to optimize treatment. We propose an advanced cross-correlation function (ACCF) between BP and heart rate with suitable threshold parameters to analyze and detect early changes in baroreflex sensitivity (BRS) in DM with AN (DM+). We studied heart rate (HR) and systolic BP responses during tilt in 16 patients with diabetes mellitus only (DM−), 19 diabetes mellitus with autonomic dysfunction (DM+), and 10 healthy subjects. The ACCF analysis revealed that the healthy and DM groups had different filtered percentages of significant maximum cross-correlation function (CCF) value (p < 0.05), and the maximum CCF value after thresholds was significantly reduced during tilt in the DM+ group (p < 0.05). The maximum CCF index, a parameter for the phase between HR and BP, separated the healthy group from the DM groups (p < 0.05). Due to the maximum CCF index in DM groups being located in the positive range and significantly different from healthy ones, it could be speculated that BRS dysfunction in DM and AN could cause a phase change from lead to lag. ACCF could detect and separate DM+ from DM groups. This fact could represent an advantage of the ACCF algorithm. A common cross-correlation analysis was not easy to distinguish between DM− and DM+. This pilot study demonstrates that ACCF analysis with suitable threshold parameters could explore hidden changes in baroreflex control in DM+ and DM−. Furthermore, the superiority of this ACCF algorithm is useful in distinguishing whether AN is present or not in DM.

A Deep Learning Method for Foot Progression Angle Detection in Plantar Pressure Images

Foot progression angle (FPA) analysis is one of the core methods to detect gait pathologies as basic information to prevent foot injury from excessive in-toeing and out-toeing. Deep learning-based object detection can assist in measuring the FPA through plantar pressure images. This study aims to establish a precision model for determining the FPA. The precision detection of FPA can provide information with in-toeing, out-toeing, and rearfoot kinematics to evaluate the effect of physical therapy programs on knee pain and knee osteoarthritis. We analyzed a total of 1424 plantar images with three different You Only Look Once (YOLO) networks: YOLO v3, v4, and v5x, to obtain a suitable model for FPA detection. YOLOv4 showed higher performance of the profile-box, with average precision in the left foot of 100.00% and the right foot of 99.78%, respectively. Besides, in detecting the foot angle-box, the ground-truth has similar results with YOLOv4 (5.58 ± 0.10° vs. 5.86 ± 0.09°, p = 0.013). In contrast, there was a significant difference in FPA between ground-truth vs. YOLOv3 (5.58 ± 0.10° vs. 6.07 ± 0.06°, p < 0.001), and ground-truth vs. YOLOv5x (5.58 ± 0.10° vs. 6.75 ± 0.06°, p < 0.001). This result implies that deep learning with YOLOv4 can enhance the detection of FPA.

Hypertension and Stroke Cardiovascular Control Evaluation by Analyzing Blood Pressure, Cerebral Blood Flow, Blood Vessel Resistance and Baroreflex

Cardiovascular diseases have been the leading causes of mortality in Taiwan and the world at large for decades. The composition of cardiovascular and cerebrovascular systems is quite complicated. Therefore, it is difficult to detect or trace the related signs of cardiovascular and cerebrovascular diseases. The characteristics and changes in cardiopulmonary system disease can be used to track cardiovascular and cerebrovascular disease prevention and diagnosis. This can effectively reduce the occurrence of cardiovascular and cerebrovascular diseases. This study analyzes the variability in blood pressure, cerebral blood flow velocity and the interaction characteristics using linear and nonlinear approaches in stroke, hypertension and healthy groups to identify the differences in cardiovascular control in these groups. The results showed that the blood pressure and cerebral blood flow of stroke patients and hypertensive patients were significantly higher than those of healthy people (statistical differences (p < 0.05). The cerebrovascular resistance (CVR) shows that the CVR of hypertensive patients is higher than that of healthy people and stroke patients (p < 0.1), indicating that the cerebral vascular resistance of hypertensive patients is slightly higher. From the patient's blood flow and vascular characteristics, it can be observed that the cardiovascular system is different from those in healthy people. Baroreflex sensitivity (BRS) decreased in stroke patients (p < 0.05). Chaotic analysis revealed that the blood pressure disturbance in hypertensive patients has a higher chaotic behavior change and the difference in initial state sensitivity. Cross-correlation (CCF) analysis shows that as the course of healthy→hypertension→stroke progresses, the maximum CCF value decreases significantly (p < 0.05). That means that blood pressure and cerebral blood flow are gradually not well controlled by the self-regulation mechanism. In conclusion, cardiovascular control performance in hypertensive and stroke patients displays greater variation. This can be observed by the bio-signal analysis. This analysis could identify a measure for detecting and preventing the risk for hypertension and stroke in clinical practice. This is a pilot study to analyze cardiovascular control variation in healthy, hypertensive and stroke groups.

Effects of various walking intensities on leg muscle fatigue and plantar pressure distributions

Background

Physical activity may benefit health and reduce risk for chronic complications in normal and people with diabetes and peripheral vascular diseases. However, it is unclear whether leg muscle fatigue after weight-bearing physical activities, such as brisk walking, may increase risk for plantar tissue injury. In the literature, there is no evidence on the effect of muscle fatigue on plantar pressure after various walking intensities. The objectives of this study were to investigate the effects of various walking intensities on leg muscle fatigue and plantar pressure patterns.

Methods

A 3 × 2 factorial design, including 3 walking speeds (1.8 (slow and normal walking), 3.6 (brisk walking), and 5.4 (slow running) mph) and 2 walking durations (10 and 20 min) for a total of 6 walking intensities, was tested in 12 healthy participants in 3 consecutive weeks. The median frequency and complexity of electromyographic (EMG) signals of tibialis anterior (TA) and gastrocnemius medialis (GM) were used to quantify muscle fatigue. Fourier transform was used to compute the median frequency and multiscale entropy was used to calculate complexity of EMG signals. Peak plantar pressure (PPP) values at the 4 plantar regions (big toe, first metatarsal head, second metatarsal head, and heel) were calculated.

Results

Two-way ANOVA showed that the walking speed (at 1.8, 3.6, 5.4 mph) significantly affected leg muscle fatigue, and the duration factor (at 10 and 20 min) did not. The one-way ANOVA showed that there were four significant pairwise differences of the median frequency of TA, including walking speed of 1.8 and 3.6 mph (185.7 ± 6.1 vs. 164.9 ± 3.0 Hz, P = 0.006) and 1.8 and 5.4 mph (185.7 ± 6.1 vs. 164.5 ± 5.5 Hz, P = 0.006) for the 10-min duration; and walking speed of 1.8 and 3.6 mph (180.0 ± 5.9 vs. 163.1 ± 4.4 Hz, P = 0.024) and 1.8 and 5.4 mph (180.0 ± 5.9 vs. 162.8 ± 4.9 Hz, P = 0.023) for the 20-min duration. The complexity of TA showed a similar trend with the median frequency of TA. The median frequency of TA has a significant negative correlation with PPP on the big toe ( r = -0.954, P = 0.003) and the first metatarsal head ( r = -0.896, P = 0.016).

Conclusions

This study demonstrated that brisk walking and slow running speeds (3.6 and 5.4 mph) cause an increase in muscle fatigue of TA compared to slow walking speed (1.8 mph); and the increased muscle fatigue is significantly related to a higher PPP.

Lumbar Disc Herniation Automatic Detection in Magnetic Resonance Imaging Based on Deep Learning

Background: Lumbar disc herniation (LDH) is among the most common causes of lower back pain and sciatica. The causes of LDH have not been fully elucidated but most likely involve a complex combination of mechanical and biological processes. Magnetic resonance imaging (MRI) is a tool most frequently used for LDH because it can show abnormal soft tissue areas around the spine. Deep learning models may be trained to recognize images with high speed and accuracy to diagnose LDH. Although the deep learning model requires huge numbers of image datasets to train and establish the best model, this study processed enhanced medical image features for training the small-scale deep learning dataset. Methods: We propose automatic detection to assist the initial LDH exam for lower back pain. The subjects were between 20 and 65 years old with at least 6 months of work experience. The deep learning method employed the YOLOv3 model to train and detect small object changes such as LDH on MRI. The dataset images were processed and combined with labeling and annotation from the radiologist's diagnosis record. Results: Our method proves the possibility of using deep learning with a small-scale dataset with limited medical images. The highest mean average precision (mAP) was 92.4% at 550 images with data augmentation (550-aug), and the YOLOv3 LDH training was 100% with the best average precision at 550-aug among all datasets. This study used data augmentation to prevent under- or overfitting in an object detection model that was trained with the small-scale dataset. Conclusions: The data augmentation technique plays a crucial role in YOLOv3 training and detection results. This method displays a high possibility for rapid initial tests and auto-detection for a limited clinical dataset.

Evaluating the Far-Infrared Radiation Bioeffects on Micro Vascular Dysfunction, Nervous System, and Plantar Pressure in Diabetes Mellitus

The most frequent clinical complication is diabetes. Diabetes is characterized by elevated blood glucose levels resulting in sensory nerve damage or lesions. Diabetic foot wounds are often slow to heal and require medical attention and monitoring. This study evaluates the effect of far-infrared radiation on the microcirculation and plantar pressure in the diabetic foot. Ten diabetics and 4 nondiabetics were recruited in this study. The diabetic group was examined before and after the intervention in each month for 3 consecutive months. Four nondiabetic groups were also measured before and after the intervention for 2 weeks in each month. The surface temperature and blood flow in the diabetic foot was significantly improved (temperature: 32.1 ± 2.3°C vs 33.5 ± 2.2°C, P < .05; blood flow image: 118.3 ± 58.1 PU [perfusion unit] vs 50.4 ± 4.3 PU, P < .05). The sympathetic nerve activity index LF also increased from 40.8 ± 18.6% to 61.8 ± 13.5% (P = .07) in the second month. Plantar pressure tended to increase in the third month. This might indicate that far-infrared radiation could affect the mechanical properties of the plantar foot soft tissue. These results indicated that the effects of far-infrared radiation would improve blood circulation and change the soft tissue properties in the diabetic foot.

Center of pressure progression patterns during level walking in adolescents with idiopathic scoliosis

The purpose of this study was to determine whether functional walking performance measured with Timed Up-and-Go (TUG) and center of pressure (CoP) progression pattern is different across adolescents with various curve severity of idiopathic scoliosis (IS). The CoP coordinates during a stance phase for self-paced level walking between adolescent with three different severities of IS (mild IS, moderate IS, and severe IS) and age-matched normal subjects were measured with foot pressure measurement. The average data of three trials were compared among groups with repeated measure analysis of variance. Results showed that the TUG was different between normal and AIS subjects, indicating use of TUG as a marker of functional walking performance in AIS is plausible but studies with larger sample size is needed before using TUG to identify AIS with different scoliosis severity. The results also showed that the CoP displacement, velocity and acceleration during a stance phase was different across groups, and with the most prominent deviations found in the moderate IS group. The medial-lateral shifting of the CoP trajectory at mid-foot regions in all IS groups deviated the most. A tendency of asymmetry in CoP progression pattern between feet in IS groups was also found. The deviation of the spine alignment in frontal plane could change the CoP progression patterns during level walking, suggesting the risk of the locomotors subjecting to abnormal loading during daily walking. Education and conservative interventions might be needed for preservation of medical outcome and prevention of back pain and/or musculoskeletal consequences later in the lives of AIS with and without surgical correction.

Dynamic changes in seating pressure gradient in wheelchair users with spinal cord injury

Pressure ulcer interventions are commonly assessed with measures of seating interface pressure, such as peak pressure gradients (PPGs). Decreases in PPG magnitudes may reduce pressure ulcer risk by decreasing tissue deformation and increasing tissue perfusion of at-risk weight-bearing tissues. Changes in PPG directions, which have previously been overlooked in the seating pressure literature, may provide a transient increase in blood flow to at-risk tissues, even if the PPG magnitude and location remain the same. The purpose of this study was to assess both PPG components in response to combinations of wheelchair tilt and recline angles. Thirteen power wheelchair users were recruited into the study. Six combinations of wheelchair tilt (15°, 25°, and 35°) and recline (10° and 30°) were tested in random order. Each combination was tested with 5-min upright sitting, 5-min tilt and recline, and 5-min maximal pressure relief recovery. Changes in PPG magnitudes and PPG directions under the left ischial tuberosity were computed for the six angle combinations. The findings in this study suggested that when combining wheelchair tilt and recline, the recline function may be particularly useful in reducing PPG magnitudes, while the tilt function may be particularly useful in manipulating PPG directions.

Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis

Subjective visual vertical (SVV) judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS). Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs), the present study examined the effect of postural control demands (PDs) on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group) and 13 age-matched adolescents (control group) aged 12–18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test) as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion), SVV (accuracy and reaction time), and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components) was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1) during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2) the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for central processing attentional resources under the dual-task postural control paradigm.

Quantifying Dynamic Changes in Plantar Pressure Gradient in Diabetics with Peripheral Neuropathy

Diabetic foot ulcers remain one of the most serious complications of diabetes. Peak plantar pressure (PPP) and peak pressure gradient (PPG) during walking have been shown to be associated with the development of diabetic foot ulcers. To gain further insight into the mechanical etiology of diabetic foot ulcers, examination of the pressure gradient angle (PGA) has been recently proposed. The PGA quantifies directional variation or orientation of the pressure gradient during walking and provides a measure of whether pressure gradient patterns are concentrated or dispersed along the plantar surface. We hypothesized that diabetics at risk of foot ulceration would have smaller PGA in key plantar regions, suggesting less movement of the pressure gradient over time. A total of 27 participants were studied, including 19 diabetics with peripheral neuropathy and 8 non-diabetic control subjects. A foot pressure measurement system was used to measure plantar pressures during walking. PPP, PPG, and PGA were calculated for four foot regions – first toe (T1), first metatarsal head (M1), second metatarsal head (M2), and heel (HL). Consistent with prior studies, PPP and PPG were significantly larger in the diabetic group compared with non-diabetic controls in the T1 and M1 regions, but not M2 or HL. For example, PPP was 165% (P = 0.02) and PPG was 214% (P < 0.001) larger in T1. PGA was found to be significantly smaller in the diabetic group in T1 (46%, P = 0.04), suggesting a more concentrated pressure gradient pattern under the toe. The proposed PGA may improve our understanding of the role of pressure gradient on the risk of diabetic foot ulcers.

Severity of spine malalignment on center of pressure progression during level walking in subjects with adolescent idiopathic scoliosis

Center of pressure (CoP) progression during level walking in subjects with Adolescents Idiopathic Scoliosis (AIS) was measured. Participants were divided into three groups according to scoliosis severity. CoP progression among groups was compared quantitatively and qualitatively. The results showed that scoliosis severity affects CoP progression significantly in the hind-foot and forefoot areas. This result indicated that spine alignment might affect the control of heel, ankle and toe rockers in the ankle-foot complex. The effects of scoliosis severity is mainly on the CoP of right foot plantar surface, indicating asymmetrical influence of IS on bilateral lower limb coordination during walking. These results might contribute to musculoskeletal complains over the apparatus within trunk-foot in the later lives of this population.

Static ankle-foot orthosis improves static balance and gait functions in hemiplegic patients after stroke

The purpose was to examine the effects of static anterior and posterior ankle-foot orthoses (AAFOs & PAFOs) using with regular shoes on improving static and gait function in patients recovering from stroke. Static and dynamic balance control were measured under four conditions: barefeet, wearing regular shoes only, and wearing regular shoes with AAFOs or PAFOs. The results indicated that wearing regular shoes markedly increased the center of pressure (CoP) sway (p < 0.05) in static standing conditions. Both AAFOs and PAFOs decreased CoP sway and increased bilateral limb loading symmetry compared to barefoot and wearing shoes alone (p < 0.05). PAFOs decreased CoP sway more than AAFOs (p > 0.05) and also boosted medial-lateral weight shifting more effectively (p < 0.05). Both types of AFOs increased walking efficiency but influenced the roll-over shape of the CoP adversely during level walking. The conclusions are that both AAFOs and PAFOs improved static and dynamic balance control when they were used with regular shoes and PAFOs appeared to be more efficient than AAFOs. Shoes worn daily with AFOs is a key consideration influencing balance control in stroke patients. However, AFOs with static design impeded the function of the three rocker systems of the foot during ambulation.

Effect of viscoelastic properties of plantar soft tissues on plantar pressures at the first metatarsal head in diabetics with peripheral neuropathy

Diabetic foot ulcers are one of the most serious complications associated with diabetes mellitus. Current research studies have demonstrated that biomechanical alterations of the diabetic foot contribute to the development of foot ulcers. However, the changes of soft tissue biomechanical properties associated with diabetes and its influences on the development of diabetic foot ulcers have not been investigated. The purpose of this study was to investigate the effect of diabetes on the biomechanical properties of plantar soft tissues and the relationship between biomechanical properties and plantar pressure distributions. We used the ultrasound indentation tests to measure force-deformation relationships of plantar soft tissues and calculate the effective Young's modulus and quasi-linear viscoelastic parameters to quantify biomechanical properties of plantar soft tissues. We also measured plantar pressures to calculate peak plantar pressure and plantar pressure gradient. Our results showed that diabetics had a significantly greater effective Young's modulus and initial modulus of quasi-linear viscoelasticity compared to non-diabetics. The plantar pressure gradient and biomechanical properties were significantly correlated. Our findings indicate that diabetes is linked to an increase in viscoelasticity of plantar soft tissues that may contribute to a higher peak plantar pressure and plantar pressure gradient in the diabetic foot.

Relation between fractal dimension and roughness index for fractal surfaces

This paper discusses the relation between fractal dimension and roughness index for fractal surfaces of solids. The applicability of the relation to fracture of Mode III+Mode I complex loading is shown. The applicability to other rough surfaces is discussed.

Prognostic significance of DNA flow cytometric analysis in patients with nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a prevalent malignant tumor among Southern Chinese. Previously, the authors described the prognostic significance of a serum antibody assay to a recombinant Epstein-Barr virus Bam HI-Z replication activator protein (ZEBRA) in NPC patients with long term follow-up. In this study, the authors further reported the use of DNA flow cytometry (DNA-FCM) as an additional technique for determining the prognosis of NPC patients in the same series.

METHODS

One hundred and forty-three archival biopsies from 110 NPC patients were deparaffinized and subjected to DNA-FCM analysis. DNA ploidy state and various proliferative indices (PI) of the tumors were correlated with patient survival and frequency of recurrence.

RESULTS

Among the biopsies analyzed, 119 were histologically positive NPC and 24 were negative. Fifty-one tumor biopsies that fulfilled the guideline criteria of the DNA Cytometry Consensus Conference were correlated with the clinical manifestations of the patients. Among them, 43 tumors (84%) were DNA diploid and 8 (16%) were aneuploid. Two PI, S-phase fraction (SPF) and proliferation fraction (PF), appear to be potentially useful prognostic indicators. For example, PF in patients who developed locoregional recurrence (15.1%) and distant recurrence (16.4%) after radiation therapy both were significantly higher than PF in patients who were in complete remission (8.2%) (P = 0.0005 and P = 0.004, respectively). Significant differences in SPF between patients with distant recurrence (10.6%) and those in remission (5.7%) also was found (P = 0.005). Using Kaplan-Meier analysis, patients with high PF, high SPF, and aneuploid tumors had significantly poorer 12-year survival rates (35%, 26%, and 28%, respectively) than those patients with low PF, low SPF, and diploid tumors (77%, 67%, and 59%, respectively) (P < 0.0009, P < 0.004, and P < 0.01, respectively).

CONCLUSIONS

Determination of tumor PI and DNA ploidy state by DNA-FCM at diagnosis of NPC can be potentially useful in selecting a poor prognostic subgroup of NPC patients. These parameters may enable oncologists to plan for more stringent treatment strategies such as hyperfractionated and accelerated radiation therapy or concomitant chemoradiotherapy for these patients.