The effectiveness of video-based exercise training program for people with intellectual disability: a multicenter study.

Objective: To examine the effectiveness of a specially designed video-based exercise program in promoting physical and balance performance in people with intellectual disability. Methods: This study was a multicenter controlled trial. Participants with intellectual disability were divided into exercise group and control group by cluster sampling. The participants in the exercise group received 1 h exercise training sessions twice a week for 8 weeks, and the controls continued their usual care without exercise training. The exercises were specially designed to match the physical ability level of the participants classified as high and low, and a third group called "special" was designed for those wheelchair-bound persons with limited mobility. Elements of light-tempo music and animation were introduced in the videos to motivate the participants. Recording the exercises in video format makes it easier for the class instructors and participants to perform the exercises together, and ensure consistency across different exercise groups conducted in different centers. Each participant underwent the pre- and post-intervention assessment including 30-s chair stand repetitions, five-time chair stand duration, 4-m comfortable walk time, standing static balance level, 6-min walk test, and short physical performance battery score. These variables were compared within each group at pre- and post-intervention stages, and they were also compared between the two groups. Results: A total of 180 participants were enrolled in 16 subcenters, including 160 participants in the exercise group and 20 participants in the control group. After 8 weeks of exercise training, there were significant improvements in their physical performance including 30-s chair stand repetitions and five-time chair stand duration, 4-m comfortable walk time and also 6-min walk test, within the exercise group (all P < 0.05). Approximately 39% of the participants in the exercise group also showed significant improvement in standing static balance level. No significant differences were found when compared with the control group participants who did not have any regular exercise participation. Conclusion: A specially designed video-based exercise program has demonstrated some positive effects on physical and balance performance after 8 weeks of training among adults with intellectual disability.

Patients with Adolescent Idiopathic Scoliosis Have Higher Metabolic Cost during High-Intensity Interval Training.

BACKGROUND: Patients with adolescent idiopathic scoliosis (AIS) are found to have a lower level of physical activity, and may have reduced exercise capacity due to spinal deformity. Previous study showed the benefits of high-intensity interval training (HIIT), named E-Fit, which is specifically designed for patients with AIS to improve musculoskeletal health and psychological well-being. To optimize the beneficial effects of training, the current study aimed to investigate the appropriate exercise intensity and metabolic demand in patients with AIS when performing E-Fit. METHODS: In all, 22 female subjects, 10 diagnosed with AIS and 12 gender-matched healthy controls, aged between 10 and 16 years, were recruited. Subjects were instructed to perform two trials of a seven min E-Fit. Breath-by-breath gas exchange parameters including oxygen consumption (VO2), heart rate (HR) and the rate of perceived exertion (PRE) were measured during exercise. Demographic data and clinical features of AIS and body composition were obtained. Metabolic demand between AIS and control groups was compared using MANOVA with covariates adjustment. RESULTS: Patients with AIS had an earlier onset of menarche (p = 0.01), higher visceral adipose tissue (p = 0.04) and percentage body fat (p = 0.03) as compared to controls. Patients with AIS showed a significantly higher adjusted means of VO2 average in both the first (p = 0.014) and second trials (p = 0.011) of E-Fit. The adjusted mean of the highest measured VO2 was higher than healthy controls and reached statistical significance in the second trial (p = 0.004). Both the AIS and control group exercised at a similar percentage of VO2 peak (64.26% vs. 64.60%). CONCLUSION: Patients with AIS showed higher oxygen consumption during E-Fit than heathy controls, which might indicate a higher metabolic cost. Patients with AIS could carry out exercise at a moderate exercise intensity similar to that of healthy controls, but special considerations in designing an exercise program, such as frequent rest intervals, would be useful to avoid fatigue among patients with AIS.

Corrigendum: A Practical Guide to Sparse k-Means Clustering for Studying Molecular Development of the Human Brain.

[This corrects the article DOI: 10.3389/fnins.2021.668293.].

A Practical Guide to Sparse k-Means Clustering for Studying Molecular Development of the Human Brain.

Studying the molecular development of the human brain presents unique challenges for selecting a data analysis approach. The rare and valuable nature of human postmortem brain tissue, especially for developmental studies, means the sample sizes are small (n), but the use of high throughput genomic and proteomic methods measure the expression levels for hundreds or thousands of variables [e.g., genes or proteins (p)] for each sample. This leads to a data structure that is high dimensional (p ≫ n) and introduces the curse of dimensionality, which poses a challenge for traditional statistical approaches. In contrast, high dimensional analyses, especially cluster analyses developed for sparse data, have worked well for analyzing genomic datasets where p ≫ n. Here we explore applying a lasso-based clustering method developed for high dimensional genomic data with small sample sizes. Using protein and gene data from the developing human visual cortex, we compared clustering methods. We identified an application of sparse k-means clustering [robust sparse k-means clustering (RSKC)] that partitioned samples into age-related clusters that reflect lifespan stages from birth to aging. RSKC adaptively selects a subset of the genes or proteins contributing to partitioning samples into age-related clusters that progress across the lifespan. This approach addresses a problem in current studies that could not identify multiple postnatal clusters. Moreover, clusters encompassed a range of ages like a series of overlapping waves illustrating that chronological- and brain-age have a complex relationship. In addition, a recently developed workflow to create plasticity phenotypes (Balsor et al., 2020) was applied to the clusters and revealed neurobiologically relevant features that identified how the human visual cortex changes across the lifespan. These methods can help address the growing demand for multimodal integration, from molecular machinery to brain imaging signals, to understand the human brain's development.

Effect of EMG-biofeedback robotic-assisted body weight supported treadmill training on walking ability and cardiopulmonary function on people with subacute spinal cord injuries - a randomized controlled trial.

BACKGROUND: Body weight supported treadmill training (BWSTT) is a frequently used approach for restoring the ability to walk after spinal cord injury (SCI). However, the duration of BWSTT is usually limited by fatigue of the therapists and patients. Robotic-assisted body weight supported treadmill training (RABWSTT) was developed to tackle the aforesaid limitation. Currently, limited randomized controlled trials are available to investigate its effectiveness, especially on cardiopulmonary function. The aim of this two-arm, parallel-group randomized controlled trial is to examine the feasibility of adapting an EMG-biofeedback system for assist-as-needed RABWSTT and its effects on walking and cardiopulmonary function in people with SCI. METHODS: Sixteen incomplete SCI subjects were recruited and randomly allocated into an intervention group or control group. The intervention group received 30 min of RABWSTT with EMG biofeedback system over the vastus lateralis muscle to enhance active participation. Dose equivalent passive lower limbs mobilization exercise was provided to subjects in the control group. RESULTS: Significant time-group interaction was found in the Walking Index for Spinal Cord Injury version II (WISCI II) (p = 0.020), Spinal Cord Independence Measure version III (SCIM III) mobility sub-score (p < 0.001), bilateral symmetry (p = 0.048), maximal oxygen consumption (p = 0.014) and peak expiratory flow rate (p = 0.048). Wilcoxon signed-rank test showed that the intervention group had significant improvement in the above-mentioned outcomes after the intervention except WISCI II, which also yielded marginal significance level. CONCLUSION: The present study demonstrated that the use of EMG-biofeedback RABWSTT enhanced the walking performance for SCI subjects and improve cardiopulmonary function. Positive outcomes reflect that RABSTT training may be able to enhance their physical fitness. TRIAL REGISTRATION: The study protocol was approved by the Research Ethics Committee (Kowloon Central/ Kowloon East), Hospital Authority on 6 December 2013, and the Human Subjects Ethics Sub-committee of The Hong Kong Polytechnic University on 15 May 2013, with reference numbers KC/KC-13-0181/ER-2 and HSEARS20130510002 respectively. The study was registered in ClinicalTrials.gov on 20 November 2013, with reference number NCT01989806 .).

Efficacy of Biophysical Energies on Healing of Diabetic Skin Wounds in Cell Studies and Animal Experimental Models: A Systematic Review.

We have systematically assessed published cell studies and animal experimental reports on the efficacy of selected biophysical energies (BPEs) in the treatment of diabetic foot ulcers. These BPEs include electrical stimulation (ES), pulsed electromagnetic field (PEMF), extracorporeal shockwave (ECSW), photo energies and ultrasound (US). Databases searched included CINAHL, MEDLINE and PubMed from 1966 to 2018. Studies reviewed include animal and cell studies on treatment with BPEs compared with sham, control or other BPEs. Information regarding the objective measures of tissue healing and data was extracted. Eighty-two studies were eventually selected for the critical appraisal: five on PEMF, four each on ES and ECSW, sixty-six for photo energies, and three about US. Based on the percentage of original wound size affected by the BPEs, both PEMF and low-level laser therapy (LLL) demonstrated a significant clinical benefit compared to the control or sham treatment, whereas the effect of US did not reveal a significance. Our results indicate potential benefits of selected BPEs in diabetic wound management. However, due to the heterogeneity of the current clinical trials, comprehensive studies using well-designed trials are warranted to confirm the results.

A Tailor-Made Exercise Program for Improving Balance and Mobility in Older Adults With Type 2 Diabetes.

Effectiveness of an exercise program designed for improving postural control and mobility in older adults with type 2 diabetes was investigated. Ninety-three adults 65 or older diagnosed with type 2 diabetes and able to walk unaided were recruited. The intervention group received exercise training focused on ankle strengthening and mobility twice per week for 10 weeks. The control group did not participate in any exercise program. After 10 weeks, the intervention group showed significantly greater improvement in the mean Sensory Organization Test composite score (4.4 vs. 0.3; p = 0.01) as well as visual ratio (0.1 vs. 0.002; p = 0.01) and vestibular ratio (0.1 vs. 0.003; p < 0.001) than the control group after adjusting for covariates. A greater trend of improvement in the Timed Up and Go and Single-Leg Stance Test was also found in the intervention group. Exercise training focusing on the ankle is effective in enhancing the postural stability of older adults with type 2 diabetes and can potentially be effective in improving single-leg standing balance and mobility. [Journal of Gerontological Nursing, 44(2), 41-48.].

Robot-Assisted Training for People With Spinal Cord Injury: A Meta-Analysis.

OBJECTIVE: To investigate the effects of robot-assisted training on the recovery of people with spinal cord injury (SCI). DATA SOURCES: Randomized controlled trials (RCTs) or quasi-RCTs involving people with SCI that compared robot-assisted upper limbs or lower limbs training with a control of other treatment approach or no treatment. We included studies involving people with complete or incomplete SCIs. STUDY SELECTION: We searched MEDLINE, CINAHL, Cochrane Central Register of Controlled Trials (Cochrane Library), and Embase to August 2016. Bibliographies of relevant articles on the effect of body-weight-supported treadmill training on subjects with SCI were screened to avoid missing relevant articles from the search of databases. DATA EXTRACTION: All kinds of objective assessments concerning physical ability, mobility, and/or functional ability were included. Assessments could be clinical tests (ie, 6-minute walk test, FIM) or laboratory tests (ie, gait analysis). Subjective outcome measures were excluded from this review. DATA SYNTHESIS: Eleven RCT studies involving 443 subjects were included in the study. Meta-analysis was performed on the included studies. Walking independence (3.73; 95% confidence interval [CI], -4.92 to -2.53; P<.00001; I2=38%) and endurance (53.32m; 95% CI, -73.15 to -33.48; P<.00001; I2=0%) were found to have better improvement in robot-assisted training groups. Lower limb robot-assisted training was also found to be as effective as other types of body-weight-supported training. There is a lack of upper limb robot-assisted training studies; therefore, performing a meta-analysis was not possible. CONCLUSIONS: Robot-assisted training is an adjunct therapy for physical and functional recovery for patients with SCI. Future high-quality studies are warranted to investigate the effects of robot-assisted training on functional and cardiopulmonary recovery of patients with SCI.

Direct comparison of gluco-oligosaccharide oxidase variants and glucose oxidase: substrate range and H2O2 stability.

Glucose oxidase (GO) activity is generally restricted to glucose and is susceptible to inactivation by H2O2. By comparison, the Y300A variant of gluco-oligosaccharide oxidase (GOOX) from Sarocladium strictum showed broader substrate range and higher H2O2 stability. Specifically, Y300A exhibited up to 40 times higher activity on all tested sugars except glucose, compared to GO. Moreover, fusion of the Y300A variant to a family 22 carbohydrate binding module from Clostridium thermocellum (CtCBM22A) nearly doubled its catalytic efficiency on glucose, while retaining significant activity on oligosaccharides. In the presence of 200 mM of H2O2, the recombinant CtCBM22A_Y300A retained 80% of activity on glucose and 100% of activity on cellobiose, the preferred substrate for this enzyme. By contrast, a commercial glucose oxidase reported to contain ≤0.1 units catalase/ mg protein, retained 60% activity on glucose under the same conditions. GOOX variants appear to undergo a different mechanism of inactivation, as a loss of histidine instead of methionine was observed after H2O2 incubation. The addition of CtCBM22A also promoted functional binding of the fusion enzyme to xylan, facilitating its simultaneous purification and immobilization using edible oat spelt xylan, which might benefit the usage of this enzyme preparation in food and baking applications.

Effects of pulsed electromagnetic fields on peripheral blood circulation in people with diabetes: A randomized controlled trial.

Cutaneous blood flow provides nourishment that plays an essential role in maintaining skin health. We examined the effects of pulsed electromagnetic fields (PEMFs) on cutaneous circulation of dorsal feet. Twenty-two patients with diabetes mellitus (DM) and 21 healthy control subjects were randomly allocated to receive either PEMFs or sham PEMFs (0.5 mT, 12 Hz, 30 min). Blood flow velocity and diameter of the small vein were examined by using ultrasound biomicroscopy; also, microcirculation at skin over the base of the 1st metatarsal bone (Flux1) and distal 1st phalange (Flux2) was measured by laser Doppler flowmetry before and after intervention. Results indicated that PEMFs produced significantly greater changes in blood flow velocity of the smallest observable vein than did sham PEMFs (both P < 0.05) in both types of subjects. However, no significant difference was found in changes of vein diameter, nor in Flux1 and Flux2, between PEMFs and sham PEMFs groups in subjects with or without DM. We hypothesized that PEMFs would increase blood flow velocity of the smallest observable vein in people with or without DM. Bioelectromagnetics. 37:290-297, 2016. © 2016 Wiley Periodicals, Inc.

Pulsed electromagnetic field therapy promotes healing and microcirculation of chronic diabetic foot ulcers: a pilot study.

OBJECTIVE: To examine the effects of pulsed electromagnetic field (PEMF) therapy on promoting the healing and microcirculation of chronic diabetic foot ulcers. DESIGN: A randomized, double-blind, placebo-controlled clinical trial on a homogenous subset of chronic diabetic foot ulcers. SETTING: Hospital and university. PATIENTS: Thirteen subjects (7 in the PEMF group and 6 in the control group) diagnosed with type 2 diabetes and had unsatisfactory healing of ulcer(s) in the preceding 4 weeks were recruited. INTERVENTIONS: Subjects were randomly allocated to receive either active PEMF therapy (duration: 60 minutes; frequency: 12 Hz; intensity: 12 Gauss) or nonactive PEMF for 14 sessions within 3 weeks. MAIN OUTCOME MEASURES: Assessment on wound closure, wound depth, and microcirculation were performed at the baseline, end of the treatment period, and 1-month follow-up. MAIN RESULTS: By the end of the treatment period, there was an 18% decrease in wound size in the active PEMF group as compared with a 10% decrease in the control group. The PEMF group demonstrated significant cumulative increase in cutaneous capillary blood velocity (by 28%) and 14% increase in capillary diameter. In contrast, the control group showed a decrease in both capillary blood velocity and diameter. CONCLUSION: In this study, PEMF therapy seemed to accelerate wound healing and improve microcirculation.

An innovative ultrasound foot scanner system for measuring the change in biomechanical properties of plantar tissue from sitting to standing.

The present study investigated the reliability of an innovative ultrasound foot scanner system in assessing the thickness and stiffness of plantar soft tissue and the comparison of stiffness and thickness in sitting and standing. Fifteen young healthy individuals were examined. The target sites on the foot sole for investigation included the heel pad, the fifth metatarsal head, the second metatarsal head, the first metatarsal head, and the pulp of the hallux. The test (day 1) and retest (day 2) were performed 1 week apart at the exact time with humidity and temperature of the assessment room under control. The thickness and stiffness of the plantar soft tissue obtained in sitting and standing positions on day 1 were used for comparison. The results showed significant test-retest reliability [intraclass correlation coefficient(3,2)>0.90, P<0.001] at all five sites in both sitting and standing positions. When changing from sitting to standing, the plantar soft tissue became significantly thinner (with decrease ranging from 10 to 14% at various sites) and stiffer (with increase ranging from 123 to 164% at various sites, all P<0.05). The present innovative system is a reliable device for the measurement of the thickness and stiffness of plantar soft tissue in either the sitting or the standing position. The change in positions from sitting to standing resulted in a significant thinning and stiffening of plantar soft tissues. This system could be a potential clinical device to monitor the biomechanical properties of plantar tissue in the elderly or in patients with diseases such as diabetes to estimate the risk of developing foot ulcer or other foot complications.

Solving a four-destination traveling salesman problem using Escherichia coli cells as biocomputers.

The Traveling Salesman Problem involves finding the shortest possible route visiting all destinations on a map only once before returning to the point of origin. The present study demonstrates a strategy for solving Traveling Salesman Problems using modified E. coli cells as processors for massively parallel computing. Sequential, combinatorial DNA assembly was used to generate routes, in the form of plasmids made up of marker genes, each representing a path between destinations, and short connecting linkers, each representing a given destination. Upon growth of the population of modified E. coli, phenotypic selection was used to eliminate invalid routes, and statistical analysis was performed to successfully identify the optimal solution. The strategy was successfully employed to solve a four-destination test problem.

Effects of relative embodiment in lexical and semantic processing of verbs.

Research examining semantic richness effects in visual word recognition has shown that multiple dimensions of meaning are activated in the process of word recognition (e.g., Yap et al., 2012). This research has, however, been limited to nouns. In the present research we extended the semantic richness approach to verb stimuli in order to investigate how verb meanings are represented. We characterized a dimension of relative embodiment for verbs, based on the bodily sense described by Borghi and Cimatti (2010), and collected ratings on that dimension for 687 English verbs. The relative embodiment ratings revealed that bodily experience was judged to be more important to the meanings of some verbs (e.g., dance, breathe) than to others (e.g., evaporate, expect). We then tested the effects of relative embodiment and imageability on verb processing in lexical decision (Experiment 1), action picture naming (Experiment 2), and syntactic classification (Experiment 3). In all three experiments results showed facilitatory effects of relative embodiment, but not imageability: latencies were faster for relatively more embodied verbs, even after several other lexical variables were controlled. The results suggest that relative embodiment is an important aspect of verb meaning, and that the semantic richness approach holds promise as a strategy for investigating other aspects of verb meaning.

Pulsed electromagnetic fields (PEMF) promote early wound healing and myofibroblast proliferation in diabetic rats.

Reduced collagen deposition possibly leads to slow recovery of tensile strength in the healing process of diabetic cutaneous wounds. Myofibroblasts are transiently present during wound healing and play a key role in wound closure and collagen synthesis. Pulsed electromagnetic fields (PEMF) have been shown to enhance the tensile strength of diabetic wounds. In this study, we examined the effect of PEMF on wound closure and the presence of myofibroblasts in Sprague-Dawley rats after diabetic induction using streptozotocin. A full-thickness square-shaped dermal wound (2 cm × 2 cm) was excised aseptically on the shaved dorsum. The rats were randomly divided into PEMF-treated (5 mT, 25 Hz, 1 h daily) and control groups. The results indicated that there were no significant differences between the groups in blood glucose level and body weight. However, PEMF treatment significantly enhanced wound closure (days 10 and 14 post-wounding) and re-epithelialization (day 10 post-wounding), although these improvements were no longer observed at later stages of the wound healing process. Using immunohistochemistry against α-smooth muscle actin (α-SMA), we demonstrated that significantly more myofibroblasts were detected on days 7 and 10 post-wounding in the PEMF group when compared to the control group. We hypothesized that PEMF would increase the myofibroblast population, contributing to wound closure during diabetic wound healing.

The potential influence of diabetic history on peripheral blood flow in superficial skin.

Vascular complication occurrence increases with the duration of diabetes. The present study compared the peripheral blood flow in superficial skin among subjects with a short or long history of diabetes as compared to a healthy control group. Thirty-two subjects with type 2 diabetes were recruited and stratified into a group of those with a short history of diabetes (i.e., shorter than or equal to ten years) and a group of those with a long history of diabetes (i.e., over ten years). Thirty-eight healthy age-matched volunteers were recruited as the control. The blood flow velocity of the superficial small veins in the skin over the base of the 1st metatarsal bone was measured by ultrasound biomicroscopy. The blood flow (flux) of the cutaneous microcirculation over the base of the 1st metatarsal bone (Flux1) and over the distal 1st phalanges bone (Flux2) was measured by Laser Doppler Flowmetry. One-way analysis of variance was used to analyze the differences between the three groups. No significant between-group difference was found in any outcome (all P>0.05). However, the group with a long history of diabetes tended to have a more reduced blood flow than did the healthy control group. A difference was found between the diabetes group and the healthy control in any outcomes. A trend of hemodynamic changes in the three groups was observed, but the difference did not reach significance. Ten years seems to be the time when angiopathy becomes noticeable among people with diabetes.

Risk of fall for people with diabetes.

PURPOSE: To examine the risk of fall for people with diabetes compared with healthy control subjects. Correlation between tactile sensation and postural control was examined for subjects with diabetes. METHODS: Subjects with type 2 diabetes were classified into two groups: (i) diabetes without neuropathy (n = 23) and (ii) diabetic peripheral neuropathy (DPN) (n = 9). Age-matched healthy control subjects (n = 32) were recruited. Tactile sensation, equilibrium scores (ES), strategy scores and sensory analysis scores from the Sensory Organization Test (SOT) were compared among the groups. RESULTS: Subjects with diabetes without neuropathy demonstrated impaired postural control upon the disruption of somatosensory inputs. Subjects with DPN lost balance upon being deprived of visual inputs. A decrease in tactile sensation was associated with a decrease in the ESs in all subjects with diabetes (r = -0.35 to -0.77; p < 0.05), and they tend to use more hip strategy for postural control upon being deprived of visual inputs. CONCLUSIONS: Different postural control strategies are adopted by various subgroups of subjects with diabetes. Subjects with DPN demonstrated a significant shift from ankle to hip strategies for balance tests when vision was deprived. Implications for Rehabilitation The severity of diabetic peripheral neuropathy (DPN) is associated with the risk of fall. Different compensatory strategies in balance control have been adopted by different subgroups of people with diabetes. In order to minimize the risk of fall, specific balance training program should be offered to different subgroups of people with diabetes. The balance training should emphasize on optimizing the competence of their existing compensatory postural control strategies.

Electrophysical therapy for managing diabetic foot ulcers: a systematic review.

To systematically assess published reports on the efficacy of electrophysical therapy in the treatment of diabetic foot ulcers, including electrical stimulation, low-level laser therapy, therapeutic ultrasound and electromagnetic therapy. Databases searched included MEDLINE, CINAHL, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) from 1966 to 2011. Studies reviewed included only randomised controlled trials (RCTs) on treatment with electrophysical modalities compared with sham, conventional treatment or other electrophysical modalities. Information extracted were objective measures of healing and data useful for the calculation of effect size. Eight RCTs were eventually included in the critical appraisal, with a combined total of 325 participants. Five studies were conducted on electrical stimulation, two on phototherapy and one on ultrasound. All studies reported that the experimental group was significantly more favourable than the control or sham group. The pooled estimate of the number of healed ulcers of the three studies on electrical stimulation compared to the control or sham electrical stimulation showed statistical significance [mean difference of 2·8 (95% CI = 1·5-5·5, P = 0·002] in favour of electrical stimulation. The results indicated potential benefit of using electrophysical therapy for managing diabetic foot ulcers. However, due to the small number of trials ever conducted, the possibility of any harmful effects cannot be ruled out, and high-quality trials with larger sample sizes are warranted.

Do the biomechanical properties of the ankle-foot complex influence postural control for people with Type 2 diabetes?

BACKGROUND: The ankle-foot complex plays an important role in the mechanics of postural control. The objectives of this study were to compare the biomechanical properties of the ankle-foot complex of people with diabetes who had or did not have peripheral neuropathy with those healthy individuals; and to examine its correlation with postural control. METHODS: A total of 64 individuals participated in this study: 9 people with diabetic peripheral neuropathy, 23 diabetes without neuropathy, and 32 healthy controls. A hand-held ultrasound indentation system was used to assess the soft tissue biomechanical properties of the ankle-foot complex. The Sensory Organization test was performed using The Smart EquiTest system to assess postural control. FINDINGS: The soft tissue of the Achilles tendon was significantly thickened in all individuals with diabetes (P<0.001), and was associated with the vestibular ratio (r=0.40; P<0.05). The Young's modulus of the plantar soft tissue was significantly increased in the diabetic neuropathy group (all P<0.05). Also, the Young's modulus of the plantar soft tissue at the first metatarsal head was positively correlated with the somatosensory ratio (r=0.46; P<0.05) and visual ratio (r=0.39; P<0.05). INTERPRETATION: Diabetic patients with or without neuropathy had a thicker Achilles tendon and stiffer plantar soft tissue than the healthy control. Changes in the biomechanical properties of the ankle-foot complex were correlated with the use of vestibular, somatosensory or visual inputs to maintain balance in individuals with diabetes.

The effect of aging on the biomechanical properties of plantar soft tissues.

BACKGROUND: Foot problems are common in elderly people and stiffened plantar soft tissues may lead to ulceration in people with Diabetes Mellitus. It is unclear how the biomechanical properties of plantar soft tissues change with advancing age. Therefore, this study examined the age-related differences in the biomechanical properties of plantar soft tissues. METHODS: Sixty healthy volunteers without foot problems, aged from 41 to 83 years, were examined using tissue ultrasound palpation system. The thickness and stiffness of the plantar soft tissues under the big toe, first metatarsal head, third metatarsal head, fifth metatarsal head, and heel were measured. The load-deformation curve of the plantar soft tissues was plotted. The correlation between age and biomechanical properties was examined and comparisons were made between four age groups. FINDINGS: The mean stiffness of the plantar soft tissues at big toe, first metatarsal head, third metatarsal head, fifth metatarsal head, and the heel significantly increased with age (P<0.001). The plantar soft tissues at the heel were the thickest (P<0.001), with the plantar soft tissue tending to be increasingly thicker with age, although there was no statistical significance. Strong positive correlations between age and stiffness of the plantar soft tissues were found at the big toe (r=0.608), first metatarsal head (r=0.549), third metatarsal head (r=0.657), fifth metatarsal head (r=0.633), and heel (r=0.584) (all P<0.001). INTERPRETATION: The loss of compliance in the plantar soft tissues may be one of the factors responsible for the higher incidence of foot problems in elderly individuals.