Interactive Game-Based Platform System for Assessing and Improving Posture Control in the Elderly.

Inadequate response to balance perturbations lead to posture instability in the elderly. The fall risks are increased by a reduced capacity to control the center of pressure (COP) displacement within the safety limit of the supporting base. This study developed an interactive evaluation and training platform. The system incorporated a computerized program with instantaneous force plate evaluation. Ten young subjects underwent a baseline evaluation and twenty-nine community-dwelling elderly received pre- and post-intervention testing. The ability to reach the stability limit was assessed by measuring the maximum voluntary excursion of the COP in anterior-posterior and medial-lateral directions. Functional mobility tests including Berg Balance Scale, Timed-Up-and-Go and functional reach were used as functional outcomes. The experimental group (n = 15) received a 40 min intervention three times a week for six weeks. The interactive game-based training focused on multi-directional weight shifting by tracing a COPcontrolled target to challenge an individual's stability limit. The control group (n = 14) maintained daily activities as usual. The young group revealed a superior COP displacement through active ankle control than the elderly, especially in the anterior-posterior direction. The experimental group improved their COP displacement control more in the medial-lateral direction due to the predominant side-to-side gameplay movement. The functional outcome measures were also significantly improved after training. Using the COPcontrolled game-based program, the stability limit was challenged to facilitate dynamic posture control by an incremental increase in self-initiated perturbations. The platform system could assist in transferring the immediate training effects into daily functional mobility in the elderly.

Microvascular reactivity using laser Doppler measurement in type 2 diabetes with subclinical atherosclerosis.

Microangiopathy should be noted in diabetes with subclinical vascular diseases. Little is known about whether various surrogate markers of systemic arterial trees exacerbate simultaneously in preclinical atherosclerosis. To clarify the association of skin microvascular reactivity with arterial stiffness is essential to elucidating early atherosclerotic changes. The post-occlusive reactive hyperemia of skin microcirculation was evaluated in 27 control and 65 type 2 diabetic subjects, including 31 microalbuminuria (MAU) and 34 normoalbuminuria (NAU) patients. The laser Doppler skin perfusion signals were transformed into three frequency intervals for the investigation of endothelial, neurogenic, and myogenic effects on basal and reactive flow motion changes. The analysis of spectral intensity and distribution provided insight into potential significance of microvascular regulation in subclinical atherosclerotic diseases. Systemic arterial stiffness was studied by the brachial ankle pulse wave velocity (baPWV). Following occlusive ischemia, the percent change of endothelial flow motion was lower in MAU than in NAU and control groups. The MAU group revealed a relative increase in myogenic activity and a decrease in endothelial activity in normalized spectra. The baPWV showed more significant associations with reactive endothelial change (r = - 0.48, P < 0.01) and normalized myogenic value (r = - 0.37, P < 0.05) than diabetes duration and HbA1c. By multivariate regression analysis, only endothelial vasomotor changes independently contributed to the decreased baPWV (OR 3.47, 95% CI 1.63-7.42, P < 0.05). Impaired microcirculatory control is associated with increased arterial stiffness in preclinical atherosclerosis. To identify the early manifestations is necessary for at-risk patients to prevent from further vascular damage.

Functional Assessment of 3D-Printed Multifunction Assistive Hand Device for Chronic Stroke Patients.

Patients with chronic stroke often have difficulty opening their hands and performing grasping movements. Several passive hand orthoses for assisting hand rehabilitation have been developed and demonstrated to be clinically effective. However, current devices have several limitations, such as supporting only a single grasping motion and using an abnormal grasping posture. Therefore, this study developed a three-dimensional (3D)-printed multifunctional hand device (3DP-MFHD) to solve these problems and evaluated the feasibility of using the device during home rehabilitation. Six participants were enrolled, and each of them was provided with the 3DP-MFHD. In addition to a task-oriented training course, the participants were asked to train at home for 4 weeks for at least 5 days per week and 40 min per day. The results revealed that hand grip force increased by 36.1%, lateral pinch force increased by 17.6%, and the Action Research Arm Test score increased by 54.1%. The 3DP-MFHD is a promising means to facilitate hand rehabilitation and improve hand strength and function in patients with chronic stroke. The 3DP-MFHD can be used as part of home rehabilitation.

Biomechanical Evaluation and Strength Test of 3D-Printed Foot Orthoses.

Foot orthoses (FOs) are commonly used as interventions for individuals with flatfoot. Advances in technologies such as three-dimensional (3D) scanning and 3D printing have facilitated the fabrication of custom FOs. However, few studies have been conducted on the mechanical properties and biomechanical effects of 3D-printed FOs. The purposes of this study were to evaluate the mechanical properties of 3D-printed FOs and determine their biomechanical effects in individuals with flexible flatfoot. During mechanical testing, a total of 18 FO samples with three orientations (0°, 45°, and 90°) were fabricated and tested. The maximum compressive load and stiffness were calculated. During a motion capture experiment, 12 individuals with flatfoot were enrolled, and the 3D-printed FOs were used as interventions. Kinematic and kinetic data were collected during walking by using an optical motion capture system. A one-way analysis of variance was performed to compare the mechanical parameters among the three build orientations. A paired t-test was conducted to compare the biomechanical variables under two conditions: walking in standard shoes (Shoe) and walking in shoes embedded with FOs (Shoe+FO). The results indicated that the 45° build orientation produced the strongest FOs. In addition, the maximum ankle evertor and external rotator moments under the Shoe+FO condition were significantly reduced by 35% and 16%, respectively, but the maximum ankle plantar flexor moments increased by 3%, compared with the Shoe condition. No significant difference in ground reaction force was observed between the two conditions. This study demonstrated that 3D-printed FOs could alter the ankle joint moments during gait.

Biomechanical Evaluation of Three-Dimensional Printed Dynamic Hand Device for Patients With Chronic Stroke.

Provision of adequate task-oriented training can be difficult for stroke survivors with limited hand movement. The current passive devices are mainly intended for gross grasp and release training. Additional assistive devices are required to improve functional opposition. This paper investigated the functional recovery of chronic stroke patients after using a three-dimensional (3D) printed dynamic hand device (3D-DHD) as an adjunct to conducting a task-oriented approach (TOA). Ten participants were randomly assigned to either the 3D-DHD group (n = 5) or the control group (n = 5). The TOA was used for the 3D-DHD group by using the 3D-DHD twice a week for four weeks, followed by a two-week home program. Only the TOA was used for the control group. The outcome measures, including the box and blocks test (BBT) of manual dexterity and prehensile strength, were conducted at baseline and at follow-up at four and six weeks later. The 3D-DHD group exhibited significantly superior improvements to the control group in the BBT and the palmar pinch force test. Both the groups had significant within-group improvements in the BBT and in all strength measures compared with baseline measurements. The use of 3D-DHD could position stroke-affected hands in coordinated functional opposition and had the potential to facilitate manual dexterity and advanced prehensile movement.

Microcirculatory vasomotor changes are associated with severity of peripheral neuropathy in patients with type 2 diabetes.

Systemic microvascular complications are related to the presence of diabetic neuropathy. This study investigated the associations of blood flow oscillations with peripheral neuropathy in 25 controls and 3 diabetic groups including clinical (24), subclinical (27) and without neuropathy (26). Laser Doppler skin perfusion was transformed into three low-frequency subintervals corresponding to endothelial, neurogenic and myogenic vasomotor controls. The average vasomotion was significantly reduced in clinical neuropathy group and characterized by endothelial and neural but not smooth muscle-related changes. The normalized spectrums revealed a relative increase of myogenic and decrease of neurogenic activity in subclinical neuropathy group. The myogenic component showed a statistically inverse correlation with postural fall in systolic blood pressure (r = -0.32, p < 0.01). The diabetic patients with decreased low-frequency vasomotor responses were associated with increased odds ratio of peripheral neuropathy [odds ratio = 3.51 (95% confidence interval = 1.19-10.31), p = 0.02]. This study elucidated possible interaction between impaired microvascular flow motion and diabetic peripheral neuropathy. The vasomotor changes of skin microcirculation could be detected even in the absence of overt cardiovascular dysfunction.

Biomechanical analysis of foot with different foot arch heights: a finite element analysis.

Clinically, different foot arch heights are associated with different tissue injuries to the foot. To investigate the possible factors contributing to the difference in foot arch heights, previous studies have mostly measured foot pressure in either low-arched or high-arched feet. However, little information exists on stress variation inside the foot with different arch heights. Therefore, this study aimed to implement the finite element (FE) method to analyse the influence of different foot arches. This study established a 3D foot FE model using software ANSYS 11.0. After validating the FE model, this study created low-arched, high-arched and normal-arched foot FE models. The FE analysis found that both the stress and strain on the plantar fascia and metatarsal were higher in the high-arched foot, whereas the stress and strain on the calcaneous, navicular and cuboid were higher in low-arched foot. Additionally, forefoot pressure was increased with an increase in arch height.

Impaired microvascular flow motion in subclinical diabetic feet with sudomotor dysfunction.

Impaired cutaneous blood flow and sweating dysfunction might be among the earliest manifestations of diabetic autonomic neuropathy. This study assessed the pathophysiological basis underlying skin vasomotion changes and their relation with progressive sudomotor dysfunction and other autonomic and somatic measures in subclinical diabetic feet. Laser Doppler skin perfusion was assessed on 68 diabetic and 25 control subjects. The low-frequency vasomotion was transformed into three frequency intervals 0.0095-0.021, 0.021-0.052 and 0.052-0.145 Hz, respectively, for the investigation of endothelial, neurogenic and myogenic effects on microcirculatory alterations. The diabetic patients were categorized into three groups by increasing severity of sudomotor dysfunction: SSR+ (sympathetic skin response present; 27 patients), SSR- (SSR absent; 23 patients) and at-risk (SSR absent and of preulcerative cracked skin; 18 patients). All diabetic patients underwent nerve conduction and cardiovascular autonomic studies. The total spectral and endothelial activity was significantly decreased only in the at-risk group. The SSR- group had lower neurogenic vasomotion than the SSR+ group (p<0.05). Although no statistical difference was noted between any group in absolute myogenic spectrum, the SSR- group had higher normalized myogenic activity than the SSR+ group (p<0.01). The larger drop in orthostatic pressure was paralleled by a reduction in the myogenic amplitude (r=-0.33, p<0.01). These results suggested that early impairment of low-frequency flow motion correlated closely with the presence of sudomotor dysfunction of subclinical feet mainly in neurogenic and endothelial components. Impaired systemic vascular tone as manifested by orthostatic hypotension was proportional to the degree of myogenic dysregulation in diabetic patients.

Improving preventive foot care for diabetic patients participating in group education.

BACKGROUND: Diabetic foot care has yet to be enhanced in a universal health-care system in which specialized podiatric medical services are unavailable. This baseline assessment surveyed diabetic patients attending group education to improve current foot-care practices. METHODS: Of 302 diabetic patients receiving usual outpatient care, 155 received group patient education on general diabetes-related information, which included foot care and an annual checkup by a diabetes association during the previous 2 years, and 147 did not. Patient foot-care behaviors, physician practice patterns, and patient self-perceived foot risk as cross-checked with the neurologic and vascular assessments were investigated by conducting retrospective medical record reviews and structured interviews. RESULTS: More than half of the patients in both groups reported inappropriate self-care behaviors (eg, walking barefoot and heating or soaking their feet). The percentages of patients receiving documented examinations and referrals for foot problems were low in both groups and were not significantly different. Among at-risk patients, 56% of the diabetes association group but only 30% of the non-diabetes association group perceived themselves to be at risk for future foot problems (P<.01). CONCLUSIONS: Many diabetic patients were not offered adequate foot-specific information during group lectures, even those with high-risk foot problems. To improve this, combining caregiver and patient education in foot-care practices is important, and systems of networked multidisciplinary professionals are believed to be needed, particularly in delivering customized interventions to at-risk patients based on the initial evaluation.

Effects of varying material properties on the load deformation characteristics of heel cushions.

Various insole materials were used in attenuation of heel-strike impact. This study presented a compression test to investigate the deformation characteristics of common heel cushions. There were two materials (thermoplastic elastomer "TPE" and silicone) with three hardness and six thickness being analyzed. They underwent consecutive loading-unloading cycles with a load control mode. The displacement of material thickness was recorded during cyclic compression being applied and released from 0 to 1050 N. The energy input, return and dissipation were evaluated based on the load deformation curves when new and after repeated compression. The TPE recovered more deformed energy and thickness than the silicone after the first loading cycle. The silicone would preserve more strain energy with increasing its hardness for the elastic recovery in the unloading process. The deformed energy was decreased as the original thickness did not completely recover under cyclic tests. The reduction in hysteresis area was gradually converged within 20 cycles. The silicone attenuated more impact energy in the initial cycles, but its energy dissipation was reduced after repeated loading. To increase hardness or thickness should be considered to improve resilience or accommodate persistent compression without flattening. The careful selection of cushion materials is imperative to meet individual functional demands.

The impact of overt and subclinical hyperthyroidism on skeletal muscle.

OBJECTIVE: Patients with overt hyperthyroidism (OH) commonly have proximal limb muscle weakness that improves after correction of hyperthyroidism. It is unclear, however, if patients with milder degrees of hyperthyroidism (referred to as subclinical hyperthyroidism or SCH) may also have a degree of muscle weakness. This may have clinical relevance as SCH patients are often elderly and may therefore have concurrent sarcopenia of aging and would represent a previously unrecognized complication of SCH. DESIGN: We measured both thigh strength and cross-sectional area in patients with OH (n = 30) or SCH (n = 24), both prior to treatment of hyperthyroidism and again at 6-9 months after the restoration of a euthyroid state. Euthyroid controls (n = 48) were studied at similar time intervals. MAIN OUTCOME: Prior to treatment, both knee flexor and extensor muscle strength was reduced in both patients with OH and SCH compared to controls (p < 0.05). After treatment all strength measurements improved in the OH group (p < 0.01) while in the SCH group the majority of muscle strength measurements improved (p < 0.05). Midthigh muscle cross-sectional area was reduced in both the OH and SCH group at baseline (p < 0.05) compared to controls and increased significantly following treatment (p < 0.05). There were no significant changes in any parameter in the euthyroid control (EC) group during the study period. CONCLUSIONS: The finding that muscle strength and cross-sectional area are reduced in SCH and improved after treatment lends support for the clinical decision to treat rather than observe this condition. This may have particular relevance to certain SCH patient groups including the elderly who are prone to falls and athletically active younger patients who require optimal skeletal muscle function.

Relationship of skin temperature to sympathetic dysfunction in diabetic at-risk feet.

The relationship of plantar skin temperature to diabetic neuropathy was studied using clinical, nerve conduction and autonomic evaluations. The sympathetic skin response (SSR) was found present in both feet of 25 control subjects and 29 (out of 69) diabetic patients (SSR+ group). For those diabetic patients absent with the SSR in both feet, 18 patients (at-risk group) had preulcerative skin lesions (dry and fissured skin) and 22 did not (SSR- group). The at-risk group showed significantly higher mean foot temperature (30.2+/-1.3 degrees Celsius) than the SSR- (27.9+/-1.7 degrees Celsius), the SSR+ (27.1+/-2.0 degrees Celsius) and the control group (26.8+/-1.8 degrees Celsius). The SSR- group had smaller temperature differences (7.2+/-1.7 degrees Celsius versus 8.6+/-1.6 degrees Celsius, p<0.05) and smaller normalized temperature (referencing to the forehead temperature) (0.19 versus 0.24, p<0.01) than the SSR+ group. Although the three diabetic groups had no significant differences in clinical and cardiovascular abnormalities, the at-risk group showed more nerve conduction abnormalities than the SSR- and SSR+ groups (55% versus 23% and 14%, p<0.02). This study indicated that the thermoregulatory sweating abnormality signified early sympathetic damage in diabetic feet. Assessing skin conditions and sudomotor activities should help identify small fiber neuropathy in diabetic patients with at-risk feet conditions.

Assessing foot temperature using infrared thermography.

BACKGROUND: Previous reports recommended using skin temperature as a guide to monitor neuropathic feet during their rehabilitation course. However, the diagnostic usefulness was limited because of poor thermal measurement and procedures. The purpose of this study was to propose a standardized protocol to quantify foot temperature. METHODS: An infrared image system was used to measure skin temperature. The first experiment was conducted on 16 healthy volunteers to study temperature variation with respect to time. This study mapped out six subregions of anatomic interest over the sole, and average temperature values for each were studied. The second experiment was conducted on 62 diabetic patients, with and without sympathetic skin response (SSR), to study proposed sole temperature normalization with respect to forehead temperature for clinical diagnosis. RESULTS: In the first experiment, the temperature in each plantar subregion varied as a function of time. In the sole area, the highest temperature was noted in the arch region (29.3 +/- 0.9 degrees C). The toes had the lowest temperature value (26.2 +/- 1.2 degrees C) in all areas. Equilibrium was reached after 15 minutes for the mean plantar temperature (27.8 +/- 1.0 degrees C). In the second experiment, the diabetic patients without SSR had a slightly higher mean plantar temperature (27.6 +/- 1.8 degrees C) than those with SSR (26.8 +/- 2.2 degrees C), but the difference was not statistically significant (p > 0.05). The SSR-absent group (0.19) and the SSR-present group (0.24) had significant differences in their normalized temperatures as proposed (p < 0.05). CONCLUSIONS: The mean temperature of the entire plantar area was found to be more stable than the individual subregions, serving as a more practical indicator for thermoregulatory functions. The study also found that the overall mean plantar temperature stabilized after 15 minutes, and, thus, this time was recommended for clinical thermographic measurements. The normalized temperature may have more useful application than the plantar absolute temperature, as exemplified by the better correlation in diabetic feet. The mean plantar temperature, the wait time to start measurement, and the proposed normalization are believed to play important roles in neuropathic foot disorders.