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Background One of the effects of diabetes mellitus (DM), peripheral neuropathy, affects the sensation in the feet and can increase the chance of falling. The purpose of the study was to investigate the effect of 8 weeks of Tai Chi (TC) training combined with mental imagery (MI) on improving balance in people with diabetes and an age matched control group. Material/Methods Seventeen healthy subjects and 12 diabetic sedentary subjects ranging from 40–80 years of age were recruited. All subjects in both groups attended a Yang style of TC class using MI strategies, 2 sessions a week for 8 weeks. Each session was one hour long. Measures were taken using a balance platform test, an Activities-specific Balance Confidence (ABC) Scale, a one leg standing test (OLS), functional reach test (FRT) and hemoglobin A1C. These measures were taken twice, pre and post-study, for both groups. Results Both groups experienced significant improvements in ABC, OLS, FRT (P

Background The aim of this study was to examine the effects of a 6-week training program of simulated barefoot running (SBR) on running kinetics in habitually shod (wearing shoes) female recreational runners. Material/Methods Twelve female runners age 25.7±3.4 years gradually increased running distance in Vibram FiveFingers minimal shoes over a 6-week period. The kinetic analysis of treadmill running at 10 Km/h was performed pre- and post-intervention in shod running, non-habituated SBR, and habituated SBR conditions. Spatiotemporal parameters, ground reaction force components, and electromyography (EMG) were measured in all conditions. Results Post-intervention data indicated a significant decrease across time in the habituation SBR for EMG activity of the tibialis anterior (TA) in the pre-activation and absorptive phase of running (P

Background A high occurrence of knee injuries have been observed in women during the menstrual cycle (MC). As a result, numerous studies have been conducted regarding knee ligament elasticity during the MC. Some researchers believe that since estrogen receptor b exists in ligaments and tendons in the knee, estrogen may modulate towards a state of laxity. However, increased tissue temperature also observed during the MC can predispose ligament and tendon laxness. Therefore, the purpose of this study was to assess in women the relationship between Estradiol (E2) serum concentrations and tissue temperature during the MC and their combined effect on knee laxity. Material/Methods Ten non-athletic young healthy females, 18 to 30 years of age participated in the study. E2 serum concentrations, anterior cruciate ligament (ACL) elasticity, and force to flex the knee (FFK), knee flexion-extension hysteresis (KFEH) were assessed both at ambient temperature (22°C) and after 38°C warming. Testing was performed multiple times during the participant’s MC, for one full MC. Results ACL elasticity was significantly higher (P

Background The purpose of this study was to investigate the changes in the Power Spectrum Density (PSD) of the electroencephalography (EEG) in common sensorimotor balance training tasks of varying difficulty. Sensorimotor balance exercises including alteration of vision, base of support or surface compliance are used to improve postural control. These exercises are presumed to induce supraspinal adaptation, however, there were no studies that investigated the power changes of the cortical activity in these static balance tasks. Our objective was to provide evidence in the cortical involvement with the static balance tasks frequently used in sensorimotor training. Material/Methods Postural sway and EEG changes of alpha, beta and sigma wave bands were measured in seventeen participants during eight balance tasks of varying difficulty with eyes open and closed, feet in tandem or apart and on foam or a firm surface. Results The power of beta and sigma bands increased significantly at the parietal and central area of the brain in tasks with eyes open together with one sensory factor (base of support or surface compliance) or two sensory factors (base of support and surface compliance) altered, and in task with three sensory factors (vision, base of support and surface compliance) altered from the control task. Conclusions This study demonstrated the cortical involvement in the sensorimotor balance tasks, suggesting that these exercises may induce cortical adaptation for postural control. The results support subcortical control with increased task difficulty and the increase in cortical processing when task became extremely challenging.

Background The purpose of this study was to investigate the changes in the Power Spectral Density (PSD) of the electroencephalogram (EEG) during 8 common sensorimotor balance training tasks of varying difficulty in single-limb trans-tibial amputees. Material and methods Eight sensorimotor balance exercises, including alteration in vision, base of support, and surface compliance, were used to test postural control and how it related to the electroencephalogram (EEG). A control group was compared to a group of people with trans-tibial amputation of 1 leg to see how the brain responds to loss of a single limb during progressively harder balance testing. Postural sway and EEG changes of the alpha, beta, and sigma wave bands were measured in 20 participants (10 controls, 10 amputees) during 8 balance tasks of varying difficulty with eyes open and closed, feet in tandem or apart, and on a foam or a firm surface. Results The power of alpha, beta, and sigma bands increased significantly in most tests when comparing the amputees to the control subjects. Balance was significantly worse in the amputees even when standing on both legs. In amputees, balance required more cortical activity than in the controls. Conclusions This study demonstrated that amputees have considerably more difficulty in motor control for the brain during balance tasks. Balance was impaired even when standing feet apart on 2 legs and EEG showed more spectral power in all areas of the brain in the amputees.

Background It is well established that there is a reduction in the skin blood flow (SBF) in response to heat with age and diabetes. While it is known that high BMI creates a stress on the cardiovascular system and increases the risk of all cause of morbidity and mortality, little is known of the effect of high BMI on SBF response to heat. Since diabetes is associated with age and a higher BMI, the interrelationship between age, BMI and SBF needs to be investigated to better understand the contribution diabetes alone has to endothelial impairment. Material/Methods This study examined the SBF to heat in young and old people with low and high BMI and people with diabetes with high BMI to determine the contribution these variables have on SBF. Subjects were ten young and older people with BMI 20 and ten subjects with diabetes with BMI >20. The SBF response, above the quadriceps, was determined during a 6 minutes exposure to heat at 44°C. Results Even in young people, SBF after the stress of heat exposure was reduced in subjects with a high BMI. The effect of BMI was greatest in young people and lowest in older people and people with diabetes; in people with diabetes, BMI was a more significant variable than diabetes in causing impairment of blood flow to heat. BMI, for example, was responsible for 49% of the reduction in blood flow after stress heat exposure (R=−0.7) while ageing only accounted for 16% of the blood flow reduction (R=−0.397). Conclusions These results would suggest the importance of keeping BMI low not only in people with diabetes to minimize further circulatory vascular damage, but also in young people to diminish long term circulatory vascular compromise.

Summary Background Previous studies show that Asians have an impaired blood flow response (BFR) to occlusion after a single high fat (HF) meal. The mechanism is believed to be the presence and susceptibility to high free radicals in their blood. The free radical concentration after a HF meal has not been examined in Asians. Further the BFR to heat after a single HF meal in Koreans has not been measured. Material/Methods This study evaluated postprandial endothelial function by measuring the BFR to vascular occlusion and local heat before and after a HF meal and the interventional effects of anti-oxidant vitamins on improving endothelial function in young Korean-Asians (K) compared to Caucasians (C) with these assessments. Ten C and ten K participated in the study (mean age 25.3±3.6 years old). BFR to vascular occlusion and local heat and oxidative stress were assessed after a single low fat (LF) and HF meal at 2 hours compared to baseline. After administration of vitamins (1000 mg of vitamin C, 800 IU of vitamin E, and 300 mg of Coenzyme Q-10) for 14 days, the same measurements were made. Results This study showed that the skin BFR to vascular occlusion and local heat following a HF meal significantly decreased and free radicals significantly increased at 2 hours compared to baseline in K (p

Previous data has shown that when pressure is applied to the skin of the ankle and on the foot, there is a reactive increase in circulation. In the present investigation, these studies were expanded to look at the response of the hand, back, and foot to applied pressure.Ten young subjects whose average age was 26.5+/-3.3 yrs, 10 older subjects whose average age was 73.3+/-19.7 yrs and 10 people with diabetes whose average age was 60.1+/-5.7 yrs participated in the study. There was no statistical difference in the height or weight of the subjects. Hemoglobin A1c of the group with Diabetes averaged 6.98+/-1.15% with the mean duration of diabetes 13.6+/-9.5 yrs. An infrared laser Doppler flow meter was used to measure circulation on the hand, lower back, and on the bottom of the foot during applications of pressure at 15, 30, 45, and 60 kPa.For all three areas of the body, circulation was significantly less in the group with diabetes than the other two groups (p0.05). When pressure was applied at 15 kPa, the blood flow to the skin initially decreased, but then increased in the younger subjects and in the older subjects but did not increase in subjects with diabetes for any area of the body. Further, after pressure was released, for any of the four pressures examined here, while the younger subjects showed a pronounced reactive hyperemia, subjects with diabetes showed a diminished hyperemia not proportional to the pressure that was applied.It appears that the normal protective mechanism of a pressure induced hyperemia is absent or diminished in patients with diabetes with more effect on the periphery than on the core area of the body. More importantly, after pressure was applied and released, subjects with diabetes lacked a proportional hyperemia to recovery form the transient ischemia of the pressure.

Ageing reduces the resting blood flow to the skin as well as the blood flow response to thermal stimuli. However, the interrelationships between skin thickness, subcutaneous fat, and skin blood flow in determining the heat dissipation characteristics of the skin have not been investigated.In the present investigation, 60 male and female subjects were examined with either a continuous 0.15 watt heat source or a 40 degrees C instantaneous heat source applied to the skin. Data was correlated to skin and subcutaneous fat thickness measured by ultrasound and to skin blood flow measured by a laser Doppler flow meter.The results of the experiments showed a significant negative correlation between age and skin thickness (p0.0001) and between age and subcutaneous fat thickness (p0.001). Blood flows in the skin, with the subject in a 24 degrees C, room were 61.8% less in the older subjects compared to the younger subjects. This was due to both a reduction in red cell concentration and red cell velocity. The lower concentration of red cells matches the reduction in skin thickness, implying a loss in the dermal layer of the skin associated with ageing. The skin blood flow response to continuous heat and to a single heat exposure were both reduced in the older subjects (p0.01). Ageing also caused a slower response of the skin to heat stress.The results support a reduction in both the resting and post local heat skin blood flows associated with ageing. Some of this may be due to a reduction in dermal layer thickness due to ageing.

Wounds, especially in the elderly, can be life threatening. One modality which allegedly increases blood flow (BF) as an aid to heal chronic wounds is electrical stimulation. This technique applies electrical current (ES) across wounds. However, while many studies show positive findings, others do not. The purpose of this investigation was to investigate some of this inconsistency in results by determining the effect of environmental temperature on the circulation of the skin which may negate the effects of electrical stimulation in a clinical setting.Ten people with no wounds, controls (C), and 12 people with wounds (W) were examined in a thermally neutral or cool room (20 degrees C) and a warm room (34 degrees C) to observe the effect of reducing sympathetic vasoconstrictor activity on the response to 5 and 15 mA sine wave biphasic ES delivered by 2x2 cm surface electrodes.C and W subjects showed a greater BF in the skin in a warm room. In group C, after 30 minutes of stimulation at a current of 15 milliamps, BF increased significantly (p0.05) but by an average of only 4 flux in the cool room. In the warm environment, BF increased significantly (p0.01) by 19.3+/-7 flux and increased further during the 60 minute recovery phase. In the W group, BF during ES increased much more during stimulation in a warm room compared to a cool room.The results show that local vasoconstriction due to exposure to a warm global temperature greatly increases the response of the skin the ES.

Decrease in skin blood flow (BF) due to diabetes may be one reason why only 31% of neuropathic diabetic ulcers heal in 20-weeks. Recent evidence shows that skin blood flow may be increased if therapy is done in a warm room. The purpose of this investigation was to compare healing rates and skin blood flow of chronic stage III and IV wounds in people with diabetes (D) and those without diabetes (WD) using a warm room and electrical stimulation.Twenty subjects with chronic stage III and IV wounds were treated at an outpatient wound center. Ten were D, and ten were WD. Treatment consisted of biphasic electrical stimulation up to 20 ma for 30 minutes, 3 x week for 4 weeks in a 32 degrees C room. Skin blood flow was measured by a Laser Doppler Imager.BF increased not only during the stimulation (the increase in BF was greater for D at 87% than WD at 6%) at the outside of the wound but even at rest before stimulation started after the initial treatment creating a carryover effect. There was no increase in skin blood flow in the center of the wound. Healing rates over four weeks of up to 70% were seen in subjects with diabetes using biphasic current.Using stimulation in a warm room significantly increased healing and skin blood flow in these wounds.

Ageing diminishes the blood flow (BF) response of the skin to autonomic stressors. While the diminished response of skin BF to global heating has been well documented, the effect of this reduction in skin BF on the ability of the skin to dissipate heat has not. When heat is added to the skin by the application of hot packs, if heat is not adequately removed, the skin can become dangerously hot and become damaged. The present investigation examined the heat dissipating properties of the skin in older individuals. This study has importance for the therapeutic application of hot packs which might cause burns easier in older people.In the present investigation, 10 younger and 10 older subjects were examined. The average age of the younger group was 25.9+/-3.4 years and the older group was 60 +/- 5.8 years. Heat was applied through a 49 gram brass probe that was heated to 41 degrees C and by a Peltier junction in a cool and warm environment.Skin required about 20 calories of heat to raise skin temperature 1 degrees C the cool room and double this Figure in the warm room. Ageing reduced the caloric requirement to increase skin temperature under both conditions (p0.01).The results of the experiments showed that older individuals had impaired ability of the skin to dissipate heat in both environments. Special precautions should be taken in physical therapy when applying hot packs in older populations.