Everett Lohman

The effect of virtual reality gaming on dynamic balance in older adults

BACKGROUND physical therapy interventions that increase functional strength and balance have been shown to reduce falls in older adults. AIM this study compared a virtual reality group (VRG) and a control group (CG). DESIGN randomised controlled 6-week intervention with pre- and post-test evaluations. SETTING outpatient geriatric orthopaedic and balance physical therapy clinic. POPULATION forty participants were randomised into two groups. METHOD the VRG received three different Nintendo® Wii FIT balance interventions three times per week for 6 weeks and the CG received no intervention. RESULTS compared with the CG, post-intervention measurements showed significant improvements for the VRG in the 8-foot Up & Go test [median decrease of 1.0 versus -0.2 s, (P=0.038) and the Activities-specific Balance Confidence Scale (6.9 versus 1.3%) (P=0.038)]. CONCLUSION virtual reality gaming provides clinicians with a useful tool for improving dynamic balance and balance confidence in older adults.

Effects of contrast baths on skin blood flow on the dorsal and plantar foot in people with type 2 diabetes and age-matched controls

Contrast baths have been used for therapy for over 2,000 years. The basic concept is to alternate warm and cool water baths during a treatment session. It is believed that this will increase circulation better than just placing the limb in a warm water bath. However, there is little supportive evidence for this assertion. Further, for subjects with diabetes, with underlying impairments in their circulation, this may not work at all. Fourteen people with type 2 diabetes were compared to 14 age-matched controls. Skin blood flow of the foot (BF) was measured during 16 minutes of contrast baths at two different intervals: 3 minutes warm and 1 minute cold and 6 minutes warm and 2 minutes cold. In control subjects, warm and cold contrast baths with the ratio 3 minutes warm to 1 minute cold elicited significantly (p < 0.01) greater BF than placing the limb continuously in warm water or using a 6:2 ratio of warm to cold bath time. In control subjects, there was also a greater plantar than dorsal BF. For subjects with diabetes, there was no statistical difference between BF with contrast baths versus warm whirlpool; but in both cases BF was significantly less than that seen in control subjects under similar circumstances. There was also very little difference between BF on the plantar and dorsal aspects of the foot in the subjects with diabetes. Patients with diabetes do not show a vascular response to contrast bath therapy. The BF response to contrast temperatures may be a good diagnostic test for diabetic vascular impairment.

Postural sway and Rhythmic Electroencephalography analysis of cortical activation during eight balance training tasks

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.

Cortical Activation Associated with Muscle Synergies of the Human Male Pelvic Floor

Human pelvic floor muscles have been shown to operate synergistically with a wide variety of muscles, which has been suggested to be an important contributor to continence and pelvic stability during functional tasks. However, the neural mechanism of pelvic floor muscle synergies remains unknown. Here, we test the hypothesis that activation in motor cortical regions associated with pelvic floor activation are part of the neural substrate for such synergies. We first use electromyographic recordings to extend previous findings and demonstrate that pelvic floor muscles activate synergistically during voluntary activation of gluteal muscles, but not during voluntary activation of finger muscles. We then show, using functional magnetic resonance imaging (fMRI), that a region of the medial wall of the precentral gyrus consistently activates during both voluntary pelvic floor muscle activation and voluntary gluteal activation, but not during voluntary finger activation. We finally confirm, using transcranial magnetic stimulation, that the fMRI-identified medial wall region is likely to generate pelvic floor muscle activation. Thus, muscle synergies of the human male pelvic floor appear to involve activation of motor cortical areas associated with pelvic floor control.

Effect of oculo-motor and gaze stability exercises on postural stability and dynamic visual acuity in healthy young adults

The purpose of this study was to investigate the effectiveness of oculo-motor exercises and gaze stability exercises on postural stability and dynamic visual acuity (DVA) in healthy young adults. Subjects were randomly divided into experimental (n=28) and control groups (n=13). The experimental group performed oculo-motor exercises and gaze stability exercise for three weeks and the control group did not. Pre and post postural stability during quiet standing, standing with active head rotation, and DVA were measured on both groups. Significant differences were found in postural stability during standing with active head rotation and DVA in the experimental group (p<0.05). No significant differences were found in postural stability or DVA in the control group. Improvements in postural stability and DVA after three weeks of oculo-motor exercises and gaze stability exercises suggest that this specific type of vestibular and ocular system exercises may be beneficial for healthy young adults.

The Influence of Environmental Temperature on the Response of the Skin to Local Pressure: The Impact of Aging and Diabetes

BACKGROUND To protect against ischemia, pressure-induced vasodilation (PIV) causes an increase in skin blood flow. Endothelial dysfunction, which is commonly found in older patients and those with diabetes, and global temperatures can affect the resting blood flow in skin, which may reduce the blood flow during and after the application of local pressure. The present study investigated the PIV of the skin with exposure to three global temperatures in younger and older populations and those with diabetes. MATERIALS AND METHODS Older subjects (n = 15, mean age 64.2 +/- 14.0 years), subjects with diabetes (n = 15, mean age 62 +/- 5.9 years, mean duration 13.2 +/- 9.1 years), or younger subjects (n = 15, mean age 25.7 +/- 2.9 years) participated. An infrared laser Dopler flow meter was used to measure skin blood flow on the bottom of the foot, lower back, and hand during and after applications of pressure at 7.5, 15, 30, 45, and 60 kPa at 16 degrees C, 24 degrees C, and 32 degrees C global temperatures. RESULTS The resting blood flow for all subjects was significantly lower in the 16 degrees C environment (P < 0.05). Blood flow in the group with diabetes was significantly lower at rest, during the application of all pressure, and after the release of pressure in all global temperatures (P < 0.05). The younger group showed a significant increase in blood flow after every pressure application, except 7.5 kPa, in all global conditions (P < 0.001). Older subjects and patients with diabetes did not have a significant reactive hyperemia, especially in the 16 degrees C environment. CONCLUSION The protective mechanism of PIV is severely reduced in older populations and those with diabetes, especially in colder environments where skin blood flow is already diminished.

Impact of hydrotherapy on skin blood flow: How much is due to moisture and how much is due to heat?

ABSTRACT Hydrotherapy and whirlpool are used to increase skin blood flow and warm tissue. However, recent evidence seems to show that part of the increase in skin blood flow is not due to the warmth itself but due to the moisture content of the heat. Therefore, two series of experiments were accomplished on 10 subjects with an average age of 24.2 ± 9.7 years and free of diabetes and cardiovascular disease. Subjects sat in a 37°C hydrotherapy pool under two conditions: one in which a thin membrane protecting their skin from moisture while their arm was submerged in water and the second where their arm was allowed to be exposed to the water for 15 minutes. During this period of time, skin and body temperature were measured as well as skin blood flow by a Laser Doppler Imager. The results of the experiments showed that the vapor barrier blocked any change in skin moisture content during submersion in water, and while skin temperature was the same as during exposure to the water, the blood flow with the arm exposed to water increased from 101.1 ± 10.4 flux to 224.9 ± 18.2 flux, whereas blood flow increased to only 118.7 ± 11.4 flux if the moisture of the water was blocked. Thus, a substantial portion of the increase in skin blood flow associated with warm water therapy is probably associated with moisturizing of the skin rather than the heat itself.

A device to evaluate motor and autonomic impairment

Various devices have been developed to assess impairment of the autonomic nervous system, while other devices have been developed to evaluate the motor system. However, no devices have been developed to examine the interaction between the autonomic and somatic nervous systems. Therefore, the device described here, a square platform which was 0.7x0.7 m in length and 0.1m thick, was developed to examine somatic-autonomic interaction. The device can be used by placing it directly on the floor or on 1 of 2 pivots; one that allowed the platform to move 0.2m (+/-44.1 degrees) in the front to back or side to side direction and one that allowed both movements together. Strain gauge load cells in the platform measured sway and tremor during the subjects attempt to balance and a continuous blood pressure monitor and the ECG were used to assess the response of the autonomic nervous system (heart rate variability). The device was tested on 5 normal subjects and the following was evaluated: (1) sway during standing, (2) weight shift during standing, (3) frequency of sway and extent of sway during standing, (4) sympathetic and parasympathetic alterations in the ANS during attempted balance, and (5) phase delays between motor and autonomic responses. The results showed that, with increasing balance challenge, sway increased, tremor increased, the sway angle increased and sway was positively correlated with heart rate and negatively correlated with blood pressure. A balance challenge significantly increased sympathetic activity but not parasympathetic activity. This device should have useful applications in assessing motor impairments and sensory and autonomic impairments in a variety of conditions.

Differences in endothelial function between Korean-Asians and Caucasians.

Summary Background The vascular endothelium plays an integral role in maintaining vascular homeostasis, including the regulation of blood flow, vascular tone, and platelet aggregation. The aim of this study was to see if there were any differences in endothelial function between Koreans and Caucasians. Material/Methods This was accomplished by 2 measures of endothelial function – the response to local heat and the response to vascular occlusion. Ten Caucasian and 10 Korean male and female subjects participated (<35 years old). Endothelial function was assessed by the skin blood flow response to local heat using a thermode for 6 minutes at 3 temperatures (38°C, 40°C and 42°C) and by vascular occlusion for 4 minutes followed by release and measurement of skin blood flow for 2 minutes. Results When applying 6 minutes of local heat at 3 different temperatures (38°C, 40°C, and 42°C), the skin blood flows were significantly higher for all temperatures in Caucasians as compared with Koreans, with peak blood flow of 223±48.1, 413.7±132.1, and 517.4±135.8 flux in Caucasians and 126.4±41.3, 251±77.9, and 398±97.2 flux in Koreans, respectively (p=0.001). Results of this study support the idea that the skin blood flow response to occlusion was significantly higher in Caucasians (peak 411.9±88.9 flux) than Koreans (peak 332.4±75.8 flux) (p=0.016). Conclusions These findings suggest that Koreans may have lower endothelial function than Caucasians, which may be explained, in part, by genetic variations between the 2 ethnic groups.

Effect of tai chi exercise combined with mental imagery theory in improving balance in a diabetic and elderly population

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<0.01) after completing 8 weeks of TC exercise with no significant improvement between groups. Subjects using the balance platform test demonstrated improvement in balance in all different tasks with no significant change between groups. There was no significant change in HbA1C for the diabetic group. Conclusions All results showed an improvement in balance in the diabetic and the control groups; however, no significant difference between the groups was observed. Since the DM group had more problems with balance impairment at baseline than the control, the diabetic group showed the most benefit from the TC exercise.