Prevention of bone deterioration by whole-body vibration in a rat model of pre-type 2 diabetes

OBJECTIVES

To examine effects of whole-body vibration (WBV) on bone properties in pre-type 2 diabetes mellitus (T2DM) rats.

METHODS

Six-week-old male Hos:ZFDM-Lepr fa, fa/fa (DM) and Hos:ZFDM-Leprfa,fa/+ (CON; untreated non-DM) rats were used in the experiments. Half of DM rats were subjected to WBV (45 Hz, 0.5 g, 15 min/day, 5 days/week) for 8 weeks (WBV group), and the other half was not (DM group).

RESULTS

Bone mass, trabecular bone microstructure (TBMS), and cortical bone geometry (CBG) parameters were worse in the DM and WBV groups compared with the CON group. Maximum load was significantly decreased in the DM group compared with the CON group, and the break point was significantly higher in the WBV group compared with the DM group. Serum levels of bone specific alkaline phosphatase were significantly lower in the WBV group compared with the CON group. Glycemic control was not worse in the WBV group compared with the DM group, but not the same levels as the CON group.

CONCLUSIONS

These findings suggest that WBV can potentially delay the decrease in maximum load, although it does not prevent the deterioration of bone mass, TBMS, and CBG parameters.

Long-term wheel-running prevents reduction of grip strength in type 2 diabetic rats

Diabetic skeletal muscles show reduced contractile force and increased fatigability. Hands are a target for several diabetes-induced complications. Therefore, reduced handgrip strength often occurs as a consequence of diabetes. The aim of this study was to examine whether long-term exercise can prevent reduction of grip strength in type 2 diabetes mellitus (T2DM) model OLETF rats, and to explore the mechanisms underlying diabetes-induced grip strength reduction. Ten 5-week-old OLETF rats were used as experimental animals, and five non-diabetic LETO rats as controls of OLETF rats. Half OLETF rats performed daily voluntary wheel-running for 17 months (OLETF + EXE), and the rest of OLETF and LETO rats were sedentary. Grip strength was higher in OLETF + EXE and LETO groups than in OLETF group. OLETF group with hyperglycemia showed an increase in HbA1c, serum TNF-α, and muscle SERCA activity, but a decrease in circulating insulin. Each fiber area, total fiber area, and % total fiber area in type IIb fibers of extensor digitorum longus muscles were larger in OLETF + EXE and LETO groups than in OLETF group. There was a positive correlation between grip strength and the above three parameters concerning type IIb fiber area. Therefore, type IIb fiber atrophy may be the major direct cause of grip strength reduction in OLETF group, although there seems multiple etiological mechanisms. Long-term wheel-running may have blocked the diabetes-induced reduction of grip strength by preventing type IIb fiber atrophy. Regular exercise may be a potent modality for preventing not only the progression of diabetes but muscle dysfunction in T2DM patients.

Effects of whole-body vibration on bone properties in aged rats

OBJECTIVE

This study aimed to explore optimal conditions of whole-body vibration (WBV) for improving bone properties in aged rats.

METHODS

Eighty-week-old rats were divided into baseline control (BC), age-matched control (CON) and experimental groups, which underwent WBV (0.5 g) at various frequencies (15, 30, 45, 60 or 90 Hz) or WBV (45 Hz) with various magnitudes (0.3, 0.5, 0.7 or 1.0 g) for 7 weeks. After interventions, femur bone size, bone mechanical strength and circulating bone formation/resorption markers were measured, and trabecular bone microstructure (TBMS) and cortical bone geometry (CBG) of femurs were analyzed by micro-CT.

RESULTS

Several TBMS parameters and trabecular bone mineral content were significantly lower in the 15 Hz WBV (0.5 g) group than in the CON group, suggesting damage to trabecular bone. On the other hand, although frequency/magnitude of WBV did not influence any CBG parameters, the 0.7 g and 1.0 g WBV (45 Hz) group showed an increase in tissue mineral density of cortical bone compared with the BC and CON groups, suggesting the possibility of improving cortical bone properties.

CONCLUSION

Based on these findings, it should be noted that WBV conditions are carefully considered when applied to elderly people.

Possible effects of whole body vibration on bone properties in growing rats

Objectives

To examine the effects of whole body vibration (WBV) on bone properties in growing rats, and to explore the optimal conditions for enhancing bone properties.

Methods

Thirty-six 4-week-old male rats were divided into 1 control and 5 experimental groups. Each experimental group underwent WBV at 15, 30, 45, 60, and 90 Hz (0.5 g, 15 min/d, 5 d/wk) for 8 weeks. We measured bone size, muscle weight and bone mechanical strength of the right tibia. Trabecular bone mass and trabecular bone microstructure (TBMS) of the left tibia were analyzed by micro-computed tomography. Serum levels of bone formation/resorption markers were also measured.

Results

WBV at 45 Hz and 60 Hz tended to enhance trabecular bone mass and TBMS parameters. However, there was no difference in maximum load of tibias among all groups. Serum levels of bone resorption marker were significantly higher in the 45-Hz WBV group than in the control group.

Conclusions

WBV at 45–60 Hz may offer a potent modality for increasing bone mass during the period of rapid growth. Further studies are needed to explore the optimal WBV conditions for increasing peak bone mass and TBMS parameters. WBV modality may be a potent strategy for primary prevention against osteoporosis.

Whole body vibration at low-frequency can increase trabecular thickness and width in adult rats

OBJECTIVE

This study aimed to examine whether WBV becomes a possible modality for the primary prevention of osteoporosis by exploring WBV frequency that has positive effects on bone properties in adult rats.

METHODS

Thirty-six 24-week-old rats were divided into one control and 5 experimental groups, which underwent WBV at various frequencies (15, 30, 45, 60 or 90 Hz), with a magnitude of 0.5 g, for 15 min/day, 5 days/week, for 8 weeks. Bone size, muscle weight and bone mechanical strength were measured at the end of experimental period. Bone mass, trabecular bone microarchitecture (TBMA) and cortical bone geometry were analyzed by micro-CT. Circulating bone formation/resorption markers were determined by ELISA.

RESULTS

Body weight-corrected soleus weight in all experimental groups and body weight-corrected extensor digitorum longus muscle weight in the 15 and 30 Hz groups were significantly higher than those of the control group, respectively. Femur trabecular thickness and width were significantly higher in the 15 Hz group than in the control group. However, there was no difference in bone mechanical strength or bone formation/resorption markers among all groups.

CONCLUSION

These results suggest that WBV at low-frequencies may become a potent modality for the primary prevention of osteoporosis in adults.

Upward running is more beneficial than level surface or downslope running in reverting tibia bone degeneration in ovariectomized rats

OBJECTIVE

We investigated the effects of upslope, level surface, and downslope running on indices of tibia and femur bone recovery in ovariectomized (OVX) rats.

METHODS

Rats were randomly divided into five groups: one sham-operated (SHAM) group and four OVX groups. One OVX group was a non-running control (OVX-Cont) and the others performed upslope running (OVX-Up), level surface running (OVX-Level), or downslope running (OVX-Down) on a treadmill after ovariectomy. The metaphysis region of the proximal tibia, distal femur, and proximal femur were scanned by micro-computed tomography and various geometric and microarchitectural parameters as well as bone mineral density measured using bone analysis software.

RESULTS

Tibial bone geometric parameters, BV/TV and trabecular thickness, were significantly improved in OVX-Up and OVX-Level groups compared to that in OVX-Cont and OVX-Down groups, and improved to a greater degree in OVX-Up group than in OVX-Level group.

CONCLUSIONS

Therefore, running slope substantially influences the beneficial effects of treadmill running on OVX-induced bone degeneration, with upward running being more effective than level surface running or downslope running, likely due to the greater bone loads associated with upslope running. The benefits of upslope treadmill running were particularly observed in the proximal tibia.

High-fat/high-sucrose diet results in higher bone mass in aged rats

Intake of high-fat/high-sucrose (HFS) diet or high fat diet influences bone metabolism in young rodents, but its effects on bone properties of aged rodents still remain unclear. This study aimed to examine the effects of HFS diet intake on trabecular bone architecture (TBA) and cortical bone geometry (CBG) in aged rats. Fifteen male Wistar rats over 1 year were randomly divided into two groups. One group was fed a standard laboratory diet (SLD) and the other group was fed a HFS diet for six months. The femur/tibia, obtained from both groups at the end of experimental period, were scanned by micro-computed tomography for TBA/CBG analyses. Serum biochemical analyses were also conducted. Body weight was significantly higher in the HFS group than in the SLD group. In both femur and tibia, the HFS group showed higher trabecular/cortical bone mass in reference to bone mineral content, volume bone mineral density and TBA/CBG parameters compared with the SLD group. In addition, serum calcium, inorganic phosphorus, total protein, triacylglycerol, HDL and TRACP-5b levels were significantly higher in the HFS group than in the SLD group. There were good correlations between body weight and bone parameters in the femur and tibia. These results suggest that HFS diet intake results in higher bone mass in aged rats. Such effects of HFS diet intake might have been induced by increased body weight.

Long-Term Intake of Green Tea Extract Causes Mal-Conformation of Trabecular Bone Microarchitecture in Growing Rats

The purpose of this study was to examine the effects of green tea extract (GTE) intake on bone structural and physiological properties, such as bone mass, trabecular bone microarchitecture, cortical bone geometry, and bone mechanical strength, in growing rats. Four-week-old male Wistar rats were divided into the following four groups: standard diet feeding for 85 days (S-CON) or 170 days (L-CON), and GTE diet feeding for 85 days (S-GTE) or 170 days (L-GTE). At the end of the experiment, in addition to measurement of circulating bone formation/resorption markers, bone mass, trabecular bone microarchitecture, and cortical bone geometry were analyzed in the left femur, and bone mechanical strength of the right femur was measured. There was no difference in all bone parameters between the S-CON and S-GTE groups. On the other hand, the L-GTE group showed the decrease in some trabecular bone mass/microarchitecture parameters and no change in cortical bone mass/geometry parameters compared with the L-CON group, and consequently the reduction in bone weight corrected by body weight. There was no difference in bone formation/resorption markers and bone mechanical strength between the S-CON and S-GTE groups and also between the L-CON and L-GTE groups. However, serum leptin levels were significantly lower in the L-GTE group than in the L-CON group. Thus, the long-term GTE intake had negative effects on bone, especially trabecular bone loss and microarchitecture mal-conformation, in growing rats.

Association between bone mass as assessed by quantitative ultrasound and physical function in elderly women: The Fujiwara-kyo study

Objectives

This study aimed to investigate differences in physical function by bone mass category as assessed by speed of sound, and the association between bone mass and physical function in Japanese elderly women.

Methods

Participants (≥65 years, n = 954) were divided into the osteoporosis, osteopenia, and normal groups based on speed of sound values, and physical function parameters were compared among groups. In addition, the predictive ability of physical function for low bone mass was determined by area under the curve analysis. Data were collected in 4 cities in Nara, Japan, in 2007 or 2008.

Results

All physical functions were significantly lower in the osteoporotic group than in the normal group. Lower bone mass was associated with poor muscle strength and physical function after adjusting for age, height and weight. In addition, one-leg standing time and 10-m gait time were predictive of low bone mass (osteopenia and osteoporosis levels, respectively). Elderly women with low physical function, especially those with a short one-leg standing time, should be suspected of having decreased bone mass.

Conclusions

Measurements of physical function can effectively identify elderly women with low bone mass at an early stage without the need for bone mass measurements. In particular, one-leg standing time and 10-m gait time were good predictors of low bone mass, and is easy to measure, low-cost, and can be self-measured. These findings will be helpful in the prevention and treatment of osteoporosis.

Long-term wheel-running can prevent deterioration of bone properties in diabetes mellitus model rats

OBJECTIVES

The purpose of this study was to examine the effects of long-term wheel-running on tibia bone properties in T2DM Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

METHODS

Ten five-week-old male OLETF rats were used as experimental animals and 5 Long-Evans Tokushima Otsuka (LETO) rats as controls. Half of OLETF rats performed daily voluntary wheel-running for 17 months (OLETF-EXE), while neither the remainder of OLETF nor LETO rats had exercise. At the end of experiment, in addition to serum biochemical and bone formation/resorption marker analyses, bone mass, trabecular bone microarchitecture and cortical bone geometry were analyzed in left tibia, and bone mechanical strength of right tibia was measured.

RESULTS

Tibia bone mass, trabecular bone microarchitecture, cortical bone geometry and bone mechanical strength deteriorated in diabetic OLETF rats. However, such deterioration was obviously attenuated in OLETF-EXE rats, which maintained normal levels of blood glucose, HbA1c and blood urea nitrogen.

CONCLUSIONS

Daily wheel-running could prevent the deterioration of bone properties in OLETF rats. This would be induced mainly by suppressing the development of T2DM. Regular physical exercise may be a potent strategy for preventing not only the development of diabetes but also the deterioration of bone properties in patients with chronic T2DM.

Femoral bone structure in Otsuka Long-Evans Tokushima Fatty rats

Objectives

Type 2 diabetes mellitus (T2DM) increases fracture risk despite normal to high levels of bone mineral density. Bone quality is known to affect bone fragility in T2DM. The aim of this study was to clarify the trabecular bone microstructure and cortical bone geometry of the femur in T2DM model rats.

Methods

Five-week-old Otsuka Long-Evans Tokushima Fatty (OLETF; n = 5) and Long-Evans Tokushima Otsuka (LETO; n = 5) rats were used. At the age of 18 months, femurs were scanned with micro-computed tomography, and trabecular bone microstructure and cortical bone geometry were analyzed.

Results

Trabecular bone microstructure and cortical bone geometry deteriorated in the femur in OLETF rats. Compared with in LETO rats, in OLETF rats, bone volume fraction, trabecular number and connectivity density decreased, and trabecular space significantly increased. Moreover, in OLETF rats, cortical bone volume and section area decreased, and medullary volume significantly increased.

Conclusions

Long-term T2DM leaded to deterioration in trabecular and cortical bone structure. Therefore, OLETF rats may serve as a useful animal model for investigating the relationship between T2DM and bone quality.

Differences in physical function by body mass index in elderly Japanese individuals: The Fujiwara-kyo Study

OBJECTIVE

This study examined differences in physical function according to body mass index (BMI) in elderly Japanese individuals.

METHODS

Participants (1754 men and 1795 women aged ≥65 years) were divided into the following five BMI groups: low BMI (≤20.0), low-medium BMI (20.1-22.5), medium BMI (22.6-25.0), medium-high BMI (25.1-27.5) and high BMI (≥27.6). Physical function was measured according to BMI and sex, and associations between BMI and physical function were examined.

RESULTS

Compared with the medium BMI group, handgrip strength (HGS), knee extension torque (KET), and knee flexion torque (KFT) were significantly lower in both sexes in the low BMI group, while KET and KFT were significantly higher among men in the high BMI group. One-leg standing time (OLST) with open eyes was significantly shorter among men in the high BMI group than in the medium BMI group. The high BMI group was significantly inferior to the medium BMI group in 10m gait time (10MGT), OLST, and maximum one-step length to height ratio among women. All physical functions, except for 10MGT in men, were associated with BMI adjusted age and/or sex. Muscle strength showed a positive association with BMI in both sexes. There was a stronger association between BMI and physical performance in women compared to men.

CONCLUSION

We found that BMI influences a variety of factors related to muscle strength and physical performance. Our findings may help contribute to the prevention of mobility impairments in elderly Japanese individuals.

Tidal volume and diaphragm muscle activity in rats with cervical spinal cord injury

[Purpose] The purpose of this study was to make an experimental model of cervical spinal cord injury (CSCI) using Wistar rats, in order to analyze the influence of CSCI on the respiratory function. [Subjects] Thirty-two male 12-week-old Wistar rats were used. [Methods] The CSCI was made at the levels from C3 to C7, and we performed pneumotachography and electromyography (EMG) on the diaphragm. Computed tomography was used to determine the level of spinal cord damage. [Results] After the operation, the tidal volume of the rats with a C3 level injury decreased to approximately 22.3% of its pre-injury value. In addition, in the same rats, the diaphragmatic electromyogram activity decreased remarkably. Compared with before CSCI, the tidal volume decreased to 78.6% of its pre-injury value in CSCI at the C5 level, and it decreased to 94.1% of its pre-injury value in CSCI at the C7 level. [Conclusion] In the rats that sustained a CSCI in this study, the group of respiratory muscles that receive innervation from the thoracic spinal cord was paralyzed. Therefore, the EMG signal of the diaphragm increased. These results demonstrate that there is a relationship between respiratory function and the level of CSCI.

Time course of influence by ovariectomy and calcium diet on bone properties in mice

This study was investigated the influence by ovariectomy (OVX) and calcium diet on bone properties in eighty-one female ICR strain mice with age of 5 weeks. The animals were randomly assigned to sham operation (SHAM), OVX, SHAM+low Ca intake (L.Ca) and OVX+L.Ca group. They were euthanized with lethal dose of pentobarbital sodium at day 50, 100 and 140 post-operatively. For determining the bone properties, both femur and tibial bones were excised from the hind limb, and removed off surrounding tissues. Thereafter, bone length, bone dry weight, and also mechanical strength and ash content of the bones were determined. The bone length on both femur and tibia was significantly longer in OVX group than in the other groups after 50 day of experiment, this situation was continued to the end of the experiment. Bone dry weight, mechanical strength, and ash content were significantly decreased by OVX and L.Ca over the time of the experiment, and those of OVX+L.Ca group were the lowest in all groups. OVX and L.Ca have a great potential for weakening the mechanical strength and have an additive effect when combined. OVX and L.Ca block the gain of bone mass.

A screening model for low bone mass in elderly Japanese men using quantitative ultrasound measurements: Fujiwara-Kyo Study

Screening for low bone mass is important to prevent fragility fractures in men as well as women, although men show a much lower prevalence of osteoporosis than women. The purpose of this study was to establish a screening model for low bone mineral density (BMD) using a quantitative ultrasound parameter and easily obtained objective indices for elderly Japanese men. We examined 1633 men (65-84 yr old) who were subjects of the Fujiwara-Kyo Study. Speed of sound (SOS) at the calcaneus was determined, and BMD was measured by dual-energy X-ray absorptiometry at the lumbar spine (LS), total hip (TH), and femoral neck (FN). Low BMD was defined as >1 standard deviation below the young adult mean, in accordance with World Health Organization criteria. We performed receiver operating characteristic (ROC) analysis to identify a better screening model incorporating SOS and determined the optimal cutoff value using Youden index. Prevalences of low BMD at the 3 skeletal sites were 27.8% (LS), 33.5% (TH), 48.6% (FN), and 43.3% at either LS or TH. The greatest area under the ROC curve (0.806, 95% confidence interval: 0.785-0.828) and smallest Akaike's information criterion were obtained in the multivariate model incorporating SOS, age, height, and weight for predicting low BMD at all skeletal sites. This model predicted low BMD at TH with the sensitivity of 0.726 and specificity of 0.739, whereas a similar model predicted low BMD at LS with much lower validity. We conclude that the multivariate model for TH could be used to screen for low BMD in elderly Japanese men.

[Bronchial schwannoma diagnosis by surgical treatment; report of a case]

18-year-old male was referred to our hospital due to persistent cough. The patient was admitted for the investigation of the abnormal shadow on a chest X-ray and chest computed tomography (CT). Chest CT showed a 2.5 cm nodular shadow in the right lower lobe. Bronchofiberscopy revealed the polypoid lesion at the right lower lobe bronchus obstructing the entire lumen of B8-10. The tumor surface was smooth and rich in small vessels. Right lower lobectomy was peformed. The diagnosis of schwannoma was confirmd with the S-100 positive immunohistochemical stain. Bronchial schwannoma is relatively rare disease; less than 90 cases have been reported with respect to schwannoma of case report in Japan.

Understanding and prevention of low back pain in care workers

The aim of this study was to investigate the actual situation of low back pain (LBP) prevention in care workers with questionnaires, and this data were used to clarify and decrease LBP factors. Subjects were 52 care workers (30.7 ± 10.0 years old) in a nursing home who filled out two kinds of questionnaires about LBP, one about the prevalence of LBP (QN1) and the other about LBP control measures (QN2). They had either license of certified care worker, 1st or 2nd class care worker. The data were collected for the purpose of finding differences in age and career (QN1) and differences in LBP control measures (QN2) between subjects with and without LBP. The average career of the subjects was 19.1 ± 12.5 months, and the prevalence of LBP among them was 46.2% (24 care workers), of which 66.7% began having LBP after starting work as care workers. Moreover, 75.0% of these subjects began having LBP within a year after starting work. Further, of the 24 care workers with LBP, 66.7% reported constantly experiencing LBP. The major risk factors given for LBP in care work were transfer, the replacement of diapers, and movement in a half-sitting posture. Compared with LBP subjects, rates of taking preventative steps in the non-LBP group were low. More than 80% of the subjects with LBP engaged in prevention methods such as using body mechanics, learning the proper way to perform care activities, using LBP support belts, and increasing their skills and knowledge with regard to their job responsibilities. Most subjects began to engage in such prevention methods after the onset of LBP. The results of this investigation indicated that most subjects did not engage in measures to counter their LBP until after it had already started, and that they selected prevention methods which were easy to perform and effective. It is important for care workers to learn the best ways to inhibit pain and prevent the occurrence, or recurrence, of LBP. It is necessary for physical therapists to grasp the actual situation of LBP prevention as an occupational disease and to educate this.

The progression of bone and muscle atrophy in mice hind limb with immobilization

This study investigated the time course of changes of bone and muscle atrophy in mice with immobilization by denervation and fixation. The animals were fifty-two male C57 BL/6J mice, aged 10 weeks old. Eight mice were used as the base line, and the remaining ones were cut at the sciatic nerve of the left hind limb and fixed with a plaster cast. At week 1, 2, 3, and 4 after the operation, a cross-sectional area of the rectus femoris muscles and bone mechanical strength with a three-point bending test of the femur and tibia were measured. The time course of changes of the bone mechanical strength and of the cross-sectional area of the rectus femoris muscles between the intact and experimental limbs in each period compared with the control limbs, was determined. The bone mechanical strength of the femur, tibia, and the cross-sectional area of the rectus femoris muscles of the experimental limbs significantly decreased compared with those of the intact limbs at week 4, 3, 2 and 1 after the operation (p<0.05). Compared with the intact limbs, the bone mechanical strength and the cross-sectional area of the rectus femoris muscles of the experimental limbs declined approximately 10% and 30%, respectively, during the experiment (p<0.05). It was demonstrated that bone and muscle atrophy occurred at an early stage after immobilization by denervation and fixation, and that both types of atrophy progressed simultaneously in the present study.

Change of bone mechanical strength in rats after spinal cord injury over a short term

This study investigated the time-course of changes in bone mechanical strength in rats with spinal cord injury (SCI). Sixty-four male Wistar rats underwent spinal cord transection at the thoracic nerve. Control rats underwent a sham procedure (SHAM). Animals were sacrificed at day 1, 4, 7 and 14 after operation. The mechanical strength of the left femur and tibia was measured by the three-point bending strength test. The bones were dried, weighed and burned to ash. A specimen of right tibia was prepared and examined under a microscope. Bone mechanical strength, dry bone weight, and ash content of the femur and tibia in SCI rats were significantly lower than those in SHAM animals. Dry bone weight and ash content began to decrease from the 4th day after SCI and reached their lowest at day 7 after operation. Bone mechanical strength had reduced significantly by the 14th day. Gaps and spaces were observed in the trabecular area at the same time. After SCI, calcified cartilage decreased and the reduction of bone mass occurred rapidly. Moreover, a decline of bone mechanical strength is caused within 2 weeks. Thus, SCI led to the atrophy of bone and caused the reduction of mechanical strength at an early stage. It is thus necessary to prevent bone loss after SCI immediately.

Three-dimensional measurement of rolling in tetraplegic patients

OBJECTIVE

To investigate the differences between traumatic tetraplegic patients who can roll and those who cannot.

DESIGN

Motion analysis using 3-dimensional measurement.

SETTING

Rehabilitation centers in southwestern Japan.

PARTICIPANTS

Nineteen male participants, all of whom had traumatic C6 complete injury.

METHODS

We used an electromagnetic device to examine the degree of spinal movement in axial rotation during rolling (shifting from supine to side lying). This system (3-Space Win) measures the position and orientation of sensors in space. Two sensors were mounted on a subject over the spinous process of T1 and L5.

RESULTS

The spinal rotation of patients who could not roll was significantly lower than that of patients who could roll. (The average rotation of non-rollers was 31.5+/-17.5 degrees, while the average rotation of rollers was 66.3+/-17.3degrees). In this study, there were no statistically significant differences in the members of the two groups in terms of age, height, weight or time after injury.

CONCLUSION

Rolling requires greater and adequate flexibility in the back of tetraplegic patients.

The effect of low calcium diet on bone in ovariectomized mice

This study investigates the effects of Ca on bone in the ovariectomized mice. Twenty-six female ICR mice aged 5 weeks were used. They were ovariectomized (OVX) or sham-operated (SHAM) and fed standard mouse diet (SF) or special low calcium diet (L.Ca), respectively. All animals were sacrificed at day 100 after operation. Mechanical strength of the left femur and tibia was measured by the three-point bending strength test. The bones were dried, weighed and burned to ash. Correlation between mechanical strength and ash content was found. A specimen of the right tibia was prepared. Mechanical strength, ash content and ratio of dry bone weight to body weight of the femur and tibia in OVX and L.Ca mice were significantly less than in SHAM and SF mice. SHAM/SF mice and OVX/L.Ca group showed highest and lowest values in all cases. The values for the femur and tibia in OVX/SF mice were lower than in SHAM/SF group and in OVX/L.Ca group were less than in OVX/SF mice. Correlation coefficients for mechanical strength and ash content were 0.704 and 0.776 for the femur and tibia. Ca is thus related to inhibition of bone loss and maintenance of bone mass and effective prevention of osteoporosis.

Modification of postural response caused by footwear conditions

The purpose of this study was to clarify the effect of changing footwear conditions on postural response against postural perturbation. Twenty-three healthy subjects participated in this study. Postural response was induced by moving a platform forward, hereafter referred to as forward-perturbation of a platform. The center of pressure (COP) from the force plate and the electromyograms (EMG) of the tibialis anterior (TA) and quadriceps femoris (QUAD), which are both agonists of the response, were measured. The effect of plantar material and shape of footwear on postural response was examined as footwear condition. Changing plantar materials had an effect on integrated EMG of the agonists (IEMG) but not on the response pattern. On the other hand, the shape of footwear had an effect on the response pattern but not on IEMG. It was supposed from this result that changes in somatosensory input, caused by coupling of plantar material and shape of footwear, modifies postural response variously.

Possibility of independence in ADL (Activities of Daily Living) for patients with cervical spinal cord injuries--an evaluation based on the Zancolli Classification of Residual Arm Functions

For patients with cervical spinal cord injuries to become independent in their ADL (Activities of Daily Living), residual arm function is very important. Also, age, sex, physical strengths, obesity, spasticity, pain, contracture and motivation are related. We investigated the possibility of independence in ADL for patients with cervical spinal cord injuries, carrying out our evaluation based on the Zancolli Classification of Residual Arm Functions. Zancolli classification C6BII is taken as the boundary level for ADL independence. Rehabilitation is not only controlled by the patients with cervical spinal cord injuries themselves but also by the ability of the rehabilitation staff. This implies that taking responsibility in rehabilitation important.