ABSTRACT
The most common type of osteoporosis is bone loss associated with ovarian hormone deficiency at menopause. There is evidence that diets which contain high levels of phytoestrogenic isoflavones are associated with a low incidence of osteoporosis and menopausal symptoms. Plant extracts, which contain high levels of isoflavones, such as Red clover (Trifolium pratense L.), have been used to reduce menopausal symptoms. The objective of this study was to evaluate the preventive effects of Red clover total isoflavones on the progression of bone loss induced by estrogens deficiency (ovariectomy) in rats. Bilateral ovariectomy was performed on female Wistar rats. One week after the operation the rats were treated with an oral dose of 20 and 40 mg of total isoflavones daily for 14 weeks. The results from this study showed that the ovariectomy reduced bone mineral content, femoral weight, femoral density, mechanical strength of the tibia and increased the levels of bone specific alkaline phosphatase in the serum and the number of osteoclasts in the femur sections compared with sham operated controls. Treatment with isoflavones significantly increased bone mineral content, mechanical strength of the tibia, femoral weight, femoral density and prevented the rise of serum alkaline phosphatase levels. In addition, the treatment with isoflavones significantly reduced the number of osteoclasts compared with the ovariectomized control rats. These findings suggest that Red clover isoflavones are effective in reducing bone loss induced by ovariectomy, probably by reducing of the bone turnover via inhibition of bone resorption.
Subject(s)
Isoflavones/therapeutic use , Osteoporosis/drug therapy , Phytotherapy , Trifolium/chemistry , Animals , Body Weight/drug effects , Bone Density/drug effects , Bone Resorption/drug therapy , Disease Models, Animal , Female , Femur/anatomy & histology , Femur/drug effects , Isoflavones/chemistry , Isoflavones/pharmacology , Plant Extracts/chemistry , Plant Extracts/therapeutic use , Rats , Rats, Sprague-Dawley , Rats, Wistar , Tibia/drug effects , Tibia/physiology , Vaginal SmearsABSTRACT
The majority of injuries to truckers are caused by falls during the descent from the cab of the truck. Several studies have shown that the techniques used to descend from the truck and the layout of the truck's cabin are the principal cause of injury. The goal of the present study was to measure the effects of the descent techniques used by the trucker and the layout of the truck's cabin on the impact forces absorbed by the lower limbs and the back. Kinematic data, obtained with the aid of a video camera, were combined with the force platform data to allow for calculation of the lower limb and L5-S1 torques as well as L5-S1 compressive forces. The trucker descended from two different conventional tractor cabin layouts. Each trucker descended from cabin using either "facing the truck" (FT) or "back to the truck" (BT) techniques. The results demonstrate that the BT technique produces greater ground impact forces than the FT technique, particularly when the truck does not have a handrail. The BT technique also causes an increase in the compressive forces exerted on the back. In conclusion, the use of the FT technique along with the aids (i.e., handrails and all the steps) help lower the landing impact forces as well as the lumbosacral compressive forces.
