Bone density at weight-bearing and nonweight-bearing sites in ballet dancers: the effects of exercise, hypogonadism, and body weight

1994 ◽  
Vol 78 (2) ◽  
pp. 449-454 ◽  
Author(s):  
N. Young
Keyword(s):  
Body Weight ◽  
Bone Density ◽  
Weight Bearing ◽  
Ballet Dancers

Body weight versus body fat distribution, adiposity, and frame size as predictors of bone density.

1995 ◽  
Vol 80 (4) ◽  
pp. 1118-1123 ◽  
Author(s):  
H S Glauber ◽  
W M Vollmer ◽  
M C Nevitt ◽  
K E Ensrud ◽  
E S Orwoll
Keyword(s):  
Body Weight ◽  
Bone Density ◽  
Body Fat ◽  
Fat Distribution ◽  
Body Fat Distribution ◽  
Frame Size

Does weight-bearing exercise protect against the effects of exercise-induced oligomenorrhea on bone density?

1996 ◽  
Vol 6 (6) ◽  
pp. 448-452 ◽  
Author(s):  
G. Pearce ◽  
S. Bass ◽  
N. Young ◽  
C. Formica ◽  
E. Seeman
Keyword(s):  
Bone Density ◽  
Weight Bearing ◽  
Exercise Induced

Analysis of BP response and Ca2+ metabolism using the saturation kinetics model

1987 ◽  
Vol 253 (3) ◽  
pp. R501-R508
Author(s):  
N. Karanja ◽  
J. A. Metz ◽  
L. P. Mercer ◽  
D. A. McCarron
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Bone Density ◽  
Spontaneously Hypertensive Rat ◽  
Kinetics Model ◽  
Maximal Dose ◽  
Spontaneously Hypertensive ◽  
Rates Of Change ◽  
Saturation Kinetics ◽  
Serum Ionized Calcium

The provision of supplemental dietary calcium (dCa) lowers blood pressure (BP) in the spontaneously hypertensive rat (SHR). Whether calcium's antihypertensive effects can be expressed in the presence of potentially hypertensinogenic nutrients is not known. Furthermore, the amount of dCa required to attenuate hypertension in the SHR remains undetermined. Along with establishing the effects of dCa on BP under conditions of a high Na+ intake, we sought to define the lowest dose of dCa associated with the greatest attenuation in arterial pressure in the young SHR. Thirty-five 6-wk-old SHR were fed one of five diets containing either 0.1, 0.25, 0.5, 1.0, or 2.0% dCa. All diets contained 1.0% Na+. The rates of change (delta) in body weight, BP, and serum ionized calcium were determined between 6 and 20 wk of age. Bone density (BD) was measured only at 20 wk of age. The data were analyzed using the saturation kinetics model. Results indicate that the half-maximal dose (K50) of dCa needed to lower pressure is 0.67 +/- 0.18%, which is higher than the K50 for weight (0.23 +/- 0.18) and BD (0.36 +/- 0.22). It is concluded that supplemental dCa lowers BP despite a high Na+ intake. Furthermore, a dose of approximately 1.5 dCa is sufficient to attenuate the rate of hypertension in the young growing SHR.

scholarly journals Assessment of First Metatarsal Head Bone Density for Optimal Screw Placement in Minimally-Invasive Hallux Valgus Surgery

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0003
Author(s):  
Katherine M. Dederer ◽  
Patrick J. Maloney ◽  
John T. Campbell ◽  
Clifford L. Jeng ◽  
Rebecca A. Cerrato
Keyword(s):  
Bone Density ◽  
Minimally Invasive ◽  
Hallux Valgus ◽  
Screw Fixation ◽  
Weight Bearing ◽  
Metatarsal Head ◽  
Screw Placement ◽  
Cannulated Screws ◽  
First Metatarsal ◽  
History Of

Category: Bunion; Basic Sciences/Biologics Introduction/Purpose: Minimally-invasive surgery (MIS) for hallux valgus correction has become increasingly common. This technique involves an osteotomy of the first metatarsal, followed by fixation with two cannulated screws. Since screws are typically not bicortical, they rely upon bone quality within the metatarsal head for fixation strength. However, bone mineral density (BMD) within different regions of the metatarsal head is unknown. Measuring the BMD in the target region may predict the strength of the bone-screw fixation. Similar to previous work which determined the optimal position for lag screw placement in the femoral head during hip fracture fixation, this study aimed to determine average BMD within four quadrants of the metatarsal head using CT and thus predict the optimal trajectories for cannulated screws during the MIS bunion procedure. Methods: All patients between 18-75 years of age scheduled to undergo MIS hallux valgus correction by one of two surgeons experienced in the MIS technique were eligible to participate. Patients were excluded if they had a prior first metatarsal surgery, pre-existing hardware, previous first metatarsal fracture, or a history of osteoporosis treatment. Patients were enrolled prospectively, and a weight-bearing CT scan of the affected foot was obtained pre-operatively. Demographic factors including age, sex, laterality, body mass index (BMI), comorbidities, and smoking status as well as standard three-view weight-bearing radiographs were collected for all patients.Using the coronal CT slice at maximal metatarsal head diameter, each head was divided into equal quadrants. Hounsfield units (HU) within each quadrant were measured independently by three study investigators using our hospital’s radiology viewing software (Merge PACS; IBM Corporation, Armonk, NY), and these density measurements were averaged. Statistical analysis was conducted using ANOVA and Student’s t-test. Results: Fifteen patients were included for preliminary analysis. All patients were female. The average age was 45.7 years. 9 of the 15 included feet were right feet. Average BMI was 28.0. One patient reported active smoking prior to surgery. Comorbidities included obesity in three patients; none were diabetic. One had a history of diplegic cerebral palsy. The average HVA on a weight- bearing AP foot x-ray was 28.2°, and the average IMA was 12.6°. The BMD within the metatarsal head varied by quadrant, with the two combined dorsal quadrants having higher average BMD than the two combined plantar quadrants (122 vs 85 HU; p<0.001). The dorsal lateral quadrant had the highest average BMD of any quadrant (132 HU, p<0.001; Table 1). Conclusion: The density of the metatarsal head did vary by region within the head. The highest BMD was found in the dorsal lateral quadrant, and the lowest in the plantar lateral and plantar medial quadrants, which did not differ significantly from each other. Because strength of screw fixation is predicated upon screw design as well as bone density, these results suggest that surgeons may wish to direct screws toward the dorsolateral region of the metatarsal head in order to achieve optimal fixation. Further work is needed to determine whether this varies with patient age, gender, or hallux valgus angle. [Table: see text]

Effect of maternal weight gain during pregnancy on exercise performance

1990 ◽  
Vol 68 (3) ◽  
pp. 1173-1176 ◽  
Author(s):  
M. W. Carpenter ◽  
S. P. Sady ◽  
M. A. Sady ◽  
B. Haydon ◽  
D. R. Coustan ◽  
...  
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Exercise Performance ◽  
Weight Bearing ◽  
Work Load ◽  
Maternal Weight Gain ◽  
Maternal Weight ◽  
Exercise Tests ◽  
The Individual ◽  
Weight Gain During Pregnancy

We examined the effect of maternal weight gain during pregnancy on exercise performance. Ten women performed submaximal cycle (up to 60 W) and treadmill (4 km/h, up to 10% grade) exercise tests at 34 +/- 1.5 (SD) wk gestation and 7.6 +/- 1.7 wk postpartum. Postpartum subjects wearing weighted belts designed to equal their body weight during the antepartum tests performed two additional treadmill tests. Absolute O2 uptake (VO2) at the same work load was higher during pregnancy than postpartum during cycle (1.04 +/- 0.08 vs. 0.95 +/- 0.09 l/min, P = 0.014), treadmill (1.45 +/- 0.19 vs. 1.27 +/- 0.20 l/min, P = 0.0002), and weighted treadmill (1.45 +/ 0.19 vs. 1.36 +/- 0.20 l/min, P = 0.04) exercise. None of these differences remained, however, when VO2 was expressed per kilogram of body weight. Maximal VO2 (VO2max) estimated from the individual heart rate-VO2 curves was the same during and after pregnancy during cycling (1.96 +/- 0.37 to 1.98 +/- 0.39 l/min), whereas estimated VO2max increased postpartum during treadmill (2.04 +/- 0.38 to 2.21 +/- 0.36 l/min, P = 0.03) and weighted treadmill (2.04 +/- 0.38 to 2.19 +/- 0.38 l/min, P = 0.03) exercise. We conclude that increased body weight during pregnancy compared with the postpartum period accounts for 75% of the increased VO2 during submaximal weight-bearing exertion in pregnancy and contributes to reduced exercise capacity. The postpartum increase in estimated VO2max during weight-bearing exercise is the result of consistently higher antepartum heart rates during all submaximal work loads.

scholarly journals Prediction of pathological fracture in patients with metastatic disease of the lower limb

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Emma L. Howard ◽  
Paul Cool ◽  
Gillian L. Cribb
Keyword(s):  
Body Weight ◽  
Metastatic Disease ◽  
Lower Limb ◽  
Prospective Observational Study ◽  
Pathological Fracture ◽  
Weight Bearing ◽  
Total Body Weight ◽  
Threshold Level ◽  
Total Body ◽  
Optimum Threshold

Abstract The aim of this study was to investigate if the risk of pathological fracture can be predicted with the proportion of body weight that can be put through the affected leg in patients with metastatic bone disease of the lower limb. A prospective observational study was conducted in patients with metastatic disease in the lower limb. Receiver Operator Characteristic curves were used to identify the optimum threshold level of single stance weight bearing to predict fracture and compared to the Mirels score. Patients who underwent surgery could weight bear significantly less than those who did not have surgical intervention. The optimum threshold to predict pathological fracture was 85% of total body weight. No patient below the threshold level of 85% single stance body weight sustained a pathological fracture. The use of single stance body weight can be a useful in conjunction with the Mirels score to predict pathological fracture. If less than 85% of total body weight can be put through the affected limb, the risk of fracture increases, and consideration of treatment is suggested.

scholarly journals The Effectiveness of Physical Exercise on Bone Density in Osteoporotic Patients

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Maria Grazia Benedetti ◽  
Giulia Furlini ◽  
Alessandro Zati ◽  
Giulia Letizia Mauro
Keyword(s):  
Bone Density ◽  
Physical Exercise ◽  
Bone Mass ◽  
Weight Bearing ◽  
Reaction Force ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Body Vibration ◽  
Body Regions ◽  
Resistance Exercises

Physical exercise is considered an effective means to stimulate bone osteogenesis in osteoporotic patients. The authors reviewed the current literature to define the most appropriate features of exercise for increasing bone density in osteoporotic patients. Two types emerged: (1) weight-bearing aerobic exercises, i.e., walking, stair climbing, jogging, and Tai Chi. Walking alone did not appear to improve bone mass; however it is able to limit its progressive loss. In fact, in order for the weight-bearing exercises to be effective, they must reach the mechanical intensity useful to determine an important ground reaction force. (2) Strength and resistance exercises: these are carried out with loading (lifting weights) or without (swimming, cycling). For this type of exercise to be effective a joint reaction force superior to common daily activity with sensitive muscle strengthening must be determined. These exercises appear extremely site-specific, able to increase muscle mass and BMD only in the stimulated body regions. Other suggested protocols are multicomponent exercises and whole body vibration. Multicomponent exercises consist of a combination of different methods (aerobics, strengthening, progressive resistance, balancing, and dancing) aimed at increasing or preserving bone mass. These exercises seem particularly indicated in deteriorating elderly patients, often not able to perform exercises of pure reinforcement. However, for these protocols to be effective they must always contain a proportion of strengthening and resistance exercises. Given the variability of the protocols and outcome measures, the results of these methods are difficult to quantify. Training with whole body vibration (WBV): these exercises are performed with dedicated devices, and while it seems they have effect on enhancing muscle strength, controversial findings on improvement of BMD were reported. WBV seems to provide good results, especially in improving balance and reducing the risk of falling; in this, WBV appears more efficient than simply walking. Nevertheless, contraindications typical of senility should be taken into account.

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