Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FOREARM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources
PubMed1971

Human forearm metabolism during progressive starvation.

Forearm muscle metabolism was studied in eight obese subjects after an overnight, 3 and 24 day fast. Arterio-deep-venous differences of oxygen, carbon dioxide, glucose, lactate, pyruvate, free fatty acids, acetoacetate, and beta-hydroxybutyrate with simultaneous forearm blood flow were measured. Rates of metabolite utilization and production were thus estimated. Oxygen consumption and lactate and pyruvate production remained relatively constant at each fasting period. Glucose, initially the major substrate consumed, showed decreased consumption after 3 and 24 days of fasting. Acetoacetate and beta-hydroxybutyrate consumption after an overnight fast was low. At 3 days of fasting with increased arterial concentrations of acetoactate and beta-hydroxybutyrate, consumption of these substrates rose dramatically. At 24 days of fasting, despite further elevation of arterial levels of acetoacetate and beta-hydroxybutyrate, the utilization of acetoacetate did not increase further and if anything decreased, while five out of eight subjects released beta-hydroxybutyrate across the forearm. Acetoacetate was preferentially extracted over beta-hydroxybutyrate. At 24 days of starvation, free fatty acids were the principal fuels extracted by forearm muscle; at this time there was a decreased glucose and also ketone-body consumption by skeletal muscle.

Acetoacetates↗
PubMed1993

Vasodilatory effect of arginine vasopressin is mediated by nitric oxide in human forearm vessels.

Arginine vasopressin (AVP) causes biphasic changes in vascular resistance in human forearms; vasoconstriction at lower doses and vasodilation at higher doses. Vasoconstriction is mediated by the V1 receptor. However, the mechanism of AVP-induced vasodilation is not known. We investigated whether AVP-induced vasodilation is mediated by nitric oxide (NO) in human forearms by examining the effects of L-arginine (a precursor of NO) and NG-monomethyl-L-arginine (L-NMMA, a blocker of NO synthase) on AVP-induced vasodilation. AVP was infused intraarterially at doses of 0.05, 0.1, 0.2, 0.5, and 1.0 ng/kg per min (n = 8). The lower doses of AVP (< or = 0.1 ng/kg per min) increased, whereas the higher doses of AVP (> or = 0.5 ng/kg per min) decreased forearm vascular resistance (FVR) (P < 0.01). Intraarterially infused L-arginine at 10 mg/min did not alter arterial pressure, baseline FVR, or heart rate. L-arginine did not alter the magnitude of AVP-induced vasoconstriction at the lower doses, but L-arginine augmented the magnitude of AVP-induced vasodilation at doses of 0.2 (P < 0.05), 0.5 (P < 0.01), and 1.0 (P < 0.05) ng/kg per min. In another group (n = 6), intraarterially infused L-NMMA (4 mumol/min for 5 min) increased baseline FVR without systemic effects, and inhibited acetylcholine-induced vasodilation (P < 0.01). L-NMMA at this dose inhibited AVP-induced vasodilation (P < 0.01) but did not affect vasoconstriction. L-arginine reversed the inhibitory effect of L-NMMA. Our results suggest that the vasodilatory effect of AVP may be mediated by NO in human forearms.

Adult↗
PubMed1996

NG-monomethyl-L-arginine inhibits the blood flow but not the insulin-like response of forearm muscle to IGF- I: possible role of nitric oxide in muscle protein synthesis.

In human skeletal muscle, insulin-like growth factor-I (IGF-I) exerts both growth hormone-like (increase in protein synthesis) and insulin-like (decrease in protein degradation and increase in glucose uptake) actions and augments forearm blood flow two- to threefold. This study was designed to address whether (a) the increase in blood flow due to IGF-I could be blocked by an inhibitor of nitric oxide synthase; and (b) the metabolic actions of IGF-I were altered by use of a nitric oxide synthase inhibitor. Forearm blood flow, glucose, lactate, oxygen, nitrite, and phenylalanine balances and phenylalanine kinetics were studied in a total of 17 healthy, adult volunteers after an overnight fast in two different protocols. In protocol 1, after basal samples IGF-I was infused alone for 4 h with samples repeated during the last 30 min. After the 4-h sample period, NG-monomethyl-L-arginine (L-NMMA) was infused into the brachial artery for 2 h to bring flow back to baseline and repeat samples were taken (6 h). In response to IGF-I alone, forearm blood flow rose from 3.8 +/- 1.0 (bas) to 7.9 +/- l.9 (4 h) ml/min/100 ml (P < 0.01) and was reduced back to baseline by L-NMMA at 6 h (P < 0.01). In protocol 1, IGF-I alone increased forearm nitrite release at 4 h (P < 0.03), which was reduced back to baseline by L-NMMA at 6 h (P < 0.05). Despite the reduction in flow with L-NMMA, IGF+L-NMMA yielded increases in glucose uptake (P < 0.005), lactate release (P < 0.04), oxygen uptake (P < 0.01), and a positive shift in phenylalanine balance (P < 0.01) due to both an increase in muscle protein synthesis (P < 0.02) and a decrease in protein degradation (P < 0.03). In protocol 2, L-NMMA was coinfused with IGF-I for 6 h, with the dose titrated to keep blood flow +/- 25% of baseline. Coinfusion of L-NMMA restrained blood flow to baseline and also yielded the same, significant metabolic effects, except that no significant increase in muscle protein synthesis was detected. These observations suggest: (a) that IGF-I increases blood flow through a nitric oxide-dependent mechanism; (b) that total blood flow does not affect the insulin-like response of muscle to IGF-I; and (c) that nitric oxide may be required for the protein synthetic (growth hormone-like) response of muscle to IGF-I.

Adult↗
PubMed2006

The effect of tennis racket grip size on forearm muscle firing patterns.

BACKGROUND: Inappropriately sized tennis racket grip is often cited in the popular media as a risk factor for overuse injuries about the forearm and elbow. Currently, a hand measurement technique developed by Nirschl is commonly used by tennis racket manufacturing companies as the method for determining a player's "recommended" grip size. HYPOTHESIS: Quarter-inch changes from that recommended by Nirschl in tennis racket grip size will have no significant effect on forearm muscle firing patterns. STUDY DESIGN: Controlled laboratory study. METHODS: Sixteen asymptomatic Division I and II collegiate tennis players performed single-handed backhand ground strokes with rackets of 3 different grip sizes (recommended measurement, undersized (1/4) in, and oversized (1/4) in). Fine-wire electromyography was used to measure muscle activity in extensor carpi radialis longus and brevis, extensor digitorum communis, flexor carpi radialis, and pronator teres. Repeated-measure analysis of variance was used for within-group comparisons, comparing different grips in specified phases for backhand ground strokes (P <or= .05). RESULTS: There were no significant differences in muscle activity between small, recommended, or big grips in any muscle tested. CONCLUSION: Based on these findings, tennis racket grip size (1/4) in above or below Nirschl's recommended measurement does not significantly affect forearm muscle firing patterns. CLINICAL RELEVANCE: Alterations in tennis racket grip size within (1/4) in of Nirschl's recommended sizing do not have a significant effect on forearm muscle activity and therefore may not represent a significant risk factor for upper extremity cumulative trauma, such as lateral epicondylitis.

Adult↗
PubMed1990

Glucose and gluconeogenic substrate exchange by the forearm skeletal muscle in hyperglycemic and insulin-treated type II diabetic patients.

To determine the contribution of skeletal muscle to fasting hyperglycemia in noninsulin dependent type II diabetes (NIDDM), the forearm balance of glucose, lactate, and alanine was quantified in 25 control subjects, 21 hyperglycemic (blood glucose: 11.6 mmol/L), and 19 insulin-treated patients with NIDDM (blood glucose: 5.8 mmol/L). Forearm glucose uptake was similar in controls (4.6 +/- 0.6 mumol L-1 min-1) and in hyperglycemic diabetic patients (4.5 +/- 0.9 mumol L-1 min-1). In spite of this, in the diabetic patients lactate (5.1 +/- 0.8 mumol L-1 min-1) and alanine (2.6 +/- 0.4) release by the forearm was 3- and 2-fold higher than in the control group (lactate: 1.7 +/- 0.8, P less than 0.005; and alanine: 1.3 +/- 0.2, P less than 0.05, respectively). The ratio of lactate release to glucose uptake was 57% and 18% in diabetic and control subjects, respectively. Insulin administration did not affect either glucose uptake or the release of gluconeogenic substrates by the forearm. It is concluded that: 1) in fasting patients with NIDDM, glucose is taken up by the skeletal muscle in normal amounts but preferentially used nonoxidatively with lactate formation. This suggests that, although the muscle does not contribute directly to fasting hyperglycemia, it may play an indirect role through an increased delivery of glucose precursors; and 2) insulin-induced normoglycemia is maintained by mechanisms that do not involve the exchange of glucose and gluconeogenic substrates by the skeletal muscle.

Adult↗
PubMed1994

Recombinant human insulin-like growth factor-I increases forearm blood flow.

Several recent reports have described systemic effects associated with insulin-like growth factor-I (IGF-I) infusions in humans, including dizziness, syncope, unconsciousness, bradycardia, and asystole. Eleven healthy volunteers (10 males and 1 female) underwent brachial arterial and deep forearm venous catheterizations to evaluate the effects of an intraarterial infusion of IGF-I on blood flow. Saline was infused into the brachial artery for 1 h, followed by infusions of recombinant human IGF-I (1.25, then 10 micrograms/kg BW.h) over 2 subsequent 90-min periods. Blood flow across the forearm was determined from dye dilution curves after an infusion of indocyanine green dye (20 mg/h) into the proximal arterial port. The rate of saline infusion had no effect on forearm blood flow. Likewise, the low dose arterial IGF-I infusion had no effect on blood flow, even though deep venous IGF-I concentrations increased slightly (127 +/- 37 to 172 +/- 19 ng/mL; P = NS). The 10 micrograms/kg.h infusion rate increased deep venous IGF-I concentrations approximately 4-fold above control values (477 +/- 80 vs. 150 +/- 27 ng/mL, respectively; P < 0.0001), whereas IGF-I concentrations in the peripheral circulation were increased approximately 2-fold (299 +/- 50 ng/mL) above control values (P < 0.0001). Arteriovenous glucose differences, peripheral glucose concentrations, and binding protein-3 concentrations were not influenced by either dose of IGF-I. The 10 micrograms/kg.h dose of IGF-I was associated with a 68% increase in forearm blood flow (71 +/- 8 vs. 42 +/- 6 mL/min, respectively; P < 0.0004). These data suggest that an intravascular infusion of IGF-I results in significant alterations in regional blood flow, which may be related to the observed physiological effects or side-effects associated with its use.

Adult↗
PubMed2000

Biomechanical simulation of an amputated forearm with and without a prosthesis.

In this study a computer simulation was developed for analysing the performance of a below-elbow amputated forearm, with and without a prosthesis. The upper extremity was represented in terms of two rigid bodies, the arm and the forearm. Five muscles, three elbow flexors and two elbow extensors, were included in the model. The muscle model used was the five-component model, including the contractile, parallel, series and viscous elements and the muscle mass. Dynamic and static simulations were conducted, with and without prosthesis, to study parametrically the effects of stump length, tendon distal transfer, tendon or muscle shortening and muscle physiological cross-sectional area. The performance measures which were the most affected included flexion moment of the forearm about the elbow, muscle moment, force in the joint, flexion rate and mechanical energy. The simulation presented an interesting case when the amputation site is more proximal than the anatomical insertion point of a muscle, necessitating shortening of the muscle to avoid the situation where it exerts no force. It was also found that, of the changeable parameters, the most beneficial changes in the forearm parameters for improved dynamic performance were: (a) tendon distal transfer and (b) increase of the muscle cross-sectional area, the latter achievable by means of physical training.

Amputation, Surgical↗
PubMed1988

Exercise training augments cardiopulmonary baroreflex control of forearm vascular resistance in middle-aged subjects.

Nine subjects (average age 56 +/- 7 years old) underwent sitting cycle ergometer exercise for four months. Exercise capacity and maximal VO2 increased after exercise training in these subjects. Forearm vascular responses to lower body negative pressure (LBNP) at -10 and -40 mmHg were compared before and after exercise training. The magnitude of reflex forearm vasoconstriction in response to LBNP at -10 mmHg was greater after exercise training than before. The decreases in central venous pressure during LBNP at -10 mmHg were similar before and after exercise training. The pressor and forearm vasoconstrictive responses to the cold pressor test also did not differ before and after exercise training. These results suggest that mild exercise training in middle-aged subjects augments the tonic inhibitory influence of the cardiopulmonary receptors on forearm vascular resistance.

Adult↗
PubMed2001

Sodium chloride loading does not alter endothelium-dependent vasodilation of forearm vasculature in either salt-sensitive or salt-resistant patients with essential hypertension.

The purpose of this study was to determine whether a high NaCl intake impairs endothelium-dependent and -independent vasodilation of forearm circulation in salt sensitive (SS) patients with essential hypertension. We evaluated the effects of intra-arterial acetylcholine (ACh) and isosorbide dinitrate (ISDN) on forearm hemodynamics in 29 patients with essential hypertension, while consuming a low NaCl (50 mmol/d) or high Na Cl (340 mmol/d) diet for 1 week. The forearm blood flow (FBF) was measured by strain-gauge plethysmography. Patients were classified as SS (n=12) or salt resistant (SR; n=17) based on salt-induced changes in blood pressures. The FBF responses of ACh and ISDN were similar in the SS and SR patients while on either NaCl diet, and was not altered by salt loading (ACh, SS: low NaCl 22.8+/-4.3 vs. high NaCl 21.1+/-3.6 ml/min per 100 ml, SR: low NaCl 22.5+/-4.0 vs. high NaCl 23.3+/-4.1 ml/min per 100 ml; ISDN, SS: low NaCl 13.9+/-2.1 vs. high NaCl 14.1+/-2.2 ml/min per 100 ml, SR: low NaCl 13.8+/-2.3 vs. high NaCl 14.0+/-2.2 ml/min per 100 ml). There were no significant differences in the vascular responses to ACh and ISDN in the presence of N(G)-monomethyl-L-arginine, a nitric oxide synthase inhibitor, in either group for either NaCl diet. These findings suggest that forearm resistance artery endothelial function may not be influenced by salt loading in either SS patients which finding may play a role in determining salt sensitivity in patients with essential hypertension or SR patients.

Diet, Sodium-Restricted↗
PubMed1994

Cardiopulmonary bypass and forearm blood flow.

STUDY OBJECTIVE: To assess the effect of cardiopulmonary bypass (CPB) on muscle blood flow (MBF) when measured in the forearm by venous occlusion plethysmography. DESIGN: This was a prospective study. SETTING: Operating room area of a tertiary care university medical center. PARTICIPANTS: Twenty-seven patients (25 men and 2 women), aged 62 +/- 1.5 years, undergoing elective coronary bypass grafting. INTERVENTIONS: Measurements were made during the surgical procedure: before, during cold and warm, and after discontinuation of CPB. MEASUREMENTS AND RESULTS: Changes in forearm blood flow (FBF), derived forearm vascular resistance (FVR), mean arterial pressure (MAP), and cardiac output (CO) were evaluated by repeated measures analysis of variance. The control FBF (measured before CPB) was found to be approximately 50 percent lower than that previously reported for awake volunteers and patients. The FVR was similarly higher. From these low values, the FBF increased significantly (p < 0.001) during normothermic bypass and after CPB. Forearm vascular resistance decreased significantly (p < 0.001) throughout the cold, warm, and postbypass periods. Only during the warm and the postbypass periods did FBF and FVR reach normal values. Mean arterial pressure decreased significantly (p < 0.01) throughout. There was no statistically significant association between any of the variables and FBF or FVR. After correcting for patient and surgical phase variability, only MAP had a statistically significant effect (p = 0.042) on FVR; blood temperature, skin temperature, hematocrit level, PaCO2, serum potassium, and systemic vascular resistance (SVR) had no effect on either FBF or FVR when tested singly or in combination. When correction for multiple comparisons was applied, the lowest probability value became greater than 0.25. There was no correlation between combinations of covariates and FBF or FVR after adjustments for the surgical phase of the study either. CONCLUSION: These findings indicate that the increase in MBF seen during warm and the post-CPB periods is only a recovery toward normal blood flow. The role of this change in the low SVR that usually accompanies CPB is equivocal.

Blood Pressure↗
PubMed2001

How reliable is the ultrasound densitometer for community screening to diagnose osteoporosis in spine, femur, and forearm?

Dual X-ray absorptiometry (DXA) is the most widely used noninvasive, quantitative diagnostic method of measuring bone density, but it exhibits several limitations for the purpose of general screening and community-based study. Thus, we evaluated the feasibility of the ultrasound densitometer SoundScan Compact for screening the osteoporosis community. We compared the reliability of the SoundScan Compact's measurement to predict both osteopenia and osteoporosis at the spine, femur, and forearm measured by the XR-36. World Health Organisation criteria and Korean reference were used for the diagnosis of osteopenia and osteoporosis. Of the 1827 subjects screened in the community, we randomly selected and invited 106 subjects to our university hospital center for clinical epidemiology for further evaluation of their bone health using DXA. The site-specific relationships among speed of sound and bone mineral density at L2-L4 spine, femoral neck, trochanter, Ward's triangle, distal radius + ulna, proximal radius + ulna, and proximal radius were highly correlated with r values of 0.633, 0.632, 0.674, 0.632, 0.668, 0.78, and 0.777 respectively (all p < 0.0001). Of the 42 subjects defined as normal in the spine by SoundScan Compact's, 27 (64.3%) were also in agreement as the normal by the XR-36. However, an agreement of 43.5% (10/23) in osteopenia and 53.7% (22/41) in osteoporosis was less sensitive. Reliability tested by kappa statistics (kappa = 0.35; t = 5.3; p < 0.0001) revealed that the degree of agreement was not coincidental. On the femur, 54.8% (23/42) agreed as normal, 73.9% (17/23) as osteopenia, and 39% (16/41) as osteoporosis (kappa = 0.33; t = 5.5; p < 0.0001). Higher reliability was found in the forearm, with a kappa value of 0.48, t = 7.2, and p < 0.0001. A magnitude of agreement was also greater in the forearm, with 83.3% (35/42) agreement in normal, 52.2% (12/23) in osteopenia, and 64% (16/25) in osteoporosis. Although the SoundScan Compact's measures different bone properties and measurements are taken at different sites, it is a very useful instrument with a high correlation and high degree of variation and reliability to predict bone health at other sites such as the spine, femur, and forearm. The ultrasound densitometer such as SoundScan Compact's merits its use for community screening and in the primary care setting to detect osteopenia and osteoporosis for the purpose of early detection and prevention.

Absorptiometry, Photon↗
PubMed2006

Bilateral cardiac catheterizations: the safety and feasibility of a superficial forearm venous and transradial arterial approach.

The transradial approach for left heart catheterization has become increasingly popular recently because of its clinical benefits. We examined the safety and feasibility of a transforearm approach for bilateral cardiac catheterizations, using the radial artery and a superficial forearm vein (the cephalic, basilic, or median antecubital vein). Between August 2002 and October 2003, 296 right heart catheterizations were performed in our hospital. A superficial forearm vein was used in one group of 101 patients, of which 98 had a concomitant left heart catheterization through the radial artery. The femoral vein was used for right heart catheterization in the second group of 195 patients. Of these patients, 37 underwent left heart catheterization through the radial artery and 157 through the femoral artery. All instances of bilateral catheterizations were successful except for one complication of pseudoaneurysm occurring in the transfemoral group. The procedure time for right heart catheterization was significantly less in the forearm group than the femoral group. The transforearm group had a larger proportion of males and of patients undergoing diagnostic right heart catheterization for congestive heart failure, dilated cardiomyopathy, and ischemic cardiomyopathy. Patients with aortic stenosis (AS), atrial septal defect (ASD), and mitral stenosis (MS) were mainly restricted to the transfemoral approach. We conclude that the transradial artery and superficial forearm venous approach for bilateral cardiac catheterizations is a safe and feasible alternative to the femoral approach in a wide range of patients, with the exception of patients with AS, ASD, or MS.

Adult↗
PubMed2002

Proximal radial resection for posttraumatic radioulnar synostosis: a new technique to improve forearm rotation.

BACKGROUND: Heterotopic ossification about the elbow joint can lead to considerable functional disability, including the loss of forearm rotation. Many procedures have been described for the treatment of proximal radioulnar synostosis. Varying degrees of success have been achieved with regard to the improvement of the flexion arc, but less success has been reported in terms of the restoration of forearm rotation. The success of treatment is associated with the extent of heterotopic ossification, soft-tissue scarring, and anatomical distortion. A new and simple technique to address the unresectable proximal radioulnar synostosis is described. METHODS: Seven patients were managed with a partial proximal radial resection distal to the synostosis and were followed for an average of eighty months (range, twenty-four to 144 months). RESULTS: Forearm rotation improved from an average fixed pronation of 5 degrees to an average arc of 98 degrees (range, 40 degrees to 175 degrees ). The average functional score improved from 57 points preoperatively to 81 points at the time of the final review. Complications included reankylosis at the site of the resection and ulnar-nerve sensory neurapraxia in one patient each. CONCLUSIONS: Resection of a 1-cm-thick section of the proximal part of the radial shaft provides a safe and reliable method of improving forearm rotation in patients with heterotopic ossification of the elbow. A single technical factor that seems to positively influence the result is the application of bone wax at the resection site. This simple procedure is ideally suited for patients who have a proximal radioulnar synostosis that (1) is too extensive to allow a safe and discrete resection, (2) involves the articular surface, and (3) is associated with an anatomical deformity.

Adult↗
PubMed2003

A prospective, randomized trial comparing the limited contact dynamic compression plate with the point contact fixator for forearm fractures.

BACKGROUND: The most effective type of plate fixation for diaphyseal forearm fractures has not been defined. We performed a prospective, randomized trial in which the limited contact dynamic compression plate (LC-DCP) was compared with the Point Contact Fixator (PC-Fix) for the treatment of forearm fractures at one center. METHODS: Ninety-two patients with 125 forearm fractures were recruited for the study and were randomly assigned to fracture fixation with one of the two devices. The average age of the patients was thirty-six years. The average duration of follow-up was twenty-two months. Patients were assessed periodically with use of radiographs and were assessed with regard to pain and function at time of the latest follow-up. RESULTS: Three patients (four fractures) in the PC-Fix group and five patients (five fractures) in the LC-DCP group had a delayed union, but no patient in either group had a nonunion. With the numbers available, there was no significant difference between the two groups with regard to operative time, time to union, callus formation, pain, or functional outcome. Deep infection occurred in one patient with a closed fracture in the PC-Fix group and in one patient with an open fracture in the LC-DCP group. In addition, one refracture occurred in each group. Both refractures occurred at the site of a screw track. CONCLUSION: Despite the differences in the concept of fracture fixation, these two implants appear to be equally effective for the treatment of diaphyseal forearm fractures.

Adult↗
PubMed2006

Comparison of short and long arm plaster casts for displaced fractures in the distal third of the forearm in children.

BACKGROUND: Various methods of cast immobilization have been recommended for the treatment of distal forearm fractures in children. The purpose of this study was to determine if short arm casts are as effective as long arm casts in the treatment of displaced fractures of the distal third of the forearm in these patients. METHODS: In a prospective randomized trial, consecutive patients, four years of age or older, who presented to The Women's and Children's Hospital of Buffalo with a displaced fracture of the distal third of the forearm were randomized to treatment with a short or long arm plaster cast. Radiographs were analyzed for displacement, angulation, and deviation at the time of injury, after reduction, and at subsequent follow-up intervals. The cast index at the fracture level, used to assess the quality of the cast molding, was determined from the postreduction radiographs. Changes between postreduction and final values for displacement, angulation, and deviation; the ranges of motion of both wrists and elbows; the need for physical therapy; and responses to a questionnaire used to evaluate the effects of the cast on activities of daily living were compared between the groups. RESULTS: One hundred and thirteen of the 151 patients who were assessed for eligibility were analyzed. The follow-up rate was 92%, and the average duration of follow-up was eight months. Sixty long arm casts and fifty-three short arm casts were used. There were no significant differences between the two groups with regard to patient demographics, initial fracture characteristics, mechanism of injury, cast index, or the change in displacement, angulation, or deviation during treatment. The fractures that lost reduction in the cast had significantly higher cast indices, indicating poor cast-molding. A comparison of partially and completely displaced fractures revealed no difference between the groups with regard to the change between the postreduction and final amount of displacement. Patients treated with a short arm cast missed fewer school days and were less likely to require assistance with various activities of daily living. CONCLUSIONS: A well-molded short arm cast can be used as effectively as a long arm cast to treat fractures of the distal third of the forearm in children four years of age and older, and they interfere less with daily activities.

Activities of Daily Living↗
PubMed1989

1989 ARRS Executive Council Award. Exercise-enhanced MR imaging of variations in forearm muscle anatomy and use: importance in MR spectroscopy.

31P MR spectroscopic studies of forearm exercise frequently assume that the volume sampled is appropriate for the muscle of interest and that individual variations in muscle anatomy and use are not important. Postexercise MR imaging was used to assess variations in the size, location, and use of forearm flexors and the accuracy of palpation as a method for locating the muscle of interest. By using the information obtained with MR, the effects of errors in surface-coil position relative to the muscle of interest on 31P MR spectroscopy were examined. In the midforearm of seven men, the greatest diameter of the flexor carpi ulnaris was 29 +/- 4 mm, and that of the flexor digitorum superficialis was 28 +/- 6 mm. However, in the proximal forearm, 58 +/- 10% of the diameter was covered by the palmaris longus, when present (79% of subjects). An unexpected finding was that a focal portion of the superficial finger flexor was used primarily as a wrist flexor in 26% of subjects. Palpation incorrectly identified flexor muscle margins by more than 15 mm in 50% of attempts. When a surface coil was positioned over wrist flexors during handgrip, attenuation of exercise-induced changes in 31P spectra resulted. Exercise-enhanced MR imaging reveals variations in forearm muscle anatomy and use that are common and difficult to appreciate by palpation. It therefore allows improved localization of the sensitive volume for MR spectroscopic studies of muscle physiology.

Adult↗
PubMed1987

Decreased uptake of glucose by human forearm during infusion of leucine, isoleucine, or threonine.

Competition between glucose and free fatty acids as metabolic fuels is supported by both in vitro and in vivo data, but whether amino acids can also compete with glucose as a source of energy in vivo remains to be established. To determine the effect of increased availability of an amino acid on whole-body glucose flux and glucose carbon uptake by the human forearm, five groups of overnight-fasted normal subjects were infused with either saline, leucine (at 0.5 or 1.0 mumol X kg-1 X min-1), isoleucine (0.5 mumol X kg-1 X min-1), or threonine (0.5 mumol X kg-1 X min-1). Plasma glucose concentrations and glucose flux decreased similarly in all groups. No significant changes in forearm output of leucine carbon, isoleucine carbon, or threonine were seen during saline infusion. In contrast, during leucine infusion there was a dose-dependent increase (r = .86, P less than .001) in leucine carbon uptake with increased arterial leucine and alpha-ketoisocaproate concentrations. During infusions of isoleucine and threonine, increases (P less than .05) in isoleucine carbon uptake and threonine uptake, respectively, were observed. Glucose uptake by forearm tissues did not change during the saline infusion, but it decreased (P less than .05) in all four groups receiving an amino acid infusion. Changes in leucine carbon uptake were strongly correlated (r = -.76, P less than .001) with changes in glucose uptake. Therefore, amino acids affect glucose uptake in human forearm tissue and presumably compete as oxidative fuels.

Adult↗
PubMed2002

Rapid changes in postprandial blood glucose produce concentration differences at finger, forearm, and thigh sampling sites.

OBJECTIVE: To compare pre- and postmeal capillary blood glucose concentrations measured at the finger, forearm, and thigh in adults with diabetes. RESEARCH DESIGN AND METHODS: For phase 1, capillary blood glucose concentrations were measured at six time points (premeal and at approximately 60, 90, 120, 150, and 180 min postmeal) using a blood glucose monitoring system and technician-obtained samples collected from finger, forearm, and thigh sites of 42 adults with diabetes. The finger samples were also tested with a laboratory instrument. For phase 2, approximately 14 weeks later, the testing procedures were repeated with 38 subjects from the original study population. RESULTS: Meter finger results were accurate at all time points. Alternate sites tended to produce lower glucose readings compared to finger readings at times when glucose was increasing rapidly (60 and 90 min postmeal). Forearm-to-finger differences correlated with rates of glucose change (r = 0.56, P < 0.001), as did the thigh-to-finger differences (r = 0.52, P < 0.001). Other factors, such as subject age, BMI, diabetes type, and insulin dependence did not have a significant impact on site differences. When the testing procedures were repeated with the same subjects, the pattern of site differences was consistent, although individual results were variable. CONCLUSIONS: Changes in blood glucose immediately after a meal may be identified at finger sites before detection at forearm or thigh sites. Alternate site testing appears to be a useful option for routine self-monitoring before meals; however, patients and clinicians should recognize that results may be different from fingertip results when glucose levels are changing rapidly.

Adult↗