Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ARM”

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 415 records · Page 23Linked to original sources
PubMed1986

Phase-dependent organization of postural adjustments associated with arm movements while walking.

This study examines the interactions between anteroposterior postural responses and the control of walking in human subjects. In the experimental paradigm, subjects walked upon a treadmill, gripping a rigid handle with one hand. Postural responses at different phases of stepping were elicited by rapid arm pulls or pushes against the handle. During arm movements, EMG's recorded the activity of representative arm, ankle, and thigh segment muscles. Strain gauges in the handle measured the force of the arm movement. A Selspot II system measured kinematics of the stepping movements. The duration of support and swing phases were marked by heel and toe switches in the soles of the subjects' shoes. In the first experiment, subjects were instructed to pull on the handle at their own pace. In these trials all subjects preferred to initiate pulls near heel strikes. Next, when instructed to pull as rapidly as possible in response to tone stimuli, reaction times were similar for all phases of the step cycle. Leg muscle responses associated with arm pulls and pushes, referred to as "postural activations," were directionally specific and preceded arm muscle activity. The temporal order and spatial distribution of postural activations in the muscles of the support leg were similar when arm pull movements occurred while the subject was standing in place and after heel strike while walking. Activations began in the ankle and radiated proximally to the thigh and then the arm. Activations of swing leg muscles were also directionally specific and involved flexion and forward or backward thrust of the limb. When arm movements were initiated during transitions from support by one leg to the other, patterns of postural activations were altered. Alterations usually occurred 10-20 ms before hell strikes and involved changes in the timing and sometimes the spatial structure of postural activations. Postural activation patterns are similar during in-place standing and during the support phase of locomotion. Walking and posture control appear to be separately organized but interrelated activities. Our results also suggest that the stepping generators, not peripheral feedback time locked to heel strikes, modulate postural activation patterns.

Adult↗
PubMed1994

Arm position constraints when throwing in three dimensions.

1. Overarm throwing is a skilled multijoint movement with potentially many degrees of freedom. Considering only the arm > or = 7 degrees of freedom are involved (shoulder 3, elbow 2, wrist 2). For each arm segment 3 degrees of freedom are potentially required to specify its angular position (orientation) at any moment during a throw. Simplification of the control problem for the CNS would occur if there were constraints on these degrees of freedom. The objective was to determine whether such constraints exist at ball release when throwing at targets in different directions using only the arm. 2. The angular positions in three dimensions of the distal phalanx of the middle finger, the hand, the forearm, and the upper arm were simultaneously recorded with search coils as subjects sat with a fixed trunk and threw balls at nine targets in an approximate +/- 40 degree work space. Ball release was signaled by microswitches on the proximal and distal phalanges of the middle finger (proximal and distal triggers). 3. On throwing at any one target the hand at ball release adopted a similar orientation for each throw, i.e., for a particular vertical and horizontal angular position the hand adopted a similar torsional position. On throwing at targets throughout the work space, angular position (rotation) vectors describing hand positions in space at ball release were confined to a two-dimensional surface rather than a three-dimensional volume. This constraint in hand torsion occurred near and at ball release but not throughout the entire throw. It was not due to mechanical factors because such a surface was not obtained when subjects deliberately twisted their arms when throwing. Thus at ball release during a "natural" throw the hand was constrained to 2 of its possible 3 angular degrees of freedom. 4. The same constraint was also found for finger, forearm, and upper arm angular positions in space at ball release as determined at both the proximal and distal triggers. A consequence is that at ball release the entire arm was constrained to 2 of its possible 7 degrees of freedom. 5. The two-dimensional position vector surface for each arm segment was similar to that obtained when pointing with a straight arm at the same targets. In both cases they showed torsion and were twisted like the surface obtained by rotations around the horizontal and vertical axes of a Fick gimbal. However, in some subjects the throwing surfaces were tilted from the vertical.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1999

Comparison of external load compensation during rhythmic arm movements and rhythmic jaw movements in humans.

Experiments were performed on human elbow flexor and extensor muscles and jaw-opening and -closing muscles to observe the effect on rhythmic movements of sudden loading. The load was provided by an electromagnetic device, which simulated the appearance of a smoothly increasing spring-like load. The responses to this loading were compared in jaw and elbow movements and between expected and unexpected disturbances. All muscles showed electromyographic responses to unexpected perturbations, with latencies of approximately 65 ms in the arm muscles and 25 ms in the jaw. When loading was predictable, anticipatory responses started in arm muscles approximately 200 ms before and in jaw muscles 100 ms before the onset of loading. The reflex responses relative to the anticipatory responses were smaller for the arm muscles than for the jaw muscles. The reflex responses in the arm muscles were the same with unexpected and expected perturbations, whereas anticipation increased the reflex responses in the jaw muscles. Biceps brachii and triceps brachii showed similar sensory-induced responses and similar anticipatory responses. Jaw muscles differed, however, in that the reflex response was stronger in masseter than in digastric. It was concluded that reflex responses in the arm muscles cannot overcome the loading of the arm adequately, which is compensated by a large centrally programmed response when loading is predictable. The jaw muscles, particularly the jaw-closing muscles, tend to respond mainly through reflex loops, even when loading of the jaw is anticipated. The differences between the responses of the arm and the jaw muscles may be related to physical differences. For example, the jaw was decelerated more strongly by the load than the heavier arm. The jaw was decelerated strongly but briefly, <30 ms during jaw closing, indicating that muscle force increased before the onset of reflex activity. Apparently, the force-velocity properties of the jaw muscles have a stabilizing effect on the jaw and have this effect before sensory induced responses occur. The symmetrical responses in biceps and triceps indicate similar motor control of both arm muscles. The differences in reflex activity between masseter and digastric muscle indicate fundamental differences in sensory feedback to the jaw-closing muscle and jaw-opening muscle.

Adult↗
PubMed1995

Ventilatory response to arm elevation. Its determinants and use in patients with chronic obstructive pulmonary disease.

During arm elevation, normal individuals predominantly recruit the diaphragm, whereas chronic obstructive pulmonary disease (COPD) patients use more the accessory inspiratory and abdominal expiratory muscles. To test that arm elevation is useful to study the ventilatory muscle response in COPD, and to define the factors that determine this response, we studied 34 patients (FEV1 0.95 +/- 0.08 L) during 2 min of arm elevation. Transnasal balloons were used to determine end-inspiratory and end-expiratory gastric (Pg), pleural (Ppl) and transdiaphragmatic (Pdi) pressures. The slope of delta Pg/delta Ppl (= Pgi - Pge/Ppli - Pple) was used to infer respiratory muscle recruitment. With linear regression, the delta Pg/delta Ppl during arm elevation significantly correlated with resting delta Pg/delta Ppl (r = 0.68), hyperinflation (FRC/TLC, r = 0.52), and diaphragmatic tension time index (TTIdi) (r = 0.47). With multiple regression, resting delta Pg/delta Ppl, percentage predicted FRC (FRC %pred) and TTIdi influenced delta Pg/delta Ppl during arm elevation (r = 0.84). Over the 2 min of arm elevation, the dependency upon resting breathing pattern decreased, while hyperinflation and TTIdi became increasingly important. Higher resting TTIdi values were associated with a faster and shallower breathing pattern (f/VT > or = 38) during arm elevation. We conclude that the pattern of respiratory muscle recruitment during arm elevation depends primarily on the resting breathing pattern. Over 2 min, the degree of hyperinflation and the force reserve of the diaphragm increasingly impact on the ability to recruit the diaphragm. Measurement of f/VT during arm elevation is useful to determine functional reserve of the diaphragm in severe COPD.

Arm↗
PubMed2006

Evaluation of arm anthropometry for assessing pediatric body composition: evidence from healthy and sick children.

Arm anthropometry is used as a proxy of body composition in clinical and field research but its validity has not been established in children. To address this issue, mid-upper arm circumference (MUAC) and triceps skinfold thickness (TS) were measured in 110 healthy children aged 4.4-13.9 y (55 boys) and 49 cystic fibrosis (CF) patients aged 8.1-13.4 y (22 boys). Reference values were arm and whole-body fat mass (FM) and fat-free mass (FFM) measured by dual x-ray absorptiometry and four-component model, respectively. Arm fat area (AFA), MUAC, and TS correlated well with arm FM (r = 0.84-0.92) and total FM (r = 0.78-0.92). Arm muscle area (AMA) and MUAC correlated well with arm FFM (r = 0.68-0.82) and total FFM (r = 0.60-0.86). After adjusting for age, sex, and height, arm anthropometry correlated strongly with FM but weakly with FFM. AFA, MUAC, and TS explained 67, 63, and 61% of variability in total FM in healthy children and 70, 72, and 63% in CF. AMA and MUAC explained only 24 and 16% of variability in total FFM in healthy children and 33 and 28% in CF. Arm anthropometry is useful for predicting FM and ranking healthy children and patients for fatness. It has poorer success in predicting regional or total FFM.

Absorptiometry, Photon↗
PubMed1988

Effect of arm training on central and peripheral circulatory function.

The purpose of this study was to examine the effect of endurance arm training on metabolic and circulatory function during arm and leg exercise. Thirty-eight females (aged 18 to 35 yr) participated in the study, with 19 subjects in the training group and 19 in a control group. Both a specific and general training response was observed at the conclusion of the 5-wk training period. As a result of training, during peak arm exercise, significant increases (P less than 0.05) were observed for oxygen uptake (VO2), ventilation, cardiac output, stroke volume, arterial-venous oxygen difference, cumulative work, and total performance time. During peak leg exercise following arm training, significant increases (P less than 0.05) were observed for VO2, ventilation, cardiac output, cumulative work, and total performance time. Standardized partial regression coefficients were used to examine the relative influence of the metabolic and circulatory components which define VO2. Prior to training during arm work, the arterial-venous oxygen difference accounted for the largest proportion of variance in VO2; but after training, stroke volume contributed the largest portion of variance. On the other hand, during leg exercise, stroke volume accounted for the largest portion of variation in leg VO2 both before and after arm training. The data suggest that endurance arm training as prescribed in this study elicits significant circulorespiratory function adaptations to support improved performance in both arm and leg work. Further, the findings suggest both a specific and general training effect, with the more dominant effect specific to arm work.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Respiratory response and ventilatory muscle recruitment during arm elevation in normal subjects.

Despite the fact that the arms are used extensively in daily life and that some of the muscles of the shoulder girdle share both a respiratory and a positional function for the arms, surprisingly little is known about the respiratory response to unsupported upper extremity activity. To determine the respiratory consequences of simple arm elevation during tidal breathing, we measured minute ventilation (VE), tidal volume (VT), respiratory rate (f), heart rate (HR), oxygen uptake (VO2), and carbon dioxide production (VCO2) in 22 normal subjects seated with arms elevated in front of them to shoulder level (AE) for 2 min and down at the sides (AD) for the same time period. The sequence was randomized. Compared with AD, during AE there were significant increases in VO2 (336 +/- 18 vs 289 +/- 14 ml/min, p less than 0.001), VCO2 (315 +/- 23 vs 245 +/- 16 ml/min, p less than 0.001), HR (84 +/- 6 vs 73 +/- 4 beats/min, p less than 0.05), VE (11.5 +/- 0.9 vs 9.3 +/- 0.6 L/min, p less than 0.001), and VT (868 +/- 66 vs 721 +/- 48 ml, p less than 0.001). In 11 subjects, breath-by-breath metabolic and ventilatory parameters were studied with AD for 2 min, AE for 2 min, and with AD for 3 min while also recording gastric (Pg), pleural (Ppl), and transdiaphragmatic pressures (Pdi). With AE, there was a significant increase in Pg at end inspiration (PgI, 15.4 +/- 3.2 vs 11.9 +/- 2.7 cm H2O, p less than 0.01) and in Pdi (26.5 +/- 3.4 vs 21.4 +/- 2.4 cm H2O, p less than 0.01) with no change in Pg at end expiration (PgE) or in Ppl. The increases in VO2, VCO2, VE, and VT during arm elevation persisted for 2 min after arm lowering, whereas Pgi and Pdi abruptly dropped as the arms were lowered. We conclude that simple arm elevation during tidal breathing results in significant increases in metabolic and ventilatory requirements. These increased demands are associated with higher PgI and Pdi suggesting an increased diaphragmatic contribution to the generation of ventilatory pressures. The sudden drop in Pg with arm lowering indicate a change in ventilatory muscle and or torso recruitment independent of the metabolic drive and ventilatory needs. These findings may help explain the limitation that has been reported in some normal subjects and in many patients with lung disease during unsupported upper extremity activity.

Adult↗
PubMedDate not supplied

The influence of the sexual stages of adolescent boys on the circumference of the arm, muscle area and skinfold measurements.

The purpose of this study was to detect the changes in the circumference of the arm, skinfold thickness (SFT), arm muscle area (AMA) and arm fat area (AFA), during the sexual development of healthy adolescent boys. This study was done with 74 adolescent boys, aged 9-17 years, with no chronic diseases, no developmental delay, no current medication with height ages appropriate for their bone ages, and body mass indexes between 50-75 percentiles. Body weight and height, the circumference of the arm and the SFT were measured. Body mass index, AMA and AFA were calculated. The mean arm circumference and AMA increased significantly from Tanner stage 1 to 5. AMA was significantly and positively correlated with age, weight, height, body mass index, arm circumference, SFT. After adjusting for Tanner stages, AMA was not correlated with age. A significant negative correlation was found between AMA and arm fat area. In the present study, it was seen that the sexual stages affected the circumference of arm, AMA, and the skinfold thickness in healthy adolescent boys, who were appropriate for their bone ages, and had good nutritional status. Further studies are required to detect the effect of pubertal stage on arm anthropometry in different nutritional status including obesity and malnutrition.

Adolescent↗
PubMed1993

Effects of the direction and distance of horizontal arm movements on local muscular strain--a fundamental study on the teller workplace in bank.

This study was conducted to examine the relative differences in the muscular strain of the hand-arm-shoulder system in the repetitive arm movements which would directly depend on the layout of devices at teller counter. The subjects were five young male adults. The manual handling task was standardized and the repetition frequency was in self-pace. The arm movements were characterized by the different direction measured from the frontal plane of the subject between 0 degrees to 150 degrees combined with the distance measured from the acromion to the fixed points of 300, 500 and 700mm. The movements to all of the fourteen points tested were evaluated on both sides of the arms and shoulders by the integration of the EMG signals (IEMG) as to m. deltoid pars media and clavicularis, m. trapezius pars descendens, m. pectoralis major pars clavicularis and m. extensor carpi radialis brevis. It was found that IEMG of the deltoid muscles were sensitive to the direction and distance of the arm movements while the trapezius muscle showed the relative lower dependence on the direction. There were significant combined effects of the direction and distance in all muscles; i.e. effect of reach distance was greater with decreasing the arm angle, which was obvious at distance longer than 500mm in the arm abduction. When IEMG was divided by the task time in self-pace which increased in the arm abduction, the peak value was observed at the angle of 30 degrees. It was suggested that if the repetitive movement was required at the same frequency as at the angle of 30 degrees the position near the arm abduction (the angle of 0 degrees) would become the most expensive working direction.

Adult↗
PubMed2004

Lateral difference and interhemispheric transfer on arm-positioning movement between right and left handers.

We investigated the transfer of an arm-positioning movement between the right and left arms of right and left handers. 30 male (15 strong right handers and 15 strong left handers) subjects were asked to perform a constrained criterion movement, 12 cm in length, with right or left arm and a test movement at estimated 6-, 12-, or 24-cm length with the contralateral arm. In the right handers, the constant error of the left arm test movement was near zero, and that of the right arm indicated overshooting. In the left handers, the constant errors of the left arm test movement were farther from zero than those of right arm test movement. Left handers as well as right handers showed manual asymmetry on positioning movement. A plausible explanation for the manual asymmetry on the arm-positioning task is related to interhemispheric transfer of spatial information on positioning movement.

Adolescent↗
PubMedDate not supplied

Phase-dependent modulation of the soleus H-reflex during rhythmical arm swing in humans.

The purpose of this study is to investigate modulation of the soleus H-reflex during rhythmic arm swing in humans. Significant depression of the soleus H-reflex was observed when subjects swung their ipsilateral arms or both arms reciprocally during testing. The degree of soleus H-reflex depression appeared directly proportional to the speed of the arm swing. This depression was observed in the conditioning-testing intervals of 400, 500, and 600 msec during the ipsilateral backward arm swing and at the onset of the ipsilateral arm forward swing. This phase of depression partially overlapped the phase of depression of the soleus H-reflex during walking. However, the pattern of modulation during arm swing was not exactly the same as that during walking. Therefore, we concluded that the ipsilateral arm swing may partially affect the depression of the soleus H-reflex during the arm swing phase of walking but is not responsible for depression of the soleus H-reflex throughout the entire walking cycle.

Adult↗
PubMed2001

Relationship between arm pain and distension of arteries and veins caused by elevation of transmural pressure in local vascular segments.

BACKGROUND: Exposure to high +Gz forces may induce arm pain, which has been hypothesized to be caused by pressure-induced overdistension of local blood vessels. The purpose of the present investigation was to study the pressure-distension relation of veins and arteries in the human arm and the relation between arm pain and distension of local vessels. METHODS: Increased distending pressures (DP) in the vasculature of the arm were accomplished by placing the subject (n = 8) in a pressure chamber with one arm positioned through a port in the chamber door, and increasing chamber pressure to +180 mm Hg in a stepwise manner. Diameters in the brachial artery and in the brachial, radial and cephalic veins were measured by ultrasonography. Changes in forearm volume were estimated from measurement of tissue impedance. Perceived pain was rated using a 10-point scale. RESULTS: Arm pain increased with pressure to a maximum rating of 8.5 (= median; range: 4-10). Increasing DP from 30 to 180 mm Hg resulted in a steady increase (p < 0.05) in venous diameter which varied from 12 +/- 8% (mean +/- SD) in the brachial vein to 23 +/- 14% in the radial vein. Inthe brachial vein diameter increases were most pronounced at the sites of the venous valves. Arterial diameter was unchanged up to a DP of about 200 mm Hg (calculated as diastolic arterial pressure + applied chamber pressure), but then increased by 32 +/- 9% (p < 0.001). Forearm impedance dropped with increasing pressure (delta = 23 +/- 5%; p < 0.01); the rate of change was non-linear with a faster change at the highest DP which may indicate pressure distension of precapillary resistance vessels. CONCLUSIONS: Elevation of pressure in arm vessels to levels that may occur in pilots flying high-performance aircraft results in distension not only of veins but also of arteries and probably of smaller precapillary vessels. Therefore, and because these changes coincide with the development of severe arm pain, local overdistension of blood vessels remains a plausible cause of G-induced arm pain.

Adult↗
PubMed1999

Assessment of two methods to reduce simulated +Gz-induced arm pain using a non-centrifuge model.

Complaints of +Gz-induced arm pain have been expressed by centrifuge subjects and, to a lesser degree, by high performance fighter pilots, usually when the control stick and throttle are positioned below heart level; the pain may be higher during pressure breathing for +Gz protection. Elevated transmural pressure and overdistension of the blood vessels in the arms have been suggested as causal factors. An earlier-developed non-centrifuge model was used to provoke arm pain similar to that induced by +Gz exposure. Eleven healthy subjects placed inside a hyperbaric chamber with an arm externalized through a sealed opening. They were exposed to chamber pressures at 75, 100 and 125 mmHg fitted with elastic bandage of the arm, or a localized pressure of 50 mmHg applied to the vessels of the upper arm or were provided no protection (control). Arm pain was estimated using a modified Borg scale. The sizes of the ulnar, radial and interosseous arteries, and corresponding veins, at the elbow level were measured using a sonographic imaging system. No statistically significant differences in pain were detected comparing control to proposed (counteracting) devices. There were no statistical differences in arm arterial or venous vessel size with the different devices at the different pressures. Thus, the devices tested did not show any protection against the provoked arm pain.

Adult↗
PubMed2006

Clinical comparison of automatic, noninvasive measurements of blood pressure in the forearm and upper arm with the patient supine or with the head of the bed raised 45 degrees: a follow-up study.

BACKGROUND: Noninvasive measurement of blood pressure in the forearm is used when the upper arm is inaccessible and/or when available blood pressure cuffs do not fit a patient's arm. Evidence supporting this practice is limited. OBJECTIVE: To compare noninvasive measurements of blood pressure in the forearm and upper arm of medical-surgical inpatients positioned supine and with the head of the bed raised 45 degrees . METHODS: Cuff size was selected on the basis of forearm and upper arm circumference and manufacturers' recommendations. With a Welch Allyn Vital Signs 420 Series monitor, blood pressures were measured in the forearm and then in the upper arm of 221 supine patients with their arms resting at their sides. Patients were repositioned with the head of the bed elevated 45 degrees and after 2 minutes, blood pressures were measured in the upper arm and then the forearm. Starting position was alternated on subsequent subjects. RESULTS: Paired t tests revealed significant differences between systolic and diastolic blood pressures measured in the upper arm and forearm with patients supine and with the head of the bed elevated 45 degrees . The Bland-Altman procedure revealed that the distances between the mean values and the limits of agreement were from 15 to 33 mm Hg for individual subjects. CONCLUSIONS: Noninvasive measurements of blood pressure in the forearm and upper arm cannot be interchanged in medical-surgical patients who are supine or in patients with the head of the bed elevated 45 degrees .

Adolescent↗
PubMed1989

[Measurements of the arm in inhabitants of the Lublin region].

Anthropological measurements in 1630 inhabitants of the Lublin region were carried out. In all the examined material the length of the right arm in men ranged from 26.5 to 39 cm (mean-32.96) and of the left one--from 26.5 to 38 cm (mean-32.77 cm). The length of the right arm in women ranged from 23 to 36 cm (mean-30.74 cm) and of the left one--from 23 to 36 cm (mean--30.57 cm). The length of the right arm in men was bigger than in women. It was found that both in men and women the right arm is often longer than the left arm. Differences of the length of the arms related to body's side in both sexes were statistically significant. However, no significant differences were found in the length of arms in relation to age. Length index of the arms both in men and women was on the right side 19.7 and on the left side 19.6 and was classified as that of mean arms.

Adult↗
PubMed1987

Effects of arm position and support on blood-pressure readings.

The effect of changes in arm position and of arm support on blood-pressure readings was assessed in 240 hypertensive outpatients with the arm in various positions. Mean blood pressure was lowest with the arm supported at heart height and highest with the arm dependent, the difference averaging 8 mmHg for both systolic and diastolic pressure and being greater for men than for women. Arm support at heart height lowered blood pressure only slightly, when compared to that taken on the unsupported arm at heart height. These findings suggest that an increase in apparent blood pressure associated with arm dependency during the recording can spuriously increase the height of the blood pressure and the prevalence of hypertension. In the individual patient it may lead to unnecessary increase in antihypertensive dosage. Whenever standing blood pressure is quoted, arm position should be stated.

Antihypertensive Agents↗
PubMed1987

Ergometer modification for combined arm-leg use by lower extremity amputees in cardiovascular testing and training.

A commercial arm-leg ergometer was adapted so that combined bilateral arm-single leg work could be performed by unilateral lower extremity amputees from their own wheelchairs. Three middle-aged to elderly unilateral amputees performed progressive discontinuous bilateral arm crank and combined bilateral arm-single leg cycle exercise tests on the same air-braked ergometer adapted for either form of ergometry. Select amputees may achieve greater peak oxygen uptakes (VO2), power outputs (PO), and heart rates (HR) during combined bilateral arm-single leg cycle testing versus bilateral arm crank testing. Following 14 weeks of combined arm-leg training on the modified ergometer, a 73-year-old above-knee amputee demonstrated peak VO2 and PO increases of 25% (+3.8 mL X kg-1 X min-1) and 33% (+25W) respectively. Combined arm-leg ergometry as described herein may activate the largest available muscle mass and elicit the greatest oxygen uptake during exercise testing. In addition this exercise modality may simultaneously condition the arms and leg, providing functional gains in both wheelchair propulsion and prosthetic ambulation.

Amputees↗
PubMed1983

[Critical analysis of the validity of arm circumference as an indicator of protein-energy nutritional status in preschool children].

Arm circumference has been recommended as a useful indicator for malnutrition screening, particularly in rural areas. The great advantages of the arm circumference over other anthropometric indicators are that the measure is easily obtained in rural areas and that the method for assessing arm circumference is simple, inexpensive and rapid. In this paper the validity (specificity and sensitivity) of arm circumference is analyzed as compared to more valid indicators of nutritional status in preschool children. We conclude that arm circumference is relatively valid for detecting global malnutrition (as indicated by weight-for-age), but of limited validity when used for detecting acute or chronic protein-calorie malnutrition. Furthermore, when compared to weight-for-age in detecting populations or individuals at high risk of acute or chronic protein-calorie malnutrition, it was found that weight-for-age has a higher level of specificity and sensitivity than arm circumference. Finally, it was found that sensitivity and specificity of arm circumference vary with age, suggesting that arm circumference cannot be considered an age-independent indicator of nutritional status. It is therefore recommended that these possible limitations of arm circumference be kept in mind when used in public health programs.

Anthropometry↗