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At least 91 records · Page 5Linked to original sources
PubMed2003

Morton neuroma: MR imaging in prone, supine, and upright weight-bearing body positions.

PURPOSE: To assess the effect of prone, supine, and upright weight-bearing body positions on visibility, position, shape, and size of Morton neuroma during magnetic resonance (MR) imaging. MATERIALS AND METHODS: Eighteen patients with 20 Morton neuromas underwent MR imaging of the forefoot in prone (plantar flexion of the foot), supine (dorsiflexion of the foot), and upright weight-bearing positions. Visibility (3 = good, 2 = moderate, 1 = poor), position relative to the metatarsal bone, shape, and transverse diameter of Morton neuroma were assessed on transverse T1-weighted MR images. Associations between different body positions and variables of interest were calculated with Wilcoxon signed rank test, chi2 test, and paired Student t test. RESULTS: In the prone position, visibility of all 20 Morton neuromas was rated with a score of 3; visibility in the supine and weight-bearing positions was inferior (mean score, 2.4). All 20 (100%) Morton neuromas changed their position relative to the metatarsal bone between prone and supine and between prone and weight-bearing positions. When compared with the prone position, there was a difference in the shape of all 20 Morton neuromas in the weight-bearing position (P <.001). Between prone (mean transverse diameter of Morton neuroma, 8 mm) and supine (mean transverse diameter of Morton neuroma, 6 mm) positions, the transverse diameter of Morton neuroma significantly decreased by 2 mm (P =.03); between prone and weight-bearing positions, the decrease of the mean transverse diameter was also significant (difference, 2 mm; P =.03). CONCLUSION: Morton neuroma appears significantly different during MR imaging in prone, supine, or weight-bearing positions. The transverse diameter of Morton neuroma is significantly larger on images obtained in the prone position than it is on images obtained in the supine and upright weight-bearing positions. Visibility of Morton neuroma is best on MR images obtained in the prone position.

Adult↗
PubMed1999

Pulmonary perfusion is more uniform in the prone than in the supine position: scintigraphy in healthy humans.

The main purpose of this study was to find out whether the dominant dorsal lung perfusion while supine changes to a dominant ventral lung perfusion while prone. Regional distribution of pulmonary blood flow was determined in 10 healthy volunteers. The subjects were studied in both prone and supine positions with and without lung distension caused by 10 cmH2O of continuous positive airway pressure (CPAP). Radiolabeled macroaggregates of albumin, rapidly trapped by pulmonary capillaries in proportion to blood flow, were injected intravenously. Tomographic gamma camera examinations (single-photon-emission computed tomography) were performed after injections in the different positions. All data acquisitions were made with the subject in the supine position. CPAP enhanced perfusion differences along the gravitational axis, which was more pronounced in the supine than prone position. Diaphragmatic sections of the lung had a more uniform pulmonary blood flow distribution in the prone than supine position during both normal and CPAP breathing. It was concluded that the dominant dorsal lung perfusion observed when the subjects were supine was not changed into a dominant ventral lung perfusion when the subjects were prone. Lung perfusion was more uniformly distributed in the prone compared with in the supine position, a difference that was more marked during total lung distension (CPAP) than during normal breathing.

Adult↗
PubMed1999

Kinetics of oxygen uptake during supine and upright heavy exercise.

It is presently unclear how the fast and slow components of pulmonary oxygen uptake (VO(2)) kinetics would be altered by body posture during heavy exercise [i.e., above the lactate threshold (LT)]. Nine subjects performed transitions from unloaded cycling to work rates representing moderate (below the estimated LT) and heavy exercise (VO(2) equal to 50% of the difference between LT and peak VO(2)) under conditions of upright and supine positions. During moderate exercise, the steady-state increase in VO(2) was similar in the two positions, but VO(2) kinetics were slower in the supine position. During heavy exercise, the rate of adjustment of VO(2) to the 6-min value was also slower in the supine position but was characterized by a significant reduction in the amplitude of the fast component of VO(2), without a significant slowing of the phase 2 time constant. However, the amplitude of the slow component was significantly increased, such that the end-exercise VO(2) was the same in the two positions. The changes in VO(2) kinetics for the supine vs. upright position were paralleled by a blunted response of heart rate at 2 min into exercise during supine compared with upright heavy exercise. Thus the supine position was associated with not only a greater amplitude of the slow component for VO(2) but also, concomitantly, with a reduced amplitude of the fast component; this latter effect may be due, at least in part, to an attenuated early rise in heart rate in the supine position.

Adult↗
PubMed2004

Lower pulmonary diffusing capacity in the prone vs. supine posture.

We evaluated the effect of prone positioning on gas-transfer characteristics in normal human subjects. Single-breath (SB) and rebreathing (RB) maneuvers were employed to assess carbon monoxide diffusing capacity (DlCO), its components related to capillary blood volume (Vc) and membrane diffusing capacity (Dm), pulmonary tissue volume (Vti), and cardiac output (Qc). Alveolar volume (Va) was significantly greater prone than supine, irrespective of the test maneuver used. Nevertheless, Dl(CO) was consistently lower prone than supine, a difference that was enhanced when appropriately corrected for the higher Va prone. When adequately corrected for Va, diffusing capacity significantly decreased by 8% from supine to prone [SB: Dl(CO,corr) supine vs. prone: 32.6 +/- 2.3 (SE) vs. 30.0 +/- 2 ml x min(-1) x mmHg(-1) stpd; RB: Dl(CO,corr) supine vs. prone: 30.2 +/- 2.2 (SE) vs. 27.8 +/- 2.0 ml x min(-1) x mmHg(-1) stpd]. Both Vc and Dm showed a tendency to decrease from supine to prone, but neither reached significance. Finally, there were no significant differences in Vti or Qc between supine and prone. We interpret the lower diffusing capacity of the healthy lung in the prone posture based on the relatively larger space occupied by the heart in the dependent lung zones, leaving less space for zone 3 capillaries, and on the relatively lower position of the heart, leaving the zone 3 capillaries less engorged.

Adult↗
PubMed1988

Supine position and sleep loss each reduce prolonged maximal voluntary ventilation.

Because of the prevalence of supine posture and sleep deprivation in both health and disease, we wondered how each of them influences prolonged maximal voluntary ventilation (MVV). Accordingly, we compared 12-second, 1-min, and 10-min isocapnic MVV supine with that measured in the upright posture in 8 healthy subjects. MVV decreased 6-10% supine, independent of test duration (p less than 0.01). Although end-expiratory lung volume was 0.47 liter lower during supine resting breathing (p less than 0.001), end-expiratory lung volumes during short-term MVV maneuvers were identical. To investigate any additional effect on MVV due to sleep loss, 12 healthy subjects performed 12-second, 1-min, and 30-min isocapnic MVV maneuvers in the supine position, either after normal sleep or after a 24-hour sleepless period. Sleep deprivation reduced MVV by 7-14%, again independent of test duration (p less than 0.05). Sleep loss also reduced the ventilation chosen to represent a submaximal (75%) breathing effect (p = 0.05), and it increased subjective ratings of fatigue and confusion (p less than 0.01). We conclude that supination and sleep deprivation together decrease both short- and long-term MVV by nearly 20%, with impairment of supination not caused by lung volume changes, and with the sleep loss effect occurring in tandem with a rise in the subjective assessment of breathing effort.

Adult↗
PubMed2003

Association between supine hypertension and orthostatic hypotension in autonomic failure.

Supine hypertension occurs commonly in primary chronic autonomic failure. This study explored whether supine hypertension in this setting is associated with orthostatic hypotension (OH), and if so, what mechanisms might underlie this association. Supine and upright blood pressures, hemodynamic responses to the Valsalva maneuver, baroreflex-cardiovagal gain, and plasma norepinephrine (NE) levels were measured in pure autonomic failure (PAF), multiple-system atrophy (MSA) with or without OH, and Parkinson's disease (PD) with or without OH. Controls included age-matched, healthy volunteers and patients with essential hypertension or those referred for dysautonomia. Baroreflex-cardiovagal gain was calculated from the relation between the interbeat interval and systolic pressure during the Valsalva maneuver. PAF, MSA with OH, and PD with OH all featured supine hypertension, which was equivalent in severity to that in essential hypertension, regardless of fludrocortisone treatment. Among patients with PD or MSA, those with OH had higher mean arterial pressure during supine rest (109+/-3 mm Hg) than did those lacking OH (96+/-3 mm Hg, P=0.002). Baroreflex-cardiovagal gain and orthostatic increments in plasma NE levels were markedly decreased in all 3 groups with OH. Among patients with PD or MSA, those with OH had much lower mean baroreflex-cardiovagal gain (0.74+/-0.10 ms/mm Hg) than did those lacking OH (3.13+/-0.72 ms/mm Hg, P=0.0002). In chronic autonomic failure, supine hypertension is linked to both OH and low baroreflex-cardiovagal gain [corrected]. The finding of lower plasma NE levels in patients with than without supine hypertension suggests involvement of pressor mechanisms independent of the sympathetic nervous system.

Aged↗
PubMed2000

Effect of supine posture on respiratory mechanics in chronic left ventricular failure.

The mechanisms of orthopnea and the role of changes in respiratory mechanics in left ventricular failure (LVF) are poorly understood. We have measured total respiratory airflow resistance (Rrs) using forced oscillation in the sitting and supine positions in 10 patients with chronic LVF (NYHA II-III) shortly after recovery from acute LVF and in 10 matched control subjects (CON). Seated, the patients with LVF had small lung volumes but no evidence of airway obstruction (mean FEV(1)/FVC, 81%). Mean Rrs at 6 Hz was only slightly higher in LVF (3.4 cm H(2)O. L(-1). s) than in CON (2.6 cm H(2)O. L(-1). s). After 5 min supine, breathlessness in LVF increased. Despite much smaller mean falls in mid-tidal lung volume (MTLV) in LVF than in CON, the supine rise in Rrs was 80.5% in LVF and 37.6% in CON; mean increases in specific Rrs (SRrs = Rrs.MTLV) were 75.8% in LVF and 16.6% in CON (p 0.001). Five minutes after resuming the sitting position all values had reverted almost to the original sitting values. In 5 LVF patients, nebulized ipratropium, a muscarinic antagonist, only slightly attenuated the supine rise in SRrs. We conclude that patients with chronic LVF, who had little evidence of airways obstruction when seated, showed a large rise in airflow resistance after lying supine for 5 min. This cannot be attributed to reduction in lung volume when supine and no evidence was found of vagally-induced bronchoconstriction. Further experiments are required to establish the cause of the rapid supine rise in airflow resistance in LVF.

Aged↗
PubMedDate not supplied

Reproducibility of central venous pressures in supine and lateral positions: a pilot evaluation of the phlebostatic axis in critically ill patients.

OBJECTIVE: To determine if the phlebostatic axis (PA) can be used to obtain reproducible central venous pressures (CVP) in laterally positioned critically ill patients. DESIGN: A quasi-experimental study design was used. The outcome variable was central venous pressure. The explanatory variables were position (supine, 30 degrees right lateral, 30 degrees left lateral) and transducer leveling procedure (supine PA, upper PA, dependent PA). Each subject was used as his or her own control. SETTING: General intensive care unit of a 929 bed metropolitan teaching hospital in New South Wales, Australia. SUBJECTS: A convenience sample of 25 critically ill patients (15 men and 10 women) with an average age of 59.6 years +/- 15.2. METHOD: Each subject's baseline CVP range was collected over a 25-minute period in a supine position. CVP measurements were then obtained in the left and right lateral positions (initial lateral position alternated for each subsequent subject). When the subject was lateral, three CVP readings corresponding to the three transducer leveling procedures were taken. DATA ANALYSIS: One-way repeated measures analysis of variance (one for each leveling procedure) were performed. Clinical significance was deemed evident when the lateral CVP measurement exceeded the baseline range. RESULTS: Statistically significant changes were associated with the upper PA (p < 0.001) and the dependent PA (p < 0.001). Only the supine PA yielded statistically nonsignificant changes in CVP (p = 0.073). However, power analysis indicated that the results were not conclusive (power = 0.520). Clinical significance was determined in 100% and 92% of subjects in the left lateral and right lateral positions, respectively, when using the upper PA whereas the dependent PA yielded clinical significance in all (100%) subjects. Clinical significance was seen in 46% and 42% of subjects for the left lateral and right lateral positions, respectively, when the supine PA was used. CONCLUSION: Of the three leveling procedures, the supine PA yielded the most reproducible CVP measures. However, further studies are required before the supine PA can be recommended as a valid and reliable transducer position for CVP measurement in laterally positioned patients.

Adult↗
PubMed1996

High performance supine flight assessment using the NAWC dynamic flight simulator.

INTRODUCTION: To determine the feasibility of high-performance supine flight, the USAF Canopy Escape Module (65 degree seat-back-angle) was modified and deployed into the Naval Air Warfare Center Dynamic Flight Simulator. METHODS: Seven male subjects performed a flight syllabus consisting of instrument flight maneuvers (high-G level turns, ILS task, vertical S-2, Half Cuban Eight). Subjects were trained and performed under both 1 g (static) and dynamic conditions in supine and upright postures. Data were assessed to determine the effects of motion (G) and seat position. A weighted objective performance grading scheme was devised based on the ability to achieve specified flight parameters. RESULTS: This paper presents the analysis of the first two tasks. During the turns, motion effects did not effect the ability to maintain specified G loads when supine, whereas there were significant differences when upright. Also, there were lower error rates under static, as compared to dynamic, conditions. Even though subjects demonstrated lower error rates during dynamic turns when upright, there were few significant differences referable to body position. Overall, subjects with the most flight experience performed better upright than supinated, while a naive subject flew significantly better supine. Notably, one subject did experience a G-induced loss of consciousness (G-LOC) and an almost LOC event during a supinated high-G turn. Body position or motion effects did not significantly alter ILS task performance. CONCLUSIONS: High performance supine flight is feasible and additional study is warranted. Important and unanticipated performance-related decrements were discovered only through the use of dynamic flight simulation.

Aerospace Medicine↗
PubMed1983

Supination-adduction injuries of the ankle in children--radiographical classification and treatment.

Diagnostical and therapeutical problems associated with supination-adduction injuries are presented. 457 ankle fractures were collected from a retrospective material of 919 children aged 0-18 years with fractures of the tibio-fibular shaft or the ankle. The ankle fractures were classified anatomically according to Salter and Harris and traumatologically according to Gerner-Smidt. 147 fractures were classified as due to supination-adduction, of which 128 had open growth plates. The first stage, a Salter-Harris type I, II, or III fracture through the lateral malleolus or only epiphyseal fracture without fracture through the growth plate, is easily overlooked and is probably more common than earlier registered. The stage II injury with, an addition, a vertical or oblique fracture of the medial malleolus sometimes continuing through the physis and metaphysis is often more easily recognized at the radiographical examination. The mean age of supination-adduction injuries is lower than for supination-eversion injuries. The supination-adduction injuries are the second most common type of ankle fractures in children (32%) only exceeded by injuries due to supination-eversion (39%). Early recognition of the fracture pattern of supination-adduction injuries is important as growth disturbance and joint problems are not uncommon when there is fracture through the medial malleolus. The need for correct diagnosis and treatment is stressed by the risk for late problems.

Adolescent↗
PubMed1985

Comparison of effects of isometric and supine bicycle exercise on left ventricular performance in patients with aortic regurgitation and normal ejection fraction at rest.

The effects of handgrip and supine bicycle exercise on hemodynamics and left ventricular (LV) performance were compared in 25 patients with moderate to severe aortic regurgitation (AR) and normal LV ejection fraction at rest (greater than or equal to 50%) and in 10 control subjects. In both groups, heart rate, systolic blood pressure, rate-pressure product, and LV output were higher during supine bicycle exercise. Compared with the controls, in patients with AR, stroke volume was unchanged during supine bicycle exercise. LV end-diastolic volume increased during handgrip exercise but was unchanged during supine bicycle exercise. LV end-systolic volume increased and ejection fraction decreased during both forms of exercise. Of 25 patients with AR, 15 (60%) during handgrip exercise and 19 (76%) during supine bicycle exercise had an abnormal ejection fraction response (p less than 0.05). In patients with moderate to severe AR and normal LV ejection fraction at rest, both handgrip and supine bicycle exercise induced LV dysfunction. An abnormal LV ejection fraction response occurred more often with supine bicycle exercise. Handgrip exercise may be a useful alternative method for detecting LV dysfunction in patients with AR in whom adequate bicycle exercise cannot be accomplished.

Adult↗
PubMed1987

Differences in the frequency of ST segment depression during upright and supine exercise: assessment in normals and in patients with coronary artery disease.

Increased utilization of ambulatory ST segment monitoring mandates an appreciation of nonischemic variables that may influence the ST segment. While a greater frequency of ST segment depression has been reported with supine vs upright exercise, the relative false positive rate in both positions is not known. Thus, we compared the frequency of exercise ECG abnormalities during upright and supine bicycle exercise in two groups--17 normals and 46 patients with coronary artery disease. Exercise was performed in combination with radionuclide ventriculographic imaging. Peak exercise heart rate, peak systolic blood pressure, and exercise duration time were all slightly higher in the upright vs supine position (p less than 0.05). Nevertheless, the frequency of positive ST segment responses was more common in the supine position, both in the patients with coronary artery disease (54% vs 30%, p less than 0.05) and in the normal subjects (29% vs 6%, p = NS). The corresponding radionuclide ventriculographic responses, however, were normal during upright and supine exercise in 6 of the 11 CAD patients and in all five of the normal subjects with an abnormal ST segment response during supine exercise only. The frequency of exercise-induced chest pain was also similar in the two positions. Thus, we theorize that nonischemic factors may govern some positive ST segment responses in the supine position. This finding is of relevance for understanding the potential sources of physiologic false positive ST segment responses for ambulatory ST segment monitoring.

Adult↗
PubMed2005

The interaction between changes in upright mandibular position and supine airway size in patients with obstructive sleep apnea.

INTRODUCTION: The purpose of this study was to investigate the interaction between upright mandibular position change and supine upper airway size in men with obstructive sleep apnea fitted with titratable oral appliances. METHODS: Baseline supine cephalometry before placement of the oral appliance and after titration with the oral appliance in place were undertaken in 14 patients, and upright mandibular position change was evaluated with and without the titrated oral appliance in place with a DigiGraph workstation (Dolphin Imaging Systems, Valencia, Calif). RESULTS: The apnea-hypopnea index was significantly reduced after titration of the oral appliance (P < .01). Upright mandibular position change was associated with significant vertical (P < .01) and horizontal (P < .01) mandibular repositioning. The size of the supine velopharynx (P < .05), but not the supine oropharynx, was significantly enlarged at the titrated mandibular position. The supine oropharyngeal size change was correlated with the upright horizontal repositioning of the mandible (r = 0.69, P < .01). CONCLUSIONS: Evaluation of upright mandibular position changes with the DigiGraph workstation enables one to predict supine oropharyngeal enlargement with oral appliance therapy. Dose-dependent effects of the horizontal component of upright mandibular protrusion on supine oropharyngeal size in addition to velopharyngeal enlargement might contribute to oral appliance effectiveness in obstructive sleep apnea patients.

Adult↗
PubMed2002

Incidence of foot rotation, pelvic crest unleveling, and supine leg length alignment asymmetry and their relationship to self-reported back pain.

OBJECTIVE: To determine the incidence of pelvic unleveling, foot rotation, and supine leg length alignment asymmetry in a nonclinical population and to examine the validity (sensitivity, specificity, positive and negative predictive values) of these visual tests and their relationship to self-reported back pain. DESIGN: Volunteers answered a questionnaire regarding back pain and were then examined by a chiropractor who was unaware of the status of their back pain. PARTICIPANTS: Seventy-four unscreened volunteers answered the questionnaire. MAIN OUTCOME MEASURES: The association of visual tests with back pain and their validity indices; Visual Analogue Scale ratings. RESULTS: Fifty-one percent (n = 74) of volunteers examined had supine leg length alignment asymmetry (LLA). Pain intensity on a Visual Analogue Scale was significantly higher (P <.001) for those demonstrating supine LLA than for those without LLA. Those with back pain and recurrent back pain were significantly (P <.001) more likely to have supine LLA. The validity indices of the supine leg check showed acceptable levels for sensitivity (74%), specificity (78%), and positive predictive value (82%) [corrected] in recurrent back pain. Findings also indicated a high incidence of supine LLA in volunteers with chronic back pain (85%). CONCLUSION: The results indicated that, in this group of volunteers, the supine leg length alignment check had clinical validity as a stand-alone test for recurring back pain. Further testing on a larger, statistically defined cross-section of the population is recommended.

Adolescent↗
PubMed1992

Gas exchange in dogs in the prone and supine positions.

To determine the cause of the difference in gas exchange between the prone and supine postures in dogs, gas exchange was assessed by the multiple inert gas elimination technique (MIGET) and distribution of pulmonary blood flow was determined using radioactively labeled microspheres in seven anesthetized paralyzed dogs. Each animal was studied in the prone and supine positions in random order while tidal volume and respiratory frequency were kept constant with mechanical ventilation. Mean arterial PO2 was significantly lower (P less than 0.01) in the supine [96 +/- 10 (SD) Torr] than in the prone (107 +/- 6 Torr) position, whereas arterial PCO2 was constant (38 Torr). The distribution of blood flow (Q) vs. ventilation-to-perfusion ratio obtained from MIGET was significantly wider (P less than 0.01) in the supine [ln SD(Q) = 0.75 +/- 0.26] than in the prone position [ln SD (Q) = 0.34 +/- 0.05]. Right-to-left pulmonary shunting was not significantly altered. The distribution of microspheres was more heterogeneous in the supine than in the prone position. The larger heterogeneity was due in part to dorsal-to-ventral gradients in Q in the supine position that were not present in the prone position (P less than 0.01). The decreased efficiency of oxygenation in the supine posture is caused by an increased ventilation-to-perfusion mismatch that accompanies an increase in the heterogeneity of Q distribution.

Animals↗
PubMed1984

Influence of arm positions on EMG-reaction time of the biceps brachii for elbow flexion and forearm supination.

The influence of starting positions of the arm on EMG-RTs of the biceps brachii muscle for elbow flexion and forearm supination was examined using 16 normal subjects. Two angles of the elbow joint, 45 degrees and 110 degrees flexion, and two positions of the forearm, 45 degrees supination and 90 degrees pronation, were used as the factorial combinations of all four. The EMG-RT for elbow flexion decreased in the order of 110 degrees Pronation greater than 45 degrees Pronation = 110 degrees Supination greater than 45 degrees Supination, and that for forearm supination decreased in the order of 45 degrees Supination greater than 45 degrees Pronation = 110 degrees Supination greater than 110 degrees Pronation. These results were kinesiologically interpreted that variations of EMG-RTs were based on the change in the number of synergic muscles participating in an intended movement and the muscle length of the prime mover at the start of the movement.

Adolescent↗
PubMed2004

[Anatomical and clinical study of the supinator syndrome evoked embitterment test].

OBJECTIVE: To explore the mechanism and feasibility of the supinator syndrome evoked embitterment test from anatomy and clinic. METHODS: 25 cases of The supinator syndrome were reviewed. 18 of them were male and 7 were female. Drop finger deformation were apparent in 25 cases and The supinator syndrome evoked embitterment test was positive for All patients. Operative neurolysis was done in 8 cases, conservation treatment 17 cases; 92 cadaver upper extremities were dissected for a study the relationship between supinator tunnel and posterior interosseous nerve. RESULTS: 22 cases had been followed up for an average of 9 months. 16 cases had a full recovery and 6 cases, a partial recovery. the anatomical study shows that The posterior interosseous nerve was compressed by Forhse arcade and the distal border of the supinator muscle during passive pronation forearm. CONCLUSION: The supinator syndrome evoked embitterment test was a new test for the diagnosis of supinator syndrome, it was found to be more sensitive and specific than the others test.

Exercise Test↗
PubMed1987

Prone and supine positioning effects on energy expenditure and behavior of low birth weight neonates.

The effect of body position (supine v prone) on energy expenditure and behavior of 42 healthy low birth weight (920 to 1,760 g) infants was evaluated in 66 studies. Each infant was randomly assigned to the supine or prone position for the first three-hour epoch; the position was reversed for the second three-hour epoch. The difference in energy expenditure and the percentage of time in active sleep, quiet sleep, and wakefulness between the two positions was computed. The median difference (supine minus prone) in overall energy expenditure between positions was +3.1 kcal/kg/d (interquartile range 0.6 to 6.5; P less than .001). When only periods of active sleep were analyzed, the median difference in energy expenditure remained significant, the supine position being higher than prone by +2.6 kcal/kg/d (interquartile range 0.1 to 4.8; P less than .001). In the supine position, the time awake was 5.7% higher (interquartile range 1.8 to 17.4; P less than .001) than in the prone position. The percentage of time in active sleep was not significantly different between the positions, hence quiet sleep decreased in the supine position. In summary, when low birth weight infants are changed from the supine to the prone position, energy expenditure decreases, time spent in quiet sleep increases, and time spent awake decreases. These data suggest that prone is the position of choice for the low birth weight infant.

Child Behavior↗