Psychometric Properties of Pressure Pain Thresholds Measured in 2 Positions for Adults With and Without Neck-Shoulder Pain and Tenderness.

OBJECTIVE: The purpose of this study was to determine the psychometric properties of pressure pain threshold (PPT) testing in adults with and without neck-shoulder pain and tenderness and to compare the differences in PPT measurements between the seated and prone positions. METHODS: Thirty asymptomatic adults and 30 symptomatic patients with intermittent neck-shoulder pain and tenderness completed the study. A pressure algometer was used to assess PPTs at specific points on the middle deltoid, levator scapulae, and upper trapezius muscles of the dominant side of the asymptomatic individuals and the painful side of the patients. Four trials were performed on each muscle in both the seated and prone positions. To determine between-day reliability, a subset of the participants returned to repeat the testing. RESULTS: The intraclass correlation coefficients showed good to excellent within-session reliability and fair to excellent between-day reliability of PPT measurements in both the seated and prone positions for both groups. There were significant differences between groups for all muscles in both positions (P < .05) except for the upper trapezius muscle in the prone position. In addition, significant differences were found between the 2 testing positions for the middle deltoid and upper trapezius muscles in the symptomatic group and for the middle deltoid muscle in the asymptomatic group. CONCLUSION: The results of the study suggest that PPT testing could be useful for distinguishing individuals with and without neck-shoulder pain and tenderness. Further, the patient's position should be considered when testing PPT, specifically at the middle deltoid or upper trapezius muscles.

The Variation of Cross-Sectional Area of the Sciatic Nerve in Flexion-Distraction Technique: A Cross-Sectional Study.

OBJECTIVE: The purpose of this study was to compare the cross-sectional area of the sciatic nerve in different positions of spinal manipulation using flexion-distraction technique. METHODS: Thirty healthy participants were assessed in 6 different flexion-distraction technique positions of varying lumbar, knee, and ankle positions. Participants stood in the following 3 positions with the lumbar in the neutral position: (A) with knee extended, (B) with knee flexed, and (C) with the knee extended and ankle dorsiflexion. Participants then stood in the following 3 positions with the lumbar flexed: (D) with the knee extended, (E) with the knee flexed, and (F) with knee extended and ankle dorsiflexion. The cross-sectional area (CSA) of the sciatic nerve was measured with ultrasound imaging in transverse sections in the posterior medial region of the left thigh. The CSA values measured at each position were compared. RESULTS: We analyzed 180 ultrasound images. The cross-sectional area of the sciatic nerve (in mm2) in position B (mean; standard deviation) (59.71-17.41) presented a higher mean cross-sectional area value compared with position D (51.18-13.81; P =.005), position F (48.71-15.16; P = .004), and position C (48.37-16.35; P = .009). CONCLUSION: The combination of knee extension and ankle dorsiflexion reduced the CSA of the sciatic nerve, and flexing the knee and keeping the ankle in the neutral position increased it.

The prone bridge test: Performance, validity, and reliability among older and younger adults.

INTRODUCTION: The prone bridge maneuver, or plank, has been viewed as a potential alternative to curl-ups for assessing trunk muscle performance. The purpose of this study was to assess prone bridge test performance, validity, and reliability among younger and older adults. METHOD: Sixty younger (20-35 years old) and 60 older (60-79 years old) participants completed this study. Groups were evenly divided by sex. Participants completed surveys regarding physical activity and abdominal exercise participation. Height, weight, body mass index (BMI), and waist circumference were measured. On two occasions, 5-9 days apart, participants held a prone bridge until volitional exhaustion or until repeated technique failure. Validity was examined using data from the first session: convergent validity by calculating correlations between survey responses, anthropometrics, and prone bridge time, known groups validity by using an ANOVA comparing bridge times of younger and older adults and of men and women. Test-retest reliability was examined by using a paired t-test to compare prone bridge times for Session1 and Session 2. Furthermore, an intraclass correlation coefficient (ICC) was used to characterize relative reliability and minimal detectable change (MDC95%) was used to describe absolute reliability. RESULTS: The mean prone bridge time was 145.3 ± 71.5 s, and was positively correlated with physical activity participation (p ≤ 0.001) and negatively correlated with BMI and waist circumference (p ≤ 0.003). Younger participants had significantly longer plank times than older participants (p = 0.003). The ICC between testing sessions was 0.915. CONCLUSION: The prone bridge test is a valid and reliable measure for evaluating abdominal performance in both younger and older adults.

Onset and maximum values of electromyographic amplitude during prone hip extension after neurodynamic technique in patients with lumbosciatic pain: A pilot study.

OBJECTIVE: The mechanisms underlying the effects of neurodynamic techniques are still unknown. Therefore, the aim of this study was to provide a starting point for future research on explaining why neurodynamic techniques affect muscular activities in patients with sciatic pain. METHODS: A double-blind trial was conducted in 12 patients with lumbosciatica. Surface electromyography activity was assessed for different muscles during prone hip extension. Pre- and post-intervention values for muscle activity onset and maximal amplitude signals were determined. RESULTS: There was a significant reduction in the surface electromyography activity of maximal amplitude in the erector spinae and contralateral erector spinae (p < 0.05). Additionally, gluteus maximus (p < 0.05) activity onset was delayed post-intervention. CONCLUSIONS: Self-neurodynamic sliding techniques modify muscular activity and onset during prone hip extension, possibly reducing unnecessary adaptations for protecting injured components. Future work will analyze the effects of self-neurodynamic sliding techniques during other physical tasks.

Stiffness of resting lumbar myofascia in healthy young subjects quantified using a handheld myotonometer and concurrently with surface electromyography monitoring.

This study aimed to non-invasively quantify passive stiffness of superficial myofascia at a lower lumbar (L3-L4) anatomical level in young healthy male and female subjects and investigate its possible morphological variation. Resting prone lumbar myofascial measurements were quantified using MyotonPro(®) and statistically analyzed in 20 young healthy individuals over 3-weekly intervals, concurrently with surface electromyography (sEMG). Averaged mean ± SE stiffness (Newton/meter) over three weeks was significantly (p < 0.001) greater in males (247.8 ± 11.3) than females (208.4 ± 11.3), on the right (237.7 ± 12.8) than left sides (218.5 ± 12.3), at 10-min (231.4 ± 9.1) than initial baseline (224.8 ± 9.1) values. A polymorphism of stiffness values in 10 male and 10 female subjects was suggested by box plot analyses of the 3 weekly measurements and greater inter-individual than intra-individual variances. Greater knowledge of lumbar myofascial stiffness can improve understanding of their contributions in health and chronic low back disorders.

The Effects of Prone with Respect to Supine Position on Stress Relaxation, Respiratory Mechanics, and the Work of Breathing Measured by the End-Inflation Occlusion Method in the Rat.

PURPOSE: The working hypothesis is that the prone position with respect to supine may change the geometric configuration of the lungs inside the chest wall, thus their reciprocal mechanical interactions, leading to possible effects on stress relaxation phenomena and respiratory mechanics. METHOD: The effects of changing body posture from supine to prone on respiratory system mechanics, particularly on stress relaxation, were investigated in the rat by the end-inflation occlusion method. RESULTS: In the prone with respect to supine position, an increment of the frictional resistance of the airway (from 0.13 ± 0.01 to 0.19 ± 0.02 cm H2O/l sec(-1), p < 0.05) and a decrement of the stress relaxation-linked pressure dissipation (from 0.51 ± 0.05 to 0.45 ± 0.05 cm H2O/l sec(-1), p < 0.01) were found. Respiratory system elastance and total resistive pressure dissipation did not change significantly. Accordingly, a significant increase of the frictional "ohmic" mechanical inspiratory work of breathing and a decrease of the visco-elastic work of inspiration were demonstrated, while no significant changes occurred for the total mechanical work of breathing and its total resistive and elastic components. CONCLUSION: It is concluded that postural changes affect the visco-elastic characteristics of the respiratory system and the related stress relaxation phenomena by influencing the disposition and relation of the lungs inside the chest wall and their relative geometrical configuration, and the interaction phenomena of the constitutive parenchymal structures, i.e., elastin and collagen fibers. Since the prone position resulted in no serious or disadvantageous respiratory system mechanical derangement, it is suggested it may be usefully applied in nursing or for therapeutic goals.

Effect of Chinese herbal medicine on vascular functions during 60-day head-down bed rest.

PURPOSE: Chinese herbal medicine is a promising countermeasure against cardiovascular dysfunction associated with a sedentary lifestyle. We examined the impact of the Chinese herb, Taikong Yangxin, on the micro- and macrovascular dysfunction associated with a 60-day bed rest. METHODS: Fourteen healthy men were randomly divided into two groups: those given herbal supplement, and the control group; the two groups underwent a 60-day bed rest. The macrovasculature was assessed by sonography. Skin microvascular functions were assessed with laser Doppler. The plasma level of endothelial microparticles (EMPs), markers of endothelial injury, was determined. RESULTS: Bed rest induced a 33 % decrease in the femoral artery diameter and compliance whereas carotid wall thickness, diameter, and compliance remained unchanged. The early phase of endothelium-dependent vasodilation to ACh was unmodified by bed rest, while the late phase was reduced by 30 % along with a twofold increase in EMPs. In those given Taikong Yangxin, the early phase was amplified by 2.5-fold, and the effects of bed rest on the late phase were prevented. CONCLUSION: These findings indicate that Taikong Yangxin ameliorates endothelium-dependent vasodilation, likely by improving the NO pathway. The study suggests Taikong Yangxin as a new countermeasure to prevent the changes in microvascular function induced by physical inactivity.

Influences of breast milk composition on gastric emptying in preterm infants.

OBJECTIVES: The aim of the present study was to determine whether specific biochemical and energy concentrations influence gastric emptying of unfortified and fortified mother's own milk (MOM) in stable preterm infants, and whether gastric emptying differs between feeds of unfortified MOM and feeds fortified with S-26 or FM 85 human milk fortifier (HMF) when infants are fed the same volume under similar conditions. Influences of infant gestation, age, and weight, and feed characteristics were also explored. METHODS: Stomach volumes of 25 paired unfortified and fortified MOM feeds were monitored prefeed and postfeed delivery and at 30-minute intervals thereafter. For each feed, MOM samples were analyzed to determine concentrations of total protein, casein, whey, carbohydrate, lactose, fat, and energy. Fortified feed compositions were calculated by adding fortifier biochemical and energy concentrations to unfortified MOM concentrations. Ultrasound images were used to calculate infant stomach volumes. Statistical comparisons were made of paired stomach volume measurements. RESULTS: Higher feed concentrations of casein were associated with faster gastric emptying during feed delivery (P = 0.007). When compared with unfortified MOM, S-26 fortified feeds emptied similarly, whereas FM 85 fortified feeds emptied more slowly both during feed delivery and during the postprandial period (P = 0.002, <0.001, respectively). Gastric emptying was slower for 2-hourly feeds compared with that for 3-hourly feeds (P = 0.003) and in supine position compared with that in prone (P = 0.001). CONCLUSIONS: Breast milk composition influences gastric emptying in stable preterm infants, with feeds of higher casein concentration emptying faster during feeding than otherwise equivalent feeds, and FM 85 fortified MOM emptying more slowly than unfortified MOM.

The effect of body position on pulmonary function, chest wall motion, and discomfort in young healthy participants.

OBJECTIVE: The purpose of this study was to investigate the effect of different recumbent positions on pulmonary function, chest wall motion, and feelings of discomfort in young nonobese healthy volunteers. METHODS: Twenty healthy volunteers (age, 28.0±1.4 years; height, 167.5±10.1 cm; weight, 62.3±10.2 kg) were studied in the sitting position and in the following 6 recumbent positions: supine, left retroversion at a 45° tilt, left anteversion at a 45° tilt, right retroversion at a 45° tilt, right anteversion at a 45° tilt, and prone. After 5 minutes of a selected position, pulmonary functions, including vital capacity (VC), forced expiratory volume in 1 second, maximal inspiratory and expiratory mouth pressures (MIP and MEP, respectively), and breathing pattern components at the chest wall were assessed. Discomfort was assessed using a modified Borg scale. RESULTS: When participants changed position from sitting to each of the 6 recumbent positions, forced expiratory volume in 1 second values decreased significantly (P < .05). None of the participants showed changes in the MIP or MEP in any of the 6 recumbent positions. Rib cage motion was restricted in all recumbent positions except supine, left anteversion at a 45° tilt, and prone. In all 6 recumbent positions, discomfort was experienced during the pulmonary tests. However, in the left retroversion at a 45° tilt position, no discomfort was experienced during the MIP and MEP assessments. CONCLUSION: In young, nonobese, healthy volunteers, recumbent positions caused diminished pulmonary functions and induced feelings of discomfort.

Comparison of spine motion and trunk muscle activity between abdominal hollowing and abdominal bracing maneuvers during prone hip extension.

The aim of this study was to examine the effects of lumbopelvic stabilization maneuvers on spine motion and trunk muscle activity during prone hip extension (PHE). In this study, 14 healthy male volunteers (mean age, 21.2 ± 2.6 years) were instructed to perform PHE without any maneuvers (control), with abdominal hollowing (AH), and with abdominal bracing (AB). Surface electromyography data were collected from the trunk muscles and the lumbopelvic motion was measured. Lumbar extension and anterior pelvic tilt degree were significantly lower in the AH and AB than in the control condition during PHE (p < 0.001). Lumbar extension and anterior pelvic tilt degree did not differ significantly between the AH and AB (p > 0.05). Global muscle group activity such as external obliques was lower in the AH than in the AB. These findings suggest that PHE with AH effectively minimizes unwanted lumbopelvic motion which does not result in global muscle activation.

Longitudinal changes in ventral and dorsal neck muscle layers during loading against gravity in healthy volunteers using speckle tracking.

OBJECTIVE: This study aimed to describe and compare the longitudinal mechanical activity, deformation, and deformation rate of the different layers of dorsal and ventral neck muscles in healthy volunteers during head lifts against gravity. METHODS: The cross-sectional study included 19 healthy volunteers (mean age, 28 years; SD, 7 years). Ultrasound with speckle-tracking analysis was used to investigate longitudinal mechanical activation, deformation, and deformation rate of dorsal and ventral neck muscles in real time during a head lift. Significance levels were set as P = .025 or P = .0125, depending on the number of comparisons. RESULTS: The dorsal neck muscles did not significantly differ in deformation (P > .04); however, the multifidus had a higher deformation rate than all other dorsal muscles (P < .003). The sternocleidomastoid had significantly higher deformation than the longus capitis (P = .005) and colli (P = .001) but a lower deformation rate than the longus colli (P = .02). CONCLUSION: The sternocleidomastoid deformed more than the deeper muscles, but it did significantly slower than the longus colli. Among the dorsal muscles, the deepest (the multifidus) had the highest deformation rate.

Prone hip extension with lower abdominal hollowing improves the relative timing of gluteus maximus activation in relation to biceps femoris.

Hamstring injuries are common. The hamstrings and gluteus maximus (GM) work as synergists during hip extension. When contraction of GM is delayed relative to Biceps Femoris (BF) the hamstrings may be predisposed to injury due to increased demand. This study investigated whether specific training affected neuromuscular control of BF and GM during Prone Hip Extension (PHE). Twenty healthy volunteers were randomly allocated to the intervention or the control group. Mean onset times for BF and GM during PHE were recorded via surface electromyography (sEMG). The intervention group performed a 10min exercise with focus on proximal to distal muscle activation involving abdominal hollowing and active GM contraction prior to PHE. The control group undertook an exercise which included only PHE. Post exercise descriptive analysis indicated that the intervention exercise reduced the delay of GM firing relative to BF, however, when baseline differences between the two groups are taken into account as a covariant, the difference attributable to the intervention is not statistically significant (P=0.166). The results suggest that a short duration exercise intervention has the potential to alter the timing of activation of GM relative to BF during PHE but this needs validation through future research.

Reliability of a test measuring transversus abdominis muscle recruitment with a pressure biofeedback unit.

BACKGROUND: There are indications that segmental stabilising exercises (SSEs) are effective in the treatment of low back pain. The evaluation of successful training in SSE performance in patients requires a reliable outcome measure. The PRONE test gives an indication of the activity of the transversus abdominis muscle. Performed in prone lying using a pressure biofeedback unit, it has been used as an aid to training and to assess the subject's ability to perform SSEs correctly. OBJECTIVES: To evaluate inter-observer and test-retest reliability of the PRONE test. DESIGN: Repeated measures by three observers on 2 days. SETTING: Department of Physical Medicine and Rehabilitation, Ludwig-Maximilian University, Munich, Germany. PARTICIPANTS: Forty nurses (39 females and one male), aged between 24 and 62 years, with at least one episode of low back pain. MAIN OUTCOME MEASURES: During the test, movement of the abdominal wall was monitored by measuring a change in pressure during muscle contraction termed 'abdominal hollowing'. Defined observation and palpation criteria were verified by the observers to ensure correct execution of the test. METHODS: Participants were tested on two separate days. On the first day, Observer A performed two similar test sets, each with four exercises. On the second test day, Observers B and C conducted one test set each. RESULTS: This study found an intra-class correlation coefficient (ICC) of 0.47 [95% confidence interval (CI) 0.20 to 0.67] for inter-observer reliability, and an ICC of 0.81 (95% CI 0.67 to 0.90) for test-retest reliability. Kappa values and the limits of agreement were also calculated with similar results. CONCLUSIONS: For this subject group, the PRONE test had relatively low inter-observer reliability but, as may be expected, higher test-retest reliability. It is suggested that by providing visual feedback, the PRONE test may enhance patients' insight into their deep abdominal muscle recruitment and thereby increase their motivation to exercise.

Changes in cerebral blood flow under the prone condition with and without massage.

To investigate changes in regional cerebral blood flow (rCBF) under the prone condition with and without light massage on the back, we measured rCBF quantitatively in healthy human subjects using positron emission tomography with H(2)15O. Biochemical tests showed that the light massage (palm-pressure) reduced levels of stress-related serum cortisol and salivary stress protein chromogranin-A measured after the PET examination. Absolute rCBF significantly increased in the parietal cortex (precuneus) under the prone condition compared with the supine condition, and this rCBF increase was in parallel with comfortable sensation and slowing heart rate during the massage. Correlation analysis in statistical parametric mapping showed that the amygdalar and basal forebrain rCBF correlated with parasympathetic function (heart rate reduction), indicating involvement of the forebrain-amygdala system in mediating activities in the autonomic nervous system in the presence of comfortable sensation. To conclude, prone posture itself can stimulate the precuneus region to raise awareness, and the light massage on the back may help accommodate the brain to comfortable stimulation.

Sudden infant death--focus subject of medico-legal research.

The compilation of research activities concerning SID in the field of legal medicine could only choose those out of a great abundance of high-quality examinations which represent applied research. By this they have contributed either to the clarifying of the aetiology which has not been cleared up or to the prophylaxis. For this looking through in a widest sense the basic approach was to consider SID being the result of an intrinsic and/or extrinsic disturbance of the modulation of respiratory regulation of the infant. This namely means a metabolic disturbance of respiratory neurons. One must not share this opinion even if it is given a certain plausibility by newer physiological examinations. But this also means that some examinations did not receive the acknowledgement which they would have received if there had been an immunological approach. The compilation was completely done without a presentation of the primary crisis intervention and the long-term care as being a fundamental medico-legal approach. Altogether may be summarized that legal medicine has completely fulfilled its duty to take care of the problem SID and that the examinations did not remain without success.

Four types of visual mental imagery processing in upright and tilted observers.

We investigated the role of body position on performance in four distinct types of mental imagery processing. Previous studies used the upright body position as standard procedure and therefore do not address the issue of whether mental imagery tasks are processed in accordance with ego-centered or gravitational coordinates. In the present study, the subjects were brought into one of three different body positions: upright, horizontal, or supine. In each of these body positions, we measured performance in four imagery tasks, which assessed (1) the ability to generate vivid, high-resolution mental images; (2) the ability to compose mental images from separate parts; (3) the ability to inspect patterns in mental images; and, (4) the ability to mentally rotate patterns in images. Not all processes were affected in the same way when subjects performed them in different body positions. Performance in the image composition and detection tasks depended on body position, whereas there was no such effect for the transformation and resolution tasks.

Decreased cardiac responses to auditory stimulation during prone sleep.

OBJECTIVE: To evaluate the relationship between body position during sleep and the infants' cardiac responses to auditory stimulation. METHODS: Thirty healthy infants with a median age of 11 weeks were studied polygraphically for one night, while sleeping successively prone and supine, or vice versa. Their behavioral and cardiac responses were recorded during rapid eye movement (REM) sleep, both before and after exposure to 90 dB (A) of white-noise. RESULTS: Ten infants were excluded from the study, because they woke up during the challenge. For the 20 infants included in the analysis, no significant difference was seen between the prone and the supine position for total sleep time, sleep efficiency, percent of REM and nonrapid eye movement sleep, number of gross body movements, transcutaneous oxygen saturation levels, mean cardiac rate, heart rate variability, number of heart rate drops; mean respiratory rate, and number or duration of central or obstructive apneas. Auditory challenges induced significantly less overall changes in heart rate, less heart rate drops, less heart rate variability, as well as fewer and shorter central apneas in the prone than in the supine position. Autoregressive power spectral analysis of the heart rate was consistent with a possible increase in orthosympathetic tone in the prone position. CONCLUSION: Prone sleeping was associated with a decrease in cardiac responses to auditory stimulation and a possible increase in orthosympathetic activity. Prone positioning could favor a reduced reactivity to danger-signaling stimuli during REM sleep.