Lumbar lordosis measurement. A new method versus Cobb technique

STUDY DESIGN: A historic cross-sectional study of lumbar lordosis in 199 healthy individuals aged 1-30 years. OBJECTIVE: To evaluate the magnitude and rate of the development of the normal lumbar lordotic curve with age using two methods of measurement. SUMMARY OF BACKGROUND DATA: There is no agreement among spine physicians on the range of the normal lumbar lordotic curve. In certain conditions, such as a tethered spinal cord, a change in lordotic curve may indicate or even precede the onset of neurologic symptoms. Reliable measurements of the lumbar lordotic curve may aid in the early diagnosis and management of these conditions, before irreversible neurologic change ensues. METHODS: The lumbar lordotic curve was measured by the traditional Cobb technique and by a newly designed method, tangential radiologic assessment of lumbar lordosis. The data were subjected to the Morgan-Pitman test for correlated variances to observe which of the two methods was more reliable in measuring the magnitude and rate of change in the lumbar lordotic curve. RESULTS AND CONCLUSIONS: The rate of development of the lumbar lordotic curve appears to be nonlinear, increases during first year of life and during puberty, and reaches a plateau of approximately 50 degrees at maturity. The tangential radiologic assessment of lumbar lordosis method is more reproducible and more reliable in the lumbar lordotic curve, providing a smaller range of normal values (8 degrees-16 degrees less) than the Cobb method.     

The spinal curve in standing and sitting postures in children with idiopathic scoliosis

STUDY DESIGN: A sample of convenience of children with moderate idiopathic scoliosis without bracing or surgery was studied. The sample consisted of 19 children, aged 9 to 16 years, with mean Cobb angle of 24 degrees. The spinal configurations and paraspinal muscle activity in several commonly assumed postures were examined. OBJECTIVES: To determine how the apex angles, verticality of spine, and muscle activity vary with the assumed posture and whether the location and the number of spinal curves affect these variables. SUMMARY OF BACKGROUND DATA: It has been suggested that the configuration of the spine in commonly assumed postures can affect the spinal curve in scoliosis because of gravitational bending moments. There is, however, a paucity of data obtained in subjects in sitting postures that school-age children assume daily for prolonged periods. Absence of bilateral symmetry in pressure during sitting has been described, but its effect on the spinal apex angle has not been investigated. METHODS: Infrared-emitting markers, whose three-dimensional positions could be tracked by a pair of cameras, were affixed to the spine. The natural postures studied were relaxed standing, relaxed sitting, erect sitting, and writing while seated. Electromyographic activity in muscles close to the spinal apexes was recorded bilaterally for each test posture. RESULTS: Subjects leaned laterally and, in general, anteriorly, in all test postures, rather than placing the C7 vertebra vertically above S1. The direction of lean and the change in the spinal apex angle from standing to sitting varied depending on whether the spinal curve was single or double, thoracic or lumbar. Subjects with single curves, whether thoracic or lumbar, tended to lean laterally toward the convexity of their curve apex--that is, the lean was in a direction that reduced the apex angle. Subjects with double curves (thoracic and lumbar), in all postures except relaxed sitting, tended to lean toward the convexity of the lumbar curve, thereby reducing the lumbar apex angle and exacerbating the thoracic angle. Most subjects' apex angles were smaller in relaxed or erect sitting than in relaxed standing. Electromyographic activity was in general greater on the convex side of the curve, with greatest activity in erect sitting. CONCLUSIONS: The findings indicate that in self-selected postures the gravitational effect of leaning and the muscle activity in paraspinal muscles may serve to reduce the apex angle. Thus, a fully upright, centered posture may not be best for correction of every patient's spinal curve.     

Lumbar lordosis in spinal fusion. A comparison of intraoperative results of patient positioning on two different operative table frame types

STUDY DESIGN: One hundred one patients undergoing spine surgery for degenerative conditions were entered into a prospective radiographic evaluation of changes in lumbar lordosis as affected by positioning on two different operative tables. OBJECTIVES: The hypothesis of the present study is twofold: 1) the positioning of patients on specific types of operative tables may affect significantly the overall degree of lumbar lordosis obtainable, and 2) certain operative positioning may more accurately reproduce physiologic standing lateral lumbar lordosis. SUMMARY OF BACKGROUND DATA: In the management of degenerative and post-traumatic spinal deformities, lumbar fusion using posterior instrumentation permits more accurate and physiologic lordotic positioning of the involved fusion segments of the lumbar spine. However, various types of operating frames are available for use in this type of surgery, and despite the overall importance of correct lordotic positioning, there is some question as to what effect on positioning, as measured in degrees of lumbar lordosis, a particular frame might have. METHODS: Total, multisegmental, and unisegmental Cobb angle measurements of preoperative standing lateral radiographs and intraoperative lateral radiographs after positioning on respective operative tables were determined. Fifty-one patients were positioned on an Andrews-type table, and 50 patients were positioned on the four-poster-type frame. Statistical comparison using analysis of variance testing of changes in lordosis before and after surgery between study groups was evaluated. RESULTS: Lumbar lordosis measured from L1 to S1 with standing lateral radiographs showed a combined mean preoperative measurement of 45.18 degrees, with no statistical significance between groups. In comparison, there was a statistically significant difference between intraoperative measurements from L1 to S1 on the Andrews table versus the four-poster frame, revealing an average of 32.81 degrees versus 47.71 degrees, respectively (P < 0.005). Multisegmental lordosis measurement from L2 to S1 displayed statistical significance between groups, with a combined preoperative standing lateral radiograph average of 43.32 degrees, and intraoperative values of 31.28 degrees on the Andrews table versus 45.34 degrees on the four-poster frame (P < 0.005). Multisegmental lordosis measurements from L4 to S1 displayed statistical significance between groups, with a combined preoperative standing lateral radiograph average of 31.40 degrees and intraoperative values of 23.14 degrees on the Andrews table versus 32.94 degrees on the four-poster frame (P < 0.005). Segmental lordosis at L5-S1 was less dependent on frame type, with a combined preoperative standing lateral radiograph average of 20.53 degrees and intraoperative measurements of 20.06 degrees on the Andrews table versus 21.02 degrees on the four-poster frame (P < 0.43). CONCLUSION: Results from the present study display a statistically significant difference between multisegmental and total lumbar lordosis, depending on the type of operative table used in patient positioning. Segmental lordosis at L5-S1 depended less on frame type. This table-dependent positional change in lumbar lordosis could be incorporated easily into a lumbar fusion procedure, especially when supplemented with instrumentation, affecting the permanent overall degree of lordosis. These results suggest that a more physiologic degree of lumbar lordosis is obtained accurately with use of an operative table similar to the four-poster frame.     

X-ray cinematographic analysis of lordosis in female rats.

X-ray movies were used to analyze skeletal movements of 10 hormone-primed female Sprague-Dawley rats during the onset of lordosis. The pattern of movements of the vertebral column and rear legs during lordosis indicates that this behavior is caused mainly by muscles acting to dorsiflex the vertebral column. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Compensatory spinopelvic balance over the hip axis and better reliability in measuring lordosis to the pelvic radius on standing lateral radiographs of adult volunteers and patients

STUDY DESIGN: Sagittal alignments, including lumbar lordosis and spinopelvic balance (measured from C7, S1, and hip axis reference points for the relative positions of the spine and sacropelvis over the hips), were studied on standing 36-in. lateral radiographs of adult volunteers (control subjects) and patients who had specific spinal disorders. OBJECTIVES: To determine the most reliable methods for measuring lumbopelvic lordosis and to define significant spinopelvic compensations for sagittal balance. SUMMARY OF BACKGROUND DATA: Measurements for standing sagittal balance, obtained using a C7 plumb line, and segmental angulations of the spinal vertebrae, including lordosis to the sacrum, have been reported. Absolute values, even for normative data, have had wide variation and limited clinical usefulness. Correlations of sagittal balance with the reported spinopelvic angulations (spinal vertebral and sacropelvic angulations) have not been well defined. In addition, determinates of balance (spinal and pelvic) have not been studied for reliability, and compensatory mechanisms for maintenance of balance have not been carefully evaluated. Better recognition of the correlations and more reliable methods to measure lordosis and balance and the spinopelvic compensations for its maintenance may be beneficial in treating patients who have spinal disorders. METHODS: Measurements on standing 36-in. lateral radiographs were made for sagittal alignments in adult volunteers (n = 50) and in adult patients who had symptomatic degenerative lumbar disc disease (n = 50), low grade L5-S1 isthmic (lytic) spondylolisthesis (n = 30), and idiopathic or degenerative scoliosis (n = 30). All participants exhibited clinical compensation for balance. Data were analyzed for significant correlations within each group to determine compensatory correlations of spinopelvic balance with the other sagittal alignments. Intraobserver and interobserver reliability for the parameters evaluated were calculated. This included two methods for determining lordosis (S1 end-plate and pelvic radius techniques). RESULTS: Plumb line measurements for balance from the S1 and hip axis reference points, as defined, were similar in all four groups. However, the groups appeared to adjust for balance by using common and distinctive spinopelvic compensations that resulted in significantly and characteristically different angular alignments among the four groups. Lordosis and balance measurements were closely correlated, and the correlation was characterized by pelvic rotation and translation around the hip axis. The subjects with less lordosis typically stood with the C7 plumb line anterior to and at a longer distance from the sacral reference point. This was primarily because of posterior sacropelvic translation around the hip axis and not because the sagittal plumb line initially moved anteriorly away from the sacrum. This was true in all four groups and gave the appearance that the sacropelvis was less well balanced over the hips in the subjects with less lordosis. Even small differences in lordosis appeared to be associated with considerable adjustments in the other spinopelvic alignments. Therefore, it was important to determine that lordosis was lumbopelvic more reliably measured by the pelvic radius technique. CONCLUSIONS: Lower lumbar lordosis, by the pelvic radius technique, and compensatory sacropelvic translation around a hip axis, in addition to measurements from this axis to the C7 plumb line, were the primary determinates and most reliable radiographic assessments for sagittal balance. Understanding the common and characteristically different compensations that occur with balance in these patients who had specific spinal disorders may help to improve their care.     

Vaginal stimulation in rats induces prolonged lordosis responsiveness and sexual receptivity.

Conducted 2 experiments, using a total of 131 female Sprague-Dawley rats. Sexual receptivity to males resulted from stimulation of the vagina with a glass rod in previously unreceptive ovariectomized, estrogen-treated Ss. Several minutes of rejection behavior preceded the receptivity. In Exp II manual palpation was used to determine the duration of the lordosis response facilitation. Initially, all Ss were unresponsive to manual flank-perineum stimulation (palpation). Vaginal stimulation plus palpation, which together elicited lordosis, facilitated subsequent lordosis responses to palpation. This effect persisted for several hours after the vaginal stimulation was applied. Vaginal stimulation alone, which was ineffective in eliciting lordosis, also facilitated lordosis in response to subsequent palpation. Repeated palpation did not facilitate lordosis. These prolonged effects were independent of hormone treatment. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Brain transections differentially alter lordosis and ear wiggling of 6-day-old rats.

The involvement of various brain regions in lordosis and ear-wiggling, which resemble components of adult female sexual behavior, was examined by making acute transections along the neuraxis from the olfactory tract to the medulla in 6-day-old rats. Four to 5 hrs after the transection procedure, pups were tested for lordosis and ear wiggling. Lordosis was reduced or eliminated in pups with cuts through the hindbrain or diencephalon (above the level of the mammillary bodies) but was relatively unaffected by cuts through the posterior hypothalamus and rostral tegmentum and by cuts rostral to the anterior hypothalamus. Ear wiggling was disrupted by transections throughout the hindbrain and was facilitated only in females by transections throughout the forebrain (anterior to the mammillary bodies). Data suggest that facilitation from the hypothalamus is required for lordosis in the infant rat and the forebrain inhibitory systems for ear wiggling are functional in female infants by 6 days of age. Similarities and differences between the neural control of lordosis and ear wiggling in infant and adult rats suggest that the infant sex-like behaviors may be precursors of adult female sexual behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Subjective assessment of sitting comfort

Experts in ergonomics research on sitting comfort recommend a number of so-called objective assessment techniques as well as subjective judgements in order to select the best seat for a given purpose and a defined group of future users. In this paper, a variety of subjective evaluation methods such as general comfort rating, body area comfort rating, chair feature checklists, and direct ranking ranking of chairs are presented, and their pros and cons are discussed.     

The correlation of idiopathic lumbar scoliosis and lumbar lordosis

A definite correlation exists between the presence of idiopathic lumbar scoliosis and hyperlordosis of the lumbar spine. Present data do not reveal whether hyperlordosis constitutes an element which makes a "spine at risk" for developing scoliosis. However, the presence of an extreme lordosis suggests that in any comprehensive plan of treatment of idiopathic lumbar scoliosis, provision should be made for correction of severe deformities of the lumbar spine.     

Eyeheight-scaled information about affordances: A study of sitting and stair climbing.

Previous work has shown that both the perceived and actual critical (maximum) heights of surfaces that afford "sitting on" and "climbing on" can be expressed as constant proportions of each actor's leg length. The current study provides evidence that these judgments of critical action boundaries are based on an existing source of size and distance information that is already scaled with reference to the actor's eyeheight. In Experiment 1 changes in judgments of "perceived eyeheight" (an index of the intrinsic scalar) as a function of viewing distance were shown to be highly correlated with changes in the maximum height that was perceived to afford sitting on or climbing on. In Experiments 2 and 3 observers wore 10-cm blocks and made judgments about whether the heights of various surfaces afforded sitting or climbing. The use of eyeheight-scaled information as the basis for their estimates predicted the obtained pattern of errors in these judgments. With a modicum of experience wearing the blocks, however, observers were able to retune accurately their critical action boundary to a degree that would not have been predicted from their consistent overestimation of the height of the block on which they were standing. These results have implications for understanding how observers obtain information about their specific action boundary. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Idiopathic coccygodynia. Lateral roentgenograms in the sitting position and coccygeal discography

STUDY DESIGN: The authors hypothesized that the source of coccygodynia was a lesion of the coccygeal disc. OBJECTIVES: This study analyzed the motion of the painful coccyx in the sitting position as compared with the lateral decubitus in a patient and a control group and reported the first results of coccygeal discography (dynamic study). SUMMARY OF BACKGROUND DATA: Coccygodynia are usually attributed to soft tissue injuries or psychologic disturbances. No previous study has assessed the coccygeal discs as a source of pain. METHODS: Fifty-one patients with coccygodynia and 51 controls sustained a dynamic study. Coccygeal mobility was documented by superimposing graph paper with a double reading. The accuracy of the measurement was +/- 2.6 degrees intra- and interobserver variations 15.3 and 12.5%. This dynamic study was followed by coccygeal discography in the patient group. RESULTS: An abnormal motion (luxation or hypermobility) of the coccyx that occurred in the sitting position and spontaneously was reducible when placed in the lateral decubitus position was found in 25 patients. Such lesions could be responsible for the pain because no similar findings were seen in the controls and coccygeal discography was positive in these cases. Of the 26 patients with a normal dynamic study, coccygeal discography, using a combination of provocation and anesthetization, was positive in 15 of 21. CONCLUSIONS: Common coccygeal pain could come from the coccygeal disc in approximately 70% of cases.     

Personality correlates of continuation and outcome in meditation and erect sitting control treatments.

In a 6-mo double-blind study, 49 anxious (State-Trait Anxiety Inventory) college student volunteers were assigned to transcendental meditation (TM) and 51 to a control treatment, periodic somatic inactivity (PSI). The control treatment was carefully designed to match the form, complexity, and expectation-fostering aspects of TM, but it incorporated an exercise that involved sitting erect with eyes closed twice daily rather than sitting and meditating. For each treatment 30 demographic and pretest personality variables were correlated with continuation in treatment and outcome defined in terms of trait anxiety change scores. As predicted, the TM dropout was more disturbed and less self-critical than the person who continued meditating. For TM, outcome correlated significantly with anxiety, Sizothymia (16 PF, Factor A), and Autia (16 PF, Factor M). Contrary to what was predicted, there was virtually no overlap between the variables correlated with continuation and outcome for TM and for PSI. It is concluded that differing treatment rationales rendered the treatments appealing, credible, and effective for different types of individuals. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estradiol benzoate facilitates lordosis and ear wiggling of 4- to 6-day-old rats.

The effects of exogenous and endogenous steroids on components of female sexual behavior of neonatal male and female rats were investigated. In Experiment 1, 4-day-old rats were treated with 0, 0.1, 1.0, 10, or 100 μg/10 g body weight estradiol benzoate (EB) and were tested 44 hr later. In Experiment 2, male rats castrated within 24 to 48 hr of birth were compared with sham operated controls and castrates given steroid replacement. The results indicated that most 6-day-old pups will display lordosis and ear wiggling, therefore, the display of these responses is not dependent upon exogenous steroids. However, a fine-grain behavioral analysis revealed that EB treatment increased the frequency, duration, and intensity of lordosis and the frequency of ear wiggling in infant females, and it increased lordosis duration in males. Castration of infant males decreased the likelihood that male infants would display lordosis, whereas testosterone replacement restored behavior to control levels. These data question the concept that organizational and activational actions of estrogens occur during completely separable times in development and should provide new insights into the development of estrogen receptor function and the process of sexual differentiation of brain and behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differences between supine and sitting Frank-lead electrocardiograms

In babies ranging in age from 1 to 25 weeks and in children between 1 and 14 years, plasma renin activity and urinary aldosterone activity were determined in relation to urinary sodium excretion. A reciprocal correlation was found demonstrating that the hyperactivity of the renin-angiotensin-aldosterone system is stimulated in infants by a low sodium intake. A second stimulus was observed in the influence of the hypothalamo-neurohypophyseal system, when the plasma renin activity was suppressed by administration of antidiuretic hormone and sodium excretion increased due to a decreased aldosterone activity. Our study suggests that there exists a feedback between the renin-angiotensin-aldosterone system and ADH release and that this feedback plays an important role in the regulation of water and electrolyte balance in the young infant.     

Lumbar disk prolapse. Alcohol, tobacco and prognosis

The aim of the study was to examine whether smoking or the intake of different alcoholic beverages are associated with the outcome after first time lumbar disc surgery. One hundred and forty-eight patients consecutively operated upon for lumbar disk herniation over a one-year period were classified according to various social and demographic variables. Two and a half years later they were asked about their drinking and smoking habits and the outcome of the operation was assessed using a rating scale. Results showed that intake of wine, but not other alcoholic drinks, was associated with a good prognosis. Logistic regression analysis calculated that intake of wine was associated with a fourfold increase in success rate. This odds ratio was not significantly reduced by the following variables: Age, sex, smoking habits, employment status, social class, household income or marital status. In conclusion, intake of wine was associated with a good prognosis after lumbar discectomy.     

Psychotherapeutic effects of transcendental meditation with controls for expectation of relief and daily sitting.

Conducted 2 experiments to isolate the trait-anxiety-reducing effects of transcendental meditation (TM) from expectation of relief and the concomitant ritual of sitting twice daily. Exp I was a double-blind study in which 49 anxious college student volunteers were assigned to TM and 51 to a control treatment, "periodic somatic inactivity" (PSI). PSI was carefully designed to match the form, complexity, and expectation-fostering aspects of TM but incorporated a daily exercise that involved sitting twice daily rather than sitting and meditating. In Exp II 2 parallel treatments were compared, both called "cortically mediated stabilization" (CMS). 27 volunteers were taught CMS-sub-2, a treatment that incorporated a TM-like meditation exercise, and 27, CMS-sub-2, an exercise designed to be the near antithesis of meditation. Assessment measures included the State-Trait Anxiety Inventory A-Trait scale, the Epstein-Fenz Manifest Anxiety Scale, the 16 PF, and the Marlowe-Crowne Social Desirability Scale. Results show 6 mo of TM and PSI to be equally effective and 11 wks of CMS-sub-2 and CMS-sub-2 to be equally effective. Differences between groups did not approach significance. Results support the conclusion that the crucial therapeutic component of TM is not the TM exercise. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lung mechanics in sitting and horizontal body positions

We measured lung compliance, pulmonary flow-resistance, and expiratory reserve volume (ERV) in ten healthy young adults in sitting, supine, and lateral positions. Average lung compliance was 0.21 in sitting, 0.19 in lateral and 0.16 L.cm H2O-1 in supine positions. The change was significant (p less than 0.01) between sitting and supine position. Flow-resistance increased from 1.78 in sitting to 2.5 cm H2O.L-1.s (p less than 0.001) in lateral positions, and did not increase further in the supine posture in spite of a 35 percent decrease in ERV (p less than 0.001). Since it is known that lower airways resistance increases with decreasing lung volume, the lack of change in flow-resistance when shifting from lateral to supine posture suggests that upper airways flow-resistance (larynx and oropharynx) is greater in the lateral decubitus than in the supine positions. The decrease of lung compliance in horizontal postures probably reflects increased pulmonary blood volume and small airways closure.     

Somatosensory determinants of lordosis in female rats: Behavioral definition of the estrogen effect.

By coating the ventral surface of 16 Sprague-Dawley male rats with a dye, regions of contact between males and females ( n = 76) during male mounting were recorded precisely on the female's hair and skin. Film analyses showed that the male's paws and pelvic thrusting stimulated the female's skin with dominant frequencies between 10 and 20/sec. Somatosensory stimuli were then applied to the female skin locations contacted by the male. Deflection of hair on the flanks or perineum alone did not cause lordosis. Light stimulation simultaneously on flanks and perineum caused lordosis only in some females given high estrogen dosages supplemented by progesterone. When flank stimuli were followed by pressure on the rump, tailbase, and perineum, lordosis was triggered reliably in hormone-treated females. In this case, the estrogen-dependence of the reflex was shown, and progesterone synergized with the estrogen effect. Among lordosis components, rump and head elevations in response to pressure stimuli on the rump, tailbase, and perineum appear to be hormone-sensitive. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)