Four degree-of-freedom lumped parameter model of the foot-ankle system exposed to vertical vibration from 10 to 60 Hz with varying centre of pressure conditions.

Modelling the foot-ankle system (FAS) while exposed to foot-transmitted vibration (FTV) is essential for designing inhibition methods to prevent the effects of vibration-induced white-foot. K-means analysis was conducted on a data set containing vibration transmissibility from the floor to 24 anatomical locations on the right foot of 21 participants. The K-means analysis found three locations to be sufficient for summarising the FTV response. A three segment, four degrees-of-freedom lumped parameter model of the FAS was designed to model the transmissibility response at three locations when exposed to vertical vibration from 10 to 60 Hz. Reasonable results were found at the ankle, midfoot, and toes in the natural standing position (mean-squared error (ε) = 0.471, 0.089, 0.047) and forward centre of pressure (COP) (ε = 0.539, 0.058, 0.057). However, when the COP is backward, the model does not sufficiently capture the transmissibility response at the ankle (ε = 1.09, 0.219, 0.039). Practitioner summary The vibration transmissibility response of the foot-ankle system (FAS) was modelled with varying centre of pressure (COP) locations. Modelling the FAS using three transmissibility locations and two foot segments (rearfoot and forefoot) demonstrated reasonable results in a natural standing and forward COP position to test future intervention strategies. Abbreviations: COP: centre of pressure; DOF: degrees-of-freedom; FAS: foot-ankle system; FTV: foot-transmitted vibration; HAVS: hand-arm vibration syndrome; LDV: laser Doppler vibrometer; LP: lumped-parameter; VWT: vibration-induced white-toes; WBV: whole-body vibration.

No. 203-Rubella in Pregnancy.

OBJECTIVE: To provide an update on rubella and pregnancy so that health professionals remain aware of the potentially devastating effects on the developing fetus. OUTCOMES: Rubella vaccination has been effective in virtually eliminating congenital rubella syndrome in Canada. EVIDENCE: Medline, PubMed, and Cochrane Database were searched for articles published between 1985 and 2007. VALUES: The quality of evidence was rated using the criteria described in the report of the Canadian Task Force on Preventive Health Care. SPONSOR: The Society of Obstetricians and Gynaecologists of Canada.

Design of a mechanism to simulate the quasi-static moment-deflection behaviour of the osteoligamentous structure of the C3-C4 cervical spine segment in the flexion-extension and lateral bending directions.

The human neck is susceptible to traumatic injuries due to impacts as well as chronic injuries caused by loads such as those attributed to the wearing of heavy headgear. To facilitate the analysis of the loads that cause injuries to the cervical spine, it is possible to replicate the human neck's behaviour with mechanical devices. The goal of this work is to lay the foundation for the eventual development of a novel mechanism used to simulate the behaviour of the cervical spine during laboratory experiments. The research presented herein focuses on the design of a mechanism capable of reproducing the non-linear relationships between moments applied to the C3 vertebra and its corresponding rotations with respect to the C4 vertebra. The geometrical and mechanical properties of the mechanism are optimized based on the ability of the latter to replicate the load-deflection profile of the osteoligamentous structure of the C3-C4 vertebral pair in the flexion-extension and lateral bending directions. The results show that the proposed design concept is capable of faithfully replicating the non-linear behaviour of the motion segment within acceptable tolerances.

The fetal safety of hydrocortisone-pramoxine (Proctofoam-HC) for the treatment of hemorrhoids in late pregnancy.

OBJECTIVE: Fetal safety has never been studied for any drug used in the treatment of hemorrhoids. Proctofoam-HC is a combination of a corticosteroid and a local anaesthetic that is proven effective for the treatment of hemorrhoids. The objective of this study was to assess prospectively the fetal safety of third trimester exposure to Proctofoam-HC. METHODS: In a multicentre study, 204 [corrected] women exposed to Proctofoam-HC in the third trimester and a similar number of control pregnant women were followed up postnatally. RESULTS: When compared to controls exposure to Proctofoam-HC was not associated with any adverse fetal effects on birth weight, gestational age, rates of prematurity, or pre- or postnatal complications. CONCLUSION: Proctofoam-HC is safe to use in the treatment of hemorrhoids in late pregnancy.

Rubella in pregnancy.

OBJECTIVE: To provide an update on rubella and pregnancy so that health professionals remain aware of the potentially devastating effects on the developing fetus. OUTCOMES: Rubella vaccination has been effective in virtually eliminating congenital rubella syndrome in Canada. EVIDENCE: Medline, PubMed, and Cochrane Database were searched for articles published between 1985 and 2007. VALUES: The quality of evidence was rated using the criteria described in the report of the Canadian Task Force on Preventive Health Care. SPONSOR: The Society of Obstetricians and Gynaecologists of Canada.

Guidelines for operative vaginal birth.

OBJECTIVE: To provide guidelines for operative vaginal birth in the management of the second stage of labour. OPTIONS: Non-operative techniques, episiotomy, and Caesarean section are compared to operative vaginal birth. outcome: Reduced fetal and maternal morbidity and mortality. EVIDENCE: MEDLINE and Cochrane databases were searched using the key words 'vacuum' and 'birth' as well as 'forceps' and 'birth' for literature published in English from January 1970 to June 2004. The level of evidence and quality of recommendations made are described using the Evaluation of Evidence from the Canadian Task Force on the Periodic Health Examination. RECOMMENDATIONS: 1. Non-operative interventions such as one-to-one support, partogram use, oxytocin use, and delayed pushing in women using epidurals will decrease need for operative birth. (I-A) 2. Manual rotation may be used alone or in conjunction with instrumental birth with little or no increased risk to the pregnant woman or to the fetus. (III-B) 3. Routine episiotomy is not necessary for an assisted vaginal birth. (II-1E) 4. When operative intervention in the second stage of labour is required, the options, risks, and benefits of vacuum, forceps, and Caesarean section must be considered. The choice of intervention needs to be individualized, as one is not clearly safer or more effective than the other. (II-B) 5. Failure of the chosen method, vacuum and/or forceps, to achieve delivery of the fetus in a reasonable time should be considered an indication for abandonment of the method. (III-C) 6. Adequate clinical experience and appropriate training of the operator are essential to the safe performance of operative deliveries. Hospital credentialing boards should grant privileges for performing these techniques only to an appropriately trained individual who demonstrates adequate skills. (III-C). VALIDATION: The Clinical Practice Obstetrics Committee and Executive and Council of the Society of Obstetricians and Gynaecologists of Canada approved these guidelines.

Exercise in pregnancy and the postpartum period.

OBJECTIVE: To design Canadian guidelines advising obstetric care providers of the maternal, fetal, and neonatal implications of aerobic and strength-conditioning exercises in pregnancy. OUTCOMES: Knowledge of the impact of exercise on maternal, fetal, and neonatal morbidity, and of the maternal measures of fitness. EVIDENCE: MEDLINE search from 1966 to 2002 for English-language articles related to studies of maternal aerobic and strength conditioning in a previously sedentary population, maternal aerobic and strength conditioning in a previously active population, impact of aerobic and strength conditioning on early and late pregnancy outcomes, and impact of aerobic and strength conditioning on neonatal outcomes, as well as for review articles and meta-analyses related to exercise in pregnancy. VALUES: The evidence collected was reviewed by the Society of Obstetricians and Gynaecologists of Canada (SOGC Clinical Practice Obstetrics Committee) with representation from the Canadian Society for Exercise Physiology, and quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on the Periodic Health Exam. RECOMMENDATIONS: 1. All women without contraindications should be encouraged to participate in aerobic and strength-conditioning exercises as part of a healthy lifestyle during their pregnancy. (II-1,2B) 2. Reasonable goals of aerobic conditioning in pregnancy should be to maintain a good fitness level throughout pregnancy without trying to reach peak fitness or train for an athletic competition. (II-1,2C) 3. Women should choose activities that will minimize the risk of loss of balance and fetal trauma. (III-C) 4. Women should be advised that adverse pregnancy or neonatal outcomes are not increased for exercising women. (II-1,2B) 5. Initiation of pelvic floor exercises in the immediate postpartum period may reduce the risk of future urinary incontinence. (II-1C) 6. Women should be advised that moderate exercise during lactation does not affect the quantity or composition of breast milk or impact infant growth. (I-A) VALIDATION: This guideline has been approved by the SOGC Clinical Practice Obstetrics Committee, the Executive and Council of SOGC, and the Board of Directors of the Canadian Society for Exercise Physiology. SPONSORS: This guideline has been jointly sponsored by the Society of Obstetricians and Gynaecologists of Canada and the Canadian Society for Exercise Physiology.

The management of nausea and vomiting of pregnancy.

OBJECTIVES: To review the evidence-based management of nausea and vomiting of pregnancy (NVP) and hyperemesis gravidarum. EVIDENCE: MEDLINE and Cochrane database searches were performed using the medical subject headings (MeSH) of treatment, nausea, vomiting, pregnancy, and hyperemesis gravidarum. The quality of evidence reported in these guidelines has been described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam. BENEFITS: NVP has a profound effect on women's health and quality of life during pregnancy, as well as a financial impact on the health care system, and its early recognition and management are recommended. (III-B) COST: Costs, including hospitalizations, additional office visits, and time lost from work, may be reduced if NVP is treated early.

Hemorrhagic shock.

OBJECTIVE: To review the clinical aspects of hemorrhagic shock and provide recommendations for therapy. OPTIONS: Early recognition of hemorrhagic shock and prompt systematic intervention will help avoid poor outcomes. OUTCOMES: Establish guidelines to assist in early recognition of hemorrhagic shock and to conduct resuscitation in an organized and evidence-based manner. EVIDENCE: Medline references were sought using the MeSH term "hemorrhagic shock." All articles published in the disciplines of obstetrics and gynaecology, surgery, trauma, critical care, anesthesia, pharmacology, and hematology between 1 January 1990 and 31 August 2000 were reviewed, as well as core textbooks from these fields. Selected references from these articles and book chapters were also obtained and reviewed. The level of evidence has been determined using the criteria described by the Canadian Task Force on the Periodic Health Examination. RECOMMENDATIONS: 1. Clinicians should be familiar with the clinical signs of hemorrhagic shock. (III-B) 2. Clinicians should be familiar with the stages of hemorrhagic shock. (III-B) 3. Clinicians should assess each woman's risk for hemorrhagic shock and prepare for the procedure accordingly. (III-B) 4. Resuscitation from hemorrhagic shock should include adequate oxygenation. (II-3A) 5. Resuscitation from hemorrhagic shock should include restoration of circulating volume by placement of two large-bore IVs, and rapid infusion of a balanced crystalloid solution. (I-A) 6. Isotonic crystalloid or colloid solutions can be used for volume replacement in hemorrhagic shock (I-B). There is no place for hypotonic dextrose solutions in the management of hemorrhagic shock (I-E). 7. Blood component transfusion is indicated when deficiencies have been documented by clinical assessment or hematological investigations (II-2B). They should be warmed and infused through filtered lines with normal saline, free of additives and drugs (II-3B). 8. Vasoactive agents are rarely indicated in the management of hemorrhagic shock and should be considered only when volume replacement is complete, hemorrhage is arrested, and hypotension continues. They should be administered in a critical care setting with the assistance of a multidisciplinary team. (III-B) 9. Appropriate resuscitation requires ongoing evaluation of response to therapy, including clinical evaluation, and hematological, biochemical, and metabolic assessments. (III-B) 10. In hemorrhagic shock, prompt recognition and arrest of the source of hemorrhage, while implementing resuscitative measures, is recommended. (III-B)VALIDATION: These guidelines have been reviewed by the Clinical Practice Obstetrics Committee and approved by Executive and Council of the Society of Obstetricians and Gynaecologists of Canada. SPONSORS: The Society of Obstetricians and Gynaecologists of Canada.