BIRTH AS A MOTOR SKILL. part 3.

THE CONCEPT

Labor and birth are intense physical challenges that require endurance and stamina over an extended period of time, the ability to cope with high intensity intervals and quick recovery, strength, mobility, emotional support, and the ability to enter a parasympathetic or alpha brain wave driven state. These factors point to a physical preparation based on evidence of exercise principles that produce progress in these areas.

These well-established principles in exercise physiology – listed below – help us meet these needs. Note these are physiological principles, not methods. Some validated methods of achieving outcomes derived from applying these principles are given as examples in the discussion that follows.

  • Training Specificity (covered in post 1)
  • Overload and Progression (covered in post 2)
  • Muscle Bonding (discussed in this post)
  • Flow (or The Zone)

MUSCLE BONDING

“Synchronized motion triggers a sublimation of selfish drives and needs in order to function as a single organism” – Left, Right, Left, Right, Muscular Bonding and the Hive Trigger http://www.abovetopsecret.com/forum/thread840994/pg1

The evolving concept of muscle bonding through synchronized motion emerged primarily in two fields of study, military behavior and ritual practices in the arts, sports and celebrations. These discussions center on the development of group cohesiveness and support that evolve over time via intense synchronized motion [16,17]. Raising the pain threshold has also been noted in exercise science due to the release of endorphins in response to the stress of intense exercise [18,19]. Recently, the effects of elevated pain threshold and bonding have been demonstrated independent of each other in synchronized dancing[20].

Figure 5: The presenting affect of the hive trigger is joy.

Muscle bonding and its hive trigger are useful for labor preparation. Cooperation needs practice. Lowering one’s pain threshold requires practice. In labor, continuous support of the mother is critical. Working as a team includes the mother accepting support. Hence, fairly intense synchronized group movement can serve as a method of enhancing these skills and helps explain why [group] aerobic activities contribute greatly to reduced needs for interventions[4,5,10].

Figure 6: Note the same joyful expression on the face of a new mom who prepared to “dance” with her birth team .

The cooperative – or “hive” – effect is independent of another outcome: alteration of the pain threshold through release of endorphins due to intense movement. Both effects are helpful in labor and birth.  Note the joyful look on the faces of active moms-to-be, moving together.

In recovery, this type of activity might also be examined as a means to reduce the incidence of postpartum mood disorders.

________

References for Post #3:

  1. Owe KM et al. Exercise during pregnancy and risk of cesarean delivery in nulliparous women: a large population-based cohort study. Am J Obstet Gynecol. 2016 Dec;215(6):791.e1-791.e13. doi: 10.1016/j.ajog.2016.08.014. Epub 2016 Aug 23.
  2. Barakat R et al. Exercise during pregnancy is associated with a shorter duration of labor. A randomized clinical trial. European Journal of Obstetrics & Gynecology and Reproductive Biology. 2018 224:33–40. https://doi.org/10.1016/j.ejogrb.2018.03.009
  1. Newton EF, May L. Adaptation of Maternal-Fetal Physiology to Exercise in Pregnancy: The Basis of Guidelines for Physical Activity in Pregnancy. Clin Med Insights: Women’s Health. 2017; 10: 1179562X17693224. Published online 2017 Feb 23. doi: 10.1177/1179562X17693224.
  1. Wray H. All together now: The universal appeal of moving in unison. Scientific American Mind. April 1, 2009. https://www.scientificamerican.com/article/were-only-human-all-together-now/
  2. Wiltermuth SS, Heath C. Synchrony and cooperation. Psychol Sci.2009 Jan;20(1):1-5. doi: 10.1111/j.1467-9280.2008.02253.x.
  3. Cohen EEA Ejsmond-Frey R, Knight N, Dunbar RIM. 2009. Biology Letters, 6, 106-108. (doi:10.1098/rsbl.2009.0670)
  4. Dishman RK, O’Connor, PJ. 2009. Lessons in exercise neurobiology: The case of endorphins. Mental Health and Physical Activity, 2: 4-9. (doi:10.1016/j.mhpa.2009.01.002)
  5. Tarr B, Launay J, Cohen E, Dunbar R. 2015 Synchrony and exertion during dance independently raise pain threshold and encourage social bonding. Biology Letters11:20150767.http://dx.doi.org/10.1098/rsbl.2015.0767

 

BIRTH AS A MOTOR SKILL. part 2

THE CONCEPT

Labor and birth are intense physical challenges that require endurance and stamina over an extended period of time, the ability to cope with high intensity intervals and quick recovery, strength, mobility, emotional support, and the ability to enter a parasympathetic or alpha brain wave driven state. These factors point to a physical preparation based on evidence of exercise principles that produce progress in these areas.

These well-established principles in exercise physiology – listed below – help us meet these needs. Note these are physiological principles, not methods. Some validated methods of achieving outcomes derived from applying these principles are given as examples in the discussion that follows.

  • Training Specificity (covered in prior post)
  • Overload and Progression (discussed in this post)
  • Muscle Bonding
  • Flow (or The Zone)

OVERLOAD and PROGRESSION

“Overload and progression are two basic training principles. Overload refers to the amount of load or resistance, providing a greater stress, or load, on the body than it is normally accustomed to in order to increase fitness. Progression is the way in which an individual should increase the load.”

http://www.ode.state.or.us/teachlearn/subjects/pe/curriculum/fittprinciple.pdf accessed 5/27/18.

That pregnant women are capable of increasing physical fitness in the same way as non-pregnant persons was established in an early Cochrane review of exercise in pregnancy [9].

Figure 3: Typical resistance exercise that uses overload and progression to increase strength

While loads, repetitions and time frames for increasing loads and repetitions generally depend on the goals of an activity, even a small increase in load will establish a measureable improvement within an 8-week period, if consistent practice is followed. Figure 3 illustrates a typical strength exercise that  progresses load by shortening the length of the resistance band.

Discussion of the evolution of pregnancy exercise studies, and current understanding about the volume of exercise, as well as the conditions under which exercise is safe and effective in pregnancy, is available in a 2017 review [10], 2002 topic textbook [11] and Varney’s Midwifery, editions 3 and 4.

In the absence of an underlying contra-indication (e.g., chronic heart disease; history of incompetent cervix), beginning exercise in pregnancy is safe. If a woman is sedentary or has had little physical activity leading up to pregnancy, the guidance of a well-trained pre/postnatal fitness specialist is indicated. Understanding what activities, what modifications, how much activity and how often an individual can be active, requires knowledge and experience. In addition, the progression an individual makes must be balanced with her individual biomechanical risks and any medical issuesthat might appear along the way.

Figure 4 Tactile aid to strengthen TrA. Pressing up against the trainer’s hand requires activating TrA.

For example,diastasis recti abdominus (DRA)is often diagnosed postpartum. However, it is possible to recognize it in pregnancy, and progressively train to prevent or attenuate the condition. Figure 4 illustrates how tactile aid helps a mom-to-be engage her transverse abdominals (TrA) during a modified plank by pressing up against the trainer’s hand, activating TrA. Strong TrA mitigates against DRA in pregnancy and helps prevent or reduce its severity during second stage, especially if the valsalva maneuver is employed.

When is it best to begin exercise for pregnancy? It is likely most beneficial to enter pregnancy already aerobically fit due to reduced risk for uterine endothelial dysfunction and/or immune related problems that arise during implantation.There is evidence to suggest a pre-pregnancy dose-related (more fit, less risk) reduction for preeclampsia (PE) [12,13]. As a start point, near the end of the first trimester or early second trimester permits adequate time for training effects, in general. There is some evidence cardiovascular conditioning during pregnancy might reverse endothelial dysfunction to an extent that PE risk is reduced or severity decreased [14].  A theory as to why women who are fit during pregnancy might be at reduced risk for preeclampsia has been outlined [15]. In any case, beginning at a safe level before or during pregnancy, and progressing with regular practice, contributes to a healthy pregnancy and birth.

_______

References for Post #2:

  1. Kramer MS, McDonald SW. Aerobic exercise for women during pregnancy. Cochrane Database of Systematic Reviews.2006, Issue 3. Art. No.: CD000180. DOI: 10.1002/14651858.CD000180.pub2.
  2. Newton EF, May L. Adaptation of Maternal-Fetal Physiology to Exercise in Pregnancy: The Basis of Guidelines for Physical Activity in Pregnancy. Clin Med Insights: Women’s Health. 2017; 10: 1179562X17693224. Published online 2017 Feb 23. doi: 10.1177/1179562X17693224.
  3. Cowlin AF. 2002. Women’s Fitness Program Development. Human Kinetics.
  4. Rudra C, Williams MA, Lee IM, Miller RS, Sorensen TK. Perceived exertion during pre-pregnancy physical activity and preeclampsia risk, Med Sci Sports Exerc2005 Nov;37(11):1836-41.
  5. Rudra CB, Sorensen TK, Luthy DA, Williams MA. A prospective analysis of recreational physical activity and preeclampsia risk, Med Sci Sports Exerc. 2008 Sep;40(9):1581-8.
  6. Cowlin AF, Brancato-Ozovek R, DeZinno P, Zelterman D, Mor G. The effect of community-based group prenatal physical activity on preeclampsia rate. 2008. Poster presentation, Society for Gynecologic Investigation 55thAnnual Meeting, San Diego, CA.
  7. Weissgerber TL, Wolfe LA, Davies GAL. The Role of Regular Physical Activity in Preeclampsia Prevention. Med Sci Sports Exerc. 2004. 36(12):2024-2031.

#Birth #PregnancyFitness #FitnessForBirth #DancingThruPregnancy #BirthOutcomes #BirthAsAMotorSkill

 

BIRTH AS A MOTOR SKILL: Applying Exercise Physiology to Labor Preparation for Improved Outcomes

INTRODUCTION
NOTE: This is the first in a series of posts that derive from a presentation authored by DTP Director Ann Cowlin for the 2018 Normal Birth Research Conference. Remaining posts will be added each week on Wednesdays for the next several weeks.

When a person desires to run a marathon, she trains, doing those things that enable the person to achieve the goal. When an exercise physiologist views labor and birth as an athletic event, she sees specific challenges and seeks to train pregnant women in ways that produce a healthy labor, birth, mother and newborn.

Designing a program to specifically address improved outcomes is tricky. Many existing prenatal fitness programs address some of the areas required, others focus on one skill as a magic bullet. The reality, as so often is the case, is the necessity of doing all those things that are effective and avoiding the so-called junk workouts. So, what does an effective program look like? This presentation offers some possibilities.

The well-established principles in exercise physiology that are emphasized here are training specificity, overload, muscle bonding, and flow (or zone). They are defined and explicated, and intersections of these principles with the physiology of labor and birth are enumerated. Childbirth literature is clear that physically fit women, with skills to prevent oxygen debt and muscle fatigue, with confidence, and who have continuous support in labor, are less likely to require intervention to give birth.

BACKGROUND

The successful preparation for any intense physical challenge includes practices shown to improve outcomes for participants because these practices enhance the physiologic systems or skills required during the activity or event. Identifying physical challenges of an activity or event permits design and testing of an evidence-based best practices model of physiologic preparation.

Childbirth and exercise physiology literature are clear that

  1. Pre/postnatal Exercise is generally safe and can be effective in helping produce birth and health outcomes that are beneficial for pregnant women and their offspring [1,2,3].
  2. Physically fit women, with skills and the capacity to prevent oxygen debt and muscle fatigue, with confidence in their bodies, and who have continuous support in labor, are less likely than sedentary women to require intervention to give birth [4] and may have shorter labors [5].

THE CONCEPT

Labor and birth are intense physical challenges that require endurance and stamina over an extended period of time, the ability to cope with high intensity intervals and quick recovery, strength, mobility, emotional support, and the ability to enter a parasympathetic or alpha brain wave driven state. These factors point to a physical preparation based on evidence of exercise principles that produce progress in these areas.

These well-established principles in exercise physiology – listed below – help us meet these needs. Note these are physiological principles, not methods. Some validated methods of achieving outcomes derived from applying these principles are given as examples in the discussion that follows.

  • Training Specificity (discussed in this post)
  • Overload and Progression
  • Muscle Bonding
  • Flow (or The Zone)

TRAINING SPECIFICITY

“Specificity is the principle of training that states that sports trainingshould be relevant and appropriate to the sport for which the individual is training in order to produce a training effect. Training must also progress from general conditioning to specific training and skills for the sport or activity. You must perform the skill in order to get better at it.”

https://www.verywell.com/principle-of-specificity-definition-3120375accessed 5/27/18

Two important relevant points are contained in this definition:

  1. An underlying general fitness precedes more detailed training and skill acquisition.
  2. The event or sport activity dictates the type of underlying fitness that is needed.

Stamina.By definition labor and birth are ultra distance endurance events. Thus, cardiovascular conditioning (a.k.a., cardiorespiratory or aerobic conditioning) is the underlying type of fitness base needed. Without this base, skill acquisition may be futile, especially if skills require mental attention. The discomfort of oxygen debt intrudes on the effort to “go with the flow” or move in response to bodily sensations. By contrast, stamina permits the mind to focus on resolving emergent needs.

What methods of cardiovascular conditioning might be most appropriate for labor and birth?Vertical, weight-bearing movement– jogging, aerobic dancing, and elliptical equipment – are ideal. See Figure 1.

Fig 1: Aerobic Dancing is a fun method for cardiovascular conditioning.

These forms mimic labor activities that elicit gate-control of pain and gravity-assist. Almost any safe aerobic activity helps the body learn to use and replace oxygen in the utero/placental environment, affected by hypoxic tendencies during contractions [5].

 

High Intensity Interval Training (HIT or HIIT).Repeated bouts of high intensity activity, alternated with a recovery phase, also characterize labor, particularly first stage active labor/transition and second stage. HIIT – the associated training strategy – raises anaerobic threshold, reduces stress on cardiac reserve, and enhances metabolism [6]. HIIT in cardiovascular and strength training regimens produce beneficial outcomes [7,8]. Practicing HIIT sequences develops muscle memory, freeing the mind to focus on response to the body’s needs.Cross-fit or boot camp training are examples. Are they safe in pregnancy? If appropriate.

 

Strength and Mobility.To achieve positions and movements that allow the body to release rather than resist the cathartic demands of birth depends on body trust– the accomplishment of successful experiences that develop strength and flexibility, enhance kinesthesia and improve confidence in one’s body.

Fig. 2: Developing kinesthesia of the vaginal birth area.
1) kinesthesia aids 2) motor control, which leads to
3) accomplishment, implementing 4) body trust.

An example of this is learning to open the pelvis through various strength, release and bulge practices. To identify the birth target area,moms-to-be can sit upright on the ischial tuberosities (sitbones) with iliofemoral flexion, shown in Figure 2.

Focusing on the vaginal opening between the sitsbones, they locate the outlet, and develop kinesthesia and a mental grasp of this area as an exit. Practicing the muscular actions (tighten, release and bulge) that control the outlet permits the pregnant women to learn the difference between a restricted and released birth target. Additional exercises to develop skeletal muscles surrounding the pelvis, help prevent postural fatigue during second stage in various positions.

______

References for Post #1:

  1. ACOG Committee Opinion 650. Physical Activity and Exercise During Pregnancy and the Postpartum Period.2015.
  2. Barakat R, et al. Exercise Throughout Pregnancy Does Not Cause Preterm Delivery. A Randomized, Controlled Trial. J Phys Act Health.2014 Jul;11(5):1012-7. doi:10.1123/jpah.2012-0344. Epub 2013 May 10
  3. Blaize AN, Pearson KJ, Newcomer SC. Impact of maternal exercise during pregnancy on offspring chronic disease susceptibility. Exerc Sport Sci Rev. 2015;43(4):198-203.
  4. Owe KM et al. Exercise during pregnancy and risk of cesarean delivery in nulliparous women: a large population-based cohort study. Am J Obstet Gynecol. 2016 Dec;215(6):791.e1-791.e13. doi: 10.1016/j.ajog.2016.08.014. Epub 2016 Aug 23.
  5. Barakat R et al. Exercise during pregnancy is associated with a shorter duration of labor. A randomized clinical trial. European Journal of Obstetrics & Gynecology and Reproductive Biology. 2018 224:33–40. https://doi.org/10.1016/j.ejogrb.2018.03.009.
  6. Dobierzewska A et al. NFAT5 Is Up-Regulated by Hypoxia: Possible Implications in Preeclampsia and Intrauterine Growth Restriction, Biol Reprod.2015 Jul;93(1):14. doi: 10.1095/biolreprod.114.124644. Epub 2015 May 20. 
  7. Laursen PB, Jenkins DG. The scientific basis for high-intensity interval training. Sports Med2002;32(1):53-73.
  8. Schubert MM, Clarbe HE, Seav RF, Spain KK. Impact of 4 weeks of interval training on resting metabolic rate, fitness, and health-related outcomes. Appl Physiol Nutr Metab. 2017, Oct;42(10):1073-1081. doi:10.1139/1pnm-2017-0268. Epub 2017 Jun 20.

#Birth #PregnancyFitness #FitnessForBirth #DancingThruPregnancy #BirthOutcomes #BirthAsAMotorSkill

Less Intervention Leads to Less Complication in Birth

Recent research on the physiological processes at work in labor and birth are leading to conclusions that there should be as little intervention as possible in this process.

There is advice coming from prenatal care providers and researchers in the field telling us that some established practices need to change. For example, eating during early labor and continual drinking of clear fluids (even with electrolytes) are now recommended to help ward off uterine fatigue. It is a bag of muscles, after all!

Some recommendations have been less universally adopted than others by various birth professionals. For example, there is evidence that hand-held manual fetoscopes used to occasionally assess the fetal heart provide more accurate assessment than continuous electronic monitoring. Not all prenatal care providers are trained in manual fetal heart monitoring, so adoption is likely to take time in some areas.

To help readers learn about the specific practices that can help reduce intervention in labor, we have found and excellent summary to be the Childbirth Connection Fact Sheet – New Professional Recommendations to Limit Labor and Birth Interventions: What Pregnant Women Need to Know. It is brief, clear and concrete. Link to the fact sheet here.

One of the most interesting recent findings is that admission to the hospital at less than 4 cm dilation is a risk factor for increased intervention and cesarean birth. The abstract of the research, with a link to the full text, can be found through PubMed here.

We strongly recommend these two references.

Physical Preparation for Birth

A recent research article on birth positioning [1] and a policy paper on reducing interventions in labor [2] reinforced my thinking that how we prepare women for labor and birth needs updating. As we learn more and more about the physiology of labor and birth [3], we are learning which practices are productive for a healthy birth and which practices work against birth.

Augmenting our knowledge and skills, as well as encouraging exercise components that improve outcomes truly prepare women for the intense challenges of giving birth. So here are some up and coming tips:

Hands and knees is mechanically efficient for mom’s body to “cradle” the fetus.

Why is this pregnant woman on her hands and knees?

Hands & knees can help low back pain in pregnancy & labor. It also reduces risk of injury to the pelvic floor during birth [1].

This position innervates transverse abdominal support of the abdomen. It opens SI joint via knee press effect. Practicing breathing, pelvic tilts, and modified planks in this position improves hands and knees endurance.

Why are these pregnant women squatting with partner support?

The most common reason given for practicing squats is that this action “opens the pelvic outlet.” This is true. But knowing how valuable kinesthesia is in executing challenging actions, I find that I must first teach women (and their partners) to sense where the target outlet is – between the sitsbones! This helps them learn to release the pelvic floor muscles and know where to focus their pushing efforts.

Also, having the support partner understand what is happening, as well as learning to support this action, is equally valuable to mom. It creates an important bonding and trusting activity. Explaining, illustrating with charts, and then teaching the ability to release, then bulge or distend the pelvic floor in the target area turns out to be one of the activities for which both partners are most grateful.

Why is this woman taking big strides and really moving out?

Aerobic fitness helps provide endurance in labor

Moving is a complicated neurological phenomenon and requires large afferent fiber pathways. The gate-control theory of pain states that movement deters other sensations that must travel up smaller pathways to reach our attention. Example: When you hit your elbow funny bone, you are likely to move around and rub the area, NOT sit and focus on the discomfort.

Labor is an endurance event, so if a mom is going to use movement (and gravity – another big helper) for 10 or 12 hours in labor, endurance fitness is a key preparation. Whether she jogs, swims, spins or dances, cardiovascular activity is possibly the most valuable exercise component she can acquire.

Some Quick Tips, based on recent research:

  • Encourage moms in early labor to stay out of the hospital as long as they can, unless they are given a significant medical reason to go in by their care provider. Once in the hospital, try to minimize the procedures that she must undergo [2]. The hospital or birthing center where she gives birth can, itself, be a factor in how she births [4].
  • If this is a healthy pregnancy, encourage her to eat in early labor and maintain her fluid intake throughout labor [5]. Endurance drinks can be useful to help maintain electrolyte balance during this long event.
  • Let her know she can ask to have hands-on support of her pelvic floor as the baby descends in pushing. Have her discuss this ahead of time with her care provider. This is another method that has been shown to reduce injury [6].
  • She can also ask to “labor down” rather than push for a few contractions after she is fully dilated, if she feels she needs to regroup once the head is through the cervix [7].
  • A good resource for positioning for birth and for recovery exercise is a Physical Therapist who has a PT certification in women’s health. For more information, go to PTPN.com or their Physiquality Blog.

REFERENCES

These references are worthy reading on our changing concepts of pregnancy, labor and birth practice. All of us who work with pregnant women are important influences in helping them gain skills and confidence to cope with this intensely physical, challenging experience.

  1. Zhang H et al. A randomised controlled trial in comparing maternal and neonatal outcomes between hands-and-knees delivery position and supine position in China. Midwifery July 2017 50:117-124. http://www.midwiferyjournal.com/article/S0266-6138(17)30236-X/abstract
  2. ACOG. Approaches to Limit Intervention During Labor and Birth. Committee Opinion Number 687, February 2017. http://www.acog.org/Resources-And-Publications/Committee-Opinions/Committee-on-Obstetric-Practice/Approaches-to-Limit-Intervention-During-Labor-and-Birth
  3. Buckley SJ. Hormonal Physiology of Childbearing: Evidence and implications for Women, Babies, and Maternity Care. Childbirth Connection, 2015. PDF: http://www.nationalpartnership.org/research-library/maternal-health/hormonal-physiology-of-childbearing.pdf
  4. Shah NT. System Complexity and the Challenge of Too Much Medicine, Annual Meeting ACOG 2017. http://annualmeeting.acog.org/growing-c-section-rates-can-be-mitigated-by-counteracting-hospital-complexities/#.WRCbmxRaHFK
  5. ASA Press Release. Most healthy women would benefit from light meal during labor. Nov. 6, 2015. http://www.asahq.org/about-asa/newsroom/news-releases/2015/10/eating-a-light-meal-during-labor
  6. Leenskjold S, Hoi L, Pirhonen J. Manual protection of the perineum reduces the risk of obstetric anal sphincter ruptures. Dan Med J May 2015; 62(5). pii: A5075. https://www.ncbi.nlm.nih.gov/pubmed/?term=Leenskjold+S%2C+Hoi+L%2C+Pirhonen+J.+Manual+protection+of+the+perineum
  7. Brancato (Ozovek) RM, Church S, Stone PW. A Meta-analysis of passive descent versus immediate pushing in nulliparous women with epidural analgesia in the second stage of labor, JOGNN 2008; 37(1):4-12. https://www.ncbi.nlm.nih.gov/pubmed/?term=Brancato+RM+A+Meta-analysis+of+passive+descent

To Kegel or Not to Kegel? That is the Question!

Every few years, the Kegel exercises come under attack. Practicing Kegels is often cited as the cause of difficulty during the pushing stage of birth, due to bearing down against contracted rather than relaxed pelvic floor muscles. This increases resistance to fetal movement, potentially damaging soft tissue, as well as stressing maternal cardiac reserve and the fetal heart. So, a call goes out to stop doing Kegels. But, Kegels were invented for a reason, and contracting the pelvic floor during birth is not it.

So, to kegel or not to kegel? Two things help us understand how to answer the question of whether or not – and when – to do Kegels. One is history (ever a useful tool) and the other is identifying the anatomy and physiological functions of the female pelvic floor.

1) History

Hands and knees is mechanically efficient for mom's body to "cradle" the fetus.

Hands and knees is mechanically efficient for mom’s body to “cradle” the fetus.

 

First thing, a quick peek at evolution. The pelvic floor did not originally support the contents of the abdomen. Starting out as 4-legged creatures, our pelvic floor originally served more as the back door.

Sacrum & Coccyx at top. Pubis at bottom. Evolution position.

Sacrum & Coccyx at top. Pubis at bottom. Evolution position.

Thus, the opening and closing of outlets were primary functions, and support of abdominal contents was largely a job for the Transverse Abdominals.

We could rock into an upright posture (squatting or sitting on our “sitsbones”), allowing gravity to assist in downward emptying of abdominal contents. When we relax our skeletal muscles, the involuntary muscles and neuro-motor emptying pathways proceed unfettered.

Squatting

Squatting

Once we discovered we could stand on our feet and still reach much of the fruit in the trees, a fast transition to upright (in evolutionary terms) placed strain on movement and support in the pelvis, spine and hip joints. Reviewing all the details involved in the ensuing adaptations is another story for another day. Suffice it to say, supporting the abdominal contents was not included in the original design of the pelvic “floor.”

Fast forward to the end of the 19th Century when birth began moving into a clinical setting and women were routinely placed on their back for labor and birth.

Pubis at top. Sacrum and coccyx at bottom. Supine position.

Pubis at top. Sacrum and coccyx at bottom. Supine position.

Yes, this slowed down the process and made it more painful. Thus, the next steps emerge in the early 20th Century: “Twilight Sleep” and increased forceps birth.

For a good understanding of this era, I recommend the following 1916 article:

  • Haultain FWN and Swift BH. The Morphine-Hyoscine method of painless childbirth or so-called “Twilight Sleep,” British Medical Journal, 1916 Oct 14;2(2911):513-5. Full text here:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2354830/pdf/brmedj07070-0003.pdf

  • The reader can also learn more about Twilight Sleep and its adaptations in the U.S. by entering “twilight sleep childbirth” into the PubMed search field.

Next: Urinary incontinence! Or, the reason Kegels were invented.

So, what was the product of placing women on their backs, putting them into a semi-conscious state, amnesia of events, and sometimes dragging the baby out of the vagina with forceps? Likely, increasing incidence of pelvic floor dysfunction. However, additional factors also influence maternal pelvic floor outcomes, including the Valsalva maneuver during pushing, and instrumental birth. Who invented “pushing” anyway? Male doctors.

  • For more on such matters, I recommend the reader examine Sheila Kitzinger’s work. She is a renowned British anthropologist who studied, wrote and spoke on global birth customs throughout her life.

Pushing, or bearing down, occurs naturally during coughing, sneezing, emesis, forced exhalation (as when a tennis player grunts while hitting a ball), urination, defecation and – when occurring without analgesia – parturition (birth). Identifying the “best” way to push remains illusive. What is the goal? Speed, damage control, fetal outcome? The Cochrane Library concludes only that maternal preferences and medical imperatives should guide the method of pushing.

  • Lemos A et al. Pushing/bearing down methods for the second stage of labour. Cochrane Database Syst Rev. 2015 Oct 9;10:CD009124. doi:10.1002/14651858.CD009124.pub2.

And, what about organ prolapse? How does that figure in here? Is weakness in the pelvic floor muscles a cause? It is becoming more clear that, even in the absence of trauma, genetic factors play a significant role in the occurrence and severity of pelvic floor dysfunction. There is great variability in how connective tissues respond to stress and stretching. A good recent account of one possible gene avenue is this article:

  • He K, Niu G, Gao J, Liu JX, Qu H. MicroRNA-92 expression may be associated with reduced estrogen receptor β1 mRNA levels in cervical portion of uterosacral ligaments in women with pelvic organ prolapse. Eur J Obstet Gynecol Reprod Biol. 2016 Mar;198:94-9. doi: 10.1016/j.ejogrb.2016.01.007. Epub 2016 Jan 11.

In the early-mid 20th Century, much less was understood about how genetics, physical training, postural sway and practice protocols might affect these matters. In 1948, Dr. Arnold Kegel, an American gynecologist, published on a non-surgical method of toning the pelvic floor in order to help women control incontinence following childbirth. By exercising the pubococcygeus muscles (PC muscles or sphincters) of the pelvic floor, he found that women could reduce their likelihood of experiencing bladder problems after pregnancy and birth. Here are the two publications that give rise to calling these exercises “Kegels.”

  • Kegel AH. Progressive resistance exercise in the functional restoration of the perineal muscles. Am J Obstet Gynecol. 1948 Aug;56(2):238-48.
  • Kegel AH. The nonsurgical treatment of genital relaxation; use of the perineometer as an aid in restoring anatomic and functional structure. Ann West Med Surg. 1948 May;2(5):213-6.

Keep these factors in mind: The experiments leading to publication included measurement of the strength of contraction of these muscles. Several devices (balls, cones and devices that read muscle strength) were developed to provide tactile aid in contracting and releasing the PC or sphincter muscles, and continue to be used today by physiotherapists. These actions are aimed at squeezing the detrusor (or urinary flow mechanism) to prevent incontinence with weak or relaxed sphincters.

What about the issue of organ prolapse? How does that tie in? Over time, the term “Kegel” has also come to refer to tightening the levator muscles (the sling-like muscles that lift the pelvic floor). This action is the opposite of what happens when bearing down. Which nicely brings us to the second topic:

2) Anatomy and Functions of the Female Pelvic Floor

There are three rings of muscles and four muscle actions that govern the opening and closing of the bony structures and soft tissue of the pelvic floor. The overall bony shape of the pelvic floor is similar to a baseball diamond, as seen in the first graphic.

Pelvic outlets, lithotomy position.

Pelvic outlets, lithotomy position.

 

The three rings are – from outside to in:

  1. Gluteals, transverse perineals and ischiocavernous that create two triangles of the pyramidal bony structure and create a rigid fence when contracted or a mobile structure when released. The deep rotators, including piriformis, and the pyramidalis also function to close the pelvic outlet.
  2. Levator and diaphragm muscle that lift and close the pelvic floor and/or support the contents of the abdomen by contracting when the woman is vertical.
  3. Sphincter muscles that squeeze and release the three orifices: urethra, vagina and anus, closing and opening these outlets.

The four muscle actions are:

  1. Contraction – tightening the muscle as in strength training. Can be done to shorten muscle (concentric) or as muscle extends (eccentric). Muscles can shorten approximately half their resting or relaxed length. Contracting muscle against resistance increases cardiovasculature and improves delivery of nutrients and oxygen, as well as improving innervation and awareness of motion.
  2. Release/Relaxation – letting go of contraction, allowing muscle to rest, relax or be stretched.
  3. Stretching – muscles can be lengthened approximately a third of their resting length by applying leverage to the bony structures the muscle controls. Stretching is also affected by genetic factors regarding elasticity of the connective tissue within and attaching to muscle and bone.
  4. Bulging or Distending – Some muscles can extend beyond their stretching range by pressure from the diaphragm, often termed “bearing down.” Both the Transverse Abdominals (TA) and pelvic floor muscles do this during parturition (efforts to expel the baby). The TA tighten in a distending position to assist in the emptying of the abdominal contents and the pelvic floor extends beyond the bony structure defined by the sit bones (ischial tubersoities) on either side of the vagina. To get a sense of how this occurs, I recommend two things: first, cough hard enough that you can sense the action of TA and pelvic floor; second, next time you take a poop, sense how your body is working. It is the same for parturition, although the target is the vagina rather than the anus and the voluntary assisting effort needed is much more intense. Two practices help prevent damage to the pelvic floor. One is following the urge to push and the other is to “labor down” when their is no urge, when the mother needs to rest a bit during pushing. Avoiding, as much as possible, the Valsalva maneuver (holding the breath while pushing) reduces strain on maternal cardiac reserve and the fetal heart.

An excellent way to get a sense of how the pelvic floor functions in birth is to view the 1974 Brazilian film, Birth in the Squatting Position. Here is the link:

https://www.youtube.com/watch?v=ZHHHcIZEi9U&oref=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DZHHHcIZEi9U&has_verified=1

So, do we do Kegels? Yes, but we also release/relax, stretch and learn the coordination of bulging/distending these muscles. After birth and as we age, we also do them as a method of recovery and because we are upright animals who have to support the contents of the abdomen. Learning to sit in an anatomically neutral position in a chair and many other healthy postural habits – not to mention understanding our genetic factors regarding elasticity – will also help us maintain a healthy pelvic floor. But these ideas are another story for another day.

 

In Labor? Eat for Endurance!!

For 30 years I have been reminding my pregnancy exercise and childbirth education classes – not to mention anesthesiologists – that the uterus is a bag of muscle, and that muscles need two things to function well: oxygen and sugar. To contract, muscles burn sugar in the presence of oxygen. Oxygen is renewed by regular, paced breathing. Sugar, on the other hand, has to be supplied first by glycogen at the muscle site, then by circulating blood glucose, optimally provided every few hours by food.

The amount of glycogen that rests at the muscle site in case the muscles need it for quick action lasts about 20 minutes at most. After that, during physical activity, the body will begin to break down fat to provide blood glucose. But. that also has time limits and acid begins to accumulate. Ultimately, nutrition of some kind is the only way that any ultra endurance activity ensures that adequate sugar is continuously supplied to the muscle. Without adequate energy, muscles do not work well.  Without nutrition, acid builds up.

For many decades, there has been a ban on food and water during labor once a laboring mom is in the hospital due to the risk of aspiration – inhaling food or water into the lungs. At last, anesthesiologists have looked at the risk of aspiration in labor and discovered that there has been only one case recorded between 2006 and 2013 associated with labor and birth. Logical conclusion: withholding food and water during the endurance event known as labor is not a great idea. Kudos to the researchers at Memorial University, St. John’s, Newfoundland, Canada, who suggest a change in practice. Yes, there are factors that might over-ride this conclusion, including obesity and preeclampsia, but for most healthy women, eating lightly in labor is a good thing.

Read the American Society of Anesthesiologists press release on this topic here: https://www.asahq.org/about-asa/newsroom/news-releases/2015/10/eating-a-light-meal-during-labor