Impaired Trunk Flexor Strength, Fatigability, and Steadiness in Postpartum Women

Sex differences in human performance

Sex as a biological variable is an underappreciated aspect of biomedical research, with its importance emerging in more recent years. This review assesses the current understanding of sex differences in human physical performance. Males outperform females in many physical capacities because they are faster, stronger and more powerful, particularly after male puberty. This review highlights key sex differences in physiological and anatomical systems (generally conferred via sex steroids and puberty) that contribute to these sex differences in human physical performance. Specifically, we address the effects of the primary sex steroids that affect human physical development, discuss insight gained from an observational study of 'real-world data' and elite athletes, and highlight the key physiological mechanisms that contribute to sex differences in several aspects of physical performance. Physiological mechanisms discussed include those for the varying magnitude of the sex differences in performance involving: (1) absolute muscular strength and power; (2) fatigability of limb muscles as a measure of relative performance; and (3) maximal aerobic power and endurance. The profound sex-based differences in human performance involving strength, power, speed and endurance, and that are largely attributable to the direct and indirect effects of sex-steroid hormones, sex chromosomes and epigenetics, provide a scientific rationale and framework for policy decisions on sex-based categories in sports during puberty and adulthood. Finally, we highlight the sex bias and problem in human performance research of insufficient studies and information on females across many areas of biology and physiology, creating knowledge gaps and opportunities for high-impact studies.

Prioritise safety, optimise success! Return to rugby postpartum

Pregnancy and childbirth involve substantial physical, physiological and psychological changes. As such, postpartum rugby players should be supported and appropriately prepared to return to the demands of rugby alongside the additional demands of motherhood. This review aims to discuss specific perinatal considerations that inform a rugby player's readiness to return-to-sport postpartum and present an approach to rehabilitation. Before engaging in full rugby training and matchplay, postpartum players should have progressed through the initial phases of rehabilitation and graded sports-specific training to prepare them for the loads they will be exposed to. Additional rehabilitation considerations include minimising deconditioning during pregnancy; medical concerns; the abdominal wall; the pelvic floor; perinatal breast changes, breastfeeding and risk of contact breast injury; body mass; nutritional requirements; hormonal considerations; athlete identity and psychological considerations; joining team training; return to contact and tackle training; evaluating player load tolerance and future research, policy and surveillance needs. A whole-systems, biopsychosocial approach following an evidence informed return-to-sport framework is recommended when rehabilitating postpartum rugby players. Health and exercise professionals are encouraged to use the perinatal-specific recommendations in this review to guide the development of postpartum rehabilitation protocols and resources.

Effect of Serial Pregnancies on Physical Fitness

INTRODUCTION

Pregnancy has a profound impact on physical fitness, and delivery does not allow for rapid return to peak performance levels as physiologic changes can persist for greater than 1 year postpartum. Multiple studies across all military services have documented decrements in physical performance with pregnancy among women. The purpose of this study was to determine the impact of serial pregnancies on physical fitness and body composition in a cohort of Army women. We hypothesized that a second pregnancy would be associated with increasing decrements in physical fitness in active duty soldiers beyond that seen following a first delivery.

MATERIALS AND METHODS

This retrospective cohort study screened all active duty soldiers who had delivered a singleton pregnancy of ≥32 weeks gestation between January 1, 2011 and March 31, 2017 at a single military medical center. This roster of eligible women was used to extract Army Physical Fitness Test (APFT) and height/weight data from the U.S. Army Digital Training Management System. Soldiers who delivered their first 2 pregnancies over this period were included. Select antepartum, intrapartum, and postpartum data were collected from the electronic medical record. The primary outcome variables were raw scores for push-ups, sit-ups, and run events as well as weight measures across the 2 pregnancies. The secondary outcomes were the failure rates on both the APFT events and body mass index measurements. Data were analyzed using paired t-tests to compare the means of APFT scores across the 2 pregnancies. The subjects served as their own controls. This study was approved by Regional Health Command-Pacific.

RESULTS

A total of 2,103 active duty soldiers delivered singleton pregnancies at Tripler Army Medical Center between January 2011 and March 2017. Among these, 16 women delivered both their first- and second-term pregnancies and had APFT data available for analysis. Average age at time of first and second delivery was 26.1 and 28.1 years, respectively. Mean time separating the first postpartum APFT from the delivery was 8.8 months for the first pregnancy and 7.3 months following the second.A significant decrease in mean sit-up score was found comparing APFT-1 with APFT-2 (72.1 vs 65.7, P = .043) and comparing APFT-1 to APFT-3 (72.1 vs 60.9, P = .002). A significant increase in mean run time was found comparing APFT-1 to APFT-3 (16.9 minutes vs 17.9 minutes, P = .010) and APFT-2 to APFT-3 (17.5 minutes vs 17.9 minutes, P = .027). Comparing APFT-1 to APFT-3 showed a significant decrease in sit-up raw scores (P = .002), run times (P = .010), and total APFT scores (P = .01). Overall, the data show a trend of decreasing performance in all APFT events across the 3 APFTs and a trend toward higher failure rates. This cohort of soldiers did not experience weight gain following the pregnancies.

CONCLUSIONS

The present study is the first to analyze the association of serial pregnancies on physical fitness utilizing a validated physical fitness test, and the results suggest that a second pregnancy is associated with progressive worsening of performance. This study is limited by the small sample size, and future studies could further elucidate the degree to which serial pregnancies affect physical fitness.

Clinical and exercise professional opinion of return-to-running readiness after childbirth: an international Delphi study and consensus statement

Female athletes have identified a lack of guidance as a barrier to successfully returning to running postpartum, and existing guidelines are vague. Our aim was to define the current practice of determining postpartum run-readiness through a consensus survey of international clinicians and exercise professionals in postpartum exercise to assist clinicians and inform sport policy changes.A three-round Delphi approach was used to gain international consensus from clinicians and exercise professionals on run-readiness postpartum. Professionals who work with postpartum runners participated in an online survey to answer open-ended questions about the following postpartum return-to-running topics: definitions (runner and postpartum), key biopsychosocial milestones that runners need to meet, recommended screening, timeline to initiate running, support items, education topics and factors that contribute to advising against running. Consensus was defined as ≥75% participant agreement.One hundred and eighteen professionals participated in round I, 107 participated in round II (response rate 90.6%) and 95 participated in round III (response rate 80.5%). Responses indicated that, following a minimum 3-week period of rest and recovery, an individualised timeline and gradual return to running progression can be considered. Screening for medical and psychological concerns, current physical capacity, and prior training history is recommended prior to a return to running.This study proposes recommendations for the initial guidance on return-to-running postpartum, framed in the context of current research and consensus from professionals. Future research is needed to strengthen and validate specific recommendations and develop guidelines for best practice when returning-to-running after childbirth.

Running biomechanics differ during and after pregnancy compared to females who have never been pregnant

BACKGROUND

Perinatal running participation has increased recently; however, pregnancy related symptoms can limit activity. Perinatal running biomechanics could inform interventions to help perinatal individuals maintain an active lifestyle.

RESEARCH QUESTION

Are perinatal running biomaechanics and muscle activation different compared to nulligravida females?

METHODS

Sixteen pregnant participants completed self-selected velocity running during second trimester (2 T), third trimester (3 T), and postpartum (PP) and 16 matched controls completed these procedures once in this case control study. Kinematic, kinetic, and electromyography (EMG) data were collected using a motion capture system, force plates, and EMG electrodes. Peak trunk, pelvis, hip, knee, and ankle kinematics and hip, knee, and ankle moments during stance phase, and average and peak erector spinae (ES), gluteus maximus (GMax), and gluteus medius (GMed) EMG amplitude and duration of activation during stance and swing phases were calculated. Independent t-tests were used to compare 2 T, 3 T, and PP to control participants (α < 0.05).

RESULTS

Running velocity was slower during 3 T compared to control participants. At all pregnancy timepoints compared to the control group, peak trunk contralateral rotation was smaller. During 2 T and 3 T peak hip flexor moments were smaller. At 3 T pelvis contralateral rotation was smaller, ES average amplitude was greater during swing, GMax percent duration during stance and GMed percent duration during swing were smaller. At PP trunk flexion was smaller and knee abduction was greater (all p < 0.05).

CONCLUSIONS

Decreased running velocity may help offset increased demand during pregnancy. During 3 T, greater ES activation, smaller trunk and pelvis motion, and altered gluteal activation could indicate trunk rigidity combined with modified hip stabilizer muscle utilization. During PP, the rigid trunk combined with greater knee abduction may indicate hip and trunk strength deficits. Altered trunk and hip motion and activation could be relevant to pathologies such as perinatal low back, pelvic girdle, or knee pain.

Clinical and exercise professional opinion on designing a postpartum return-to-running training programme: an international Delphi study and consensus statement

Returning to running postpartum presents challenges such as musculoskeletal pain and pelvic floor dysfunction for some females, but there is little guidance on developing and progressing postpartum training programmes. This study aims to establish expert consensus recommendations on designing and modifying a postpartum return-to-running training programme, highlight costs and access to qualified professionals as potential barriers and discuss clinical, research and sports policy implications.A three-round Delphi survey of clinical and exercise professionals working with postpartum runners was conducted. Round I consisted of open-ended questions related to designing the training plan, modifications based on biopsychosocial factors, key muscle groups to train and referral and payment sources. Rounds II and III involved Likert-scale voting to identify consensus (≥75% agreement).118 participants completed Round I, 107 completed Round II (response rate 90.6%) and 95 completed Round III (response rate 80.5%). Consensus was reached in 42/47 (89%) statements, including recommendations for a period of relative rest, gradual increases in duration and intensity, starting with a walk-run protocol and incorporating strength training. Training should be modified based on musculoskeletal or pelvic symptoms, sleep, mental health, lactation or energy availability concerns. Cost and access to experienced postpartum running professionals were identified as potential barriers for runners to receive care.Consensus recommendations for a postpartum return-to-running programme include an individualised exercise prescription, gradual increases in physical activity, walk-run protocols and targeted muscle strengthening. Further research and improved access to clinical and exercise professionals are needed to inform and facilitate best practices.

Ultrasound Assessment of Abdominal Muscle Thickness With and Without Lumbopelvic Pain in Pregnant Women

OBJECTIVES

Lumbopelvic pain (LPP) is a very common cause of discomfort during pregnancy, but its etiology remains unclear. The association between abdominal muscle thickness and LPP in pregnant women has not been studied extensively, despite the significant abdominal changes that occur during pregnancy. This study aimed to examine the relationship between abdominal muscle thickness and LPP in pregnant women.

METHODS

In this study, 49 pregnant women in their second trimester participated. The intensity of LPP was assessed using a numerical rating scale. Ultrasound imaging was used to measure the thickness of abdominal muscles, including the rectus abdominis, external oblique, internal oblique, and transversus abdominis muscles. Participants were classified into two groups, the LPP group and non-LPP group, and the abdominal muscle thickness was compared between the two groups. The statistical significance level was set at P < .05.

RESULTS

There were 24 and 25 participants in the LPP and non-LPP groups, respectively. Internal oblique (IO) thickness was significantly thinner in the LPP group than in the non-LPP group (5.4 ± 0.2 mm versus 6.1 ± 0.2 mm; P = .042). Multivariate logistic regression analysis showed that IO thickness was significantly associated with LPP (odds ratio, 0.516; 95% confidence interval, 0.284-0.935; P = .019).

CONCLUSIONS

This study suggested that LPP in second trimester pregnancy might be related to IO thickness. Further longitudinal studies are needed to understand the role of this muscle as an LPP risk factor for pregnant women.

New Assessment Tool-Postpartum Functional Assessment Questionnaire

Background and Objectives: Functional status of the mother after delivery is crucial for performing activities of daily living and caring for the newborn. It is important to assess functional abilities after childbirth in order to improve the quality of postpartum care. The aim of this study is to determine the psychometric properties of the questionnaire and assess the functional abilities after childbirth. Materials and Methods: This study is observational. Postpartum Functional Assessment Questionnaire includes eleven items. 301 women after childbirth, 234 after vaginal birth and 67 after caesarean section participated in the study. An assessment of pain intensity and functional abilities was performed on the first and third day after childbirth. The Factor and Cronbach's alpha analyses were performed to determine the factor structure and internal consistency. Results: The analysis reveals two factors, with seven items loading on factor 1 and four on factor 2. Cronbach's alpha for construct I (Mobility) at the first day was 0.927 and at the third day was 0.913; and for Factor II (Self-care) at the first day was 0.846 and at the third day was 0.894. All between-group differences in pain intensity and functional abilities were highly statistically significant (p < 0.001). Differences between the first and third postpartum day were statistically significant for all variables and all subgroups (p < 0.001). Conclusions: Postpartum Functional Assessment Questionnaire has good psychometric properties and is a valuable tool for use in clinical practice.

The "Mother Load" and Return to Sport: A Case Report of Returning to Professional Netball Following Cesarean Section

Background

Increasing numbers of elite female athletes are competing in professional sport, and many wish to become pregnant and return to competitive sport after childbirth. Athletes have a higher risk of pelvic floor dysfunction (PFD) than non-athletes (54% versus 7%) and there is also an increased prevalence in post-partum women compared to nulliparous women (35% versus 2.8-7.9%). Additionally, PFD has been shown to influence athletic performance. High quality evidence for elite athletes is lacking, and there are no exercise guidelines specifically for these women to prepare or effectively guide their safe return to sport (RTS). The purpose of this case report is to detail the management of an elite athlete who presented following cesarean section (CS) with the goal of RTS within 16 weeks.

Case Description

A 27-year-old primiparous Caucasian professional netballer presented at four weeks post- caesarean section (CS) for RTS screening and assessment of pelvic floor muscle (PFM) function. Assessment included readiness and fear of movement screening, dynamic pelvic floor muscle function, structural integrity of the CS wound, levator hiatal dimensions, bladder neck descent, and early global neuromuscular screening. Measures were collected at four weeks, eight weeks, and six months post-partum. The post-partum athlete demonstrated alterations in pelvic floor muscle function, reduced lower limb power and psychological readiness. A functionally staged dynamic and sport specific pelvic floor muscle training program was implemented and adapted to the patient for her early post-partum timeline.

Results

Rehabilitation strategies were effective in achieving the primary outcome of RTS at 16 weeks post-partum with no adverse events reported at 6 months follow-up.

Discussion

This case highlights the need for a holistic and individualised RTS management approach that includes women's and pelvic health risk factors in a professional athlete.

Level of Evidence

5.

Differences in Inter-Rectus Distance and Abdominopelvic Function between Nulliparous, Primiparous and Multiparous Women

Widening of the inter-rectus distance (IRD) is highly prevalent among postpartum women and can lead to dysfunction of abdominopelvic muscles. The aim of this study was to evaluate the differences in IRD and abdominopelvic function between nulliparous, primiparous and multiparous women. A cross-sectional study was conducted on 75 women (25 nulliparous, 25 primiparous and 25 multiparous at 6 months postpartum). The participants underwent ultrasound assessment under three conditions (at rest, abdominal draw-in maneuver (ADIM) and curl-up) at two locations (2 cm above and 2 cm below the umbilicus). Furthermore, abdominopelvic muscle function was determined by prone, supine and side bridge tests. In all conditions and locations, the IRD were significantly higher (p < 0.05) in the primiparous and multiparous women than in the nulliparous. The multiparous women presented greater (p > 0.05) IRD at rest and during ADIM compared to the primiparous women. Regarding abdominopelvic muscle function, differences were only significant (p < 0.05) between the nulliparous with primiparous women in prone and supine conditions. These findings suggest that parity influences IRD: women at 6 months postpartum present greater IRD compared to nulliparous women; multiparous women present greater IRD at rest and during the activation of deep abdominal muscles than primiparous women; and primiparous women exhibit worse abdominopelvic muscle function than nulliparous women.

Physical activity in the early postpartum period in primiparous women

Little is known about early postpartum physical activity (PA).

OBJECTIVES

We aimed to describe PA amount and types and compare moderate-vigorous PA (MVPA) at 12-25 (T1) and 33-46 days (T2) postpartum.

DESIGN

Cross-sectional study.

METHODS

Participants, primiparas delivered vaginally, wore wrist accelerometers and completed questionnaires. Median and interquartile range (IQR) describe minutes/day of PA intensities in total minutes, 5- and 10-minute bouts. Wilcoxon Signed Rank test compared MVPA.

RESULTS

577 (age: 28.3 (SD: 5.1)) had accelerometry or questionnaire at either time-point. 405 had accelerometry at both time-points. Median (IQR) total minutes/day for light, moderate, vigorous and MVPA were 295.8 (256.1-331.7), 54.6 (40-72.7), 0.4 (0.2-0.8), and 55.5 (40.4-74.3), respectively, at T1 and 329 (289.4-367.1), 63.6 (46.9-82.2), 0.6 (0.3-1.3), and 64.5 (47-84.8), respectively, at T2. Median (IQR) minutes/day for MVPA in 5- and 10-minute bouts were 1.6 (0-5.5) and 0 (0-3.8) at T1, and 3 (0-9.2) and 0 (0-5.5) at T2. At T1, 75% (406/541) and at T2, 72.4% (397/548) reported non-impact activities. At T1, 4% and at T2, 13% reported impact/straining activities. MVPA was greater at T2 than T1 (p < 0.0001) with medians (IQR) of: total: 64.7 (47-84.6) vs 56.5 (41-74.9) minutes; 5-minute bouts: 3 (0-9.8) vs 1.7 (0-5.6) minutes; and 10-minute bouts: 1.3(0-6) vs 0(0-3.8) minutes.

CONCLUSIONS

Women had high daily MVPA, though MVPA in bouts remained low. Significant increases in MVPA from T1 to T2 were small, few women reported impact/straining activities. Realistic return to pre-pregnancy PA levels should recognize the relative lack of sustained/strenuous activity in early postpartum.

Temporal trends in trunk flexor endurance and intra-abdominal pressure in postpartum women

Objectives: To describe change in trunk flexor endurance and intra-abdominal pressure (IAP) associated with trunk flexor assessment and explore factors associated with change in trunk flexor endurance during the first postpartum year.Design: Ancillary analysis of an ongoing prospective cohort study.Methods: Participants (N = 282) were primiparous women delivered vaginally. They completed trunk flexor endurance testing while assessing IAP, body habitus measures (body mass index, waist circumference, and body composition), and questionnaires 5-10 weeks and 11-15 months postpartum. We investigated change in trunk flexor endurance by quartile of improvement and factors associated with improvement (Q4 vs. Q1-Q3) using multivariable models, adjusted for baseline endurance.Results: Mean age was 28 ± 5 years. The median (IQR) trunk flexor hold time increased from early to late postpartum (129/IQR = 68, 217 vs 148/IQR = 80, 265 seconds, p = .01) and mean (SD) IAP decreased (55/SD = 13 vs 48/SD = 14 cmH20, p < .0001). The most improved group (Q4) increased endurance time by 176 seconds (95% CI = 103, 254), were less likely to be Hispanic, more likely to be older, more educated, and have lower measures of body habitus than women in Q1-Q3. Conclusion: Trunk flexor endurance increased and IAP decreased over one year postpartum. Lower body habitus and higher age early postpartum predicted greatest improvement in trunk flexor endurance at 1 year.

The Legacy of Pregnancy: Elite Athletes and Women in Arduous Occupations

ABSTRACT

Best-practice guidance and management of pregnant and postpartum elite athletes and women in arduous occupations is limited by the lack of high-quality evidence available within these populations. We have summarised the adaptations and implications of pregnancy and childbirth; proposed a novel integrative concept to address these changes; and made recommendations to progress research in this area.

The effect of pregnancy and the duration of postpartum convalescence on the physical fitness of healthy women: A cohort study of active duty servicewomen receiving 6 weeks versus 12 weeks convalescence

Introduction

Pregnancy profoundly affects cardiovascular and musculoskeletal performance requiring up to 12 months for recovery in healthy individuals.

Objective

To assess the effects of extending postpartum convalescence from 6 to 12 weeks on the physical fitness of Active Duty (AD) soldiers as measured by the Army Physical Fitness Test (APFT) and Body Mass Index (BMI).

Methods

We conducted a retrospective study of AD soldiers who delivered their singleton pregnancy of ≥ 32weeks gestation at a tertiary medical center. Pre- and post-pregnancy APFT results as well as demographic, pregnancy, and postpartum data were collected. Changes in APFT raw scores, body composition measures, and failure rates across the 6-week and 12-week convalescent cohorts were assessed. Multivariable regressions were utilized to associate risk factors with failure.

Results

Four hundred sixty women met inclusion criteria; N = 358 in the 6 week cohort and N = 102 in the 12 week cohort. Demographic variables were similar between the cohorts. APFT failure rates across pregnancy increased more than 3-fold in both groups, but no significant differences were found between groups in the decrement of performance or weight gain. With the combined cohort, multivariable regression analysis showed failure on the postpartum APFT to be independently associated with failure on the pre-pregnancy APFT (OR = 16.92, 95% CI 4.96–57.77), failure on pre-pregnancy BMI (OR = 8.44, 95% CI 2.23–31.92), elevated BMI at 6–8 weeks postpartum (OR = 4.02, 95% CI 1.42–11.35) and not breastfeeding at 2 months (OR = 3.23, 95% CI 1.48–7.02). Within 36 months of delivery date, 75% of women had achieved pre-pregnancy levels of fitness.

Conclusion

An additional 6 weeks of convalescence did not adversely affect physical performance or BMI measures in AD Army women following pregnancy. Modifiable factors such as pre- and post-pregnancy conditioning and weight, weight gain in pregnancy and always breastfeeding were found to be significant in recovery of physical fitness postpartum.

Recovery of Abdominal Muscle Thickness and Contractile Function in Women after Childbirth

Abdominal muscles may be both morphologically and functionally affected by pregnancy. Dysfunction of the muscles can lead to persistent postpartum low back pain. The recovery process of the abdominal muscles following childbirth is not well understood. This study aimed to demonstrate the changes in the thickness and contractile function of abdominal muscles during the first six months postpartum. Nine perinatal and 15 nulliparous females participated. The thicknesses and contraction/relaxation thickness ratios of the rectus abdominis (RA), external abdominal oblique (EO), internal abdominal oblique (IO), and transverse abdominis (TrA) were measured using ultrasound images from 36–39 weeks’ gestation until six months postpartum. The RA, IO, and TrA muscles were thinner in perinatal females than controls at 36–39 weeks of gestation (4.8 vs. 9.47 mm (RA), 5.45 vs. 7.73 mm (IO), 2.56 vs. 3.38 mm (TrA), respectively). The thinner IO muscle persisted for six months after delivery. The decreased TrA thickness ratio persisted until four months post-delivery. Abdominal muscle thickness and contractile function decreased in the postpartum period. Therefore, abdominal muscle exercises might help prevent postpartum symptoms; however, because deterioration of muscle function is significant in the first four months, careful attention should be paid to exercise intensity. The study limitation was a relatively small sample size, thus future studies should involve more participants.

The Impact of Sedentary Behavior After Childbirth on Postpartum Lumbopelvic Pain Prolongation: A Follow-Up Cohort Study

Background: A substantial number of women have postpartum lumbopelvic pain (LBPP). Additionally, many postpartum women stay for long inactivity. Therefore, we examined the impact of sedentary behavior on persistent postpartum LBPP and the difference in this impact due to parity. Materials and Methods: This cohort study followed up women who had reported LBPP at 4 months postpartum and divided them into the presence or absence of LBPP at 10 months postpartum. Sedentary time and physical activity were assessed at 4 months postpartum using the International Physical Activity Questionnaire short form. Univariate and multivariate logistic regression analysis was used to calculate persistent LBPP odds ratios (ORs) according to sedentary times, followed by stratification analysis by parity. The institutional review board approval was obtained. Results: A total of 182 women (32.1 ± 5.1 years old) were included for analysis and 112 (61.5%) participants had persistent LBPP at 10 months postpartum. Those with persistent LBPP at 10 months postpartum had increased sedentary time (5.0 [3.0-7.0] hours vs. 3.5 [2.0-6.0] hours, p = 0.05) at 4 months compared with those without LBPP. Even after adjusting for confounding factors, longer sedentary time at 4 months postpartum affected persistent LBPP at 10 months postpartum in primiparas (adjusted OR [95% confidence interval, CI] = 1.28 [1.05-1.55]), but longer sedentary time at 4 months postpartum did not affect persistent LBPP at 10 months postpartum in multiparas (adjusted OR [95% CI] = 0.96 [0.86-1.07]). Conclusion: Sedentary behavior after childbirth is associated with persistent postpartum LBPP in primiparas, but not multiparas. Reducing sedentary time might be beneficial to prevent persistent postpartum LBPP for primiparas.

Association Between Measures of Trunk Recovery 5 to 10 Weeks Postpartum and Pelvic Floor Support and Symptoms 1 Year Postpartum in Primiparas Delivered Vaginally

OBJECTIVE

To determine whether 2 aspects of trunk recovery after childbirth, intraabdominal pressure (IAP) generation and trunk flexor endurance (TFE), predict measures of pelvic floor health 1 year postpartum.

METHODS

In this prospective cohort study, we enrolled nulliparas in their third trimester and followed up those delivered vaginally for 1 year. We measured IAP while lifting a weighted car seat (IAPLIFT), IAP during TFE testing (IAPTFE), and TFE duration 5 to 10 weeks postpartum and assessed pelvic floor support and symptoms 1 year postpartum.

RESULTS

Mean age of the 624 participants was 28.7 years. At 5 to 10 weeks postpartum, mean (SD) maximal IAPLIFT and IAPTFE were 47.67 (11.13) and 51.57 (12.34) cm H2O, respectively. Median TFE duration was 126 seconds (Interquartile range, 74-211). At 1 year postpartum, 9.3% demonstrated worse support (maximal vaginal descent at or below hymen) and 54% met criteria for symptom burden (bothersome symptoms in ≥2 domains of Epidemiology of Prolapse and Incontinence Questionnaire). In multivariable models, neither IAPLIFT nor IAPTFE were associated with worse support or symptom burden (P = 0.54-1.00). Trunk flexor endurance duration increased prevalence of worse support (prevalence ratio, 1.05; 95% confidence interval, 1.01-1.08) per 60-second increase, P = 0.005) but not symptom burden (prevalence ratio, 1.00; 95% confidence interval, 0.98-1.03; P = 0.92).

CONCLUSIONS

These results provide some reassurance to early postpartum women, who are unlikely to perform routine activities that generate IAP far outside the range tested. Further research is needed to understand why women with long TFE durations have increased prevalence of worse support.

Do Measures of Muscular Fitness Modify the Effect of Intra-abdominal Pressure on Pelvic Floor Support in Postpartum Women?

OBJECTIVE

This study aimed to determine whether measures of muscular fitness modify the effect of intra-abdominal pressure (IAP) during lifting on pelvic floor support.

METHODS

Participants, primiparous women 1 year after vaginal delivery, underwent the Pelvic Organ Prolapse Quantification examination, measurement of IAP via a vaginal sensor while lifting a weighted car seat, pelvic floor muscle force assessment using an instrumented speculum, grip strength using a hand dynamometer, and trunk flexor endurance by holding an isometric contraction while maintaining a 60-degree angle to the table. We dichotomized pelvic floor support as worse (greatest descent of the anterior, posterior, or apical vagina during maximal strain at or below the hymen) versus better (all points above the hymen).

RESULTS

Of 825 participants eligible after delivery, 593 (71.9%) completed a 1-year study visit. Mean (SD) age was 29.6 (5.0) years. One year postpartum, 55 (9.3%) demonstrated worse support. There were no differences in IAP during lifting or in other measures of pelvic floor loading between women with better and worse support. In multivariable analyses, neither grip strength nor pelvic floor muscle force modified the effect of IAP on support. In women with trunk flexor endurance duration ≥13 minutes, the odds of worse support increased significantly as IAP increased. No fitness measure modified the effect of other measures of pelvic floor loading on support.

CONCLUSIONS

Primiparous women with higher IAP during lifting and greater muscular fitness did not have reduced odds of worse pelvic floor support compared with those with lower IAP at the same muscular fitness.

From Childbirth to the Starting Blocks: Are We Providing the Best Care to Our Postpartum Athletes?

There is minimal evidence to guide return to exercise after pregnancy and childbirth, and even less information on safe return to competitive sport. The International Olympic Committee has suggested a 3-phase approach to postpartum recovery in athletes. This Viewpoint expands on that 3-phase model and incorporates a multidisciplinary approach to ensure comprehensive care of postpartum athletes to facilitate safe return to sport with optimal health and performance outcomes. Adopting a multidisciplinary approach may also open new research avenues to ameliorate the dearth of knowledge regarding musculoskeletal recovery and facilitate the development of guidelines to inform clinicians and postpartum women about safe return to exercise, particularly, high-intensity or high-impact activities. J Orthop Sports Phys Ther 2020;50(6):281-284. doi:10.2519/jospt.2020.0607.

Effects of isolated soy protein and strength exercise training on exercise performance and biochemical profile in postpartum mice

OBJECTIVE

Postpartum women are at an increased risk for obesity and metabolic diseases because of excessive weight gain during pregnancy and weight retention after delivery. Maintenance of good nutrition and regular physical activity is used as a therapeutic approach for promotion of health and well-being in postpartum women. The aim of this study is to assess the independent and additive effects of isolated soy protein (ISP) and strength exercise training (ET) on weight management, exercise performance and health maintenance in postpartum mice.

DESIGN AND METHODS

Thirty-two postpartum mice (ICR, 14-weeks old) were divided into four groups (n = 8 per group): Group 1 mice were the sedentary control with vehicle (SC), Group 2 mice were the sedentary control with ISP supplementation (8.95 g·kg^-1, SC + ISP), Group 3 mice received vehicle with exercise training (ET) and Group 4 mice received isolated soy protein with exercise training (ISP + ET). Animals in the ET and ISP + ET groups underwent strength exercise training for 6 weeks, 5 days a week. Exercise performance was evaluated by forelimb grip strength and exhaustive swimming time, as well as by changes in body composition and biochemical parameters at the end of the experiment.

RESULTS

Combined intervention of ISP and ET increased lean muscle mass and prevented body weight and fat elevation. The grip strength and exhaustive swimming time of the ISP + ET group were significantly higher than the other groups. The ISP + ET group showed significantly decreased serum levels of lactate, ammonia and creatinine phosphate kinase (CPK), and increased glucose level after the 15-min swimming test. The serum levels of aspartate transaminase (AST), triglyceride (TG) and creatinine after sacrifice were significantly decreased in the ET + ISP group. ISP combined with ET promoted fat oxidation in brown adipose tissue (BAT) as evidenced from the increased utilization of plasma and BAT tissue triglyceride.

CONCLUSIONS

We suggest that long-term supplementation with ISP can have a wide spectrum of bioactivities on health promotion, performance improvement and fitness. ISP with ET conferred better energy utilization, improved biochemical profiles and may be an effective ergogenic aid in strength training.

Fatiguing Trunk Flexor Exercise Decreases Pain Sensitivity in Postpartum Women

Background

Low back pain (LBP) is common in the general population and among postpartum women. Abdominal muscle exercise is often used to treat LBP, but it is unknown if fatiguing abdominal muscle exercise can produce exercise-induced hypoalgesia (EIH).

Objectives

To assess pressure pain thresholds (PPTs) at rest and following fatiguing trunk flexor exercise (EIH) in (1) nulligravid and postpartum women to evaluate the impact of pregnancy and childbirth and (2) nulligravid women and men to examine sex differences.

Methods

Seventy healthy adults (31 postpartum women, 23 nulligravid women, 16 men) participated. Postpartum and nulligravid women were tested twice (16-18 weeks apart) to identify changes in EIH with postpartum recovery. PPTs were measured at the nailbed and superior rectus abdominis before and after exercise to investigate systemic and local EIH, respectively. Rectus abdominis muscle thickness was assessed with ultrasound.

Results

Postpartum women reported lower PPTs than nulligravid women at the abdomen (p < 0.05) whereas postpartum women had lower PPTs at the nailbed during the first session only. Men reported higher nailbed PPTs (p = 0.047) and similar PPTs at the abdomen than women (p = 0.294). All groups demonstrated EIH at the abdomen (p < 0.05). Systemic EIH was absent in postpartum and nulligravid women (p > 0.05), while men demonstrated hyperalgesia. Local EIH was positively associated with muscle thickness for men and women, which was not significant at the second timepoint.

Limitations

Acute exercise response may not reflect changes that occur with exercise training.

Conclusion

Fatiguing trunk flexor exercise produced local EIH for all groups including postpartum and nulligravid women. Clinically, trunk exercises may be useful for acute pain relief for clinical populations that are characterized by pain and/or weakness in the abdominal region muscles in populations with abdominal pain syndromes.

Fatigability of the Lumbopelvic Stabilizing Muscles in Women 8 and 26 Weeks Postpartum

Background

Pregnancy and childbirth are associated with lumbopelvic pain and instability. Fatigability of the lumbopelvic stabilizing muscles after childbirth is unknown, and no clinical tests exist to assess this important metric of muscle function.

Objectives

To compare fatigability of the lumbopelvic stabilizing muscles in postpartum and nulligravid (control) women using the Active Straight Leg Raise (ASLR) Fatigue Task, and to determine if fatigability is associated with inter-recti distance (IRD), physical function, and pain/disability.

Study design

Longitudinal case-control study.

Methods

Twenty-nine nulligravid (25.4 ± 9.1 years) and 31 postpartum women (31.4 ± 5.2 years; vaginal delivery n=18) were tested at two time points, 16 weeks apart (postpartum women tested at 8-10 and 24-26 weeks postpartum). Muscular function was assessed with manual muscle testing (MMT), the ASLR Test, and a new ASLR Fatigue Task. Other measures included IRD, rectus abdominis thickness, physical activity, and six-minute walk distance.

Results

Postpartum women were 23% more fatigable (p=0.028) and were weaker (MMT) (p<0.001) than controls up to 26 weeks postpartum. The ASLR fatigue task (time-to-failure) was associated with smaller IRD, greater rectus abdominis thickness, higher physical activity levels, greater MMT strength, and further distance walked in six minutes (p<0.05).

Conclusion

Postpartum women (up to 6 months) had greater fatigability of the lumbopelvic stabilizing muscles and lower physical function than nulligravid women, suggesting core muscle function and fatigability should be assessed after pregnancy and childbirth. The ASLR Fatigue Task could be a clinically useful tool to determine fatigability of the lumbopelvic stabilizing muscles in women postpartum.