Comparison of the Abdominal Wall Muscle Thickness in Female Rugby Players Versus Non-Athletic Women: A Cross-Sectional Study

Gender Differences in Core Muscle Morphology of Elite Alpine Skiers: Insights from Ultrasonography

This study investigates gender differences in core muscle morphology among elite alpine skiers using ultrasonography, highlighting significant disparities that could influence training and injury prevention strategies.

METHODS

A cross-sectional design was employed, examining ultrasound imaging (USI) in 22 elite skiers (11 male, 11 female) to assess the thickness of the external oblique (EO), internal oblique (IO), transversus abdominis (TrAb), and rectus abdominis (RA) muscles.

RESULTS

Significant differences were noted, with male skiers displaying greater muscle thickness, particularly in the right IO and RA and left IO, EO, TrAb, and RA.

CONCLUSIONS

These findings suggest that male and female skiers may require different training approaches to optimize performance and reduce injury risks. This research contributes to a deeper understanding of the physical demands on elite skiers and underscores the need for gender-specific training regimens to enhance athletic outcomes and prevent injuries.

Technical aspects of inter-recti distance measurement with ultrasonographic imaging for physiotherapy purposes: the scoping review

BACKGROUND

Inter-recti distance (IRD) measurement using musculoskeletal USI has been used in physiotherapy research, in particular, to investigate pregnancy-related diastasis recti abdominis (DRA) and to seek its effective treatment methods. Severe and untreated diastasis may result in the formation of umbilical or epigastric hernias.

OBJECTIVE

This study aimed to systematically map physiotherapy-related research articles that included descriptions of IRD measurement procedures using USI to present their similarities and differences, and formulate recommendations on the procedure.

DESIGN

A scoping review was conducted according to PRISMA-ScR guidelines, including 49 of 511 publications from three major databases. Publications were selected and screened by two independent reviewers whose decisions were consulted with a third reviewer. The main synthesized data items were: the examinees' body position, breathing phase, measurement sites, and DRA screening methods. The final conclusions and recommendations were the result of a consensus between seven reviewers from four research centers.

RESULTS

Studies used 1-5 measurement sites that were differently determined. IRD was measured at the umbilicus (n = 3), at its superior (n = 16) and/or inferior border (n = 9), and at different levels: between 2 and 12 cm above the umbilicus, or a third of the distance and halfway between the umbilicus and xiphoid (n = 37); between 2 and 4.5 cm below the umbilicus or halfway between the umbilicus and pubis (n = 27). Different approaches were used to screen subjects for DRA.

CONCLUSIONS

The discrepancies between the measurement procedures prevent between-study comparisons. The DRA screening method should be standardized. IRD measurement protocol standardization has been proposed.

CRITICAL RELEVANCE STATEMENT

This scoping review indicates that the inter-recti distance measurement procedures using ultrasound imaging differ between studies, preventing between-study comparisons. Based on the results synthesis, the measurement protocol standardization has been proposed.

KEY POINTS

The inter-recti distance measurement procedures using USI differ between studies. Proposed standardization concerns body position, breathing phase, measurements number per location. Determination of measurement locations considering individual linea alba length is suggested. Recommended locations: umbilical top, ½ of umbilical top-xiphoid, ¼ of umbilical top-xiphoid/pubis distances. Diastasis recti abdominis diagnostic criteria are needed for proposed measurement locations.

Applied sports science and sports medicine in women's rugby: systematic scoping review and Delphi study to establish future research priorities

Objectives

In part 1, the objective was to undertake a systematic scoping review of applied sports science and sports medicine in women's rugby, and in part 2 to develop a consensus statement on future research priorities.

Design

In part 1, a systematic search of PubMed (MEDLINE), Scopus and SPORTDiscus (EBSCOhost) was undertaken from the earliest records to January 2021. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020, the PRISMA extension for Scoping Reviews, and the PRISMA extension protocols were followed. In part 2, 31 international experts in women's rugby (ie, elite players, sports scientists, medical clinicians, sports administrators) participated in a three-round Delphi consensus method. These experts reviewed the findings from part 1 and subsequently provided a list of priority research topics in women's rugby. Research topics were grouped into expert-based themes and expert-based subthemes via content analysis. Expert-based themes and expert-based subthemes were ranked from very low to very high research priority on a 1-5 Likert scale. Consensus was defined by ≥70% agreement. The median research priority agreement and IQR were calculated for each expert-based theme and subtheme.

Data sources

PubMed (MEDLINE), Scopus and SPORTDiscus (EBSCOhost).

Eligibility criteria for selecting studies

Studies were eligible for inclusion if they investigated applied sports science or sports medicine in women's rugby.

Results

In part 1, the systematic scoping review identified 123 studies, which were categorised into six sports science and sports medicine evidence-based themes: injury (n=48), physical performance (n=32), match characteristics (n=26), fatigue and recovery (n=6), nutrition (n=6), and psychology (n=5). In part 2, the Delphi method resulted in three expert-based themes achieving consensus on future research priority in women's rugby: injury (5.0 (1.0)), female health (4.0 (1.0)) and physical performance (4.0 (1.0)).

Summary/Conclusion

This two-part systematic scoping review and Delphi consensus is the first study to summarise the applied sports science and sports medicine evidence base in women's rugby and establish future research priorities. The summary tables from part 1 provide valuable reference information for researchers and practitioners. The three expert-based themes that achieved consensus in part 2 (injury, female health and physical performance) provide clear direction and guidance on future research priorities in women's rugby. The findings of this two-part study facilitate efficient and coordinated use of scientific resources towards high-priority research themes relevant to a wide range of stakeholders in women's rugby.

Comparison of Abdominal Muscle Thickness between the Abdominal Draw-in Maneuver and Maximum Abdominal Contraction Maneuver

All abdominal muscles, including the transverse abdominis (TrA), should be modulated to improve core stability. This study aimed to investigate easier and more effective core exercise methods by comparing thickness changes in the TrA, internal oblique (IO), external oblique (EO), and rectus abdominis (RA) muscles during the abdominal draw-in maneuver (ADIM) and maximum abdominal contraction maneuver (MACM). Thirty healthy subjects who participated in this study underwent ADIM and MACM three times in random order. We measured the abdominal muscle thickness during ADIM and MACM using ultrasonography and compared the changes in the thickness of TrA, IO, EO, and RA muscles using a paired t-test. Significant differences were observed in the thicknesses of all the abdominal muscles between the ADIM and MACM groups (p < 0.05). The MACM immediately increased the thickness of the TrA (p < 0.001, effect size (ES) = 0.931), IO (p = 0.001, ES = 0.761), EO (p = 0.008, ES = 0.415), and RA (p < 0.001, ES = 0.767) muscles. These results suggest that MACM is useful for immediately increasing the thickness of TrA, IO, EO, and RA muscles and may contribute to the clinical effect of simultaneous contractions on the changes in abdominal muscle thickness.

Ultrasonographic Changes of Abdominal Muscles in Subjects with and without Chronic Low Back Pain

Chronic low back pain (CLBP) is a prevalent disfunction in the spine, affecting both women and men. The implication of the abdominal muscles in this disfunction has been studied, including wrong breathing patterns or inactivity of this area. However, there is a lack of studies examining changes in thickness of abdominal with ultrasonography. Thus, the aim of this study is to analyze the differences in the thickness of abdominal muscles at rest and during breathing between subjects with and without CLBP. A total of 72 subjects were divided in two groups: participants with CLBP (n = 36) and participants without CLBP (n = 36). In both groups, the thickness of the four abdominal muscles was measured and compared at rest and during breathing with ultrasonography. In TrA and IO there were no significant differences between groups, but those subjects with CLBP increased the muscle thickness more than participants without pain during breathing. In EO there were no differences in muscle thickness between groups and between rest and breathing. In RA, subjects with CLBP showed less muscle thickness than subjects without pain during breathing, but no changes were found at rest. In conclusion, the deepest abdominal muscles, TrA and IO, appear to increase their thickness and RA appear to decrease more in subjects with CLBP, in comparison with healthy participants.

Changes in abdominal muscles architecture induced by different types of breathing

BACKGROUND: The underlying morphology and behavior of abdominal muscles during breathing are still lacking in knowledge in healthy population. OBJECTIVE: To analyze the effects of three different types of breathing on the architectural characteristics of abdominal muscles. METHODS: Ninety-eight healthy subjects were measured to assess the effects of breathing on the abdominal muscles, subjects performed three different types of breathing and the muscular thickness was measured with ultrasound imaging, analyzing also the differences between sexes. RESULTS: During the three different types of breathing and in comparison with the resting state, an increase of the thickness has been reported in the transversus abdominis (p< 0.001; effect size = 2.44, very large) and internal oblique (p< 0.001; effect size = 1.04, moderate) in both sexes, but with a higher increase in men. External oblique and rectus abdominis increased their thickness through breathing only while the lips were with pursed (p< 0.05) with trivial effect sizes and only differences between sexes were found in rectus abdominis. CONCLUSIONS: All breathings activated the deepest abdominal muscles, but the most superficial were only activated with lips pursed. Moreover, men appeared to activate more the deepest abdominal muscles but also the rectus abdominis. Findings in this study support the use of different types of breathing depending on the muscle to be activated or the sex, helping health care professionals to address their interventions on the abdominal muscles with a more focused approach.

Are There Any Differences in Abdominal Activation between Women and Men during Hypopressive Exercises?

This study analyzes the effects of hypopressive exercises on the abdominal thickness of healthy subjects and compares the performance between women and men. We conducted a transversal observational study in 98 subjects (63% women). The muscle thickness is analyzed in transversus abdominis, internal oblique, external oblique, and rectus abdominis with ultrasound imaging at rest and during the hypopressive exercise (HE) in supine and standing position. Comparisons between rest and hypopressive exercise are carried out in the two different positions and between women and men. In the supine position, there is a significant activation of the transversus abdominis and internal oblique during hypopressive exercise (p < 0.001), and it is similar in both sexes, the external oblique is only activated significantly by men (p < 0.001) and rectus abdominis had no significant activation (p > 0.05). Our results show that standing transversus abdominis and external oblique significantly increased their thickness during HE with higher effects in men. Internal oblique also increased significantly, but with higher effects in women, and rectus abdominis had no significant increase. Men had similar effects to women during HE, with an activation of the deepest abdominal muscles. The unequal anatomy and the position could explain the different results obtained between the sexes.

Immediate effects of different types of abdominal exercises on the inter-rectus distance

BACKGROUND: The effects of abdominal exercises on the inter-rectus distance are unclear. OBJECTIVE: To compare the inter-rectus distance at rest and during different abdominal exercises: abdominal crunch, abdominal crunch with transversus abdominis pre-activation and hypopressive exercise. METHODS: A transversal experimental study was carried out in 98 healthy adults without diastasis recti abdominis were recruited. Measurements were assessed using ultrasound imaging, and two points were evaluated: just above the umbilicus (U point) and halfway between the U point and the xiphoid (UX point). The inter-rectus distance was measured at rest and during the abdominal exercises. RESULTS: The abdominal crunch with transversus abdominis pre-activation increases the inter-rectus distance in comparison with rest and with abdominal crunch in the U point. CONCLUSION: These results increase the knowledge about the behaviour of the linea alba and inter-rectus distance during abdominal exercises, with practical applications in the rehabilitation of the abdominal wall and low back.

Does Function Determine the Structure? Changes in Flexor Hallucis Longus Muscle and the Associated Performance Related to Dance Modality: A Cross-Sectional Study

Background and Objectives: Flexor hallucis longus pathology is one of the most common conditions of the ankle and foot in dancers, due to the high demand of dance movements performed in an extreme plantar flexion and dorsiflexion range of motion. The objectives of this study were to determine the bilateral differences between the thickness and cross-sectional area of the flexor hallucis longus muscle in dancers, to establish possible differences between dance modalities, and to analyze whether there is a correlation between ultrasonographic parameters or performance variables and the dance modality. Material and Methods: A sample of 50 (29 classical and 21 contemporary) full-time pre-professional female dancers were included in the study. The thickness and cross-sectional area of the flexor hallucis longus muscle were evaluated for both limbs using ultrasound imaging. The range of movement of the first metatarsophalangeal joint was measured using functional extension with maximal ankle plantarflexion, balance was measured in a unilateral stance with the heel raised, endurance was evaluated through a modified heel rise fatigue test, and a counter movement jump to assess the vertical jump performance was measured bilaterally. Results: There were no significant differences recorded between the dominant and non-dominant limbs for each variable, within both groups. Contemporary dancers showed a greater thickness and cross-sectional area of the flexor hallucis longus muscle than classical dancers. However, classical dancers showed an increase of balance, endurance, range of movement of the first metatarsophalangeal joint, and counter movement jump with respect to contemporary dancers. Conclusion: Bilateral symmetry was identified in all variables for both groups. The size and performance of the flexor hallucis longus muscle may be influenced by the specific nature of dance modality.

Ultrasound Assessment of the Abdominal Wall Muscles in Women with and without Primary Dysmenorrhea: A Cross-Sectional Study

Background: Primary dysmenorrhea (PD) is one of the most common gynecological disorders in women of reproductive age that may affect quality of life. It is believed that the underlying cause of PD may be the excessive production of prostaglandins (PGs), however, between 20%–25% of women with PD did not respond to pharmacological treatments, showing that nociceptive mechanisms underlying PD are still not understood. The purpose of this study was to measure and compare, through the use of ultrasound imaging, the thickness at rest of the abdominal wall, as well as the interrecti distance (IRD), in women with and without PD. Methods: A cross-sectional study has been performed using ultrasound imaging (USI) to measure the resting thickness of the external oblique (EO), internal oblique (IO), transversus abdominis (TrAb), rectus abdominis (RA), as well as the IRD in a sample of 39 women, 19 with PD and 20 without PD (median ± IR age: 20 ± 4 and 22.5 ± 7 years, respectively). Results: Findings of muscular thickness did not reveal statically significant differences (p < 0.05) in EO, IO, TrAb, RA, and the IRD between the PD group and control group. Conclusions: These findings suggest that the thickness of the abdominal wall is not associated with PD.