Muscular Asymmetry Research Articles

Muscular asymmetry in junior handball athletes in the absence of specific corrective intervention – case studies

Muscular asymmetry in junior handball athletes in the absence of specific corrective intervention – case studies

Incobotulinumtoxin A and Yoga-like Isometric Exercise in Adolescent Idiopathic Lumbar Scoliosis—A Randomized Pilot Study

Background: Approximately 90% of scoliosis cases are adolescent-idiopathic (AIS). From the first appearance of scoliosis at 10–14 years of age until the age of 18, the spine is most vulnerable to deterioration; young, growing people are most susceptible to the worsening of one or more scoliotic curves. An effective non-surgical means of remediation would be welcome. Design: This was a randomized, controlled, two-arm study assessing the safety and efficacy of combining incobotulinum injections with yoga to reverse lumbar and thoracolumbar AIS. Methods: In a private clinic setting, non-pregnant, healthy 12–18 year-olds were either taught a symmetrical “placebo” yoga pose (control sub-group 1), performed the side plank (Vasisthasana) three times daily with a placebo injection (control sub-group 2) or performed the three-times-daily side plank with a botulinum injection (intervention group 3). Injection: For the injection, 33 IU of incobotulinumtoxin type A (Xeomin) was injected into the concave-side lumbar paraspinals and quadratus lumborum at L2–3 and the psoas muscle at L3–4, or participants were injected similarly with a placebo. Randomization was achieved using random.org. Objective: The objective was to determine whether the treatment of muscular asymmetry with botulinum toxin injections and side planks is safe and effective in AIS. Results/Outcome: Eleven intervention and thirteen placebo patients (Groups 1 + 2), who were 12–18 years old, completed the three-month study. Mean daily side plank time = 165 s. The mean initial lumbar curvature was 36.9 degrees (SD 14.36), (p < 0.0001); the mean Group 3 curvature at 3 weeks was 29.5 degrees (SD 14.23) (p < 0.0001); and the mean Group 3 curvature at 3 months was 26.0 degrees (SD 12.81). Onset vs. 3-month value: p < 0.0001. Harms were limited to one patient in Group 2 and one in Group 3, who complained of transient shoulder pain and supported themselves temporarily on their forearm instead of the palm of the extended hand. Conclusion: Muscle strength asymmetry appears to be relevant to AIS treatment. Incobotulinum injections combined with side planks performed with the convex side downward may be more effective in reversing lumbar AIS than placebo exercises or side planks and placebo injections.

Effects of an 8-week pre-season targeted training on sprinting performance, agility and lower limb muscular asymmetries in elite soccer players.

The purpose of this study was to determine the effects of an 8 week targeted training program on speed, agility, and muscle asymmetries in soccer players. 32 elite soccer players were recruited for the study. Their age, body mass, and body height were 25.8 ± 7.3 years, 77.4 ± 11.1 kg, and 177.5 ± 9.8 cm, respectively. After the warm-up, participants performed two maximum 30 m sprints with a 5-minute rest interval between trials. After the linear sprint test, performed two repetitions of the COD randomized ZigZag test. The tests were performed at the beginning and at the end of the pre-season, which lasted for 8 weeks. EMG was measured bilaterally from the quadriceps, hamstrings, and gluteal muscles with shorts made of knitted fabric similar to elastic clothes. Athletes in the experimental group performed sport-specific targeted strength training based on movement patterns 4 times per week (Monday, Tuesday, Thursday, and Friday). The training included 6 bodyweight exercises (Bird Dog, Single-Leg Glute Bridge, Dead Bug, Side Plank, Reverse Lunge, and Clamshell), performed unilaterally in 5 sets of 10 repetitions of each exercise. The load progression included an additional set in each successive week of the experiment. The data analysis showed significant improvement in 5 m and 30 m sprints after applying the 8-week targeted training protocol. A statistically significant improvement in performance was also observed after the 8-week training period in case of COD, while the speed deficit also decreased significantly. The greatest improvements were observed during the COD test. As a result of repeated COD training over a period of 8 weeks, its technique was improved. Implementation of training methods, which target specific aspects of soccer in the pre-season training routines can improve key motor abilities for that sports discipline. A comprehensive training approach including speed, agility, and resistance training based on specific movement patterns should be applied by strength and conditioning practitioners in soccer teams to achieve peak physical performance and reduce injury risk due to the partial elimination of muscular asymmetries.

Adolescent idiopathic scoliosis is associated with muscle area asymmetries in the lumbar spine.

While the etiopathogenesis of adolescent idiopathic scoliosis (AIS) remains unclear, it is assumed that muscular asymmetries contribute to curve progression. As previous studies have found asymmetries of the thoracic paraspinal muscles in AIS patients, our study's aim was to analyze differences in the erector spinae, multifidus, quadratus lumborum, and psoas muscles of the lumbar spine depending on the curve's radiographic characteristics. We retrospectively included all patients who received posterior reposition spondylodesis for AIS treatment at our institution. Patients were classified according to the Lenke classification. Muscle cross-sectional areas were obtained from magnetic resonance imaging of the lumbar spine. Data were analyzed with the Wilcoxon rank sum test, the Kruskal-Wallis test with post hoc testing, or the Spearman's correlation coefficient. Seventy-four (14 males and 60 females) AIS patients with a median age of 16 (IQR ± 4) years and a mean Cobb angle of 56.0° (± 18.0°) were included. In curve types Lenke 1 and 2 (n = 45), the erector spinae (p < 0.001) and multifidus (p < 0.001) muscles had a significantly larger cross-sectional area on the convex side, whereas the quadratus lumborum (p = 0.034) and psoas (p < 0.001) muscles each had a significantly larger cross-sectional area on the lumbar contralateral side. Our results show an asymmetry of the lumbar spine's muscles which depends on both the convexity and the extent of the scoliotic curve. While our results cannot prove whether these differences are the deformity's cause or effect, they may contribute to a better understanding of AIS pathogenesis and may allow for more specific preoperative physiotherapy.

Analysis of the mechanism and clinical classification of thoracolumbar scoliosis using three-dimensional EOS and surface electromyography

To analyze a thoracolumbar scoliosis group, we analyzed data from the acquired database by groups: the sEMG group (n = 16) and 3D-EOS group (n = 55). The asymmetric hyper/hypoactivation ratio of muscle and LLD (>3 mm) were measured in the sEMG group. In the 3D-EOS group, we recorded the values of parameters including LLD, pelvis rotation, and kyphosis/lordosis. In the sEMG study, sEMG examinations were conducted individually in patients with idiopathic scoliosis to analyze hyper/hypoactivation of the paraspinal muscle. In the three-dimensional EOS study, the Cobb angle, femoral height difference, and thoracic kyphosis and lumbar lordosis angles were measured using 2D images and 3D reconstructed images.Sixteen patients with thoracolumbar scoliosis were classified into asymmetric hyperactivation (A-Hyper) and asymmetric hypoactivation (A-Hypo) groups. The Cobb angle of the A-Hyper subtype was significantly higher than that of the A-Hypo subtype (22.41 versus 15.2, p = 0.023). Coronal deviation (p = 0.028) and the pelvis rotation angle (p = 0.001) were significantly higher in the LLD (+) subtype than in the LLD (−) subtype. When we classified patients cross-sectionally along with A-Hyper/Hypo and LLD (±), A-Hyper elevated the Cobb angle, and LLD (+) was significantly correlated with coronal deviation and pelvis rotation. In the 3D-EOS evaluation, the pelvic height difference (p = 0.043) and coronal deviation (p = 0.001) were significantly higher in the LLD (+) subtype than in the LLD (−) subtype.In conclusions, paraspinal muscular asymmetry and LLD can be strong factors in inducing or progressing thoracolumbar scoliosis.

Musculoskeletal Asymmetries in Young Soccer Players: 8 Weeks of an Applied Individual Corrective Exercise Intervention Program

Introduction: In youth soccer, for examining injury prevention and exercise performance, most of the interventional studies concerning corrective postural asymmetries have applied general intervention programs, ignoring the specific individual corrective needs of each youth player separately. The aim, therefore, of the present study was to examine the effect of 8 weeks of an individualized corrective exercise intervention program on musculoskeletal asymmetries in young soccer players. Materials and Methods: Eighty young male soccer players (age: 14.4 ± 1.2 years; body height: 166.3 ± 9.6 cm; body mass: 59.1 ± 11.5 kg) participated in the current laboratory-based study. A battery of postural and musculoskeletal asymmetry evaluations were initially performed. After the completion of the initial assessment, each player was provided with an individual musculoskeletal asymmetry corrective exercise intervention program which lasted for 8-weeks, with the aim of restoring muscular asymmetries. Following the application of the intervention program, a re-evaluation of their musculoskeletal asymmetries was performed. Results: There was a significant improvement in the primary angle of trunk rotation (r = −0.56, p &lt; 0.001), hamstring flexibility (right: r = −0.55, p &lt; 0.001; left: r = −0.48, p &lt; 0.001), hip external rotation (right: r = −0.46, p &lt; 0.001; left: r = −0.26, p = 0.020), hip internal rotation (right: r = −0.26, p = 0.021; left: r = −0.35, p = 0.002), the opened-eyes Stork Test (right: r = −0.33, p = 0.003: left: r = −0.33, p = 0.003), the closed-eyes Stork Test (right: r = −0.39, p &lt; 0.001; left: r = −0.43, p &lt; 0.001), the Thomas test [right: (χ2(3) = 52.281, p = 0.001, γ^ = −0.751; left: (χ2(3) = 45.832, p = 0.001, γ^ = −0.696)] and of ankle prone passive dorsiflexion (flexed knees) (χ2(2) = 13.019, p = 0.005, V = 0.285). Conclusions: An 8-week individual corrective intervention exercise program may improve postural and musculoskeletal asymmetry status in young male soccer players.

The investigation of isokinetic knee strength and muscle balance of taekwondo and wrestling athletes

Taekwondo and wrestling are two different Olympic combat sports that need lower extremity strength in different ways. During the training process that lasts for many years, the harmony in the leg muscles may be dissimilar. This study aims to determine (1) the knee extension and flexion strength values of elite taekwondo and wrestling athletes with similar physical and demographic characteristics and (2) the muscle balances formed after long-term taekwondo and wrestling training. This study was conducted with the voluntary participation of 20 elite taekwondo and wrestling athletes (age: 20.4±1.27 years; experience: 10.6±1.98 years; height 176.65±5.86 cm; weight 72.96±6, 96 kg; BMI 23.35±1.47 kg/m2). Following the determination of the demographic and physical characteristics of the athletes, their isokinetic knee strengths were examined at an angular velocity of 600/s and compared between taekwondo and wrestling. Accordingly, the differences between the extension relative and average peak torque strengths of the athletes were significant in favour of the taekwondo players in the extension strength. On the other hand, the hamstring/quadriceps strength ratios of the taekwondo athletes were lower (p0.05). The study results showed that taekwondo players have higher extension strength. In the observed groups, it was determined that the muscular asymmetry occurred at different levels because of the adaptation specific to the sport type. Taekwondo trainings allows more balanced hamstring/quadriceps muscle harmony than wrestling. It is recommended to develop training programs in which the flexor muscles are trained against muscular imbalances in wrestling.

경추 추나 및 기능적 뇌척주요법(FCST) 등의 한의학적 치료로 개선된 안면비대칭 환자 3례 증례보고

Objectives This report aimed to investigate the possibility of correcting facial asymmetry using cervical Chuna manipulation treatment and functional cerebrospinal technique and introduce meaningful additional improvement of systemic symptoms of non-surgical Korean medicine treatments through three case studies. Methods Three patients with facial asymmetry were treated using Korean medicine treatments. The effects of the treatments were all measured using photographs, lateral cephalograms, and whole-body radiogram and Likert scale. Results After Korean medicine treatment, there were significant correction effects of asymmetry in photography, cephalography, and whole-body radiogram and meaningful score of Likert scale. Conclusions This study suggested that Korean medicine treatments may be effective in facial asymmetry. Improving muscular asymmetry, including soft tissue asymmetry and functional asymmetry, has meaningful effects on maintaining an overall balance of the body. Facial asymmetry should be treated by making an alignment of the whole body and there should be further well-designed, randomized, and placebo- controlled trials to verify these results.

Is the Integration Problem in the Sensoriomotor System the Cause of Adolescent Idiopathic Scoliosis?

The reason behind the balance control disorder seen in adolescent idiopathic scoliosis (AIS) has been suggested as a central nervous system dysfunction, yet it has not been investigated in detail whether this problem originates from sensory, motor, or from both systems. This study aimed to reveal the differences in the pathways that provide proprioceptive sense, motor control, and coordination between these 2 systems in female individuals with AIS. Brain Diffusion Tensor Imaging was applied to 30 healthy individuals and 30 Lenke type 1 AIS patients. All of the individuals included in the study were predominantly right-handed and aged between 10 and 18. Diffusion tensor imaging of both groups were performed bilateral tractography on the corticospinal tract (CS tr), medial lemniscus (ML), superior longitudinal fasciculus (SLF), and inferior longitudinal fasciculus (ILF) tracts using DSI Studio software. Significant differences in the parameters of CS tr, ML, SLF, ILF pathways were found between the AIS and the control groups. In the AIS group, significant differences were found in the fiber count and fiber ratio of the ML that carries the proprioceptive sense and CS tr, which is responsible for the somatomotor system. There were also significant differences between the left and right CS tr, ML, SLF, and ILF pathways of the AIS group ( P <0.05). Differences in the CS tr, ML, SLF, and ILF pathways may trigger muscular asymmetry and cause postural instability and thus spinal deformity in AIS.

Diagnostic imaging of the equine cervical spine – Are radiographs enough?

Diagnostic imaging of the equine cervical spine – Are radiographs enough?

The effect of muscular strength and strength asymmetry on jumping height in soccer players

BACKGROUND: Lower limb muscular asymmetry is not well studied and may have a negative impact on performance. OBJECTIVE: To estimate how muscular strength and strength asymmetry affect jumping performance in soccer players. METHODS: Twenty-eight male professional soccer players took part in the study. The countermovement jump (CMJ) without arm swing was used to determine jumping height. Muscle strength was measured concentrically at 60 and 300∘/s. RESULTS: The peak moment of the knee extensors was positively and significantly correlated with the CMJ; r= 0.608 at 300∘/s and r= 0.489 at 60∘/s. The asymmetry of the knee flexors between the stronger and weaker leg was negatively and moderately correlated with the CMJ at 300∘/s (r=-0.396). The regression model (R2= 0.474) showed that an increase of 0.18-Nm/kg in the relative strength of the knee extensors at 300∘/s (by one SD) was related to an increase of 3-cm in the CMJ. Reducing the asymmetry of the knee flexors by 6.8 percentage points (by one SD) was related to a rise of 1.7-cm in the CMJ. CONCLUSIONS: Greater strength in the knee extensors, preferably tested at higher velocity, and reduced asymmetry in the strength of the lower hamstring muscles have a statistically significant effect on the CMJ.

No Pain and No Gain: Kommerell’s Diverticulum with a Right-Sided Aortic Arch, and an Aberrant Left Subclavian Artery Presenting in a Body Builder with Muscle Bulk Imbalance

A 22-year-old right-handed male presented to the Sports Medicine clinic with concerns of upper extremity muscle asymmetry. Physical examination showed gross muscular asymmetry when comparing the left upper extremity to the right. Radial pulses were 2 + on the right and 1 + on the left. Due to concern for vascular anomaly, computed tomography angiography was performed which revealed a right-sided aortic arch with Kommerell’s diverticulum and aberrant left subclavian artery. The patient underwent a left carotid subclavian bypass successfully, but his recovery was complicated by an upper extremity deep venous thrombosis. He is currently on novel anticoagulant but has been released to normal activities and doing well. Kommerell’s Diverticulum (KD) is a rare congenital anomaly caused by a persistent remnant of the fourth primitive dorsal arch during embryological development. Although the prevalence of KD is rare, it is important to identify and diagnose this condition to provide definitive care.

The Relationship between Stress and Masticatory Muscle Activity in Female Students.

The aim of the study was to analyze the relationship between stress measured by the perceived stress scale (PSS-10) questionnaire and masticatory muscle activity. Experimental design assumed the study of healthy young women without temporomandibular disorders, dividing them into three groups depending on the result of the stress level and then comparing these groups in terms of bioelectrical activity of the masticatory muscles. After the exclusion criteria were applied, 63 female students (mean age: 22.3 ± 2.4 years) from Medical University of Lublin were included in the study. The subjects were then divided into 3 groups: with low (n = 18), medium (n = 18) and high stress level (n = 27), according to PSS-10 results. Resting and functional activity of temporalis anterior (TA) and masseter (MM) muscles were measured by electromyograph BioEMG III. There were statistically significant effects of group on the absolute value of asymmetry index (AsI) of TA and MM during maximum voluntary clenching on dental cotton rollers (both p = 0.02). Post hoc analysis shows that there were statistically significant differences between medium and high stress groups in AsI TA (p = 0.01) and between low and high stress groups in AsI MM (p = 0.02). Perceived stress measured by PSS-10 questionnaire seems to be associated with changes in muscular asymmetry in functional clenching activity.

Muscular Asymmetries in Anatomical Donors with Lower‐Limb Amputations

Individuals with lower-limb amputations experience asymmetrical musculoskeletal loading associated with increased gait asymmetry, fall risk, and overuse injuries. Many biomechanical modeling systems rely on cadaveric data for a gold standard, so it is important to confirm asymmetries in donors with lower-limb amputation reflect those of living individuals for an accurate standard. Previously, we examined skeletal asymmetries in these donors using a threshold of 10% for clinical significance, which is considered symmetrical in healthy controls. We found less bone mineral density and bone mineral content, and wider knee joint space on each donor's most compromised limb compared to their most intact limb. Amputation can also result in muscle atrophy, leading to changes in muscle mass, architecture, and fiber phenotype. This study investigated these between-limb muscular differences in donors with lower-limb amputations to determine if donor findings reflect findings in living individuals. We hypothesized each donor's most compromised limb would show less muscle mass, lower pennation angle and physiological cross-sectional area (PCSA), and fewer and smaller type 1 fibers compared to their most intact limb. Two male unembalmed donors 61 and 67 years of age with lower-limb amputations secondary to diabetes were obtained through the University of North Texas Health Science Center (UNTHSC) Willed Body Program. Four muscles were dissected from each limb: gluteus maximus, sartorius, rectus femoris, and biceps femoris long head. Muscle mass and fiber lengths were collected using a hanging scale and calipers, then muscles were photographed to collect pennation angle in ImageJ software. PCSA was calculated using the following formula: [(muscle mass x cos(pennation angle)] / [fiber length (cm) x muscle density (1.067 g/cm-3)]. The density of human skeletal muscle was taken from the literature. Histological (H&E) staining of muscle tissue was used to determine fiber density and cross-sectional area. Immunohistochemical (IHC) staining was used to identify the percentage of fibers containing the fast type II isoform of myosin heavy chain. Biceps femoris PCSA was 18.1-68.6% larger on each donor's most compromised limb compared to their most intact limb. Differences were largely driven by pennation angle, as opposed to muscle mass or fiber lengths. H&E staining also showed smaller cross-sectional biceps femoris muscle fibers on the most compromised side compared to the most intact side. IHC analyses of fiber phenotype in these muscles are ongoing. More donors should be included to assess the generalizability of our findings. Knowledge of muscle adaptations following amputation in donors can confirm accurate biomechanical modeling and inform rehabilitation techniques to reduce muscle atrophy. The authors would like to thank the donors and their families, as well as the UNTHSC Willed Body Program.

Unilateral and Bilateral Strength Asymmetry among Young Elite Athletes of Various Sports.

Background and objective: Type of physical activity may influence morphological and muscular asymmetries in the young population. However, less is known about the size of this effect when comparing various sports. The aim of this study was to identify the degree of bilateral asymmetry (BA) and the level of unilateral ratio (UR) between isokinetic strength of knee extensors (KE) and flexors (KF) among athletes of three different types of predominant locomotion in various sports (symmetric, asymmetric and hybrid). Material and methods: The analyzed group consisted of young elite athletes (n = 50). The maximum peak muscle torque of the KE and KF in both the dominant (DL) and non-dominant (NL) lower limb during concentric muscle contraction at an angular velocity of 60°·s−1 was measured with an isokinetic dynamometer. Results: Data analysis showed a significant effect of the main factor (the type of sport) on the level of monitored variables (p = 0.004). The type of sport revealed a significant difference in the bilateral ratio (p = 0.01). The group of symmetric and hybrid sports achieved lower values (p = 0.01) of BA in their lower limb muscles than those who played asymmetric sports. The hybrid sports group achieved higher UR values (p = 0.01) in both lower limbs. Conclusions: The results indicate that sports with predominantly symmetrical, asymmetrical, and hybrid types of locomotion affected the size of the BA, as well as the UR between KE and KF in both legs in young athletes. We recommend paying attention to regular KE and KF strength diagnostics in young athletes and optimizing individual compensatory exercises if a higher ratio of strength asymmetry is discovered.

Investigating the Correlation Between Anterior-Posterior and Lateral Asymmetric Muscular Balance With Low Back Pain.

ObjectiveThe objective of this pilot study was to determine if there is a correlation between the proposed physical testing protocol and low back pain. The proposed physical testing protocol is an attempt to assess muscular asymmetry in the anterior-posterior plane and the lateral plane.MethodsA total of 96 volunteers were recruited from Touro University after obtaining IRB approval. Volunteers were initially provided a questionnaire regarding demographics and back pain. After ensuring participants satisfied the inclusion criteria, a physical test protocol was performed. After data compilation, odds ratios as well and linear regression models were generated to assess for correlation with back pain.ResultsA total of 96 participants were recruited. The odds ratio for asymmetric anterior-posterior balance in relation to back pain is 3.00 with a 95% confidence interval 1.26-7.12. The odds ratio for total ability to tolerate asymmetric loads greater than 50% of ideal body weight is 0.44 with a 95% confidence interval 0.11-1.77. The linear regression coefficient of anterior-posterior balance greater than 25% of ideal body weight in relation to level of pain is 1.96.ConclusionsIncreased muscular asymmetry in the sagittal plane and lateral plane showed a trend toward increased levels of low back pain; however, there is a weak correlation. This is a correlation and not an association. Future studies to assess the relationship between muscular balance and low back pain are needed to determine if therapy can be targeted to improve muscular sagittal balance, which can improve symmetry and back pain.

Muscular Strength Imbalances Are not Associated with Skin Temperature Asymmetries in Soccer Players.

Although strength imbalances using isokinetic dynamometer have been examined for injury risk screening in soccer players, it is very expensive and time-consuming, making the evaluation of new methods appealing. The aim of the study was to analyze the agreement between muscular strength imbalances and skin temperature bilateral asymmetries as well as skin temperature differences in the hamstrings and quadriceps. The skin temperature of the anterior and posterior thigh of 59 healthy male soccer athletes was assessed at baseline using infrared thermography for the identification of hamstrings-quadriceps skin temperature differences and thermal asymmetries (>0.5 °C). Subsequently, concentric and eccentric peak torque of the quadriceps and hamstrings were considered in the determination of the ratios, as well as muscular asymmetries (>15%). When considering the torque parameters, 37.3% (n = 22) of the players would be classified as high risk for injuries. The percentage of those presenting skin temperature imbalances superior to 0.5 °C was 52.5% (n = 31). The skin temperature assessment showed sensitivity (22%) and specificity (32.2%) to identify torque asymmetries, demonstrating the inability to identify false negatives (15.3%) and false positives (30.5%) from all soccer athletes. In conclusion, skin temperature differences between hamstrings and quadriceps could be more related to thermoregulatory factors than strength imbalances.

Abdominal wall morphometric variability based on computed tomography: Influence of age, gender, and body mass index.

Ventral hernia surgery does not usually account for the individuality of the abdominal wall anatomy. This could be both because medical imaging is rarely performed before surgery and because data on abdominal wall variability are limited. The objective of the present study was to perform an exhaustive morphometric analysis of abdominal wall components based on computed tomography (CT) scans. A retrospective study was performed on 120 abdominopelvic CT scans of clinically normal adults aged 18-86 years equally divided between women and men and into four age groups. Each abdominal wall muscle was evaluated in terms of area, thickness, shape ratio, fat infiltration, and aponeuroses width. The influence of age, gender, and body mass index (BMI) was investigated, as well as muscular asymmetry. The abdominal wall muscle area represented 8.5 ± 2.5% of the abdominal area. The internal oblique muscle had the largest area, the rectus abdominis was the thickest, the transversus abdominis was the narrowest and had the smallest area. The width of the linea alba was 20.3 ± 12.0 mm. The evolution of the abdominal wall with age was quantified, as well as the large differences between the sexes and BMI groups, resulting in strong correlations and highlighting the specific pattern of the transversus abdominis. The asymmetry of the left and right muscle areas oscillated around 17%. The various components of the abdominal wall have been precisely described. Knowledge of their variability could be used to enhance the planning of ventral hernia surgery or to develop numerical modeling of the abdominal wall.

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

Background and Objectives: Rugby players engage in demanding, high loading muscular activity in the spine. Study of the abdominal wall architecture in female rugby athletes is relevant to the possible muscular asymmetry secondary to sport practice and the relationship between the abdominal wall and the pelvic floor muscles. Activation of the transversus abdominis (TrAb) generates an increase in the bladder neck muscle. Moreover, an increased interrecti distance (IRD) is related to urinary incontinence and has a higher prevalence in athletic women. The aim of the present study was to compare and quantify, with ultrasound imaging (USI), the thickness of the transversus abdominis (TrAb), external oblique (EO), internal oblique (IO), rectus abdominis (RA), and interrecti distance (IRD) in female rugby players versus non-athletic women in order to improve upon existing knowledge about abdominal wall configuration in female athletes. Materials and Methods: A sample of 32 women was recruited at the Universidad Europea Research Lab and divided in two groups: a rugby group (n = 16) and a non-athletic women group (n = 16). The thickness of the TrAb, EO, IO, RA, and IRD were assessed by USI in both groups. Results: There were statistically significant differences for the ultrasound evaluation thickness of the right TrAb (p = 0.011; d = 0.10), EO (p = 0.045; d = 0.74), IO (p = 0.003; d = 1.32), and RA (p = 0.001; d = 1.38) showing a thickness increase for the rugby group with respect to the control group. For the IRD thickness, there were no significant differences (p > 0.05) between groups. Conclusions: An increased TrAb, IO, EO, and RA thickness may be shown in female rugby players versus non-athletic women. Nevertheless, statistically relevant differences were not found for the IRD between both groups.

Profiling the Isokinetic Muscle Strength of Athletes Involved in Sports Characterized by Constantly Varied Functional Movements Performed at High Intensity: A Cross‐Sectional Study

Constantly varied functional movements performed at high intensity (FMHI) is a type of strength and general conditioning program that has gained widespread popularity in recent years. The very intense exercises performed with lower and upper limbs may create muscular asymmetry or imbalance between agonist and antagonist muscles, and therefore the characterization of isokinetic muscle strength, side-to-side difference, and balance ratios for lower and upper limbs may contribute to a better understanding of the modality characteristics. To evaluate the knee and shoulder strength of FMHI athletes of both sexes. Cross-sectional study. Exercise physiology laboratory. Sixty FMHI athletes (30 M/30 W) with more than 2 years' experience. Athletes performed isokinetic tests in both lower and upper limbs: concentrically at 60°/s and 240°/s and eccentrically at 240°/s. Isokinetic peak torque of knee flexor and extensor and shoulder internal and external rotator muscles. Conventional and functional strength balance ratios and side-to-side strength difference. Concentric peak torque values relative to total body mass for shoulder and knee joints were higher in men than women on both sides. Eccentric peak torque values for knee flexor-dominant and extensor-nondominant limbs showed no difference between the sexes. The knee conventional strength balance ratio for dominant and nondominant sides in women (51.5% ± 7.0% and 51.0% ± 7.1%, respectively) and for dominant and nondominant sides in men (54.4% ± 15.2% and 51.5% ± 9.9%, respectively) were no different between the sexes or limbs. The shoulder conventional strength balance ratio was higher in women (78.1 ± 13.2%) than in men (67.6% ± 10.9%) on the nondominant side. Knee and shoulder functional strength balance ratios in nondominant limbs were higher for women than men. Both sexes presented no side-to-side difference for knee joints or muscles, or for shoulder IR muscles, but ER was stronger in dominant limbs. These data from highly trained FMHI athletes can be compared to that of other athletes to help determine individual weaknesses, strengths, and imbalances, and may be useful for designing training programs. III.