Trunk muscle strength and lumbo-pelvic kinematics in adolescent athletes: Effects of age and sex

Epidemiology of Non-Contact Muscle Injuries in the Italian Male Elite Under-19 Football (Soccer) Championship

BACKGROUND

While extensive research exists on muscle injuries among adult football players, a notable gap persists in studies concerning younger footballers. The aim of the current study is to provide epidemiological data on the characteristics of time-loss muscle injuries in young football players participating in the Italian Under-19 male elite Championship ("Primavera 1").

RESULTS

Conducted as a multicentre, prospective, observational cohort study, this research gathered injury data from the 2022-23 season across 14 of the 18 Clubs in the first Italian Under-19 championship. The cohort comprised 391 players with a mean age (± standard deviation) of 18.0 ± 0.4 years. A total of 479 injuries were reported, resulting in 14,231 days of activity lost. Of these, muscle injuries were 209 (44%), accounting for 4,519 (32%) days lost. Overall muscle injuries incidence was 1.82/1000 hours, with a mean injury burden of 39.4 days lost/1000 hours. Almost all muscle injuries (206 out of 209: 98.5%) occurred in hamstrings, quadriceps, adductors, calf and iliopsoas. Hamstrings injuries were the most burdensome (18.8 days lost/1000 hours) accounting for nearly half of all days lost due to muscle injuries. Incidence and burden of adductors injuries (0.25 injuries and 4.1 days lost/1000 hours, respectively) were found to be comparable to calf injuries (0.24 injuries and 4.7 days lost/1000 hours, respectively). Iliopsoas injuries accounted for a noteworthy portion of the total, with an injury incidence of 0.16/1000 hours and a burden of 3.3 days lost/1000 hours. Injuries with myo-tendinous or myo-aponeurotic involvement demonstrated delayed return-to-football compared to those without such involvement (35.6 vs. 18.5 days, p < 0.0001).

CONCLUSIONS

The study highlighted a peculiar distribution of non-contact muscle injuries among elite young football players. While hamstring injuries were confirmed as the most burdensome, incidence and burden of adductors and calf injuries were found to be similar. A significant incidence and burden of iliopsoas injuries were observed. These findings suggest potential implementations for targeted injury prevention strategies in the Italian male elite Under-19 football Championship.

Relationship between paravertebral muscle function, pelvic incidence, and health-related quality of life in patients with degenerative spinal deformity

BACKGROUND

Patients with degenerative spinal deformity often experience symptoms that seriously affect their quality of life, such as low back pain and dysfunction. This study aimed to investigate the relationship between paravertebral muscle function and pelvic incidence (PI) and their effect on health-related quality of life (HRQL) in patients with degenerative spinal deformity.

METHODS

A total of 112 patients with degenerative spinal deformity in Southwest Hospital (Chongqing, China) were enrolled. They were divided into groups according to PI angle: high (PI > 60°, n = 37), normal (PI 50°-60°, n = 31), and low (PI < 50°, n = 44). Paravertebral muscle strength and endurance were assessed using the prone external fixation test frame. The sagittal vertical axis (SVA) was measured on X-rays of the spine in an anterolateral position, and all subjects were assessed with the Oswestry Disability Index (ODI), Roland-Morris questionnaire (RMQ), and 36-Item Short Form Health Survey (SF-36). Pearson or Spearman coefficients were used to assess the relationship of paravertebral muscle function with SVA, PI, and health-related quality of life.

RESULTS

Maximal voluntary exercise (MVE) in the high-PI group was significantly lower than the MVE of both the normal- and low-PI groups (p < 0.05). There was no significant difference in MVE between the normal- and low-PI groups (p > 0.05). There was no significant difference in endurance time, SVA, ODI, RMQ, and SF-36 among the three groups. Paravertebral muscle MVE was negatively correlated with PI, SVA, ODI, and RMQ (r = - 0.193, - 0.210, - 0.283, - 0.277, p < 0.05). Endurance time of paravertebral muscle was also negatively correlated with SVA, ODI, and RMQ (r =  - 0.200, - 0.420, - 0.348, p < 0.05) and positively correlated with SF-36 (r = 0.245, p < 0.05). In addition, paravertebral muscle MVE was positively correlated with the physical functioning score of the SF-36 (r = 0.251, p < 0.05), and the endurance time of paravertebral muscle was positively correlated with the physical functioning, physical role, bodily pain, and social function scores of the SF-36 (r = 0.342, 0.230, 0.209, 0.256, p < 0.05).

CONCLUSIONS

High PI may serve as a risk factor for decreased paraspinal muscle strength in patients with degenerative spinal deformities. Early and targeted exercises focusing on paraspinal muscle strength and endurance could potentially be of positive significance in slowing down the progression of sagittal imbalance, alleviating functional disorders, and increasing health-related quality of life in patients with degenerative spinal deformity.

Sex-related differences in motor control strategies during isometric contractions in the Sorensen test posture with different external loading

BACKGROUND

There is a sex-related difference in strength and endurance in trunk muscles: males have more strength while females have more endurance.

OBJECTIVE

Investigate sex-related differences in motor control strategies in back muscles during isometric contractions (IC) in the Sorensen test posture.

METHODS

Thirty-six healthy and young volunteers performed different tasks: three maximal voluntary contraction (MVC) tests recorded with a bio-feedback force sensor, and followed by five loaded IC (LIC) tests using bodyweight and loads of 0 to 8 kg with a 2-kg step. Surface electromyography was used to measure the activity of bilateral lumbar paravertebral (LP) and quadratus lumborum (QL) muscles.

RESULTS

Sex-related and load-related differences in EMG amplitudes were highlighted during LIC tests. Females showed significantly (p-value = 0.02) greater EMG amplitude for the highest load (8 kg) than males. Besides, significant differences between low (2 and 4 kg) and high (6 and 8 kg) loads for both LP and QL muscles and for both sexes were observed. Finally, for MVC tests, males produced significantly (p-value = 1.02e-4) greater strength during MVC tests (4.25 ± 1.37 N/kg vs 2.60 ± 0.78 N/kg).

CONCLUSION

The results were clinically relevant to bring attention to load strategy during rehabilitation, particularly in females who seemed to recruit the QL muscle more.

Back pain in adolescent athletes: a narrative review

BACKGROUND

Back pain in young athletes is common. Adolescents are at an increased risk for back pain related to several factors including rapid growth. Traditionally, the conversation around back pain in the adolescent age group has been centered around diagnosis and treatment; however, there are emerging studies regarding prevention.

OBJECTIVE

The purpose of the present investigation is to summarize sport-specific risk factors, to describe the growing emphasis on prevention/screening, and report results on minimally invasive and surgical options.

METHODS

The literature search was performed in Mendeley. Search fields were varied until redundant. All articles were screened by title and abstract and a preliminary decision to include an article was made. The full-text screening was performed on the selected articles. Any question regarding the inclusion of an article was discussed by at least 3 authors until an agreement was reached.

RESULTS

Adolescent athletes have a higher risk of developing spondylolysis and spondylolisthesis than their non-athletic counterparts. Participation in athletic activity alone, increased body mass index, varsity status, and nationally/internationally competitive status are identified are demographic risk factors. Weightlifters, gymnasts, football players, and combat athletes may be at higher risks. Increased lumbar lordosis, abdominal muscle weakness, hip flexor tightness, hamstring tightness, thoracolumbar fascia tightness, femoral anteversion, genu recurvatum, and thoracic kyphosis also predispose. Recent cadaveric and kinematic studies have furthered our understanding of pathoanatomic. There is some evidence to suggest that isokinetic testing and electromyographic data may be able to identify at-risk individuals. Perturbation-based exercise interventions can reduce the incidence of adolescent athletic back pain. There is a large body of evidence to support the efficacy of physical therapy. There is some data to support minimally invasive treatments including external bone growth simulators, steroid injections, and chemonucleolysis for specific pathologies. Endoscopic surgery results for a limited subset of patients with certain disease processes are good.

CONCLUSIONS

Back pain in adolescent athletes is common and may not lead to appropriate alterations in athletes' level of participation. Athletes with a higher body mass index should be counseled regarding the benefits of losing weight. Isokinetic testing and electromyographic data have the potential as diagnostic and screening tools. Strength deficits and postural control could be used to identify patients requiring early intervention and thus reduce the incidence. External bone growth simulators, steroid injections, and chemonucleolysis could potentially become conservative options in the future. When surgery is indicated, the endoscopic intervention has the potential to decrease operative time, decrease cost, and promote healing.

Electrical Properties of Lumbar Paraspinal Muscles in Young Adults With and Without Chronic Low Back Pain Based on Electrical Impedance Myography: A Cross-Sectional Study

Background

Lumbar paraspinal muscle (LPM) is important in spinal stabilization in patients with chronic low back pain (CLBP). However, the electrical properties of LPM in patients with CLBP remain unclear. Electrical impedance myography (EIM) is a novel and non-invasive technique that provides a simple quantitative evaluation of electrical properties of the LPM.

Purpose

This study aimed to apply EIM to assess the electrical properties of the LPM between patients with CLBP and healthy control (HC).

Methods

Thirty participants (15 CLBP participants; 15 healthy controls) were enrolled in the study. Participants in the CLBP group were asked to complete the visual analog scale (VAS), Oswestry Disability Index (ODI), and Roland–Morris Disability Questionnaire (RDQ) to assess the pain intensity and disability in daily life. Independent sample t-tests were adopted to analyze the basic characteristics between the two groups. At 5, 50, 100, and 200 kHz current frequencies, the electrical properties were measured on each side of the LPM. The EIM parameters of resistance (R), reactance (X), phase angle (PA), and Z value were analyzed by one-way analysis of variance (ANOVA), with age as covariate. Spearman's rank correlation coefficient analysis was applied to explore the relationships between the questionnaires and the EIM parameters.

Results

The R and Z values of bilateral LPM in the CLBP group were significantly larger than those in the HC group; the PA decreased and the X did not change at these four tested current frequencies. At 5 kHz, Z and R on the right side were non-significantly different between patients and HCs. Correlation analysis showed that at 50 kHz, ODI and RDQ scores correlated negatively with the R of the bilateral LPM (r = 0.523, r = 0.581, respectively; p < 0.05). RDQ scores correlated positively with the PA of the right LPM (r = 0.521, p < 0.05).

Conclusion

The electrical properties of the bilateral LPM differed between CLBP participants and healthy individuals, regardless of the different frequencies used. These altered electrical properties of the LPM in the patients with CLBP correlated to some extent with disability in daily life.

The Potential Role of Hamstring Extensibility on Sagittal Pelvic Tilt, Sagittal Spinal Curves and Recurrent Low Back Pain in Team Sports Players: A Gender Perspective Analysis

It is assumed that mechanical restriction of hamstring tightness disrupts sagittal spine–pelvis–leg alignment and alters the lumbar–pelvic rhythm predisposing to low back pain (LBP) in athletes; however, this association is not clear. A prospective cross-sectional cohort study was conducted to determine the influence of hamstring extensibility (HE) on sagittal pelvic tilt, sagittal spinal curves, and LBP in 94 soccer and basketball players (61 man and 33 woman) with (n = 36) and without recurrent LBP (n = 58). Descriptive analysis displayed significant gender differences for HE, sagittal pelvic tilt, and lumbar curve. Differences were found between the low-HE and high-HE groups in lumbosacral angle in for the maximum trunk forward flexion (LH-MTFP). Low-HE was associated with LH-MTFP, lumbar curve and LBP in male players (p ≤ 0.023). In female players, LH-MTFP and lumbar curve were associated with low-HE (p ≤ 0.020). Low-HE predicted LH-MTFP (p = 0.000; OR = 65.6950) and LBP (p = 0.028; OR = 13.915) in male players. The decision tree analysis showed that 50.8% of the players were classified with restricted LH-MTFP, 77.4% with low-HE among male players. The 100% of male players with recurrent LBP had low-HE. The 65% of female players with low-HE had restricted LH-MTFP. Measurement of HE, lumbar curve, and LH-MTFP are important in making training decisions for to reduce the incidence of recurrent LBP in soccer and basketball players.

Movement Time of Lower Trunk Muscles during Dynamic Postural Control in Response to a Sudden Visual Stimulus during Walking: A Pilot Study

Postural control during walking is maintained by the combination of various factors. Among these factors, adjustment of trunk movement is essential for maintaining postural control, and the response of muscles to unpredictable stimuli affects postural control. Loss of balance while walking increases the risk of accidents, the frequency of which depends on age and sex. In this study, we investigated whether there was a difference in the movement time of trunk muscles to sudden stimulation while walking according to age and sex. Fourteen healthy individuals aged 20-30 years (6 men, 8 women) and 12 individuals aged 50-70 years (4 men, 8 women) were included in the study. Movement time of bilateral erector spinae and rectus abdominis muscles in response to visual stimulation during walking was examined using surface electromyography. Movement time was calculated as the total muscle activation time excluding the reaction time. This study revealed no significant differences in movement time of the erector spinae muscles according to sex or age. The role of the rectus abdominis muscles in maintaining posture during walking was insignificant. In conclusion, the movement time of trunk muscles in response to sudden visual stimulation during walking did not differ by age or sex, and the difference in accident frequency may be associated with deterioration of other factors required to maintain posture.

Postural Evaluation in Sports and Sedentary Subjects by Rasterstereographic Back Shape Analysis

Posture is defined as the position of the body in space, the aim of which is to maintain balance, both in static and dynamic conditions. Our purpose was to study various postural variables involved in postural adaptations of athletes practicing symmetric and asymmetric sports at professional level. Methods: Patients include sedentary subjects, competitive athletes practicing symmetrical and asymmetrical sports. Postural evaluation of the three different groups was performed using the rasterstereographic-system Formetric-4D. Results: 157 subjects were recruited. From the comparison between subjects playing symmetrical and asymmetrical sports, arises a statistically significant difference on cervical (p = 0.041) and lumbar (p = 0.047) flèche of Stagnara, with higher values for symmetrical athletes’ group. Hemipelvis torsion (p = 0.031) and lumbar flèche (p ≤ 0.001) of Stagnara are higher in symmetrical athletes’ group (sedentary). Hemipelvis torsion, cervical and lumbar flèche resulted to be higher among athletes (sedentary) (p = 0.016, p = 0.003, p = 0.027). Conclusions: In addition to the competitive sports’ medical examination, a screening with rasterstereographic-system Formetric-4D is suggested to all sedentary subjects, without serious skeletal pathologies which want to start athletic activity. Rasterstereographic-system Formetric-4D is also suggested to all athletes practicing sports, with the aim to identify eventual unknown postures, consequent to reiterated repetition of specific movements.

Peak sagittal plane spine kinematics in female gymnasts with and without a history of low back pain

BACKGROUND

Female gymnasts have a greater prevalence of back pain compared to other female athletes. There is little evidence that female artistic gymnasts with and without back pain demonstrate different movement patterns during gymnastics skills. The purpose of this study was to determine if there were differences in back movements during back walkovers and back handsprings among female artistic gymnasts.

METHODS

Female artistic gymnasts (8-18 years old) with and without back pain wore inertial sensors on their torso, arms, and legs while performing back walkovers (N = 14) and back handsprings (N = 15) on the floor and balance beam at their training gymnastics facilities.

FINDINGS

Gymnasts with back pain had similar spine peak extension, peak flexion, and range of motion during back walkovers and back handsprings compared to gymnasts without back pain. Additionally, no differences in sagittal plane spine kinematics were found between the groups at any specific time point during either the back walkover or back handspring skills. However, a large portion of the data collected was excluded during quality assurance, thus our final sample sizes are small.

INTERPRETATION

These findings suggest that gymnasts with back pain have similar sagittal plane movements to those without back pain. The relationship between back pain and gymnastics training load/intensity is currently unclear. We suggest future studies to investigate common artistic gymnastics skills and back pain prevalence with more participants, full-body motion analysis with kinetic measurement capabilities, and longitudinally for those demonstrating back pain.