Trunk muscular strength in pre-pubertal children with and without back pain

The effect of gender, age and sports specialisation on isometric trunk strength in Greek high level young athletes

Aim of the study was to compare the isometric strength of flexors and extensors trunk muscles between male and female elite adolescent athletes of different age and training experience. Absolute and relative trunk muscle isometric peak extension (PTE) and flexion (PTF) torque, as well as flexion/extension (F/E) ratio were evaluated in 388 elite adolescent athletes 188 males (Age: 15.4±1.8 years, Body height: 175.5±11.2 cm, Body mass: 68.8±14.5 kg, BMI: 22.1±0.3 kg/m2) and 207 females (Age: 15.1±1.6 years, Body height: 166.8±7.8 cm, Body mass: 60.8±8.4 kg and BMI: 21.8±0.4 kg/m2). Participants were assigned into seven different groups according to their sport specialisation (oars-paddle, swimming, contact-combat, team, racket, winter and mixed other sports). Significant effect of age (η2: 0.077-0.112, p < 0.05), gender (η2: 0.020-0.077; p < 0.05) and sport category factors (η2: 0.057-0.154. p < 0.005) for absolute/relative PTE, PTF and F/E ratio was found. The highest values were observed in contact-combat and the lowest in mixed other sports groups. F/E ratio significantly differs between the age groups, especially in female athletes. The present data suggest that TMSs and F/E ratio are highly affected by age, gender and sports specialisation in high level trained adolescents.

Motor performance and back pain in children and adolescents: A systematic review

BACKGROUND AND OBJECTIVE

Motor performance during childhood and adolescence is recognized as a relevant determinant of present and future health, but its effects on back pain (BP) remain unclear. In this systematic review, we aimed to identify the association between motor performance and BP in children and adolescents.

DATABASES AND DATA TREATMENT

A literature search was performed in the MEDLINE, Scopus, Embase, SPORTDiscus and CINAHL databases. We included cross-sectional, cohort, case-control and controlled clinical trials (data from control groups). The inclusion criteria were as follows: (a) participants aged 6-19 years; (b) assessment motor performance components; (c) assessment of BP and (d) reported measures of association. The risk of bias was assessed by the Downs and Black instrument and the quality of evidence by the grading of recommendations, assessment, development and evaluation (GRADE).

RESULTS

A total of 2360 articles were identified, 25 of which were included in our systematic review. Of the 25 studies, 19 were evaluated as having a low risk of bias. GRADE indicated that 20 studies presented low or very low quality. Most of the studies evaluated flexibility (n = 16), muscle endurance (n = 18) and muscle strength (n = 9). Aerobic capacity, balance and speed were also examined in some studies (n < 5). Overall, motor performance (flexibility, muscle endurance, muscle strength, aerobic capacity, balance and speed) was not associated with BP. Most of the results were inconsistent because of the lack of studies, risk of bias and low quality of evidence. Only trunk extensor muscle endurance was associated with decreased BP with moderate quality of the supporting evidence. Prospective studies with a low risk of bias are warranted to further clarify this relationship in childhood and adolescence and findings may support more targeted and effective health promotion interventions.

SIGNIFICANCE

This systematic review shows that motor performance (flexibility, muscle endurance, muscle strength, aerobic capacity, balance and speed) was not associated with BP in children and adolescents. Most of the results were inconsistent because of the lack of studies, risk of bias and low quality of evidence. Only trunk extensor muscle endurance was associated with decreased BP with moderate quality of supporting evidence.

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

Considering their potential relevance for low-back pain, we investigated trunk muscle strength, sagittal lumbo-pelvic alignment while standing and lumbo-pelvic ratio during trunk flexion in adolescent athletes with regard to the effects of age and sex. Twenty-two early adolescent (EA: 13-15 years, 10 females) and 28 late adolescent (LA: 16-19 years, 14 females) high-level athletes (training duration more than 12 hours per week) participated in the study. We measured trunk extension and trunk flexion moments during maximum voluntary isometric contractions using a dynamometer. Further, we examined lumbo-pelvic kinematics in the upright standing position and during forward trunk bending using two 3-dimensional accelerometers. Using a lineal regression model in which the flexion moment from each participant was used as predictor for the corresponding extension moment, we found higher residuals (P < 0.001) in the EA compared to LA, indicating greater imbalances in the trunk muscle strength in EA. We found a higher lordosis in the upright position, greater pelvic rotation, and greater lordotic posture during the forward bending in females (P < 0.01). These age-related imbalances and sex-related characteristics in lumbo-pelvic kinematics might affect the neuromuscular control of trunk stability and the magnitude of spine loading. We recommend the implementation of specific coordination and stabilization programs for muscle groups that contribute to lumbo-pelvic kinematics and training routines that support a balanced strength development within the trunk muscles in adolescent athletes.

A systematic review on quantifiable physical risk factors for non-specific adolescent low back pain

PURPOSE

The aim of this systematic review was to analyze the results of studies on quantifiable physical risk factors (beyond questionnaires) for adolescent low back pain (LBP).

METHODS

A systematic search was conducted in Medline (OvidSP), Premedline (PubMed), EMBASE, Cochrane, CINAHL, PEDro and PsycINFO. Cross-sectional, prospective and retrospective English language studies on LBP in adolescents aged 10 to 18 years were included.

RESULTS

Twenty-two mostly cross-sectional studies were included. Trunk muscle endurance in particular seemed to be associated with adolescent LBP, while a possible association of trunk muscle strength and spinal flexibility was less clear.

CONCLUSION

There is a need for prospective studies on quantifiable physical risk factors for adolescent LBP. Such studies should focus on back and abdominal muscle endurance, possibly in combination with sagittal spinal mobility, sagittal postural alignment and neurodynamics as possible modifiable risk factors for LBP.

Trunk Muscle Activity during Drop Jump Performance in Adolescent Athletes with Back Pain

In the context of back pain, great emphasis has been placed on the importance of trunk stability, especially in situations requiring compensation of repetitive, intense loading induced during high-performance activities, e.g., jumping or landing. This study aims to evaluate trunk muscle activity during drop jump in adolescent athletes with back pain (BP) compared to athletes without back pain (NBP). Eleven adolescent athletes suffering back pain (BP: m/f: n = 4/7; 15.9 ± 1.3 y; 176 ± 11 cm; 68 ± 11 kg; 12.4 ± 10.5 h/we training) and 11 matched athletes without back pain (NBP: m/f: n = 4/7; 15.5 ± 1.3 y; 174 ± 7 cm; 67 ± 8 kg; 14.9 ± 9.5 h/we training) were evaluated. Subjects conducted 3 drop jumps onto a force plate (ground reaction force). Bilateral 12-lead SEMG (surface Electromyography) was applied to assess trunk muscle activity. Ground contact time [ms], maximum vertical jump force [N], jump time [ms] and the jump performance index [m/s] were calculated for drop jumps. SEMG amplitudes (RMS: root mean square [%]) for all 12 single muscles were normalized to MIVC (maximum isometric voluntary contraction) and analyzed in 4 time windows (100 ms pre- and 200 ms post-initial ground contact, 100 ms pre- and 200 ms post-landing) as outcome variables. In addition, muscles were grouped and analyzed in ventral and dorsal muscles, as well as straight and transverse trunk muscles. Drop jump ground reaction force variables did not differ between NBP and BP (p > 0.05). Mm obliquus externus and internus abdominis presented higher SEMG amplitudes (1.3–1.9-fold) for BP (p < 0.05). Mm rectus abdominis, erector spinae thoracic/lumbar and latissimus dorsi did not differ (p > 0.05). The muscle group analysis over the whole jumping cycle showed statistically significantly higher SEMG amplitudes for BP in the ventral (p = 0.031) and transverse muscles (p = 0.020) compared to NBP. Higher activity of transverse, but not straight, trunk muscles might indicate a specific compensation strategy to support trunk stability in athletes with back pain during drop jumps. Therefore, exercises favoring the transverse trunk muscles could be recommended for back pain treatment.

Back Pain in Adolescent Athletes: Results of a Biomechanical Screening

The aim was to use a short biomechanical test battery to screen adolescent athletes with and without back pain to reveal relevant and possibly preventable deficits. 1 559 adolescent athletes (m/f 945/614; 13.2±1.6y) were included. Back pain was assessed (1–5: 1=no pain; 5=maximum pain) for dichotomous categorization into back pain (BP: pain>2, n=113), healthy (NBP _All : pain=1, n=1 213) and matched healthy (NBP _matched : pain=1, n=113) athletes. Athletes performed stability, performance (jumps) and trunk strength testing. The center of pressure displacement [mm], jump height [cm], peak force [N], contact time [ms] and peak torque of the trunk [Nm] were analyzed. Analysis showed a statistically significant influence of trunk strength on back pain (BP/NBP _ALL ). Nevertheless, after including co-variables (anthropometrics, gender and training volume), there were no significant variables detectable any longer. ANOVA identified no group differences (BP/NBP _matched ) in the outcome measurement for the biomechanical tests (p>0.05). This short biomechanical screening shows no sufficient differentiation in adolescent athletes for back pain. Therefore, age, training load and gender has greater relevance than strength deficits or postural control. This is challenging for further understanding of the complex conditions in young athletes with back pain.

Incidence of back pain in adolescent athletes: a prospective study

Background

Recently, the incidence rate of back pain (BP) in adolescents has been reported at 21%. However, the development of BP in adolescent athletes is unclear. Hence, the purpose of this study was to examine the incidence of BP in young elite athletes in relation to gender and type of sport practiced.

Methods

Subjective BP was assessed in 321 elite adolescent athletes (m/f 57%/43%; 13.2 ± 1.4 years; 163.4 ± 11.4 cm; 52.6 ± 12.6 kg; 5.0 ± 2.6 training yrs; 7.6 ± 5.3 training h/week). Initially, all athletes were free of pain. The main outcome criterion was the incidence of back pain [%] analyzed in terms of pain development from the first measurement day (M1) to the second measurement day (M2) after 2.0 ± 1.0 year. Participants were classified into athletes who developed back pain (BPD) and athletes who did not develop back pain (nBPD). BP (acute or within the last 7 days) was assessed with a 5-step face scale (face 1–2 = no pain; face 3–5 = pain). BPD included all athletes who reported faces 1 and 2 at M1 and faces 3 to 5 at M2. nBPD were all athletes who reported face 1 or 2 at both M1 and M2. Data was analyzed descriptively. Additionally, a Chi² test was used to analyze gender- and sport-specific differences (p = 0.05).

Results

Thirty-two athletes were categorized as BPD (10%). The gender difference was 5% (m/f: 12%/7%) but did not show statistical significance (p = 0.15). The incidence of BP ranged between 6 and 15% for the different sport categories. Game sports (15%) showed the highest, and explosive strength sports (6%) the lowest incidence. Anthropometrics or training characteristics did not significantly influence BPD (p = 0.14 gender to p = 0.90 sports; r² = 0.0825).

Conclusions

BP incidence was lower in adolescent athletes compared to young non-athletes and even to the general adult population. Consequently, it can be concluded that high-performance sports do not lead to an additional increase in back pain incidence during early adolescence. Nevertheless, back pain prevention programs should be implemented into daily training routines for sport categories identified as showing high incidence rates.

Evaluation of isokinetic trunk muscle strength in adolescents with normal and abnormal postures

OBJECTIVE

The aim of this study was to assess existing differences in the isokinetic trunk muscle strength in males and females aged between 10 and 11 years depending on body posture.

METHODS

The study included 145 children (67 males and 78 females) divided into 2 age groups: 10-year-old males (x¯ = 9.98 ± 2.34 years) and females (x¯ = 9.85 ± 2.94 years) and 11-year-old males (x¯ = 11.14 ± 2.22 years) and females (x¯ = 11.15 ± 2.32 years). Posture in the sagittal plane was assessed by photogrammetry using the moiré projection technique. Based on a classification system, the participants were divided into subgroups of males and females with normal and abnormal postures. Trunk muscle strength was measured using isokinetic dynamometry.

RESULTS

A high prevalence of abnormal posture in children aged between 10 and 11 years was observed, primarily represented by an excessive curvature of the spine in the sagittal plane. The males and females with poor posture recorded lower values in isokinetic trunk muscle strength.

CONCLUSION

The results of the study point to the need for the application of suitable physiotherapy treatment (corrective measures/exercises) to treat musculoskeletal disorders to compensate for the loss of trunk flexor muscle strength in children with improper posture.

Is back pain during childhood or adolescence associated with muscle strength, muscle endurance or aerobic capacity: three systematic literature reviews with one meta-analysis

Background

Back pain is a common condition during childhood and adolescence. The causes of back pain are largely unknown but it seems plausible that some physical factors such as back muscle strength, back muscle endurance and aerobic capacity may play a role in its development, in particular in the early years.

Objectives

The objectives of this review were to investigate in childhood and adolescence 1) if muscular strength in trunk extension is associated with back pain, 2) if muscular endurance in trunk extension is associated with back pain and 3) if aerobic capacity is associated with back pain.

Design

Three systematic critical literature reviews with one meta-analysis.

Methods

Systematic searches were made in June 2014 in PubMed, Embase and SportDiscus including longitudinal, retrospective or cross-sectional studies on back pain for subjects <20 years. Articles were accepted if they were written in French or English. The review process followed the AMSTAR recommendations. The possibility of conducting a meta-analysis was assessed for each research question.

Results

Four articles were included for the first objective, four for the second and three for the last. None of the included articles found an association between back muscle strength in extension and back pain. For the second objective, a protective association between back muscle endurance in extension and back pain was found, later confirmed in a meta-analysis (OR = 0.75, 95 % CI 0.58-0.98). The association between aerobic capacity and back pain is not clear.

Conclusions

High back muscle endurance in extension appears protective of back pain in youngsters, but the roles of high back muscle strength in extension and aerobic capacity are less clear.

The effect of horse simulator riding on visual analogue scale, body composition and trunk strength in the patients with chronic low back pain

BACKGROUND

Chronic low back pain (CLBP) is one of the most common musculoskeletal disorders, and thus effective treatments are required. Recently, real horseback riding has been reported to be beneficial for the patients. However, it has some limitations, such as limited approaches and safety issues.

OBJECTIVE

The purpose of this study was to investigate the effect of horse simulator riding on back pain, body composition and trunk strength in the patients with CLBP.

PARTICIPANTS

Forty-seven men with CLBP (mean age 20.55 ± 1.38 years) were randomly divided into a control group (n = 23) and a horse simulator riding group (n = 24), and visual analogue scale (VAS), body composition and isokinetic trunk strength were measured after 8 weeks for which subjects in a horse simulator riding group had performed the horse simulator exercise (HSE).

RESULTS

Horse simulator exercise significantly reduced pain scores of VAS and enhanced isokinetic torques of trunk at 30 and 90°/s. There were also significantly increased muscle mass and decreased fat mass in horse simulator riding group.

CONCLUSION

It can be inferred that HSE may be helpful in relief of back pain and recovery of back function through developing trunk strength and balancing the ratio of trunk flexor/extensor muscles.

Isokinetic trunk muscle performance in pre-teens and teens with and without back pain

OBJECTIVE

To assess with an isokinetic dynamometer the force and endurance of the spinal flexor and extensor muscles in pre-teens or teens aged 11 to 13 and 14 to 16 years with and without low back pain (LBP).

METHOD

The control group and the LBP group were homogeneous in terms of age, weight, height and Body Mass Index (BMI). Assessment was carried out with the isokinetic dynamometer Cybex Norm®. The spinal flexors and extensors were explored concentrically at speeds of 60°, 90° and 120°/sec. The parameters chosen were: maximal moment of force (MMF), mean power (MP), total work (TW), F/E ratios (between the flexors and the extensors for the aforesaid parameters). In the LBP groups, clinical information (pain, extensibility of the spinal and sub-pelvic muscles, sports practice) and sagittal radiological data were all measured.

RESULTS

While no significant difference in isokinetic performance was found between asymptomatic and LBP children in the 11-to-13-year-old group, the isokinetic performances of the LBP children were influenced positively by BMI value, number of hours of physical activity and radiologic value of the lumbar lordosis. As regards these pre-teens, assessment with an isokinetic dynamometer does not highlight muscle characteristics that might explain LBP occurrence. As regards the 14-to-16-year-old group, muscle strength has been found to be correlated with age. LBP teens were showed to have weaker extensors and stronger flexors than the healthy teens. It is with regard to this age group that assessment with an isokinetic dynamometer clearly yields interesting results. Since we have yet to standardize our evaluation criteria (working speed, number of trials…), it is difficult to compare our results with those reported in the literature.

CONCLUSION

This is a preliminary study involving a relatively low number of patients. That said, given the fact that numerous parameters are connected with the age and height of the subjects, assessment with an isokinetic dynamometer can be constructively carried out from the age of 14. In order to further enhance understanding of this phenomenon, a longitudinal and comparative study of a larger group is needed.

Trunk extensor and flexor strength capacity in healthy young elite athletes aged 11-15 years

Differences in trunk strength capacity because of gender and sports are well documented in adults. In contrast, data concerning young athletes are sparse. The purpose of this study was to assess the maximum trunk strength of adolescent athletes and to investigate differences between genders and age groups. A total of 520 young athletes were recruited. Finally, 377 (n = 233/144 M/F; 13 ± 1 years; 1.62 ± 0.11 m height; 51 ± 12 kg mass; training: 4.5 ± 2.6 years; training sessions/week: 4.3 ± 3.0; various sports) young athletes were included in the final data analysis. Furthermore, 5 age groups were differentiated (age groups: 11, 12, 13, 14, and 15 years; n = 90, 150, 42, 43, and 52, respectively). Maximum strength of trunk flexors (Flex) and extensors (Ext) was assessed in all subjects during isokinetic concentric measurements (60°·s(-1); 5 repetitions; range of motion: 55°). Maximum strength was characterized by absolute peak torque (Flexabs, Extabs; N·m), peak torque normalized to body weight (Flexnorm, Extnorm; N·m·kg(-1) BW), and Flexabs/Extabs ratio (RKquot). Descriptive data analysis (mean ± SD) was completed, followed by analysis of variance (α = 0.05; post hoc test [Tukey-Kramer]). Mean maximum strength for all athletes was 97 ± 34 N·m in Flexabs and 140 ± 50 N·m in Extabs (Flexnorm = 1.9 ± 0.3 N·m·kg(-1) BW, Extnorm = 2.8 ± 0.6 N·m·kg(-1) BW). Males showed statistically significant higher absolute and normalized values compared with females (p < 0.001). Flexabs and Extabs rose with increasing age almost 2-fold for males and females (Flexabs, Extabs: p < 0.001). Flexnorm and Extnorm increased with age for males (p < 0.001), however, not for females (Flexnorm: p = 0.26; Extnorm: p = 0.20). RKquot (mean ± SD: 0.71 ± 0.16) did not reveal any differences regarding age (p = 0.87) or gender (p = 0.43). In adolescent athletes, maximum trunk strength must be discussed in a gender- and age-specific context. The Flexabs/Extabs ratio revealed extensor dominance, which seems to be independent of age and gender. The values assessed may serve as a basis to evaluate and discuss trunk strength in athletes.

The association between isoinertial trunk muscle performance and low back pain in male adolescents

The literature reports inconsistent findings regarding the association between low back pain (LBP) and trunk muscle function, in both adults and children. The strength of the relationship appears to be influenced by how LBP is qualified and the means by which muscle function is measured. The aim of this study was to examine the association between isoinertial trunk muscle performance and consequential (non-trivial) low back pain (LBP) in male adolescents. Healthy male adolescents underwent anthropometric measurements, clinical evaluation, and tests of trunk range of motion (ROM), maximum isometric strength (STRENGTH) and peak movement velocity (VEL), using an isoinertial device. They provided information about their regular sporting activities, history and family history of LBP. Predictors of "relevant/consequential LBP" were examined using multivariable logistic regression. LBP status was reassessed after 2 years and the change from baseline was categorised. At baseline, 33/95 (35%) subjects reported having experienced consequential LBP. BMI, a family history of LBP, and regularly playing sport were each significantly associated with a history of consequential LBP (p < 0.05). 85/95 (89%) boys participated in the follow-up: 51 (60%) reported no LBP at either baseline or follow-up (never LBP); 5 (6%) no LBP at baseline, but LBP at follow-up (new LBP); 19 (22%) LBP at baseline, but none at follow-up; and 10 (12%) LBP at both time-points (recurrent/persistent LBP). The only distinguishing features of group membership in these small groups were: fewer sport-active in the "never LBP" group); worse trunk mobility, in the "persistent LBP" group, lower baseline sagittal ROM in the "never LBP" and "new LBP" (p < 0.05). Regular involvement in sport was a consistent predictor of LBP. Isoinertial trunk performance was not associated with LBP in adolescents.