Head posture influences low back muscle endurance tests in 11-year-old children.

Poor low back muscle endurance has been shown to be a predictor of chronic low back pain. While posture is a modulator of low back muscle endurance, it is unclear whether the phenomenon is neural or mechanical. This study examined low back muscle endurance with changing head and neck posture in a sample of 117 children using the Biering-Sørensen test. Each subject performed the test in a neutral posture followed by randomly selected flexed and extended head and neck positions. Head posture was found to significantly influence low back muscle endurance within subjects (p < .001), with extension yielding the highest endurance scores (boys = 186.6 ± 66.2 s; girls = 192.1 ± 59 s), followed by a neutral posture (boys = 171.3 ± 56.5 s; girls = 181.7 ± 57.3 s), and flexion (boys = 146.2 ± 63.8 s; girls = 159.8 ± 49.3 s). Given the minimal influence of changing moment from head and neck posture, it appears other mechanisms influence endurance score.

Isometric torso muscle endurance profiles in adolescents aged 15-18: normative values for age and gender differences.

OBJECTIVE: The aim of this study was to establish normative values for torso muscle endurance in adolescents aged 15-18 years. It was hypothesized that torso endurance profiles of adolescents differs between males and females and between adolescents and adults. BACKGROUND: Decreased torso muscle endurance has been identified as a potential personal risk factor for low back pain development in both adolescents and later years together with being detrimental for athletic performance. DESIGN: Measurement of torso muscle endurance, established through four tests performed in random order in a healthy adolescent population. SETTING: High school in Novi Sad, Province of Vojvodina, Republic of Serbia. METHODS: Two hundred and ninety-four adolescents from one high school (178 males and 116 females) were grouped into four age strata. Selected isometric torso muscle endurance tests were: Biering-Sørensen test for extensor endurance; Flexor endurance test; right and left Side Bridge tests. The mean, ratio, standard deviation and 25th, 50th and 75th percentile scores were determined for each gender/age strata. RESULTS AND CONCLUSION: Males had higher lateral torso endurance than females. Adolescents in general demonstrate their peak lifetime endurance as they appear more endurable than children and comparable adult groups. These data of endurance times, their ratios and percentiles in healthy normal subjects form a database bridging existing data for children and adults that may be useful for guiding training and rehabilitation.

Changes in torso muscle endurance profiles in children aged 7 to 14 years: reference values.

OBJECTIVE: To establish torso muscle endurance values in children aged 7 to 14 years, as well as ratios between torso extensors, flexors, and lateral torso flexors, with applications in clinical assessment, rehabilitation, physical education targets, and athletic training program designs. It was hypothesized that boys and girls mature differently in terms of torso muscle endurance. DESIGN: Measurements of torso muscle endurance were performed by using 4 tests in healthy children. SETTING: Elementary school in Novi Sad, Province of Vojvodina, Republic of Serbia. PARTICIPANTS: Children from 1 elementary school (N=753, n=394 boys and n=359 girls) were grouped into 8 age strata. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Four tests established isometric physical endurance: Biering-Sørensen test for extensor endurance, flexor endurance test, and right- and left-side bridge tests. The mean, ratio, standard deviation, and 25th, 50th, and 75th percentile scores were determined for each sex/age stratum. RESULTS: A 2-way analysis of variance indicated that girls had higher mean endurance times for torso extension and torso flexion than did boys. For example, times measured by using Biering-Sørensen and right-side bridge tests were significantly greater for girls than for boys across all age groups (P<.023). Boys can sustain the side torso test longer than can girls. Furthermore, 3-dimensional torso muscle endurance is under significant impact of age. Tukey Honestly Significant Difference post hoc tests confirmed that within and between sex exist significant differences in mean endurance times in all age strata at the significance level P=.05. CONCLUSION: Both age and sex influence differences in torso endurance in children aged 7 to 14 years. These data of endurance times, their ratios, and percentiles in healthy subjects form a database that may be useful for providing training and rehabilitation targets.