Lumbar spine repositioning sense in adolescents with and without non-specific chronic low back pain--an analysis based on sub-classification and spinal regions.

OBJECTIVE: To identify differences in repositioning error in adolescents with and without non-specific chronic low back pain (NSCLBP), sub-groups of NSCLBP and in different spinal regions. METHODS: Spinal repositioning error was measured during a seated task. Variables were constant error (CE), absolute error (AE) and variable error (VE) for lower lumbar, upper lumbar and lumbar angles. 28 subjects with NSCLBP were sub-classified using O'Sullivans system and compared to 28 healthy controls. RESULTS: Significant differences were noted for AE between adolescents with and without NSCLBP, but no differences were found for CE or VE. When sub-grouped there was a pattern for lower AE and higher VE in the flexion sub-group. This group also displayed a tendency to undershoot the criterion position in the lower lumbar spine. Greater VE was noted in the extension sub-group and those with no NSCLBP in the upper lumbar compared to the lower lumbar spine. CONCLUSIONS: Differences in spinal repositioning errors were noted between adolescents with and without NSCLBP and sub-groups of NSCLBP. Those with flexion-pattern NSCLBP had the lowest levels of spinal repositioning ability. Individuals with no-LBP (low-back pain) or extension-pattern NSCLBP displayed greater variability in the upper lumbar spine.

Sitting postures and trunk muscle activity in adolescents with and without nonspecific chronic low back pain: an analysis based on subclassification.

STUDY DESIGN: A preliminary cross-sectional comparative study of adolescents with nonspecific chronic low back pain (NSCLBP) and healthy controls. OBJECTIVE: To investigate whether differences in spinal kinematic and trunk muscle activity exist in both usual and slump sitting in adolescents with NSCLBP. SUMMARY OF BACKGROUND: Evidence suggests that low back pain commonly develops in adolescence and increases the risk for low back pain in adulthood. Sitting is an important consideration in adolescents with NSCLBP: currently there are no reports investigating their motor control strategies in sitting. METHODS: Twenty-eight adolescents (14 female) with NSCLBP and 28 matched pain-free controls were recruited from a large cohort study. Pain subjects were subclassified based on O'Sullivan's classification system. Three-dimensional lumbo-pelvic kinematic data and the activation of 3 back and 2 abdominal muscles were recorded during usual and slump sitting. The flexion-relaxation phenomenon in sitting was also investigated. RESULTS: Spinal posture in usual and slump sitting were similar for adolescents with and without NSCLBP. However, differences were identified in both sitting conditions when those with NSCLPB were subclassified and compared with controls. Muscle activation differences were not consistently identified, with only lower levels of internal oblique activation in usual sitting in NSCLBP compared with pain-free controls showing significance. Flexion relaxation was observed in both iliocostalis and thoracic erector spinae in the NSCLBP group but not controls. CONCLUSION: This study provides preliminary results. Differences with sitting posture are only seen when adolescents with NSCLBP are classified. Trunk muscle activation is not a sensitive marker for discriminating subgroups of NSCLBP during adolescence.

A detailed characterisation of pain, disability, physical and psychological features of a small group of adolescents with non-specific chronic low back pain.

The objective of the study was to provide a detailed biopsychosocial evaluation of adolescent NSCLBP compared to those without LBP. NSCLBP was described by pain level, duration, levels of disability and kinesiophobia, aggravating factors and functional movements. Each pain subject was sub-classified using the O'Sullivan system. Groups were compared on physical activity levels, sitting posture, trunk extensor and thigh muscle endurance, psychosocial behaviour, depression, family functioning and exposure to stressful life events. Adolescents with NSCLBP reported moderate levels of pain (4.4/10 +/- 1.9), disability (17.9 +/- 10.1%) and fear avoidance beliefs (36.1/68 +/- 7.1). Differences between control and pain groups were only found for back muscle (p = 0.033) and squat endurance times (p = 0.032) and stressful life events (p = 0.030). Differences in sitting posture between pain and no pain groups were only found when pain subjects were sub-classified (lumbar angle p = 0.001). In conclusion, adolescents with NSCLBP reported moderate pain and disability with deficits in trunk and squat endurance. That they remained physically active is at odds with the activity avoidance and subsequent deconditioning model proposed for adults with NSCLBP. Differences between control and pain groups on history of stressful life events suggest this may contribute to adolescent NSCLBP. Differences with sitting posture are only seen when patients were sub-classified.