title: Lumbar contribution to the trunk forward bending and backward return; age-related differences.
abstract: Age-related differences in lumbar contribution to the trunk motion in the sagittal plane were investigated. Sixty individuals between 20-70 years old in five gender-balanced age groups performed forward bending and backward return with slow and fast paces. Individuals older than 50 years old, irrespective of the gender or pace, had smaller lumbar contribution than those younger than this age. The lumbar contribution to trunk motion was also smaller in female participants than male participants, and under fast pace than under the slow pace. Age-related differences in lumbar contributions suggest the synergy between the active and passive lower back tissues is different between those above and under 50 years old, differences that are likely to affect the lower back mechanics. Therefore, detailed modelling should be conducted in future to find the age-related differences in the lower back mechanics for tasks involving large trunk motion. Practitioner Summary: Lumbar contribution to the sagittal trunk motion was observed to be smaller in individuals above 50 years old than those below this age. This could be an indication of a likely change in the synergy between the active and passive lower back tissues, which may disturb the lower back mechanics.
authors.affiliation: a Department of Biomedical Engineering , University of Kentucky , Lexington , KY , USA.
authors.forename: Milad
authors.identifier: http://orcid.org/0000-0001-6771-5148
authors.initials: M
authors.lastname: Vazirian
authors.affiliation: a Department of Biomedical Engineering , University of Kentucky , Lexington , KY , USA.
authors.forename: Iman
authors.initials: I
authors.lastname: Shojaei
authors.affiliation: a Department of Biomedical Engineering , University of Kentucky , Lexington , KY , USA.|b Signal Solutions LLC , Lexington , KY , USA.
authors.forename: Anuj
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: a Department of Biomedical Engineering , University of Kentucky , Lexington , KY , USA.
authors.forename: Babak
authors.initials: B
authors.lastname: Bazrgari
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D060726:Torso / Q000502:physiology*; D055815:Young Adult
keywords: Lumbopelvic coordination; ageing; low back pain; range of motion; spinal loading