title: Lumbar posture and trunk muscle activation during a typing task when sitting on a novel dynamic ergonomic chair.
abstract: Low back pain (LBP) is a common musculoskeletal disorder and prolonged sitting often aggravates LBP. A novel dynamic ergonomic chair ('Back App'), which facilitates less hip flexion while sitting on an unstable base has been developed. This study compared lumbar posture and trunk muscle activation on this novel chair with a standard backless office chair. Twelve painfree participants completed a typing task on both chairs. Lumbar posture and trunk muscle activation were collected simultaneously and were analysed using paired t-tests. Sitting on the novel dynamic chair significantly (p < 0.05) reduced both lumbar flexion and the activation of one back muscle (Iliocostalis Lumborum pars Thoracis). The discomfort experienced was mild and was similar (p > 0.05) between chairs. Maintaining lordosis with less muscle activation during prolonged sitting could reduce the fatigue associated with upright sitting postures. Studies with longer sitting durations, and in people with LBP, are required.
  Sitting on a novel dynamic chair resulted in less lumbar flexion and less back muscle activation than sitting on a standard backless office chair during a typing task among pain-free participants. Facilitating lordotic sitting with less muscle activation may reduce the fatigue and discomfort often associated with lordotic sitting postures.
authors.affiliation: Department of Clinical Therapies, University of Limerick Limerick, Ireland. kieran.osullivan@ul.ie
authors.forename: Kieran
authors.initials: K
authors.lastname: O'Sullivan
authors.forename: Raymond
authors.initials: R
authors.lastname: McCarthy
authors.forename: Alison
authors.initials: A
authors.lastname: White
authors.forename: Leonard
authors.initials: L
authors.lastname: O'Sullivan
authors.forename: Wim
authors.initials: W
authors.lastname: Dankaerts
mesh_terms: D000328:Adult; D006804:Ergonomics; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000517:prevention & control*; D008161:Lumbosacral Region; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D013131:Spine / Q000502:physiology*; D060726:Torso; D055815:Young Adult