Beyond the mechanical lens: Systemic inflammatory responses to repetitive lifting under varying loads and frequencies. (November 2020)

• Record Type: Journal Article
• Authors: Beharriell, Tianna H.; Mavor, Matthew P.; Ramos, Wantuir; Mauger, Jean-François; Imbeault, Pascal; Graham, Ryan B.
• Is Part Of: Applied ergonomics. Volume 89(2020)
• Publication Date: 2020-11
• Subjects: Spine -- Lifting -- Inflammation -- Cumulative/Peak Spinal Moments -- Cytokines; LBD (Low Back Disorder) -- HFLR (High-force, low-repetition) -- LFHR (Low-force, high-repetition) -- IL-6 (Interleukin-6) -- IL-8 (Interleukin-8) -- M1 (primary immune macrophages) -- M2 (secondary immune macrophages) -- IL-10 (Interleukin-10) -- IL-1β (Interleukin one-beta) -- TNF-α (tumour necrosis factor alpha) -- CK (creatine kinase) -- IPAQ (International Physical Activity Questionnaire) -- ROM (range of motion) -- DEXA (dual X-ray absorptiometry) -- ROI (region of interest); Human engineering -- Periodicals; 620.82
• DOI: 10.1016/j.apergo.2020.103199
• Languages: English
• ISSNs: 0003-6870

Abstract

Abstract: Objective: Currently, low back disorder (LBD) research focuses primarily on mechanical variables to assess whether task demands exceed tissue capacity; however, it is important to assess how other nonmechanical variables affect tissue capacity in a time-dependent manner. The current investigation sought to explore physiological responses to an acute lifting task, as lifting has been implicated as a risk factor in the development of LBDs. Methods: Twelve participants completed two sessions of 2 h of repetitive symmetrical lifting from floor to knuckle height under two conditions, matched for total external work (Low Force High Repetition (LFHR) and High Force Low Repetition (HFLR)). Full-body kinematics and ground reaction forces were measured throughout. Interleukin 6 (IL-6) and interleukin 8 (IL-8), markers of systemic inflammation, were assessed from blood sampling at Baseline, 0, 4 and 24 h post-lifting on both days. Dual x-ray absorptiometry (DEXA) scans were also performed on participants to quantify body composition. Results: Significant load (HFLR and LFHR) * time (Baseline, 0, 4, 24 h) interaction effects were found for both IL-6 and IL-8, where the LFHR condition resulted in greater responses at 0 and 4 h post-lifting. Conclusions: This was the first study of its kind to concurrently measure peak and cumulative spinal moments and their relationship to systemic inflammation in both sexes, while strictly controlling for confounding variables (e.g. physical activity, caloric intake, body composition, etc.). Greater levels of IL-6 and IL-8 were seen in the LFHR condition, likely due to the greater cumulative spinal moments in this condition. Highlights: Low force, highly repetitive lifting (LFHR) induced higher cumulative moments. LFHR lifting induced larger increases in interleukins six (IL-6), and eight (IL-8). Higher force, less repetitive lifting (HFLR) induced higher peak moments.