Trunk-pelvic coordination during unstable sitting with varying task demand: A methodological study

JOURNAL OF BIOMECHANICS

卷:118

Article

Acasio, Julian C.^1,2  Nussbaum, Maury A.³  Hendershot, Brad D.^1,4,5 

[1] Walter Reed Natl Mil Med Ctr, Dept Rehabil, Res & Dev Sect, Bethesda, MD USA

[2] Henry M Jackson Fdn Adv Mil Med Inc, Bethesda, MD USA

[3] Virginia Tech, Dept Ind & Syst Engn, Blacksburg, VA USA

[4] DoD VA Extrem Trauma & Amputat Ctr Excellence USA, Res & Surveillance Div, Ft Sam Houston, TX USA

[5] Uniformed Serv Univ Hlth Sci, Dept Rehabil Med, Bethesda, MD 20814 USA

关键词: Postural control;    Low back pain;    Vector coding;    Inter-segmental coordination;    Biomechanics;   

DOI  :  10.1016/j.jbiomech.2021.110299

来源: Elsevier

【 摘 要 】

Unstable sitting is used commonly to evaluate trunk postural control (TPC), typically via measures based on center-of-pressure (CoP) time series. However, these measures do not directly reflect underlying control/movement strategies. We quantified trunk-pelvis coordination during unstable sitting using vector coding (VC) and correlated such coordination with CoP-based outcomes across varying task demands. Thirteen uninjured individuals (11 male/2 female) sat on an unstable chair at four instability levels, in a random order, defined relative to the individual gravitational gradient (del G): 100, 75, 60, and 45%del G. VC assessed trunk-pelvic coordination, and coupling angles classified movements as: 1) anti-phase, 2) in-phase, 3) trunk-phase, or 4) pelvic-phase. With decreasing %del G (i.e., increasing instability), we found: increased anti-phase movement in the sagittal and frontal planes; decreased in-phase movement in the sagittal and frontal planes; and increased in-phase and pelvic-phase movement in the transverse plane. In the sagittal and frontal planes, we observed significant weak-to-moderate correlations between anti-phase and in-phase movements (0.288 < vertical bar rho vertical bar < 0.549). Correlations between CoP-based measures and pelvic-phase and trunk-phase movements were typically weak and/or non-significant (vertical bar rho vertical bar < 0.318). VC techniques discriminated between levels of instability during unstable sitting, identifying in-phase coordination (stiffening strategy) at lower instability levels and anti-phase coordination at higher instability levels. Compared to CoP-based measures, trunk coordination outcomes during unstable sitting provide measures of TPC that more directly quantify underlying movement strategies. These results can also serve as a baseline for future work investigating populations with impaired TPC (e.g., individuals with low back pain or limb loss). Published by Elsevier Ltd.

【 授权许可】

Free