Lumbopelvic muscle activation patterns in three stances under graded loading conditions: Proposing a tensegrity model for load transfer through the sacroiliac joints.
Summary Purpose According to the conventional arch model of the pelvis, stability of the sacroiliac joints may require a predominance of form and force closure mechanisms: the greater the vertical shear force at the sacroiliac joints, the greater the reliance on self-bracing by horizontally or obliq...
| Published in: | Journal of Bodywork & Movement Therapies Vol. 18; no. 4; pp. 633 - 643 |
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| Main Authors: | , , , , |
| Format: | research Journal Article |
| Published: |
Churchill Livingstone, Inc.
Oct2014
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| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=103908565&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 103908565 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 13608592 8II jtl: Journal of Bodywork & Movement Therapies issn: 13608592 maglogo: N pubinfo: dt: Oct2014 vid: 18 iid: 4 pid: 1242 pub: Churchill Livingstone, Inc. artinfo: ui: 103908565 99064656 10.1016/j.jbmt.2014.05.005 NLM25440220 103908565 ppf: 633 ppct: 10 formats: tig: atl: Lumbopelvic muscle activation patterns in three stances under graded loading conditions: Proposing a tensegrity model for load transfer through the sacroiliac joints. aug: au: Pardehshenas, Hamed Maroufi, Nader Sanjari, Mohammad Ali Parnianpour, Mohamad Levin, Stephen M. affil: Department of Physiotherapy, Faculty of Rehabilitation, P.O. Box15875-4391, Iran University of Medical Sciences, Tehran, Iran sug: subj: Pelvis Physiology Sacroiliac Joint Physiology Muscle Contraction Lumbar Vertebrae Physiology One Leg Stand Standing Torso Physiology Weight-Bearing Human Comparative Studies Male Dominance, Cerebral Electromyography Analysis of Variance Repeated Measures Latissimus Dorsi Muscles Physiology Erector Spinae Muscles Physiology Models, Theoretical Manual Therapy Biomechanics Descriptive Statistics Alternative Therapies Male ab: Summary Purpose According to the conventional arch model of the pelvis, stability of the sacroiliac joints may require a predominance of form and force closure mechanisms: the greater the vertical shear force at the sacroiliac joints, the greater the reliance on self-bracing by horizontally or obliquely oriented muscles (such as the internal oblique). But what happens to the arch model when a person stands on one leg? In such cases, the pelvis no longer has imposts, leaving both the arch, and the arch model theory, without support. Do lumbopelvic muscle activation patterns in one-legged stances under load suggest compatibility with a different model? This study compares lumbopelvic muscle activation patterns in two-legged and one-legged stances in response to four levels of graded trunk loading in order to further our understanding the stabilization of the sacroiliac joints. Methods Thirty male subjects experienced four levels of trunk loading (0%, 5%, 10% and 15% of body weight) by holding a bucket at one side, at three conditions: 1) two-legged standing with the bucket in the dominant hand, 2) ipsilateral loading: one-legged standing with the bucket in the dominant hand while using the same-side leg, and 3) contralateral loading: one-legged standing using the same leg used in condition 2, but with the bucket in the non-dominant hand. During these tasks, EMG signals from eight lumbopelvic muscles were collected. ANOVA with repeated design was performed on normalized EMG's to test the main effect of load and condition, and interaction effects of load by condition. Results Latissimus dorsi and erector spinae muscles showed an antagonistic pattern of activity toward the direction of load which may suggest these muscles as lateral trunk stabilizers. Internal oblique muscles showed a co-activation pattern with increasing task demand, which may function to increase lumbopelvic stability ( P < 0.05). No unilateral pattern of the internal obliques was observed during all trials. Conclusions Our results suggest that the lumbopelvic region uses a similar strategy for load transfer in both double and single leg support positions which is not compatible with the arch analogy. Our findings are more consistent with a suspensory system (wire-spoke wheel model). If our proposed model holds true, the pelvic ring can only be integrated by adjusting tension in the spokes and by preserving rim integrity or continuity. Thus, we propose that in order to restore tension integrity throughout the pelvic ring, efforts to unlock restrictions, muscular correction of positional faults and lumbopelvic or even respiratory exercises following sacroiliac joint dysfunctions must be taken into consideration. Our hypothetical model may initiate thinking and act as a guide to future work based on a biomechanical approach to the problem of sacroiliac joint dysfunction. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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