Dysplastic hip anatomy alters muscle moment arm lengths, lines of action, and contributions to joint reaction forces during gait

JOURNAL OF BIOMECHANICS

卷:110

Article

Song, Ke^1,2  Gaffney, Brecca M. M.¹  Shelburne, Kevin B.³  Pascual-Garrido, Cecilia⁴  Clohisy, John C.⁴  Harris, Michael D.^1,2,4 

[1] Washington Univ, Sch Med, Program Phys Therapy, St Louis, MO USA

[2] Washington Univ, Dept Mech Engn & Mat Sci, St Louis, MO 63110 USA

[3] Univ Denver, Dept Mech & Mat Engn, Denver, CO USA

[4] Washington Univ, Sch Med, Dept Orthopaed Surg, St Louis, MO USA

关键词: Developmental dysplasia of the hip;    Muscle moment arm;    Line of action;    Joint reaction force;    Musculoskeletal modeling;   

DOI  :  10.1016/j.jbiomech.2020.109968

来源: Elsevier

【 摘 要 】

Developmental dysplasia of the hip (DDH) is characterized by abnormal bony anatomy, which causes detrimental hip joint loading and leads to secondary osteoarthritis. Hip joint loading depends, in part, on muscle-induced joint reaction forces (JRFs), and therefore, is influenced by hip muscle moment arm lengths (MALs) and lines of action (LoAs). The current study used subject-specific musculoskeletal models and in-vivo motion analysis to quantify the effects of DDH bony anatomy on dynamic muscle MALs, LoAs, and their contributions to JRF peaks during early (similar to 17%) and late-stance (similar to 52%) of gait. Compared to healthy hips (N = 15, 16-39 y/o), the abductor muscles in patients with untreated DDH (N = 15, 16-39 y/o) had smaller abduction MALs (e.g. anterior gluteus medius, 35.3 vs. 41.6 mm in early stance, 45.4 vs. 52.6 mm late stance, p <= 0.01) and more medially-directed LoAs. Abduction-adduction and rotation MALs also differed for major hip flexors such as rectus femoris and iliacus. The altered MALs in DDH corresponded to higher hip abductor forces, medial JRFs (1.26 vs. 0.87 x BW early stance, p = 0.03), and resultant JRFs (5.71 vs. 4.97 x BW late stance, p = 0.05). DDH anatomy not only affected hip muscle force generation in the primary plane of function, but also their out-of-plane mechanics, which collectively elevated JRFs. Overall, hip muscle MALs and their contributions to JRFs were significantly altered by DDH bony anatomy. Therefore, to better understand the mechanisms of joint degeneration and improve the efficacy of treatments for DDH, the dynamic anatomy-force relationships and multi-planar functions of the whole hip musculature must be collectively considered. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

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