Hall Michelle, Diamond Laura E, Lenton Gavin K, Pizzolato Claudio, Saxby David J
Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, School of Health Sciences, Melbourne, The University of Melbourne, VIC, Australia.
School of Allied Health Sciences, Griffith University, Gold Coast, QLD, Australia; Gold Coast Orthopaedic Research and Education Alliance (GCORE), Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD, Australia.
Gait Posture. 2019 Feb;68:55-62. doi: 10.1016/j.gaitpost.2018.11.009. Epub 2018 Nov 8.
Background Valgus knee braces have been reported to reduce the external knee adduction moment during walking. However, mechanistic investigations into the effects of valgus bracing on medial compartment contact forces using electromyogram-driven neuromusculoskeletal models are limited. Research question What are the immediate effects of valgus bracing on medial tibiofemoral contact forces and muscular loading of the tibiofemoral joint? Methods Sixteen (9 male) healthy adults (27.7 ± 4.4 years) performed 20 over-ground walking trials at self-selected speed both with and without an Ossür Unloader One® brace. Assessment order (i.e., with or without brace) was randomised and counterbalanced to prevent order effects. While walking, three-dimensional lower-body motion, ground reaction forces, and surface electromyograms from eight lower-limb muscles were acquired. These data were used to calibrate an electromyogram-driven neuromusculoskeletal model of muscle and tibiofemoral contact forces (N), from which muscle and external load contributions (%) to those contact forces were determined. Results Although walking with the brace resulted in no significant changes in peak tibiofemoral contact forces at the group-level, individual responses were variable and non-uniform. At the group-level, wearing the brace resulted in a 2.35% (95% CI 0.46-4.24; p = 0.02) greater relative contribution of muscle to lateral compartment contact loading (54.2 ± 11.1%) compared to not wearing the brace (51.8 ± 12.1%) (p < 0.05). Average relative contributions of muscle and external loads to medial compartment loading were comparable between brace and no brace conditions (p ≥ 0.05). Significance Wearing a valgus knee brace did not immediately reduce peak tibiofemoral contact forces in healthy adults during normal walking. It appears this population may modulate muscle activation patterns to support brace-generated valgus moments, thereby maintaining normal walking knee moments and tibiofemoral contact forces. Future investigations are warranted to better understand effects of valgus knee brace in people with medial knee osteoarthritis using an electromyogram-driven neuromusculoskeletal model.
据报道，外翻膝支具可减少行走过程中外侧膝关节内收力矩。然而，使用肌电图驱动的神经肌肉骨骼模型对外翻支具对内侧间室接触力影响的机制研究有限。
外翻支具对胫股内侧接触力和胫股关节肌肉负荷的即时影响是什么？
16名（9名男性）健康成年人（27.7±4.4岁）以自选速度进行了20次地面行走试验，试验时分别佩戴和不佩戴奥索（Ossür）Unloader One®支具。评估顺序（即佩戴或不佩戴支具）是随机的且相互平衡，以防止顺序效应。行走过程中，采集了三维下半身运动、地面反作用力以及来自8条下肢肌肉的表面肌电图。这些数据用于校准一个肌电图驱动的肌肉和胫股接触力神经肌肉骨骼模型（N），由此确定肌肉和外部负荷对这些接触力的贡献百分比（%）。
虽然佩戴支具行走在组水平上胫股接触力峰值无显著变化，但个体反应是可变且不均匀的。在组水平上，与不佩戴支具（51.8±12.1%）相比，佩戴支具导致肌肉对外侧间室接触负荷的相对贡献增加2.35%（95%CI 0.46 - 4.24；p = 0.02）（54.2±11.1%）（p < 0.05）。支具和不佩戴支具条件下，肌肉和外部负荷对内侧间室负荷的平均相对贡献相当（p≥0.05）。
在健康成年人正常行走过程中，佩戴外翻膝支具并不能立即降低胫股接触力峰值。看来该人群可能会调节肌肉激活模式以支持支具产生的外翻力矩，从而维持正常行走时的膝关节力矩和胫股接触力。未来有必要进行进一步研究，以使用肌电图驱动的神经肌肉骨骼模型更好地了解外翻膝支具对膝内侧骨关节炎患者的影响。
