Brandon Scott C E, Brown Marcus J, Clouthier Allison L, Campbell Aaron, Richards Jim D, Deluzio Kevin J
Department of Mechanical and Materials Engineering, Queen's University, McLaughlin Hall, Kingston, Ontario K7L 3N6, Canada; Human Mobility Research Centre, Kingston General Hospital, Angada 2, Kingston, Ontario K7L 2V7, Canada; School of Engineering, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Department of Mechanical and Materials Engineering, Queen's University, McLaughlin Hall, Kingston, Ontario K7L 3N6, Canada; Human Mobility Research Centre, Kingston General Hospital, Angada 2, Kingston, Ontario K7L 2V7, Canada.
Knee. 2019 Jun;26(3):564-577. doi: 10.1016/j.knee.2019.04.006. Epub 2019 May 14.
Braces for medial knee osteoarthritis can reduce medial joint loads through a combination of three mechanisms: application of an external brace abduction moment, alteration of gait dynamics, and reduced activation of antagonistic muscles. Although the effect of knee bracing has been reported independently for each of these parameters, no previous study has quantified their relative contributions to reducing medial knee loads.
In this study, we used a detailed musculoskeletal model to investigate immediate changes in medial and lateral loads caused by two different knee braces: OA Assist and OA Adjuster 3 (DJO Global). Seventeen osteoarthritis subjects and eighteen healthy controls performed overground gait trials in unbraced and braced conditions.
Across all subjects, bracing reduced medial loads by 0.1 to 0.3 times bodyweight (BW), or roughly 10%, and increased lateral loads by 0.03 to 0.2 BW. Changes in gait kinematics due to bracing were subtle, and had little effect on medial and lateral joint loads. The knee adduction moment was unaltered unless the brace moment was included in its computation. Only one muscle, biceps femoris, showed a significant change in EMG with bracing, but this did not contribute to altered peak medial contact loads.
Knee braces reduced medial tibiofemoral loads primarily by applying a direct, and substantial, abduction moment to each subject's knee. To further enhance brace effectiveness, future brace designs should seek to enhance the magnitude of this unloader moment, and possibly exploit additional kinematic or neuromuscular gait modifications.
用于内侧膝关节骨关节炎的支具可通过三种机制的组合来减轻内侧关节负荷：施加外部支具外展力矩、改变步态动力学以及减少拮抗肌的激活。尽管已经分别报道了膝关节支具对这些参数中每一个的影响，但以前没有研究量化过它们对减轻内侧膝关节负荷的相对贡献。
在本研究中，我们使用详细的肌肉骨骼模型来研究两种不同的膝关节支具（OA Assist和OA Adjuster 3，DJO Global）引起的内侧和外侧负荷的即时变化。17名骨关节炎受试者和18名健康对照在不佩戴支具和佩戴支具的情况下进行了地面步态试验。
在所有受试者中，佩戴支具使内侧负荷降低了0.1至0.3倍体重（BW），即大约10%，并使外侧负荷增加了0.03至0.2 BW。佩戴支具引起的步态运动学变化很细微，对内侧和外侧关节负荷影响很小。除非在计算中包括支具力矩，否则膝关节内收力矩不会改变。只有一块肌肉，即股二头肌，在佩戴支具时肌电图显示出显著变化，但这对内侧峰值接触负荷的改变没有贡献。
膝关节支具主要通过对每个受试者的膝关节施加直接且显著的外展力矩来降低胫股内侧负荷。为了进一步提高支具的有效性，未来的支具设计应寻求增强这种卸载力矩的大小，并可能利用额外的运动学或神经肌肉步态改变。
