Levine Iris C, Minty Lauren E, Laing Andrew C
Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
Clin Anat. 2015 Mar;28(2):253-61. doi: 10.1002/ca.22499. Epub 2014 Dec 26.
Fall-related hip injuries are a concern for the growing population of older adults. Evidence suggests that soft tissue overlying the greater trochanter attenuates the forces transmitted to the proximal femur during an impact, reducing mechanical risk of hip fracture. However, there is limited information about the factors that influence trochanteric soft tissue thickness. The current study used ultrasonography and electromyography to determine whether trochanteric soft tissue thickness could be quantified reproducibly and whether it was influenced by: (1) gender; (2) hip postures associated with potential falling configurations in the sagittal plane (from 30° of extension to 60° of flexion, at 15° intervals), combined adduction-flexion, and combined adduction-extension; and (3) activation levels of the tensor fascia lata (TFL) and gluteus medius (GM) muscles. Our results demonstrated that soft tissue thickness can be measured reliably in nine hip postures and three muscle activation conditions (for all conditions, ICC >0.98). Mean (SD) thickness in quiet stance was 2.52 cm. Thickness was 27.0% lower for males than females during quiet stance. It was 16.4% greater at maximum flexion than quiet standing, 27.2% greater at maximum extension, and 12.5% greater during combined adduction-flexion. However, there was no significant difference between combined adduction-extension and quiet standing. Thickness was not affected by changes in muscle activity. Forces applied to the femoral neck during a lateral fall decrease as trochanteric soft tissue thickness increases; gender and postural configuration at impact could influence the loads applied to the proximal femur (and thus hip fracture risk) during falls on the hip.
与跌倒相关的髋部损伤是日益增多的老年人所面临的一个问题。有证据表明，大转子上方的软组织可在撞击过程中减弱传递至股骨近端的力量，从而降低髋部骨折的机械风险。然而，关于影响转子软组织厚度的因素，目前的信息有限。本研究使用超声和肌电图来确定转子软组织厚度是否能够被可重复地量化，以及它是否受到以下因素影响：（1）性别；（2）矢状面与潜在跌倒姿势相关的髋部姿势（从伸展30°到屈曲60°，间隔15°）、内收 - 屈曲联合以及内收 - 伸展联合；（3）阔筋膜张肌（TFL）和臀中肌（GM）的激活水平。我们的结果表明，在九种髋部姿势和三种肌肉激活条件下，软组织厚度能够被可靠地测量（所有条件下，组内相关系数ICC>0.98）。安静站立时的平均（标准差）厚度为2.52厘米。安静站立时，男性的厚度比女性低27.0%。最大屈曲时比安静站立时厚16.4%，最大伸展时厚27.2%，内收 - 屈曲联合时厚12.5%。然而，内收 - 伸展联合与安静站立之间没有显著差异。厚度不受肌肉活动变化的影响。随着转子软组织厚度增加，侧方跌倒时施加于股骨颈的力量会减小；跌倒时的性别和撞击时的姿势构型可能会影响髋部跌倒过程中施加于股骨近端的负荷（进而影响髋部骨折风险）。
