Bond University, Gold Coast, Australia.
Am J Sports Med. 2010 Dec;38(12):2522-7. doi: 10.1177/0363546510377405. Epub 2010 Oct 8.
The enthesis of the plantar fascia is thought to play an important role in stress dissipation. However, the potential link between entheseal thickening characteristic of enthesopathy and the stress-dissipating properties of the intervening plantar fat pad have not been investigated.
This study was conducted to identify whether plantar fat pad mechanics explain variance in the thickness of the fascial enthesis in individuals with and without plantar enthesopathy.
Case-control study; Level of evidence, 3.
The study population consisted of 9 patients with unilateral plantar enthesopathy and 9 asymptomatic, individually matched controls. The thickness of the enthesis of the symptomatic, asymptomatic, and a matched control limb was acquired using high-resolution ultrasound. The compressive strain of the plantar fat pad during walking was estimated from dynamic lateral radiographs acquired with a multifunction fluoroscopy unit. Peak compressive stress was simultaneously acquired via a pressure platform. Principal viscoelastic parameters were estimated from subsequent stress-strain curves.
The symptomatic fascial enthesis (6.7 ± 2.0 mm) was significantly thicker than the asymptomatic enthesis (4.2 ± 0.4 mm), which in turn was thicker than the enthesis (3.3 ± 0.4 mm) of control limbs (P < .05). There was no significant difference in the mean thickness, peak stress, peak strain, or secant modulus of the plantar fat pad between limbs. However, the energy dissipated by the fat pad during loading and unloading was significantly lower in the symptomatic limb (0.55 ± 0.17) when compared with asymptomatic (0.69 ± 0.13) and control (0.70 ± 0.09) limbs (P < .05). The sonographic thickness of the enthesis was correlated with the energy dissipation ratio of the plantar fat pad (r = .72, P < .05), but only in the symptomatic limb.
The energy-dissipating properties of the plantar fat pad are associated with the sonograpic appearance of the enthesis in symptomatic limbs, providing a previously unidentified link between the mechanical behavior of the plantar fat pad and enthesopathy.
足底筋膜的附着点被认为在应力消散中起着重要作用。然而，附着病特征性的附着点增厚与介入的足底脂肪垫的应力消散特性之间的潜在联系尚未被研究。
本研究旨在确定足底脂肪垫力学是否可以解释有和无足底附着病个体的筋膜附着点厚度的差异。
病例对照研究；证据水平，3 级。
研究人群包括 9 例单侧足底附着病患者和 9 例无症状、个体匹配的对照者。使用高分辨率超声获取症状侧、无症状侧和匹配对照侧附着点的厚度。在多功能透视单元上获取动态侧位 X 线片来估计行走过程中足底脂肪垫的压缩应变。同时通过压力平台获取峰值压缩应力。从随后的应力-应变曲线中估计主要粘弹性参数。
症状性筋膜附着点（6.7 ± 2.0 mm）明显厚于无症状附着点（4.2 ± 0.4 mm），而后者又明显厚于对照侧附着点（3.3 ± 0.4 mm）（P <.05）。肢体之间的足底脂肪垫的平均厚度、峰值应力、峰值应变和割线模量均无显著差异。然而，与无症状（0.69 ± 0.13）和对照（0.70 ± 0.09）肢体相比，症状性肢体（0.55 ± 0.17）在加载和卸载过程中脂肪垫消散的能量明显较低（P <.05）。症状性附着点的超声厚度与足底脂肪垫的能量消散比相关（r =.72，P <.05），但仅在症状性肢体中。
足底脂肪垫的耗散特性与症状性肢体附着点的超声表现相关，为足底脂肪垫的机械行为与附着病之间提供了一个以前未被识别的联系。
