Schieber Molly N, Hasenkamp Ryan M, Pipinos Iraklis I, Johanning Jason M, Stergiou Nicholas, DeSpiegelaere Holly K, Chien Jung H, Myers Sara A
Department of Biomechanics, University of Nebraska at Omaha, Omaha, Neb.
Department of Surgery, Veterans Affairs Medical Center of Nebraska and Western Iowa, Omaha, Neb; Department of Surgery, University of Nebraska Medical Center, Omaha, Neb.
J Vasc Surg. 2017 Jul;66(1):178-186.e12. doi: 10.1016/j.jvs.2017.01.051.
Peripheral artery disease (PAD), a common manifestation of atherosclerosis, is characterized by lower leg ischemia and myopathy in association with leg dysfunction. Patients with PAD have impaired gait from the first step they take with consistent defects in the movement around the ankle joint, especially in plantar flexion. Our goal was to develop muscle strength profiles to better understand the problems in motor control responsible for the walking impairment in patients with PAD.
Ninety-four claudicating PAD patients performed maximal isometric plantar flexion contractions lasting 10 seconds in two conditions: pain free (patient is well rested and has no claudication symptoms) and pain induced (patient has walked and has claudication symptoms). Sixteen matched healthy controls performed the pain-free condition only. Torque curves were analyzed for dependent variables of muscle strength and motor control. Independent t-tests were used to compare variables between groups, and dependent t-tests determined differences between conditions.
Patients with PAD had significantly reduced peak torque and area under the curve compared with controls. Measures of control differed between PAD conditions only. Load rate and linear region duration were greater in the pain condition. Time to peak torque was shorter in the pain condition.
This study conclusively demonstrates that the plantar flexor muscles of the PAD patient at baseline and without pain are weaker in patients with PAD compared with controls. With the onset of claudication pain, patients with PAD exhibit altered muscle control strategies and further strength deficits are manifest compared to baseline levels. The myopathy of PAD legs appears to have a central role in the functional deterioration of the calf muscles, as it is evident both before and after onset of ischemic pain.
外周动脉疾病（PAD）是动脉粥样硬化的常见表现，其特征为小腿缺血和肌病，并伴有腿部功能障碍。PAD患者从迈出第一步起就存在步态受损的情况，踝关节周围的运动持续存在缺陷，尤其是在跖屈方面。我们的目标是制定肌肉力量概况，以更好地了解导致PAD患者行走障碍的运动控制问题。
94名有间歇性跛行的PAD患者在两种情况下进行了持续10秒的最大等长跖屈收缩：无痛状态（患者充分休息且无间歇性跛行症状）和诱发疼痛状态（患者行走后出现间歇性跛行症状）。16名匹配的健康对照仅进行了无痛状态测试。分析扭矩曲线以获取肌肉力量和运动控制的相关变量。使用独立t检验比较组间变量，使用配对t检验确定不同状态之间的差异。
与对照组相比，PAD患者的峰值扭矩和曲线下面积显著降低。仅在PAD的不同状态下，控制指标有所不同。疼痛状态下的负荷率和线性区域持续时间更大。疼痛状态下达到峰值扭矩的时间更短。
本研究确凿地表明，与对照组相比，PAD患者在基线且无痛状态下的跖屈肌较弱。随着间歇性跛行疼痛的发作，PAD患者表现出肌肉控制策略的改变，与基线水平相比，进一步出现力量不足。PAD腿部的肌病似乎在小腿肌肉功能恶化中起核心作用，因为在缺血性疼痛发作之前和之后都很明显。
