Novel Exercise Interventions to Improve Trunk Muscle Function: A Pilot Study

描述(申请人提供)：腰痛(LBP)在医疗费用和残疾方面对社会产生了惊人的负面影响。急性LBP会导致多裂肌迅速萎缩，复发的LBP会导致躯干伸肌形态和功能发生更大的不适应变化(即大小、力量和耐力下降)。LBP的康复策略通常包括阻力训练，以解决躯干伸肌的这些变化；然而，这些锻炼方案在促进躯干伸肌适应方面只有一定的效果，因为它们通常是在低负荷(例如，25%最大力量)下进行的，远远低于推荐的肌肉适应(&gt；70%最大力量)。高负荷躯干运动的使用通常是禁忌的，因为担心高脊柱压缩负荷会对脊柱造成进一步的损伤。因此，开发利用低机械负荷的治疗方法是至关重要的，该方法仍然可以向躯干伸肌提供足够的刺激，并逆转通常在LBP患者中观察到的躯干伸肌功能的变化。低负荷阻力运动加血流限制(BFR)正是为了达到这一目的的一种创新方法。这种模式包括在低负荷的情况下进行运动，同时流向工作肌肉的血液被压力袖带部分阻断。我们之前已经证明，单次BFR运动可以增加循环中的内分泌生长因子，我们最近完成了对慢性BFR运动训练的初步研究，并观察到这种方式增强了肌肉功能，而不会对动脉僵硬、神经传导、炎症和凝血等指标产生负面影响。虽然这种锻炼方式不能直接应用于躯干(限制胸部血流是不可行的)，但我们的试点数据表明，在使用附件肌进行BFR锻炼后进行低负荷躯干伸展肌锻炼时，对竖脊肌具有独特的交叉转移效应。因此，在低负荷运动之前，在BFR下进行附件肌运动，可以在没有高脊柱压缩负荷的情况下增加肌肉的大小和功能。在这项应用中，我们建议进行一项探索性试验，以确定BFR锻炼对复发性LBP患者勃起棘肌形态和功能的影响。我们的中心假设是，在低负荷躯干伸肌锻炼之前进行的附件肌BFR锻炼将产生全身性效应，比仅进行低负荷躯干伸肌锻炼更能增加躯干伸肌的大小、力量和耐力。这项工作的潜在影响是显而易见的：如果有效，这种新的锻炼方式将提供 为具有成本效益和易于实施的康复策略奠定基础，该策略在诱导肌肉适应能力方面优于现有的范例，而不需要对脊柱施加高机械和压缩负荷。

DESCRIPTION (provided by applicant): Low back pain (LBP) has a staggeringly negative impact on society in terms of medical expenses and disability. Acute occurrence of LBP results in rapid onset of atrophy of the multifidus muscle, and recurrent LBP is associated with even greater maladaptive changes in trunk extensor muscle morphology and function (i.e., decreased size, strength, and endurance). Rehabilitation strategies for LBP often include resistance training to address these changes in the trunk extensor muscles; however, these exercise protocols are only modestly effective in promoting trunk extensor muscle adaptation as they are generally performed at low-loads (e.g., 25% max strength) that are well below those recommended for muscle adaption (>70% max strength). The use of higher-load trunk exercise is commonly contraindicated because of concern that high spinal compressive loads can cause further injury to the spine. Thus, it is critical to develop therapeutic approaches utilizing low mechanical loads that can still deliver sufficient stimuli to the trunk extensor muscles and reverse the changes in trunk extensor muscle function commonly observed in patients with LBP. Low-load resistance exercise with blood flow restriction (BFR) is an innovative approach for exactly this purpose. This paradigm involves performing exercise with low loads while blood flow to the working muscles is partially occluded by a pressure cuff. We have previously shown that a single bout of BFR exercise increases circulating endocrine growth factors, and we recently completed preliminary studies on chronic BFR exercise training and observed that this modality enhances muscle function without negatively impacting indices of arterial stiffness, nerve conduction, inflammation, and blood coagulation. While this exercise modality cannot be applied directly to the trunk (unfeasible to restrict thorax blood flow), our pilot data indicate a unique cross-transfer effect to the erector spinae muscles when low-load trunk extensor exercise is performed after BFR exercise with the appendicular muscles. Thus performing exercise with the appendicular muscles under BFR prior to low-load exercise with the trunk muscles could enhance muscle size and function without high spinal compressive loads. In this application we propose to conduct an exploratory trial as it relates to determining the effects BFR exercise on erector spinae muscle morphometry and function in patients with recurrent LBP. Our central hypothesis is that BFR exercise with the appendicular muscles performed prior to low-load trunk extensor exercise will produce systemic effects that enhance increases in trunk extensor size, strength, and endurance beyond those seen with only low-load trunk extensor exercise. The potential impact of this work is clear: If effective, this novel exercise modality will provide the foundation for a cost-effective and easy-to-implement rehabilitation strategy that is superior to existing paradigms in its capacity to induce muscle adaptation in the absence of high mechanical and compressive loading on the spine.