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

描述（由申请人提供）：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。LBP的急性发生导致多裂肌萎缩的快速发作，并且复发性LBP与躯干伸肌形态和功能的甚至更大的适应不良变化相关（即，减少尺寸、强度和耐力）。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仅适度有效，因为它们通常在低负荷下进行（例如，25%最大强度），远低于肌肉适应的推荐值（>70%最大强度）。由于担心高脊柱压缩负荷可能导致脊柱进一步损伤，因此通常禁忌使用高负荷躯干锻炼。因此，开发利用低机械负荷的治疗方法是至关重要的，这些方法仍然可以向躯干伸肌提供足够的刺激，并逆转LBP患者中常见的躯干伸肌功能变化。低负荷抗阻运动与血流限制（BFR）是一种创新的方法，正是为了这一目的。这种模式涉及在低负荷下进行锻炼，而流向工作肌肉的血流被压力袖带部分阻塞。我们之前已经证明，单次BFR运动会增加循环内分泌生长因子，我们最近完成了对慢性BFR运动训练的初步研究，并观察到这种方式可以增强肌肉功能，而不会对动脉僵硬度，神经传导，炎症和凝血指标产生负面影响。虽然这种锻炼方式不能直接应用于躯干（限制胸部血流不可行），但我们的试点数据表明，在BFR运动后进行低负荷躯干伸肌运动时，对竖脊肌有独特的交叉转移效应。因此，在躯干肌肉低负荷运动之前，在BFR下进行肩胛肌运动可以在没有高脊柱压缩负荷的情况下增强肌肉尺寸和功能。在本申请中，我们建议进行一项探索性试验，因为它涉及确定BFR运动对复发性LBP患者竖脊肌形态和功能的影响。我们的中心假设是，在低负荷躯干伸肌运动之前进行的带肩胛肌的BFR运动将产生全身效应，增强躯干伸肌尺寸、力量和耐力的增加，超过仅低负荷躯干伸肌运动所见。这项工作的潜在影响是明确的：如果有效，这种新的锻炼方式将提供 这是一个具有成本效益和易于实施的康复策略的基础，上级现有的范例，在脊柱上没有高机械和压缩负荷的情况下诱导肌肉适应的能力。

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.