Shah Kshamata M, Safford Daniel W, Madara Kathleen, Cooper Jennifer, Sweitzer Brett, Karduna Andrew, McClure Philip W
Department of Physical Therapy, Arcadia University, Glenside, PA, USA.
Department of Physical Therapy, Arcadia University, Glenside, PA, USA.
J Shoulder Elbow Surg. 2025 Jun;34(6):e488-e495. doi: 10.1016/j.jse.2025.01.020. Epub 2025 Feb 17.
Shoulder exercise and subacromial injection are the first line of treatment for patients with subacromial pain syndrome (SAPS) and have been shown to be effective in about 70% of patients. Weakness is common in these patients although its true source is uncertain. The purpose of this study is to determine the changes in rotator cuff voluntary activation (VA), that is, central drive and force, immediately after a pain-relieving subacromial injection, and following a 6-week exercise program and examine baseline differences in patients with SAPS and healthy controls.
Voluntary activation, peak normalized external rotation (ER) torque, pain, and self-report function were assessed in 43 patients with positive shoulder impingement. Subjects were tested at baseline (T1), immediately after a pain-relieving injection (T2), and after 6 weeks of exercise (T3). Forty-4 controls were tested at baseline (T1). Participants received 2 stimuli on their infraspinatus, one while contracting maximally and one at rest, to determine the VA.
Subjects with SAPS demonstrated lower ER normalized torque (27.3% lower compared with controls, P = .005) and lower infraspinatus VA (median 0.99 in controls and 0.71 in patients, P < .001). As expected, the VA increased (P = .004) from T1 to T2 and remained unchanged at T3 as compared to T2. ER normalized torque increased across all time points. Pain (P < .001) decreased with the injection and exercise, and function (P < .001) improved from baseline to discharge.
Understanding neural adaptations with exercise is critical to learning how to best modify the system and optimize current rehabilitation strategies, for example, including exercises focused on motor-control training, biofeedback, or neuromuscular electric stimulation.
肩部锻炼和肩峰下注射是肩峰下疼痛综合征（SAPS）患者的一线治疗方法，已被证明对约70%的患者有效。这些患者中常见无力症状，但其真正来源尚不确定。本研究的目的是确定在进行缓解疼痛的肩峰下注射后以及经过6周锻炼计划后，肩袖自主激活（VA）的变化，即中枢驱动和力量，并检查SAPS患者与健康对照者的基线差异。
对43例肩部撞击试验阳性的患者进行自主激活、峰值标准化外旋（ER）扭矩、疼痛和自我报告功能评估。受试者在基线（T1）、缓解疼痛注射后即刻（T2）以及锻炼6周后（T3）接受测试。40名对照者在基线（T1）接受测试。参与者在其冈下肌接受2次刺激，一次在最大收缩时，一次在休息时，以确定VA。
SAPS患者表现出较低的ER标准化扭矩（与对照组相比低27.3%，P = .005）和较低的冈下肌VA（对照组中位数为0.99，患者为0.71，P < .001）。正如预期的那样，VA从T1到T2增加（P = .004），与T2相比，T3时保持不变。ER标准化扭矩在所有时间点均增加。疼痛（P < .001）随着注射和锻炼而减轻，功能（P < .001）从基线到出院有所改善。
了解运动时的神经适应性对于学习如何最佳地调整系统和优化当前的康复策略至关重要，例如，包括专注于运动控制训练、生物反馈或神经肌肉电刺激的锻炼。
