【論文摘要】Eccentric Cross-exercise Intervention for Arthrogenic Quadriceps Inhibition After Posterior Cruciate Ligament Reconstruction: A Case Report

【論文摘要】後十字韌帶重建術後導致關節源性肌肉抑制現象的離心交叉運動介入－個案報告

鄒孟璇(Meng-Hsuan Tsou) ； 陳昭瑩(Chao-Ying Chen)

《物理治療》 45卷4期 (2020/12) Pp. 349-350

https://doi.org/10.6215/FJPT.202012.P46

摘要

Background and Purpose: A 42-year-old female patient, who underwent arthroscopic reconstruction for her left posterior cruciate ligament (PCL) tear, was referred to physical therapy four weeks after surgery for post-operative rehabilitation, and arrived to the physical therapy center in a wheelchair. The patient reported that she could not actively contract her thigh muscle at all. Extensor lag during straight-leg raise and weakened quadriceps activity during quadriceps setting were noted during exercise training. The patient exhibited arthrogenic quadriceps muscle inhibition (AMI), an ongoing neural activation deficit that occurs across many knee joint pathologies. These changes in afferent discharge alter reflex pathways at the spinal and supraspinal levels, leading to inhibition of the quadriceps muscle. Although it is less often seen in patients following PCL injury or reconstruction, AMI was seen in our case, as observed in the extensor lag sign and inability to activate the quadriceps during weight-bearing and ambulation. Eccentric exercise has been discovered to facilitate neuromuscular changes in muscle fibers, improving recruitment and firing rate of alpha motor neurons, as well as induce greater excitability at the supraspinal level in the motor cortex. Since eccentric exercise of the affected limb of this case was contraindicated due to her being in the acute post-operative stage, the eccentric-cross exercise was considered. The aim of this case report was to illustrate the capability of eccentric-cross exercises in enhancing neural adaptations and neuroplasticity in patients with AMI. Methods: The main treatment goals were to improve the patient's left quadriceps activation ability, overall lower extremity muscle strength, and to improve ambulation ability. Our program was based on the postoperative rehabilitation protocol for PCL reconstruction. We included the novel eccentric cross-exercise training (5 sets of 6 repetitions at 80% of one repetition maximum) for 30 minute per session, 2 sessions per week, while the affected limb executed quadriceps setting. Results: After two weeks of intervention, although extensor lag was still noted, active quadriceps muscle contraction was observed. The patient could walk using a quadricane with partial weight-bearing, and reported that she could exercise with better activation and control over the quadriceps muscle. Conclusion: Eccentric cross-exercise is suitable and safe for patients with AMI in the acute post-operative stage, utilizing the unaffected limb to increase quadriceps activation and strength in the affected limb. From our literature review, increasing an intervention program of eccentric cross-exercise to 3 days a week for 8 weeks may facilitate greater improvement in neuromuscular control. Clinical Relevance: Our results provide an updated understanding of AMI and the potential of eccentric exercise or eccentric cross-exercise interventions in treatment programs designed for patients suffering from knee pathology.