腹直肌運動有無配合腹橫肌收縮對產後腹直肌分離婦女腹白線型態的影響

Abstract

背景與目的：腹直肌分離(diastasis recti abdominis)常見於懷孕及產後婦女，為適應胎兒生長使得兩側腹直肌距離增加。過去研究指出，相較於未經過生產的女性，產後婦女的腹直肌距離較寬，變形程度較大，組織剛性較低，然而不同的運動對於腹白線有不同立即性的影響，腹直肌運動能夠減少腹直肌間距離，而腹橫肌收縮使得腹直肌間距離增加，但是能夠減少變形程度，此外，後側腹直肌腱鞘與腹白線在組織生物力學有相同特性，因此腹橫肌在訓練上仍然至關重要。本研究的目的在於探討長期腹直肌運動訓練對腹白線的型態和功能的效應，以提供臨床上治療腹直肌分離患者的運動建議。 實驗設計：本研究為介入型、隨機對照試驗。 方法：本研究納入24位20-40歲產後一年內有腹直肌分離之婦女，隨機分為介入組與控制組，兩組每天執行腹直肌運動，共4週，每週治療師依照個案情況調整動作難度及次數。介入組在執行運動訓練前使用超音波視覺回饋方式學習正確腹橫肌收縮，執行腹直肌運動同時加上腹橫肌收縮。執行運動訓練的前後，在休息狀態及捲腹狀態下，使用亮度模式超音波於肚臍上方2公分位置測量腹直肌間距離、腹白線變形程度及肌肉厚度，並使用應變型彈性超音波測量腹白線剛性。此外，測量腹部肌耐力及以歐式下背疼痛量表評估整體生活品質，比較有無加入腹橫肌收縮之組內及組間差異。 結果：控制組執行4週的腹直肌運動後，無論在休息(p<0.000)或是捲腹狀態(p=0.01)，腹直肌間距離皆顯著減少。在介入組中，休息狀態下腹直肌間距離顯著減少(p<0.000)，且在休息和捲腹狀態下腹白線的變形程度也顯著減少(p=0.002)。腹部運動皆能夠顯著增加肌耐力(控制組：p=0.034；介入組：p= 0.01)，並且分別在相應的肌肉有顯著的肌肉厚度增加，控制組顯著增加腹直肌的肌肉厚度(左側：p=0.039；右側：p=0.03)，而介入組顯著增加腹橫肌的厚度(左側：p=0.006；右側：p=0.002)。兩組在生活品質上都有改善，但只有控制組有顯著差異(p=0.041)。 結語：執行腹直肌運動訓練後，對於腹白線型態、腹部功能及生活品質皆有正向的效果，腹橫肌的參與不會增加腹直肌間距離，能夠顯著減少腹白線的變形程度，建議有腹直肌分離者選擇訓練腹直肌為主的運動，並且加入腹橫肌的收縮。 臨床意義：提供腹直肌分離患者臨床運動治療之參考依據，透過結合腹直肌運動和腹橫肌活化，可以改善腹白線形態，增強腹部功能，並提升生活品質。

Background and purpose: Diastasis recti abdominis (DRA) is the most common problem occurred in women during pregnancy and postpartum periods. During pregnancy, the hormonal changes and the growth of the uterus contribute to an increased separation of the two rectus abdominus muscles. Previous studies indicated that postpartum women with DRA often exhibit a wider inter rectus distance (IRD), lower stiffness and higher linea alba distortion. However, it is important to note that different exercises can have varying immediate effects on the linea alba. Rectus abdominis exercise have been found to effectively reduce the inter rectus distance, whereas the contraction of the transversus abdominis (TrA) may temporarily increase the distance but can help reduce the degree of deformation in the linea alba. Moreover, the posterior rectus sheath is functionally more related to the transverse abdominis muscle. The transverse abdominis muscles play an important role in training for DRA. The objective of this study was to investigate the effects of a four-week rectus abdominis exercise program, with or without transversus abdominis activation, on the characteristics of linea alba, abdominal function and quality of life in postpartum women with rectus diastasis. Study design: This study is an interventional, randomized controlled trial. Method: A total of 24 postpartum women, aged between 20 and 40 years, and diagnosed with diastasis recti within one year postpartum, were recruited for participation in this study. They were randomly assigned to either the intervention group or the control group. Both groups participated in a four-week program that included rectus abdominal exercises. The intervention group received ultrasound visual feedback to assist in learning proper transverse abdominal muscle contraction technique. They performed exercises specifically targeting the transverse abdominal muscles. Before and after the exercise training, ultrasound and strain elastography were utilized to measure the inter rectus distance, distortion, muscle thickness and stiffness at 2 cm above the navel, both in resting and curl-up positions. Additionally, the study assessed abdominal muscle endurance and evaluated the participants' quality of life using the Oswestry Disability Index. Intra-group and inter-group differences were compared to analyze the outcomes. Result: The control group showed a significant reduction in rectus abdominis distance, both at rest (p<0.000) and in the curl-up position (p=0.01). In the intervention group, the incorporation of transverse abdominal muscle activation led to a significant reduction in distance at rest (p<0.000) and a significant decrease in linea alba distortion in both positions (p=0.002). Both groups demonstrated a significant increase in muscle endurance (control group: p=0.034, intervention group: p=0.01), accompanied by significant increases in muscle thickness in the targeted muscles. The control group exhibited a significant increase in rectus abdominis muscle thickness (left side: p=0.039, right side: p=0.03), whereas the intervention group demonstrated a significant increase in transverse abdominal muscle thickness (left side: p=0.006, right side: p=0.002). Both groups experienced improvements in quality of life, but only the control group showed a significant difference (p=0.041). Conclusion: Performing rectus abdominis exercise training has been shown to have positive effects on linea alba morphology, abdominal function, and quality of life. Additionally, the involvement of the transverse abdominis does not increase the distance between the rectus abdominis muscles, which significantly reduces the degree of deformation. For individuals with diastasis rectus abdominis, it is recommended to focus on exercises that target the rectus abdominis while incorporating contractions of the transverse abdominis. Clinical relevance: This study provides a promising option for clinical exercise therapy in the treatment of patients with diastasis rectus abdominis. By incorporating rectus abdominis exercises along with transverse abdominal muscle activation, it offers a comprehensive approach to address the condition, improve linea alba morphology, enhance abdominal function, and enhance quality of life.