產後婦女腹直肌分離現象－治療性運動介入後效果之探討

背景及目的：腹直肌分離現象常見於懷孕時期與生育後的婦女。由於懷孕時腹直肌及中間的白線容易隨著胎兒的生長而被拉扯、伸展、而且變薄，兩側腹直肌因此變得較於鬆垮，其間的距離也增大，而產生腹直肌分離；嚴重時甚至會造成腹部內臟脫垂突出。除了直接影響體態美觀之外，兩腹直肌間的距離變大與過於鬆弛的現象，可能會造成肌肉在平常時就處於一個較不易收縮的狀況。腹直肌分離現象也可能會造成此肌肉上下附著角度的改變，使得收縮腹直肌時的拉力角度處於較不利的範圍，進而減少腹直肌最大自主收縮時的肌力。包括軀幹穩定、控制骨盆等等和腹直肌有關的一些能力也很可能因此受到影響，甚至導致產後罹患背痛及腰薦拉傷的機會增加。本研究的主要目的是要了解（和未曾生育之一般女性相比）曾經生育過之婦女兩腹直肌間距離增加的現象，以及她們的腹肌肌力、耐力表現，以瞭解腹直肌分離現象對肌肉功能的影響，並探討定期之腹肌運動訓練是否能改善這些現象。方法：本研究共有二十八位產後婦女（平均年齡34.32 ± 1.03歲）及二十三位未曾生育過女性（平均年齡33.43 ± 1.20歲）參與。腹肌的功能評估主要是以超音波量測腹直肌間距、並以手握式肌力器測量腹直肌與其他相關肌群肌力，另外測量肌耐力，並同時利用軀幹與腹肌之表面肌電訊號蒐集來瞭解腹直肌自主徵召的情形，以及其他相關肌群在腹肌活動中的參與程度。經過初步評估，受試婦女進而分成一般運動及特殊運動兩組（各十人）以執行12週之腹直肌運動訓練，完成後再接受相同之腹肌功能評估以記錄其肌力、耐力與腹直肌分離的進步情形，並比較不同運動訓練對改善這些現象的效果。結果：曾經生育過之婦女其腹直肌間距明顯大於未曾生育過女性，尤其在肚臍上緣處最為明顯。雖然腹直肌等長肌力似乎表現正常，但腹肌耐力及肌肉徵召情形表現略差。經過12週運動訓練後，腹直肌分離情形、腹直肌耐力及肌肉自主徵召模式有明顯改善。結論：腹直肌分離現象確實出現在產後婦女，且會造成肌耐力及肌肉自主徵召能力下降。而本研究所設計規劃之腹直肌強化運動也證實參與此類之運動訓練能明顯改善腹肌功能。本研究增進了物理治療師對產後婦女的健康需求上的了解，並初步釐清了數種腹肌功能相關因子在產後婦女身上所造成之變化，以及可能的改善之道。本研究的發現不但有助於物理治療師對懷孕及產後婦女的健康照護，也應可以成為未來女性老化後相關問題（如背痛）與復健運動計畫上的一個重要參考。

關鍵字

腹直肌分離；產後婦女；物理治療；肌無力

並列摘要

Background and Purpose: Diastasis rectus abdominis (DRA) is common to postpartum women. As a result of the growing fetus in both its size and weight, the linea alba can be over stretched to an extent that it often becomes a thin, slack membrane. Eventually, the distance between the two RA. (the inter-recti distance; IRD) is increased. In addition to the changes in body image and posture, normal muscle mechanics and physiology can be affected to a great extent as the IRD increased. The laxity of the abdominal wall will also change the resting length of the RA, subsequently it might also reduce the force production due to the effects of decreased resting muscle tonus and increased the angle of pull during active contraction. Movement functions related to the RA, such as maintenance of posture, stability of pelvis, etc., can also be compromised as the mechanical output from the maximal voluntary contractions (MVCs) reduced. This study aimed to understand the extent of changes in RA functions in postpartum women, and how could regular exercise affect it. A group of nonparaous female was recruited as comparison. Method: There were 28 postpartum women (34.32 ± 1.03 years) and 23 nonparous females (33.43 ± 1.20 years) participated in this study. The postpartum group was further divided into two, general or specific exercise groups, for 12 weeks training in RA function. Both exercise groups were tested for RA function before and after exercise training, though the control group was only tested once, without implementing exercise program. For assessment of RA function, musculoskeletal ultrasound imaging was used to measure the IRD at areas above and below umbilicus. Mechanical and electrical output of RA and other related trunk muscles were collected with a hand-held dynamometer and surface electromyography (EMG). Static & dynamic endurance performance of the RA was also recorded. Result: The postpartum women showed larger DRA, particularly on the upper margin of umbilicus, than the controls (p<0.0001). Their RA strength seems unaffected, but with a lower RA endurance and recruitment. After 12 weeks of therapeutic exercise, obvious improvement IRD, endurance and normal recruitment pattern could be found on both exercise groups, especially in those with specific exercise. Conclusion: The DRA phenomenon is common in postpartum women and those who showed increased IRD also exhibited lower RA endurance and recruitment in trunk movement such as sit-up. The training program designed in this study demonstrated effects in reducing the IRD as well as improving the endurance and strength, even in very basic forms. There is also a need to explore whether these effects can also reduce the problems possibly caused by reinforce abdominal function (such as back pain and incontinence). The finding of these investigations is important not only in better understanding of women health, but also leading to better utilization of physical therapy in treating these dysfunction associated with pregnancy.

並列關鍵字

postpartum women ； muscle weakness ； Diastasis rectus abdominis ； physical therapy

參考文獻

1.Alaranta H, Rytokoski U, Rissanen A, Talo S, Ronnemaa T, Puukka P, Karppi SL, Videman T, Kallio V, Slatis P. (1994) Intensive physical and psychosocial training program for patients with chronic low back pain. A controlled clinical trial. Spine. Jun 15;19(12):1339-49.

Google Scholar

2.Alston W, Carlson KE, Feldman DJ, Grimm Z, Gerontinos E (1966) A quantitative study of muscle factors in the chronic low back syndrome. Journal of American Geriatric Society 14:1041-1047.

Google Scholar

3.Alway SE, MacDougall JD, Sale DG. (1989) Contractile adaptations in the human triceps surae after isometric exercise. J Appl Physiol. 66(6):2725-32.

Google Scholar

4.American Alliance for Health, Physical Education, Recreation and Dance. (1984). Health-related physical fitness: Technical manual. Reston, VA: Author.