Abstract: Objective To compare the difference on the lower-limb muscle strength between 6 to 11-year-old children with Duchenne muscular dystrophy (DMD) and typical children, so as to provide more evidence for muscle strength training of DMD children.Methods Totally 20 DMD children and 20 typical children were enrolled from April 2015 to April 2017, including 19 males and 1 female in the DMD group and 18 males and 2 females in the typical group, both with an average age of (9.0±1.7) years old. Hand-held dynamometry (HHD) was used to measure the muscle strength of hip, knee, ankle and other parts of lower extremity. The differences on muscle strength between DMD and typical children were compared. Results The lower extremity muscle strength of DMD group was significantly weaker than that of typical group except flexor plantaris(all P<0.05), and there was no significant difference on muscle strength between children over 6-year-old and 9 to 11-year-old children in DMD group. Also, the difference on the bilateral hip abduction and toe flexion was not significant between children over 6-year-old in DMD group and typical group (P>0.05), and the toe flexion muscle strength in DMD group was even higher than that in typical group. Hip flexion, hip extension, hip abduction, knee flexion, knee extension and ankle dorsiflexion muscle strength except toe flexion in 9 to 11-year-old children in DMD group had been significantly weaker than typical children with the same age(all P<0.05). Conclusions The lower limb muscles of DMD children are significantly weaker than those of typical children except flexor plantaris. All muscle groups should be taken into consideration when carrying out lower limb strength training for DMD children. In addition, extra attention should be paid to extensor muscles of hip and knee in older children with DMD.

Key words: Duchenne muscular dystrophy, muscle strength, lower extremity, children

摘要： 目的 比较6～11岁杜氏进行性肌营养不良(DMD)患儿与正常儿童下肢肌力差异,为开展DMD患儿的肌力训练提供科学依据。方法 2015年4月-2017年4月选择DMD患儿和正常儿童各20例,其中DMD患儿男19例,女1例;正常组男18例,女2例,两组儿童平均年龄均为(9.0±1.7)岁。采用手持式肌力测定仪(HHD)测定下肢髋、膝、踝等部位肌群肌力,比较DMD与正常儿童下肢肌群间及不同年龄间的肌力差异。结果 DMD组下肢肌力除足跖屈肌群以外均明显弱于正常组(P＜0.05);DMD组中6岁～组和9～11岁组各组肌群肌力差异无统计学意义(P＞0.05);在6岁～组中DMD患儿双侧髋外展和足趾屈肌力与正常组差异无统计学意义(P＞0.05),DMD组足趾屈肌力甚至高于正常儿童; 9～11岁组中DMD患儿除足趾屈肌群外髋屈曲、髋伸展、髋外展、膝屈曲、膝伸展和踝背屈肌群肌力都已经显著落后于正常儿童(P＜0.05)。结论 DMD患儿下肢肌群除足跖屈肌外均明显低于正常组儿童。开展DMD患儿下肢力量训练应关注所有肌群,在较大年龄组尤其需要重视髋膝伸展肌群。

关键词: Duchenne型肌营养不良, 肌力, 下肢, 儿童