Zakaria D, Harburn K L, Kramer J F
Physiotherapy Community Clinic, Stratford, Ontario, Canada.
J Orthop Sports Phys Ther. 1997 Jul;26(1):23-8. doi: 10.2519/jospt.1997.26.1.23.
Disagreement exists as to whether the individual components of the quadriceps femoris can be preferentially activated, i.e., that one muscle component is activated to a greater degree of its maximum voluntary contraction ability than the remaining components. Preferential activation of the vastus medialis (VM) might be useful in the treatment of knee patients demonstrating VM atrophy. The purpose of the present investigation was to determine if the vastus medialis oblique (VMO), vastus lateralis (VL), and hip adductor (HA) muscles were preferentially activated in females during the following maximal voluntary isometric exercises: 1) unilateral quadriceps setting (QS) with the ankle positioned in neutral, 2) unilateral quadriceps setting combined with ankle dorsiflexion (QS + D), and 3) maximal bilateral hip adduction. Integrated electromyography (IEMG in mV.sec) was determined for the VMO, VL, and HA muscles of the preferred leg (i.e., that used to kick a ball) of 20 healthy females. Data were normalized using QS exercise as the reference exercise. Nonnormalized IEMG (+/-SD) of the VMO and VL was similar during QS [i.e., VMO = 1050 (+/-802) mV.sec, VL = 1075 (+/-738) mV. sec] and QS + D exercises [i.e., VMO = 1191 (+/-738) mV.sec, VL = 1202 (+/-836) mV.sec], but significantly less than these values during hip adduction exercise [i.e., VMO = 174 (+/-62) mV. sec, VL = 194 (+/-70) mV.sec]. Nonnormalized IEMG of the HA muscles was similar during both QS and QS+D [i.e., 286 (+/-405) mV.sec and 195 (+/-432) mV.sec], but significantly higher than these values during hip adduction exercise [i.e., 413 (+/-235) mV.sec]. Normalized IEMG (+/-SD)(%) demonstrated similar patterns, i.e., the ratios for the VMO and the VL muscles did not differ from one another under either QS + D [i.e., VMO = 121 (+/-60)%, VL = 116 (+/-40)%] or hip adduction conditions [i.e., VMO = 33 (+/-24)%, VL = 36 (+/-25)%]. As a result, the degree of activation of the two muscles was considered the same. These results suggest no preferential activation of the quadriceps femoris component muscles during QS, QS + D, and hip adduction exercises in the nonweight-bearing position. The use of hip adduction to preferentially activate the VMO over the VL compared with QS exercises was not substantiated. A mean increase of 20% in the VMO and VL myoelectric activity during QS (as demonstrated by the normalized IEMG), by the addition of dorsiflexion, may be clinically significant. However, further study is required.
关于股四头肌的各个组成部分是否能够被优先激活，即其中一个肌肉组成部分被激活的程度超过其最大自主收缩能力的其余组成部分，目前存在争议。股内侧肌（VM）的优先激活可能对表现出VM萎缩的膝关节患者的治疗有用。本研究的目的是确定在以下最大自主等长运动中，女性的股内侧斜肌（VMO）、股外侧肌（VL）和髋内收肌（HA）是否被优先激活：1）踝关节处于中立位的单侧股四头肌收缩（QS），2）单侧股四头肌收缩并伴有踝关节背屈（QS + D），以及3）最大双侧髋内收。对20名健康女性优势腿（即用于踢球的腿）的VMO、VL和HA肌肉进行了积分肌电图（IEMG，单位为mV·秒）测定。数据以QS运动作为参考运动进行标准化。在QS [即VMO = 1050（±802）mV·秒，VL = 1075（±738）mV·秒]和QS + D运动[即VMO = 1191（±738）mV·秒，VL = 1202（±836）mV·秒]期间，VMO和VL的未标准化IEMG（±标准差）相似，但在髋内收运动期间显著低于这些值[即VMO = 174（±62）mV·秒，VL = 194（±70）mV·秒]。HA肌肉的未标准化IEMG在QS和QS + D期间相似[即286（±405）mV·秒和195（±432）mV·秒]，但在髋内收运动期间显著高于这些值[即413（±235）mV·秒]。标准化IEMG（±标准差）（%）显示出相似的模式，即无论在QS + D [即VMO = 121（±60）%，VL = 116（±40）%]还是髋内收条件下[即VMO = 33（±24）%，VL = 36（±25）%]，VMO和VL肌肉的比率彼此没有差异。因此，认为这两块肌肉的激活程度相同。这些结果表明，在非负重位置的QS、QS + D和髋内收运动中，股四头肌组成肌肉没有优先激活。与QS运动相比，使用髋内收来优先激活VMO而非VL的说法没有得到证实。通过增加背屈，QS期间VMO和VL肌电活动平均增加20%（如标准化IEMG所示），这在临床上可能具有重要意义。然而，还需要进一步研究。
