The medial and lateral bellies of gastrocnemius: A cadaveric and ultrasound investigation
The medial and lateral bellies of gastrocnemius: A cadaveric and ultrasound investigation
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DOI：
10.1002/ca.20533
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发表时间：
2008-01-01
期刊：
影响因子：
2.4
通讯作者：
Adds, Philip J.
中科院分区：
文献类型：
--
作者：
Antonios, Tony;Adds, Philip J.
据报道，内侧腹（MG）的。腓肠肌比外侧腹（LG）向远端延伸得更远。这一观察结果是在几个标准的解剖学教科书中进行的，没有解释或定量数据。对45具防腐尸体腓肠肌内、外侧腹进行了测量。两个腹部的长度观察到的差异被发现是高度显著的（长度的平均差异= 1.74cm，P <0.001）。然而，在检查的84条腿中的8条（9.5%）中，发现MG短于LG（3条右腿，5条左腿，2名患者为双侧）。令人惊讶的是，任何个体的肌腹长度差异与同侧腿长或全身长度之间都没有相关性，这表明肌腹长度的差异可能与生物力学功能无关。对五名志愿者进行了两个腹部活动模式的超声调查。肌肉活动进行了监测，在被动和主动运动的踝关节和膝关节在不同的腿的位置。在膝关节屈曲和踝关节跖屈，LG收缩第一，在四个的五个科目，其次是MG，然后一段时间的LG占主导地位或平等的收缩。第五名受试者表现出相反的活动模式，此前曾遭受踝关节内翻损伤。我们认为，初始激活的LG可能有助于稳定踝关节跖屈。我们没有发现任何证据表明腓肠肌在膝关节牵引过程中起分流肌的作用。
It is commonly reported that the medial belly (MG) of the. gastrocnemius muscle extends further distally than the lateral belly (LG). This observation is made in several standard anatomy texts with no explanation or quantitative data. In this study, the medial and lateral bellies of gastrocnemius in 45 embalmed cadavers were measured. The observed difference in length of the two bellies was found to be highly significant (mean difference in length = 1.74 cm, P < 0.001). In 8 out of 84 legs examined (9.5%), however, the MG was found to be shorter than the LG (three right legs, five left legs, bilateral in two individuals). Surprisingly, there was no correlation between the difference in muscle belly length in any individual and ipsilateral leg length or total body length, suggesting that the difference in belly length may be unrelated to biomechanical function. An ultrasound investigation into the activity pattern of the two bellies was carried out on five volunteers. Muscle activity was monitored during passive and active movements of the ankle and knee joints at different leg positions. During knee flexion and ankle plantarflexion, the LG contracted first in four of the five subjects, followed by the MG, then a period of either LG predomination or equal contraction. The fifth subject, who showed a reversed pattern of activity, had previously suffered an inversion injury of the ankle. We suggest that the initial activation of the LG may help to stabilize the ankle during plantarflexion. We found no evidence that gastrocnemius acts as a shunt muscle during distraction of the knee.