Incomplete functional subdivision of the human multitendoned finger muscle flexor digitorum profundus: An electromyographic study
Incomplete functional subdivision of the human multitendoned finger muscle flexor digitorum profundus: An electromyographic study
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DOI：
10.1152/jn.00287.2003
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发表时间：
2003-10-01
影响因子：
2.5
通讯作者：
Schieber, MH
中科院分区：
文献类型：
--
作者：
Reilly, KT;Schieber, MH
人的指深屈肌（FDP）将肌腱输送到所有4个手指。人们可能会认为，这种多腱肌肉由4个独立的神经肌肉隔室组成，每个隔室作用于不同的手指，但最近的解剖学和生理学研究提出了人类FDP不完全细分的可能性。为了研究人类FDP的功能组织，我们记录了肌电图（EMG）活动的双极细丝电极同时从2个或4个单独的肌内部位作为正常人受试者进行等距，个性化的屈曲和伸展的每个左手手指。一些记录显示在4个手指中的仅一个手指的屈曲期间的EMG活动，表明人类FDP具有作用于单个手指的高度选择性核心区域。然而，大多数记录显示，在一个手指的屈曲过程中有大量的EMG活动，而在相邻手指的屈曲过程中有较低水平的EMG活动。相邻手指屈曲时的EMG活动较少，这不太可能是由于记录相邻神经肌肉间室中的运动单位所致，而是表明人类FDP的功能细分不完整。除了最大的激动剂肌电图活动在弯曲的一个给定的手指，大多数记录也显示肌电图活动在伸展相邻的手指，显然是为了稳定给定的手指对不必要的延伸。巧合的是，人类FDP的功能组织-具有不完整的功能细分和高度选择性的核心区域-可能同时导致人类无法产生完全独立的手指运动，以及人类（与猕猴相比）更大的能力来个性化手指运动。
The human flexor digitorum profundus (FDP) sends tendons to all 4 fingers. One might assume that this multitendoned muscle consists of 4 discrete neuromuscular compartments each acting on a different finger, but recent anatomical and physiological studies raise the possibility that the human FDP is incompletely subdivided. To investigate the functional organization of the human FDP, we recorded electromyographic (EMG) activity by bipolar fine-wire electrodes simultaneously from 2 or 4 separate intramuscular sites as normal human subjects performed isometric, individuated flexion, and extension of each left-hand digit. Some recordings showed EMG activity during flexion of only one of the 4 fingers, indicating that the human FDP has highly selective core regions that act on single fingers. The majority of recordings, however, showed a large amount of EMG activity during flexion of one finger and lower levels of EMG activity during flexion of an adjacent finger. This lesser EMG activity during flexion of adjacent fingers was unlikely to have resulted from recording motor units in neighboring neuromuscular compartments, and instead suggests incomplete functional subdivision of the human FDP. In addition to the greatest agonist EMG activity during flexion of a given finger, most recordings also showed EMG activity during extension of adjacent fingers, apparently serving to stabilize the given finger against unwanted extension. Paradoxically, the functional organization of the human FDP-with both incomplete functional subdivision and highly selective core regions-may contribute simultaneously to the inability of humans to produce completely independent finger movements, and to the greater ability of humans (compared with macaques) to individuate finger movements.