Liu J, Pho R W, Pereira B P, Lau H K, Kumar V P
Department of Orthopaedic Surgery, National University of Singapore.
Anat Rec. 1997 Jul;248(3):456-63. doi: 10.1002/(SICI)1097-0185(199707)248:3<456::AID-AR19>3.0.CO;2-O.
The information available on innervation pattern of the human forearm muscles in standard anatomy texts, although adequate for routine procedures, is not detailed enough for surgical reconstruction in complex injuries of the limb and for paralytic conditions of the forearm from peripheral nerve and spinal cord injuries.
The innervation pattern in 10 cadaveric forearms was studied. The contributions of the main nerve trunks to each forearm muscle was examined. The location and number of the primary motor nerve branching points and of the terminal nerve entry points to each muscle were investigated. The location of both the primary nerve branching points and terminal nerve entry points was presented as a percentage of forearm length measured from the lateral humeral epicondyle to the radial styloid.
Seven of 19 forearm muscles were innervated from a single branch from the main nerve trunk. The remaining 12 received more than one primary branch. Two of 19 forearm muscles had only one terminal nerve entry point. The others had two or more each. In 13 of 19 forearm muscles, the statistical median location of the primary motor nerve branching points was within the proximal one-third of the forearm length and either more proximally or distally for the remainder. The statistical median location of the terminal nerve entry points was within the proximal one-third in 9 forearm muscles and within the middle one-third of the forearm in 8 forearm muscles. In two, it was located proximal to the elbow and in the distal one-third of the forearm, respectively.
In lacerations across the forearm, where main nerve trunks are divided, mere repair of the nerve trunks would not address the denervation of muscle or segments of muscle by the division of the primary (or secondary) nerve branches traversing the wound and which took origin proximal to the laceration either from the divided nerve trunks or from other undamaged nerve trunks. Although the main nerve trunks may be intact, segmental crush injuries will defunction muscles by direct muscle damage or by damage to the terminal nerve entry points to the muscle. Knowledge of the location of the nerve branches and the terminal nerve entry points facilitates the insertion of electrodes at the motor points of forearm muscles for functional electrical stimulation in upper motor neuron lesions. The information in this study may also be usefully applied in selective denervation procedures to balance muscles in spastic upper limbs.
标准解剖学教材中有关人类前臂肌肉神经支配模式的信息，虽足以用于常规手术，但对于肢体复杂损伤的手术重建以及周围神经和脊髓损伤导致的前臂麻痹情况而言，细节仍不够充分。
对10具尸体的前臂神经支配模式进行研究。检查主要神经干对每块前臂肌肉的支配情况。调查每条肌肉的主要运动神经分支点及终末神经进入点的位置和数量。主要神经分支点和终末神经进入点的位置均以从肱骨外侧髁至桡骨茎突测量的前臂长度的百分比表示。
19块前臂肌肉中有7块由主要神经干的单一分支支配。其余12块接受不止一个主要分支。19块前臂肌肉中有2块只有一个终末神经进入点。其他肌肉则各有两个或更多。19块前臂肌肉中有13块，主要运动神经分支点的统计中位数位置在前臂长度的近端三分之一内，其余的则更靠近近端或远端。9块前臂肌肉的终末神经进入点的统计中位数位置在前臂近端三分之一内，8块前臂肌肉的终末神经进入点的统计中位数位置在前臂中间三分之一内。在两块肌肉中，终末神经进入点分别位于肘部近端和前臂远端三分之一处。
在前臂横断伤中，当主要神经干被切断时，单纯修复神经干并不能解决因穿过伤口的主要（或次要）神经分支的切断而导致的肌肉或肌肉节段失神经支配问题，这些分支在撕裂伤近端要么源自被切断的神经干，要么源自其他未受损的神经干。尽管主要神经干可能完好无损，但节段性挤压伤会因直接的肌肉损伤或肌肉终末神经进入点的损伤而使肌肉失去功能。了解神经分支和终末神经进入点的位置有助于在前臂肌肉的运动点插入电极，用于上运动神经元损伤的功能性电刺激。本研究中的信息也可能有助于选择性失神经手术，以平衡痉挛上肢的肌肉。
