SEMG: Objective Methodology in Muscular Dysfunction Investigation and Rehabilitation
Mark V. Boswell, B. Eliot Cole in Weiner's Pain Management, 2005
The musculocutaneous nerve (C5–C6–C7) innervates the following muscles: coracobrachialis, biceps brachii, and brachialis. The first muscle is anatomically located too deep for SEMG testing at the present time. The testing is performed on the biceps and brachialis, in the appropriate segments of motion, i.e., the segment of motion with the highest and lowest activity found from the database for each muscle. If only one muscle is affected, the diagnosis will lead to mononeuropathy, whereas if both muscles are affected, the diagnosis will lead to musculocutaneous neuropathy as a whole. Because the nerve has a three-root innervation, one may need to proceed with differential diagnosis of radiculopathy. In this case, the deltoid muscle may be tested for C5 radiculopathy, the brachioradialis may be tested to rule out C6 radiculopathy, and the triceps may be tested to rule out C7 radiculopathy. In each case, testing for each muscle needs to be done in the clinically chosen segments of motion, most often those found in the database to produce the highest and lowest amplitude potentials. Thus, neuromuscular testing can serve to rule out mononeuropathy or radiculopathy with no invasiveness, in an effective and efficient manner, with quantitative analysis. The procedure can be quite useful in the overall diagnostic process, as well as in the process of neuromuscular rehabilitation.
Hands
Tor Wo Chiu in Stone’s Plastic Surgery Facts, 2018
Move Test motor power (MRC, M2 is movement with gravity eliminated) at shoulder, elbow, wrist, fingers and thumb.Winging of the scapula suggests a preganglionic injury (see above).Test trapezius – SAN may be used for nerve transfer.Nerve screening.Axillary nerve (shoulder abduction).RN (wrist extension – low, elbow extension – high).Musculocutaneous nerve (elbow flexion).Median and ulnar nerve (finger and wrist flexion).Passive and active ROM of all joints.
Complications of Nerve Injury and Repair
Stephen M. Cohn, Matthew O. Dolich in Complications in Surgery and Trauma, 2014
The infraclavicular portions of the brachial plexus (cords and terminal branches) are at risk during surgical procedures to the shoulder and axilla. Complete transection of the brachial plexus has been seen in association with axillary dissection during radical mastectomy. Injuries to several nerves about the shoulder, most commonly to branches of the axillary nerve, have been reported after shoulder arthroscopy. The incidence of nerve injury after anterior reconstruction for glenohumeral instability has been reported to be ∼8% [31]. Eighty-seven percent of patients with these lesions experienced full recovery within 6 months, and all were believed to have traction-type lesions. The musculocutaneous nerve was most frequently involved.
Sensory neurotization of muscle: past, present and future considerations
Published in Journal of Plastic Surgery and Hand Surgery, 2019
Steven D. Kozusko, Alexander J. Kaminsky, Louisa C. Boyd, Petros Konofaos
After analyzing the relevant experimental studies, a few key findings are apparent. First, most studies on sensory neurotization are in animals, in particular, rats. The studies are sound experimental models, but they do not report on human data. Second, there is a lack of consistency on the nerve and/or muscle chosen for neurotization. In one study, it was the posterior compartment of the leg. In another study, it was the musculocutaneous nerve of the arm. It is difficult to draw strict comparisons when multiple nerves and muscles are being analyzed. Additionally, the duration of time for sensory protection varied. Sensory protection duration was for 6 weeks in one study, while for another it lasted 6 months. The variable amount of time for sensory protection does little to establish guidelines for temporal guidelines. Lastly, measurements varied in the animal studies. Some studies analyzed muscle weight. Other studies looked at histology. Axon and motor endplate counts were acquired in another study. The variables are different in each of the animal studies. As one can see, there is a paucity of literature on the subject of sensory neurotization, and in what is present there is wide variability in study design.
Brachial distal biceps injuries
Published in The Physician and Sportsmedicine, 2019
Drew Krumm, Peter Lasater, Guillaume Dumont, Travis J. Menge
The biceps brachii muscle is made up of a short head and a long head. The short head originates on the coracoid process, while the long head originates on the supraglenoid tubercle. They each insert on the radial tuberosity. This muscle’s main action is to supinate the forearm, but it also assists in elbow flexion. Since the short head has a more distal attachment on the tuberosity than the long head, it is a greater contributor to elbow flexion. The long head attaches to the apex of the tuberosity and is a greater contributor to supination than the short head. The biceps is innervated by the musculocutaneous nerve and receives its blood supply from branches of the brachial artery. On clinical exam, the distal biceps tendon may be mistaken for the lacertus fibrosus, also known as the bicipital aponeurosis, which originates from the short head of the biceps and helps protect the neurovascular bundle in the antecubital fossa. The lateral antebrachial cutaneous nerve (LABCN), which is the terminal cutaneous branch of the musculocutaneous nerve, is at risk for injury in operative repair of distal biceps avulsion injuries. It is located between the biceps and brachialis muscles and pierces the deep fascia just lateral to the distal biceps tendon. The nerve is located in the subcutaneous tissue of the antecubital fossa and supplies sensation to the lateral aspect of the forearm. The radial nerve is also at risk for injury. The radial nerve is located between the brachioradialis and brachialis near the distal humerus. It bifurcates into the posterior interosseous nerve and radial sensory nerve in the antecubital fossa [6].
Long-term functional recovery in C5-C6 avulsions treated with distal nerve transfers
Published in Neurological Research, 2023
Irene Fasce, Pietro Fiaschi, Andrea Bianconi, Carlo Sacco, Guido Staffa, Crescenzo Capone
Currently, surgical treatment of preganglionic lesions is based on neurotization principle, which consists in the technique of transposing a proximal nerve branch, defined as donor, from its anatomical site to (or ‘pro’) an injured distal nerve, defined as recipient, to restore a loss of function [7]. When necessary, the donor could be prolonged with neural grafts. Two main types of neurotization are described in brachial plexus surgery: ‘intraplexual neurotization’, when a nerve branch or fascicle is moved from part of a healthy and intact plexus to a recipient nerve, distal to avulse plexus, innerving a different area, and ‘extraplexual neurotization’, when healthy nerves or fascicles, unrelated to the plexus, are used to reinnervate the plexus itself. The latter repair technique is defined as nerve transfer. Shoulder abduction and extra-rotation, elbow flexion and forearm supination are the lost functions that can be restored with surgical treatment in C5-C6 avulsions [8,9]. In these cases, proximal root stumps are not available for grafting and surgical repair is based on distal nerve transfers. In our series, the patients were treated with a surgical combination that consists in double or triple nerve transfer, achieving satisfactory postoperative results in terms of regaining function. We used as targets the Suprascapular nerve, the Axillary nerve, and two motor branches, for the short head of biceps and brachialis muscles, of the Musculocutaneous nerve.
Related Knowledge Centers
- Brachial Plexus
- Brachialis Muscle
- Coracobrachialis Muscle
- Lateral Cord
- Plexus
- Pectoralis Major
- Mixed Nerve
- Fascial Compartments of Arm
- Biceps
- Lateral Cutaneous Nerve of Forearm