Musculocutaneous Nerve: Difference between revisions
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<div class="editorbox"> | <div class="editorbox"> '''Original Editor '''- [[User:Lucinda Hamilton|Lucinda Hamilton]] '''Top Contributors''' - {{Special:Contributors/{{FULLPAGENAME}}}}</div> | ||
'''Original Editor '''- | |||
== Description == | |||
[[File:Nerves of the left upper extremity.gif|thumb|303x303px]] | |||
The Musculocutaneous nerve is a large branch of the [[Brachial Plexus|Brachial Plexus]].It is called musculocutaneous nerve as it supplies the muscles of the front of the arm and skin of lateral side of forearm.<ref name=":1">Chaurasia BD. Human Anatomy.6th ed. Vol1,CBS Publisers and distributors Pvt Ltd.</ref> | |||
The Musculocutaneous nerve is a terminal branch of the lateral cord of the [[Brachial Plexus|Brachial Plexus]]. It emerges at the inferior border of [[Pectoralis Minor|Pectoralis minor]] muscle.It passes lateral to the axillary and upper part of brachial artery. It leaves the axilla to then pierce the [[Coracobrachialis Muscle|Corocobrachialis]] near it humeral insertion to lie in the intermuscular septum between [[Biceps Brachii]] and [[brachialis]] muscles.Then it enters the elbow by piercing deep fascia and terminates as the Lateral Cutaneous nerve of the forearm.<ref name=":1" /> | |||
{{#ev:youtube|Wru7UCHlbFU}} | |||
== | |||
== Root == | |||
Ventral rami of C<sub>5,</sub> C<sub>6,</sub> C<sub>7</sub> | |||
Motor branches | == Branches == | ||
<ref name=":1" />Motor branches to<ref name=":1" />: | |||
* Corocobrachialis | * Corocobrachialis | ||
* Brachialis ( also has supply from Radial nerve) | * Brachialis ( also has supply from Radial nerve) | ||
* Biceps Brachii | * Biceps Brachii(both long head and short head) | ||
Sensory branches | Sensory branches<ref name=":1" />: | ||
* | * lateral cutaneous nerve to the lateral forearm (both front and back) | ||
Articular branches | Articular branches<ref name=":1" />: | ||
* Humerus and [[Elbow]] joint | * [[Humerus]] and [[Elbow]] joint | ||
== Movements | == Movements Produced == | ||
* Coracobrachialis - | * Coracobrachialis - flexes and adducts the [[Glenohumeral Joint|glenohumeral]] (GH) joint and acts to stabilise the humeral head in the [[Glenoid Labrum|glenoid]] fossa when the arm is hanging freely by side.<ref>Saladin KS. "The Muscular System." Anatomy & Physiology: The Unity of Form and Function. New York, NY: McGraw-Hill, 2012. 346. Print. </ref> | ||
* Brachialis- flexion of the elbow joint. | * Brachialis- flexion of the [[Elbow|elbow joint]]. | ||
* Biceps Brachii- a weak abductor of GH joint when arm externally rotated | * Biceps Brachii- a weak abductor of GH joint when arm externally rotated, weak flexor of GH joint, helps to stabilise GH joint when weight carried in arm, supinator and flexor of the elbow joint.<ref>Kleiber T, Kunz L, Disselhorst-Klug C. Muscular coordination of biceps brachii and brachioradialis in elbow flexion with respect to hand position. Frontiers in physiology. 2015 Aug 6;6:215.</ref> | ||
== Pathology/Injury == | |||
Isolated injuries of the Musculocutaneous Nerve are rare. It may become injured by<ref name=":0">Patient. [https://patient.info/doctor/musculocutaneous-nerve-lesion-c5-c6 Musculocutaneous nerve.] Available from: https://patient.info/doctor/musculocutaneous-nerve-lesion-c5-c6 (last accessed 20.3.2019)</ref><ref>Healthline. [https://www.healthline.com/human-body-maps/musculocutaneous-nerve#1 Musculocutaneous nerve]. Available from: https://www.healthline.com/human-body-maps/musculocutaneous-nerve#1 (last accessed 20.3.2019)</ref>: | |||
* Brachial Plexus damage | * Brachial Plexus damage | ||
* Compression injury eg weight lifting or sports involving lots of forarm flexing and supination.The biceps aponeurosis and tendon compress against the fascia of the brachialis muscle causing sensory loss below the elbow on the lateral side of the forearm. | * Compression injury eg weight lifting or sports involving lots of forarm flexing and supination.The biceps aponeurosis and tendon compress against the fascia of the brachialis muscle causing sensory loss below the elbow on the lateral side of the forearm. | ||
* Dislocation of the shoulder | * [[Shoulder Dislocation|Dislocation of the shoulder]] | ||
* Shoulder surgery | * [[Shoulder]] surgery | ||
* Entrapment of the nerve at the elbow | * Entrapment of the nerve at the elbow | ||
== Anatomical Variations == | |||
Considerable anatomical variations present with this nerve. This may lead to clinical implications in | Considerable anatomical variations present with this nerve. This may lead to clinical implications in surgery, diagnosis.<ref name=":0" /> | ||
== Physiotherapy Techniques == | == Physiotherapy Techniques == | ||
=== | === Examination === | ||
* Check strength of [[Biceps Brachii|Biceps Brachii]], Corocobrachialis and [[Brachialis]] muscles . | |||
* Check sensation on lateral forearm | |||
* See [[Nerve entrapment|Nerve Entrapement]] | |||
* Check for Differential Diagnoses- namely C5/6 [[Radiculopathy]]; [[Biceps Tendonitis|biceps Brachii]] distal insertion tear. | |||
=== Physiotherapeutic Techniques === | === Physiotherapeutic Techniques === | ||
<div class="researchbox"> | |||
see the following links | |||
[[Nerve Injury Rehabilitation Physiotherapy]] | |||
[[Brachial plexus injury|Brachial Plexus Injury]] | |||
[[Diabetic Neuropathy|Diabetic neuropathy]] | |||
</div> | </div> | ||
== References == | == References == | ||
<references /> | <references /> | ||
Latest revision as of 18:59, 8 March 2024
Original Editor - Lucinda Hamilton Top Contributors - Lucinda hampton, Kim Jackson, Redisha Jakibanjar and Habibu Salisu Badamasi
Description[edit | edit source]
The Musculocutaneous nerve is a large branch of the Brachial Plexus.It is called musculocutaneous nerve as it supplies the muscles of the front of the arm and skin of lateral side of forearm.[1]
The Musculocutaneous nerve is a terminal branch of the lateral cord of the Brachial Plexus. It emerges at the inferior border of Pectoralis minor muscle.It passes lateral to the axillary and upper part of brachial artery. It leaves the axilla to then pierce the Corocobrachialis near it humeral insertion to lie in the intermuscular septum between Biceps Brachii and brachialis muscles.Then it enters the elbow by piercing deep fascia and terminates as the Lateral Cutaneous nerve of the forearm.[1]
Root[edit | edit source]
Ventral rami of C5, C6, C7
Branches[edit | edit source]
- Corocobrachialis
- Brachialis ( also has supply from Radial nerve)
- Biceps Brachii(both long head and short head)
Sensory branches[1]:
- lateral cutaneous nerve to the lateral forearm (both front and back)
Articular branches[1]:
Movements Produced[edit | edit source]
- Coracobrachialis - flexes and adducts the glenohumeral (GH) joint and acts to stabilise the humeral head in the glenoid fossa when the arm is hanging freely by side.[2]
- Brachialis- flexion of the elbow joint.
- Biceps Brachii- a weak abductor of GH joint when arm externally rotated, weak flexor of GH joint, helps to stabilise GH joint when weight carried in arm, supinator and flexor of the elbow joint.[3]
Pathology/Injury[edit | edit source]
Isolated injuries of the Musculocutaneous Nerve are rare. It may become injured by[4][5]:
- Brachial Plexus damage
- Compression injury eg weight lifting or sports involving lots of forarm flexing and supination.The biceps aponeurosis and tendon compress against the fascia of the brachialis muscle causing sensory loss below the elbow on the lateral side of the forearm.
- Dislocation of the shoulder
- Shoulder surgery
- Entrapment of the nerve at the elbow
Anatomical Variations[edit | edit source]
Considerable anatomical variations present with this nerve. This may lead to clinical implications in surgery, diagnosis.[4]
Physiotherapy Techniques[edit | edit source]
Examination[edit | edit source]
- Check strength of Biceps Brachii, Corocobrachialis and Brachialis muscles .
- Check sensation on lateral forearm
- Check for Differential Diagnoses- namely C5/6 Radiculopathy; biceps Brachii distal insertion tear.
Physiotherapeutic Techniques[edit | edit source]
see the following links
References[edit | edit source]
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Chaurasia BD. Human Anatomy.6th ed. Vol1,CBS Publisers and distributors Pvt Ltd.
- ↑ Saladin KS. "The Muscular System." Anatomy & Physiology: The Unity of Form and Function. New York, NY: McGraw-Hill, 2012. 346. Print.
- ↑ Kleiber T, Kunz L, Disselhorst-Klug C. Muscular coordination of biceps brachii and brachioradialis in elbow flexion with respect to hand position. Frontiers in physiology. 2015 Aug 6;6:215.
- ↑ 4.0 4.1 Patient. Musculocutaneous nerve. Available from: https://patient.info/doctor/musculocutaneous-nerve-lesion-c5-c6 (last accessed 20.3.2019)
- ↑ Healthline. Musculocutaneous nerve. Available from: https://www.healthline.com/human-body-maps/musculocutaneous-nerve#1 (last accessed 20.3.2019)
