Introduction
Wrist drop is a disorder caused by radial nerve palsy. It is when the hand hangs flaccidly in a position of flexion when the patient tries to bring the arm to a horizontal position. One can say that there are many causes of wrist drop and mostly the one common is said to range from penetrative trauma to external compression (Saturday night palsy) to systemic nutritional deficiencies.
Treatment can be surgery or it depends on the nature of the injury or the extent of the injury to the radial nerve etc .
What then is a wrist drop?
Wrist drop is a symptom of radial nerve palsy in which one cannot lift his or her wrist after placing it over desk or table. A person with a wrist drop cannot lift his hand upward in which the fingers are pointing towards the ceiling.
Wrist drop is a sign of injury of radial nerve that is said to occupied proximal to the elbow joint .
Radial nerve is a continuation of posterior cord of the brachial plexus. It is branch of C5,C6,C7,C8 and T1. Brachial plexus as we all know is the plexus of nerves formed or gotten by the anterior/ventral rami of the lower 4 cervical and the first part of thoracic which is C5,C6,C7,C8 and T1 spinal nerves with very little contribution from C4 to T2 spinal nerves.
Brachial plexus consists of 4 components: roots,trunks,divisions and cords .The roots and trunks are located in the neck ,divisions is in the clavicle and the cords in the axilla. It is at the branches of posterior cord that we can find radial nerve (C5,C6,C7,C8 and T1)
One of the Causes of wrist drop include a stab wound to the shoulder area just below the clavicle in the shoulder region . This is the area where the radial nerve is the terminal branch of the Posterior cord of the brachial plexus. Humeral fracture ( fracture of the humerus) can also cause injury to the radial nerve, because the radial nerve runs through the radial groove on the lateral border of the bone. Let's list the causes of wrist drop :
Wrist drop can be caused by :
Vitamin B1(Thiamin) deficiency (beriberi) can result to wrist drop .
Prolonged / continuous use of crutches
Deep cuts on the wrist or arm
Lead poisoning
Infection or inflammation
Stab wound to the shoulder part
Injuries that can make one to keep his arm in an awkward position for too long while sleeping or working
Crutches pressing under the arm and prolonged usage
Injuries or bruises that put pressure on the radial nerve
The Symptoms are :
Pain ,Weakness, Numbness, unable to lift his wrist ,Wrist hangs limp, Difficulty making a fist ,
Clinical test for wrist drop is ;
When testing for wrist-drop deformity, the patient is asked to hold the affected part or arm out with the forearm (antebrachium) parallel to the floor. The back of the hand should be facing the ceiling and the fingers should also be pointing downwards. The patient with the wrist drop will not be able to move the hand(manus)from that position to one where the wrist and fingers are straight.
Treatment of a wrist drop and radial nerve palsy :
Physical therapy to strengthen the muscles and increase the range of motion
The use of Anti-inflammatories
The use of Pain medicines
Use of Splint or cast
A therapy that applies a gentle electric current to the muscles and may help reduce pain. This is called Transcutaneous electrical nerve stimulation.
Surgery with the main purpose of (Repairing a broken bone, removing a tumor or cyst ,repairing the nerve or relieving the entrapped nerve and subsequent pressure on the nerve etc .)
How can you prevent a wrist drop?
1.It is necessary to switch between the tasks that require different movements .
2.Maintaining a good posture at work.
3.Using pillows to avoid awkward sleeping positions.
4.Taking breaks between tasks in an occupation that requires repetitive motion.
5.Following proper ergonomics.
Summary
Wrist drop is a pathological condition in which there is an injury to the radial nerve causing radial nerve palsy . It is mainly caused by : wearing tight watches pressing on the wrist,crutches pressing under the arm and even deep cuts on the wrist or arm. It is mainly treated with splint or cast .
Thank you very much for reading . I am hear for further explanations for the one that appears vague or nebulous.
Thanks for reading !
Reference