Waiter's tip position is seen in?

HPSSSB Staff Nurse - 2016

Applied Physiology

Easy

Appeared in: HPSSSB Staff Nurse - 2016

Explanation

Erb's palsy is caused by an injury to the upper trunk of the brachial plexus, involving the C5 and C6 nerve roots.
This injury leads to paralysis of muscles responsible for shoulder abduction and external rotation, as well as elbow flexion and forearm supination.
The resulting unopposed action of the remaining muscles forces the arm into a characteristic posture known as the 'waiter's tip' or 'policeman's tip' hand.
This posture involves an adducted and internally rotated shoulder, an extended elbow, a pronated forearm, and a flexed wrist.

Option A: Bell's palsy is a paralysis or weakness of the muscles on one side of the face. It is caused by trauma or inflammation of the facial nerve (Cranial Nerve VII). It does not affect the arm.
Option B: Facial palsy is a general term for paralysis of the facial nerve (CN VII), with Bell's palsy being the most common type. It affects facial muscles, not the brachial plexus or the arm.
Option D: Congenital dislocation of the hip (now often called developmental dysplasia of the hip or DDH) is a problem with the formation of the hip joint in infants. It affects the lower limbs and is diagnosed with signs like the Ortolani and Barlow tests, not arm posture.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Clinical signs of peripheral nerve injuries as background academic context rather than a clinical decision trigger.
Recognizing the 'waiter's tip' sign is critical for nurses, especially in neonatal and pediatric units, for the early identification of a potential brachial plexus injury.
Nursing interventions for a newborn with Erb's palsy include careful handling to protect the paralyzed arm, positioning to prevent contractures, and educating parents on passive range-of-motion exercises.
What if the infant presented with a paralyzed hand and a drooping eyelid (ptosis)? This would suggest Klumpke's palsy, an injury to the lower brachial plexus (C8-T1), which is much rarer and has a different clinical presentation and prognosis.

How to Approach the Question

First, identify the key clinical sign presented in the question: 'Waiter's tip position'.
Recall or deduce the anatomical basis of this specific posture. Think about which muscles would need to be weak for an arm to fall into this position.
Connect the muscle weakness pattern to a specific nerve or nerve root injury. The 'waiter's tip' posture points to a loss of shoulder abduction/external rotation and elbow flexion, which is controlled by the upper brachial plexus.
Evaluate the given options. 'Erb's palsy' is the specific term for an upper brachial plexus (C5-C6) injury.
Eliminate the other options by identifying the body part or system they affect. Bell's/Facial palsy affects the face, and congenital hip dislocation affects the hip, making them incorrect.

Concept Tested & Keywords

QD41stt9y8PZ33ya_DVtd4

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 1077-1079

E6 Anatomy BDChaurasia V1 10e p. 61-63