Abnormal Resting Posture of Arms and Hands

CLINICAL DIAGNOSTIC MANUAL

Abnormal resting posture of the arms and hands refers to an unusual or abnormal positioning of the upper extremities when not actively in use. This condition can be a sign of neurological or muscular damage and may involve various structures of the central and peripheral nervous systems.

Injuries affecting the internal capsule, nerve roots, or peripheral nerves can alter the posture and muscle tone of the arm and hand, leading to visible deformities and loss of function. Identifying the underlying cause through detailed clinical evaluation and complementary tests is essential for directing appropriate treatment.

Condition	Clinical Symptoms and Signs	Suspected Diagnosis	Confirmatory Diagnosis
Internal capsule lesion	Contralateral hemiparesis, flexor posture of the arm, pronation of the hand, generalised weakness	Clinical history, neurological exam	Brain MRI, brain CT
Anterior root lesion at T1	Weakness and atrophy of hand muscles, claw hand posture, loss of reflexes	Clinical history, neurological exam	EMG, nerve conduction studies, spinal MRI
Ulnar nerve lesion	Weakness and atrophy of the interosseous and lumbrical muscles, claw hand posture, sensory loss in the little finger	Clinical history, neurological exam, specific signs of ulnar nerve damage	EMG, nerve conduction studies
Radial nerve lesion	Wrist drop, weakness in elbow and wrist extension, sensory loss on the back of the arm	Clinical history, neurological exam	EMG, nerve conduction studies