Elbow Flexion Test Research Articles

The drop-out splint: An alternative to the conservative management of ulnar nerve entrapment at the elbow

U lnar nerve entrapment at the elbow involves a compression neuropathy of the ulnar nerve as it courses along the medial head of the triceps, through the postcondylar groove behind the medial epicondyle and through the cubital tunnel. Numerous etiological factors have been identified that contribute to ulnar nerve neuropathy at the elbow. These factors include bony trauma, ganglia, soft tissue tumors, foreign bodies, congenital abnormalities, and cubitus valgus of developmental or traumatic origin. Toxic, metabolic, and nutritional changes secondary to diabetes, alcoholism, and vitamin deficiencies have also been identified as causative factors, as have habitual subluxation of the ulnar nerve and various anatomic sites of entrapment. 13 These sites include the arcade of Struthers, the medial head of the triceps, the aponeurosis of the flexor carpi ulnaris, and the cubital tunnel. 4 Individuals with ulnar nerve entrapment at the elbow typically present with complaints of radiating pain accompanied by paresthesias in the ulnar nerve distribution of the forearm and hand . Muscle-wasting of the ulnar-innervated intrinsics may be observed, although this is usually an indication of more prolonged or severe compression. Clinical signs include the presence of a positive percussion test (Tinel's sign), which is indicative of localized nerve irritability. A positive elbow-flexion test results in symptoms of pain, numbness, and tingling secbndary to the mechanical and pathophysiological events that occur during elbow flexion. 5 Both subjective symptoms and objective clinical signs may suggest the presence of an ulnar nerve entrapment syndrome. Electrodi-

The Elbow Flexion Test

The elbow flexion test is a little known, inadequately standardized, and poorly understood clinical test for the cubital tunnel syndrome. To evaluate and define this test, 13 patients with clinical and electrophysiologic evidence of cubital tunnel syndrome were tested with elbow flexion in a standardized manner. This consisted of full elbow flexion with full extension of the wrists for three minutes. All patients noted the onset of or the increase in one or more of the symptoms of pain, numbness, or tingling with this test. Numbness and tingling followed the sensory distribution of the ulnar nerve, but pain was not limited to the ulnar nerve distribution. The symptom complex, rapid onset, and rapid resolution of symptoms support a locally induced segmental ulnar nerve ischemia as the cause of symptoms. This study demonstrates the elbow flexion test to be a useful, reliable, and provocative test for the cubital tunnel syndrome.

The External Compression Syndrome of the Ulnar Nerve at the Cubital Tunnel

Diagnosis of the cubital tunnel external compression syndrome, and subsequent avoidance of further external pressure, minimizes the possibility of progressive crippling of the hand. The usual clinical features are local tenderness over the cubital tunnel, often accompanied by distal paresthesias, and neurological deficit in the ulnar nerve distribution with sparing of the flexor digitorum profundus and flexor carpi ulnaris muscles; the elbow flexion test, described by the author, awaits evaluation in the diagnosis of the syndrome. Clinicians and others concerned with positioning patients on the operating room table or caring for patients in the ward should be aware of the syndrome. Avoidance of a position of the elbow which predisposes to external compression of the cubital tunnel is mandatory and active elbow movement should be encouraged in bedridden and chair-bound patients. Surgical treatment is sometimes indicated, at least to halt progression of the palsy. A classification of the cubital tunnel syndrome is proposed: physiological, acute and subacute due to external pressure (both forming the cubital tunnel external compression syndrome) and chronic (space-occupying lesions and loss of volume due to lateral shift of the ulnar as a consequence of childhood injury to the capitular epiphysis). Nerve conduction studies may be helpful in the diagnosis of the doubtful cubital tunnel syndrome, particularly when there is definite impairment of power or sensation in the hand.