The double crush syndrome: a common occurrence in cyclists with ulnar nerve neuropathy-a case-control study.
OBJECTIVE
To evaluate the incidence of double crush syndrome in the upper limbs of cyclists with clinical diagnosis of ulnar nerve neuropathy.


METHODS
Case-control study.


METHODS
Outpatient clinics and university setting.


METHODS
Consecutive sampling of 70 cyclists (140 upper limbs) with a mean age of 36 years (+/-11.3). Seventy-two upper limbs were excluded, leaving 40 upper limbs with a clinical diagnosis of ulnar nerve neuropathy [ULNN (+)] and 28 without symptoms of ulnar nerve neuropathy [ULNN (-)].


RESULTS
Cyclists were examined clinically for the presence of proximal dysfunction using the following testing (independent variables): (1) thoracic outlet syndrome provocation testing: elevated arm stress test and modified Cyriax release test; (2) presence of an elevated first rib: cervical rotation lateral flexion test; and (3) presence of proximal symptoms: reports of neck pain and shoulder pain.


METHODS
The upper limbs of cyclists were categorized into 2 groups (dependent variable)-ULNN (+) and ULNN (-)-based on history, symptoms, motor, sensory, and provocative clinical testing.


RESULTS
A significantly greater number of upper limbs of cyclists with ULNN (+) presented with positive provocative testing for thoracic outlet syndrome (elevated arm stress test P = 0.005; modified Cyriax release test P = 0.002) than did the upper limbs of cyclists with ULNN (-). The likelihood for the presence of neck pain, shoulder pain, and an elevated first rib was 3, 5, and 12 times greater, respectively, in the ULNN (+) than the ULNN (-) group.


CONCLUSIONS
A statistically significant greater number of the upper limbs of cyclists with clinical diagnosis of ulnar nerve neuropathy presented with proximal dysfunctions suggestive of double crush syndrome.
Smith
Tanya M
TM
Center of Rehabilitation Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA.
Sawyer
Steven F
SF
Sizer
Phillip S
PS
Brismée
Jean-Michel
JM
D000293:Adolescent; D000328:Adult; D001642:Bicycling / Q000293:injuries*; D016022:Case-Control Studies; D003444:Crush Syndrome / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015205:Northwestern United States / Q000453:epidemiology; D015206:Southwestern United States / Q000453:epidemiology; D017769:Ulnar Nerve Compression Syndromes / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology