To investigate the validity of the Trendelenburg test (TT) using an ultrasound-guided nerve block (UNB) of the superior gluteal nerve and determine whether the reduction in hip abductor muscle (HABD) strength would result in the theorized mechanical compensatory strategies measured during the TT.
Convenience sample of 9 healthy men. Only participants with no current or previous injury to the lumbar spine, pelvis, or lower extremities, and no previous surgeries were included.
Ultrasound-guided nerve block.
Hip abductor muscle strength (percent body weight [%BW]), contralateral pelvic drop (cPD), change in contralateral pelvic drop (ΔcPD), ipsilateral hip adduction, and ipsilateral trunk sway (TRUNK) measured in degrees.
The median age and weight of the participants were 31 years (interquartile range [IQR], 22-32 years) and 73 kg (IQR, 67-81 kg), respectively. An average 52% reduction of HABD strength (z = 2.36, P = 0.02) resulted after the UNB. No differences were found in cPD or ΔcPD (z = 0.01, P = 0.99, z = −0.67, P = 0.49, respectively). Individual changes in biomechanics showed no consistency between participants and nonsystematic changes across the group. One participant demonstrated the mechanical compensations described by Trendelenburg.
The TT should not be used as a screening measure for HABD strength in populations demonstrating strength greater than 30%BW but should be reserved for use with populations with marked HABD weakness.
This study presents data regarding a critical level of HABD strength required to support the pelvis during the TT.
*Faculty of Kinesiology, Running Injury Clinic, University of Calgary, Calgary, Alberta, Canada
†Department of Radiology, Faculty of Medicine, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
‡Faculty of Kinesiology, Sport Medicine Centre, University of Calgary, Calgary, Alberta, Canada
§Department of Kinesiology and Health Promotion, School of Education, University of Kentucky, Lexington, Kentucky
¶Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
Departments of ‖Community Health Sciences and
**Pediatrics, University of Calgary, Calgary, Alberta, Canada
††Faculty of Nursing, University of Calgary, Calgary, Alberta, Canada.
Corresponding Author: Karen D. Kendall, MKin, CAT(C), KNB230, Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary, Alberta T2N 1N4, Canada (firstname.lastname@example.org).
R. Ferber is supported by a Population Health Investigator Award from Alberta Innovates Health Solutions and the Workers Compensation Board Alberta. C. Emery is supported by a Population Health Investigator Award from Alberta Innovates Health Solutions and a Professorship in Pediatric Rehabilitation (Alberta Children's Hospital Foundation), Alberta Children's Hospital Research Institute for Child and Maternal Health, Faculty of Medicine. We affirm that we have no financial affiliation (including research funding), involvement with any commercial organization, or conflict of interest that has a direct financial interest in any matter included in this manuscript.
This study was approved by the University of Calgary Conjoint Health Research Ethics Board.
Received January 25, 2012
Accepted May 8, 2012