These data provide both validation and st and ards for other users and indicate the power of the instrument for detecting change in sample population s. CONCLUSIONS The  ODI  remains a valid and vigorous measure and has been a worthwhile outcome measure .
The behavior of the instrument is incompletely understood , particularly in sensitivity to real change
STUDY DESIGN The Oswestry Disability Index ( ODI ) has become one of the principal condition-specific outcome measures used in the management of spinal disorders .
This review is based on publications using the ODI identified from the authors ' personal data bases , the Science Citation Index , and h and search es of Spine and current textbooks of spinal disorders .
OBJECTIVES To review the versions of this instrument , document methods by which it has been vali date d , collate data from scores found in normal and back pain population s , provide curves for power calculations in studies using the ODI , and maintain the ODI as a gold st and ard outcome measure .
SUMMARY OF BACKGROUND DATA It has now been 20 years since its original publication .
More than 200 citations exist in the Science Citation Index .
Comparison of trunk strength measurements between two different isokinetic devices used at clinical settings.
Intradevice reliability of isokinetic trunk strength measurements has been studied frequently , but no evidence is available on interdevice reliability . This motivated the present study , in which two isokinetic devices , the Ariel 5000 and Lido Multi-Joint II , were compared in a sample of 41 subjects ( 20 healthy and 21 low back pain subjects ) . The measurements were made in a r and om order with both machines . The results showed that the two isokinetic machines gave quite different results in trunk flexion-extension strength measurements . A statistically significant difference was present in the average peak torques between the two devices , with the exception of flexion at low angular velocity ( 60 degrees/s ) , and the correlations between the two measurements were low . The results were assumed to be more of a reflection of the interdevice variations ( hardware and software , attachment of the subject ) than of learning effects or other phenomena . We conclude that isokinetic trunk-muscle strength test results with the Ariel and Lido are device specific , and one can not automatically compare results obtained from different devices with each other
These data provide both validation and st and ards for other users and indicate the power of the instrument for detecting change in sample population s. CONCLUSIONS The  ODI  remains a valid and vigorous measure and has been a worthwhile outcome measure .
The behavior of the instrument is incompletely understood , particularly in sensitivity to real change
STUDY DESIGN The Oswestry Disability Index ( ODI ) has become one of the principal condition-specific outcome measures used in the management of spinal disorders .
This review is based on publications using the ODI identified from the authors ' personal data bases , the Science Citation Index , and h and search es of Spine and current textbooks of spinal disorders .
OBJECTIVES To review the versions of this instrument , document methods by which it has been vali date d , collate data from scores found in normal and back pain population s , provide curves for power calculations in studies using the ODI , and maintain the ODI as a gold st and ard outcome measure .
SUMMARY OF BACKGROUND DATA It has now been 20 years since its original publication .
More than 200 citations exist in the Science Citation Index .