FACTORS AFFECTING THE VARIABILITY OF THE TORQUE CURVES AT ISOKINETIC TRUNK STRENGTH TESTING

Objectives: To evaluate the relation between variability of the torque curves and factors such as age, gender, measurement speeds, and perio d from low back pain (LBP) onset at isokinetic trunk strength testing. Design: Observational. Setting: Hospital. Patients: One hundred forty -three consecutive LBP patients (acute, subacute, and chronic) who rec eived physical therapy, and 200 healthy volunteer subjects.Main Outcom e Measures: The variability of the torque curves is an indicator of co nsistency of effort, and was measured as the coefficient of variance ( CV) at different measurement speeds in isokinetic trunk flexion/extens ion strength testing. Results: The CV was lower in men than in women a t the faster measurement speed. LBP patients had higher CV values than healthy subjects, The CV was different according to gender and measur ement speed, but not different according to age and periods from LBP o nset. Conclusion: The CV was affected by measurement speed and gender, but not by age or period from LBP onset, Because the CV was higher in LBP patients than in healthy subjects, this value may be usable as an adjunctive index of LBP. (C) 1998 by the American Congress of Rehabil itation Medicine and the American Academy of Physical Medicine and Reh abilitation.