title: Consistency of strength curves for determining maximal effort production during isokinetic knee testing of anterior cruciate ligament-deficient patients.
abstract: The purpose of this investigation was to attempt to establish decision rules for determining maximal effort production during isokinetic strength testing of unilateral anterior cruciate ligament-deficient patients based on the degree of strength curve consistency within a set. Thirty-three participants performed six bilateral knee extension and flexion exertions at maximal effort and at 80% of perceived maximum at testing velocities of 60 and 180°s(-1). Within-set consistency was quantified by computation of the variance ratio across strength curves. Tolerance interval-based cutoff scores covering 99% of the population were calculated for declaring efforts as being maximal or not at confidence levels of 90%, 95%, and 99%. The sensitivity percentages attained for the injured knee for both testing velocities ranged between 9.1% and 27.2%, while specificity percentages ranged between 84.8% and 100%. For the non-injured knee, sensitivity values for both testing velocities ranged between 21.2% and 45.0%, while specificity percentages ranged between 97.0% and 100%. The developed decision rules do not effectively discriminate on an individual patient basis between maximal and non-maximal isokinetic knee musculature efforts. Further research is needed for development of methods that would enable to ascertain maximal effort production in this patient population during knee muscle strength testing.
authors.affiliation: a Resource Environmental Associates, Ltd ., Markham , ON , Canada.
authors.forename: Sivan
authors.initials: S
authors.lastname: Almosnino
authors.affiliation: b Department of Physical Therapy, The Stanley Steyer School of Health Professions, Sackler Faculty of Medicine , Tel Aviv University , Tel Aviv , Israel.
authors.forename: Zeevi
authors.initials: Z
authors.lastname: Dvir
authors.affiliation: c Department of Orthopedic Surgery , Kingston General Hospital , Kingston , ON , Canada.
authors.forename: Davide D
authors.initials: DD
authors.lastname: Bardana
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000503:physiopathology*; D000070598:Anterior Cruciate Ligament Injuries / Q000175:diagnosis* / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D003661:Decision Support Techniques; D005080:Exercise Test / Q000295:instrumentation; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011237:Predictive Value of Tests; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Anterior cruciate ligament; isokinetic; knee; maximal voluntary effort; submaximal