Differentiating between types and levels of isokinetic knee musculature efforts

Ascertaining Maximal Voluntary Effort Production During Isokinetic Knee Strength Testing of Anterior Cruciate Ligament–Reconstructed Patients

“…4 Upon arrival to the laboratory, the participants performed a general warm-up consisting of 5 mins of cycling on a stationary bicycle followed by examiner-guided stretching of the hamstring, quadriceps, and triceps surae muscle groups. Measurements of the concentric isokinetic strength of the knee extensor and flexor muscles of the ACL-reconstructed knee were performed using a commercial isokinetic dynamometer (Biodex Multi-Joint system 3; Biodex Medical Systems Inc, Shirley, NY).…”

“…4 The next two sets involved performance of efforts at a self-perceived 50% and 75% maximal effort. Before the performance of each of these two sets, the participants performed a self-selected number of practice repetitions to estimate as best as they could the level of effort required.…”

“…To blind the examiner performing the data analysis (S. Almosnino) of the actual effort performed, all header data containing set information were removed, and all files were labeled as maximal effort attempts. 4 A second examiner (E.D. Diaconescu) kept a separate list of the actual efforts corresponding to each data file.…”

“…This particular investigation relied on two predictor variables, namely, cross-correlation (R xy ) and percent root mean square difference (%RMSD) scores, calculated between pairs of strength curves to quantify the degree of strength production consistency within a given set. 4 The premise for use of these measures was that a higher degree of set internal consistency would be observed when exerting maximal efforts because of adoption of a neuromuscular strategy that attempts, during performance of consecutive repetitions, to recruit all possible motor units of agonist muscle at the highest possible frequency while minimizing antagonist muscle group activity. 5,6 In effect, this would be expected to be manifested in pairs of strength curves within a given set being more similar in shape and magnitude, resulting in higher R xy and lower %RMSD scores, respectively.…”

Use of kinematic algorithms to distinguish people with chronic non-specific low back pain from asymptomatic subjects: A validation study.

“…These subjects were asked firstly to perform all the trunk tests in a natural way (asymptomatic controls) and, secondly, to repeat the task simulating CLBP (simulators) while carrying out each movement task (14). …”