Isokinetic Evaluation of Muscular Performance

Abstract

Interfacing of microprocessors with isokinetic dynamometers has enabled the rapid quantification of many parameters of muscle function including peak torque, angle-specific torque, work, power, torque acceleration energy, and various endurance indexes, and the measurements with these devices can be made isometrically at various angular positions and isokinetically (concentrically or eccentrically) with a large scale of angular speeds. Many of these parameters, however, lack evidence of validity, reproducibility, and/or clinical relevance. Peak torque has been and still is the most properly studied isokinetic strength testing parameter and its use can be recommended for research and clinical purposes. Concerning testing of muscular endurance, the absolute endurance parameters (for example, work performed during the last five repetitions and total work in a 25-repetition test with a speed of 240 degrees/s) are the best for use. Many internal and external factors in the isokinetic testing procedure can have an undesirable effect on the test result. However, through proper education and strict adherence to the test instructions, it is possible to successfully control the confounding variables. In scientific work, isokinetic devices have greatly expanded the possibilities for studying dynamic muscle function. There is also little doubt about their usefulness in documenting the progress of muscular rehabilitation. A disadvantage of isokinetic devices is that isokinetic movement seldom occurs in actual human performance tasks and that the isokinetic training effect is, therefore, quite (although not completely) specific to that type of movement. In addition, being normally an isolated joint exercise, isokinetic training can produce large loads on the involved joints and may, therefore, under certain conditions be dangerous for healing tissues.

Functional limitation of the lower limb following anterior cruciate ligament reconstruction up to 72 weeks

“…The limb symmetry index on PT was 90 % or more (Fig.1). This is in agreement with the literature [10,16]. Sapega [16] and Kannus [10] described a difference of 10-20 % (LSI PT 90-80 %) as possible abnormal and one greater than 20 % (LSI PT < 80 %) as definitely abnormal.…”

“…The mean Cybex dynamometer index (LSI PT) was calculated as a percentage of the mean of the involved (non dominant) limb divided by the mean of the uninvolved (dominant) limb and the result was multiplied by 100. A limb symmetry score of less than 90 % was considered abnormal [10,16].…”

Assessment of Neuromuscular Function Using Percutaneous Electrical Nerve Stimulation

“…Currently, VAL evaluated using the twitch interpolation technique is the most valuable method of assessing the level of muscle activation 22 . Furthermore, peak torque assessed using an ergometer is the most properly studied strength testing parameter applicable of use in research and clinical settings 23 .…”

Relationship Between Ball Kick Velocity and Leg Strength: A Comparison Between Soccer Players and other Athletes

“…After one practice run, the test was performed twice in between one-minute intervals to eliminate the effects of fatigue. Isokinetic strength was evaluated with maximum torque (unit: Nm) and the larger value was interpreted to have the larger isometric leg strength (Kannus, 1994).…”