No idea

This is an interesting question. What specifically do researchers believe is advantageous about isokinetic rehabilitation? Cost is usually a limiting factor to this type of rehabilitation and therefore may not easily translate into general clinical settings. Furthermore, isokinetic strengthening is not the physiologic mechanism primarily used during functional movement. I would be interested in hearing others' thoughts on the matter.

Allison

During isokinetic testing or training, muscle contractions occur concentrically or eccentrically. These contraction types are physiologic, however movement of the extremity is not a natural movement. The use of isokinetic system for training may be expensive, but for eccentric training it may be preffered.

In testing the data about peak torques are ok, but I think that strength ratios are not functional even they were said be to be functional, like eccHams/conQuad. Because the peak torques occur at different knee angles (for example hamstrings at 33 degrees, quadriceps at 54 degrees), and a good H/Q ratio may not represent that hamstrings have the ability of the prevent the knee from the anterior translation forces that caused by quadriceps. Thus, I think that isometric knee strength ratios may be more functional than isokinetic ones.

No.

Hi Leon, 

I think that Isokinetic testing in orthopedic injury prevention and rehabilitation is still important because it can help you in planning the rehabilitation but it isn't the main thing to do. At the very begging of therapy you can measure very precise the preformance of injured area and continously monitor whole recovery of the patient. Also it can help you in diagnostics and prevention. The other side is that you don't get realiable functional assesment because of whole physiology of human body. Despite of it's cost, I think that is still very helpful thing to do because you get results in every angle of joint motion. 

Isokinetic testing can provide objective measures for both the patient and clinician during the rehabilitation program. This is a very technical method on assessing isokinetic strength by looking at how much force, work, etc can be produced at every joint angle. You can also use these objective measures to compare with the normative values of rest of the population. It also can help you figure out muscle group ratios which is important for rehabilitation.

However, like what others have said, it does not assess functional strength which is important to understand when deciding if a patient should return to play. The machine also costs college tuition (no big deal). In my opinion, isokinetic testing is relevant in rehabilitation (if available), but shouldn't be the determining factor on whether if the patient is ready to return to play.

As with all tests and treatments, the first requirement is to know what you are attempting to accomplish. Isokinetics were originally called accommodating resistance because the amount of resistance was a function of the velocity the person attempted to exert against the fixed velocity of the isokinetic device. If the person exerted significantly greater velocity through their muscle action the device would "put on the brakes" to prevent movement from occurring at a velocity greater than selected.  It is based on the force-velocity relationship of muscle. As velocity approaches max, resistive force approaches min; as resistive force approaches max. velocity approaches min. (isometric muscle action)..

In the 1990's some persons who lacked the understanding to realize the purpose of isokinetic training claimed isokinetics to be worthless, because a number of papers were published in the West that showed training using isokinetic resistance did not improve sprint speed, jump height, etc. Isokinetics were said to be "non-functional". Unfortunately, due to the lack of understanding in the West, people did not know that maximum maximorium force (the characteristic being measured with isokinetics) does not correlate with maximum maximorium velocity of movement (Zatsiorsky, 1969, 1995; Zatsiorsky & Kraemer, 2006). 

If you are trying to determine maximum force of a muscle group in a fixed line of action, either concentrically or eccentrically, the use of isokinetics is not only useful but one of the best choices due to the strict control of the force-velocity relationship. The information gained tells the investigator the force producing capabilities of the muscle group that produces the movement being tested. For eccentric muscle actions, a study of the literature will demonstrate isokinetic dynamometry to be nearly irreplaceable for such investigations, though the manner of testing may require an advanced understanding of the "rules" of eccentric muscle actions.

Dear Leon,

first of all a great question !

Looking sincerely at the relevance of a specific intervention , I always focus on the corresponding goals, which demand various levels of action. For example a very general question: Can then patient climb stairs? Answer: Yes or no -just by observation.

Once the questions get more specific, the evaluation becomes more specific. So what about arthrokinematics ? This will demand a highly skilled manual therapist.

So what about neuromuscular performance ? This can be started by detailled funtion tests, but needs to be further assessed by testing systems with higher standardisation etc. To me this implements isokinetic systems and several other devices as well.

And by the way one could drive your relevance question even further: How in the world do most people test only concentric performance ? Isn't eccentric activation more relevant ? Isokinetic systems can not be operated by pulling up programms and one test for all just clicking OK? To me, this is why you ask about relevance ? There are so many specific aspects in testing for specific questions and goals. It is up to all of us users worldwide to move on into a finetuned way of using isokietic systems.

We work with three diffrent isokinetic systems for over 30 years. We are clinicians who have a clear picture of the relevance & limitations of isokinetic systems.

Also there have been many moves towards the enhancement of quality application. Unfortunately very little of this is found in the mainstream of scientific publications. Many great scientific groups start great research projects,

but once it comes to details such as isokinetic test designs & parameters it's like travelling back 30 years.

With best wishes for you, your question and your ongoing projects

Manuela