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Rehabilitation on an isokinetic device

Interview by Alexandre Germain – Guillaume Vassout

Following the paper of last April 11 "backstroke in 1993 on isokinetics and eccentric work", I suggested that two physiotherapists experienced in this technique share their experience with us. I therefore took advantage of the last match of the French team in Sarajevo to bring together around the same round table a Parisian, Guillaume Vassout, and a Lyonnais, Alexandre Germain, both physiotherapists with the A. Interview.

LFC: A short presentation of your career to start?

AG: Alexandre Germain, 44, graduated from Berck-sur-mer in 99, I then went to Sedan Ardennes Football Club to work as an assistant physiotherapist with Christophe Geoffroy for a season, before joining Lyon and the Gerland medical center with doctor Jean-Marcel Ferret, then doctor of the French football team. At the same time, I worked in the professional cycling community and with French ice hockey teams. I have been a physiotherapist for the French football team since 2016. I specialized in lower limb traumatology, muscle injuries and in rehabilitation after ACL ligamentoplasty, rehabilitation and RTP.

GV: Guillaume Vassout, 35, graduated from the Assas school in Paris, I did 4 years as a liberal before joining the Clairefontaine medical center in 2013 where we only take care of athletes today high level, 90% footballers. The most frequent pathologies that I deal with are operated ACLs, pubalgia and muscular pathologies. If I had to cite a referent in isokinetics, it would be Professor Jean-Louis Croisier from the school of Liège.

LFC: How long have you been working with isokinetic devices?

GV: Since 2013 and my arrival in Clairefontaine. I worked on the 3 machines, Cybex Norm, Biodex and Con-Trex, which I use interchangeably for rehabilitation and evaluations.

AG: In 2000, I started working on two Cybex machines in Gerland. The partnership with Médimex, which is based in Lyon, was very strong and the experience of Jean-Marcel Ferret important. I spent half of my time during the week on an isokinetic device for rehabilitation/evaluation work as well as for training. I only work on Con-Trex today.

LFC: What pathologies do you treat?

AG: Lots of crossovers, in rehabilitation and testing. We now test them at 3 months when they are our patients, so used to working in iso, then at 6 months and 9 months. The rest are muscle damage, lots of hamstrings and Achilles and patellar tendinopathy. The tests after ligament reconstruction are performed concentrically for the quadriceps and hamstrings at 240 and 90°/sec and eccentrically for the hamstrings at 30°/sec. The reference in concentric is 60°/sec, but we stayed on this “historic” speed of 90°/sec in Gerland.

We are working on this protocol with the surgeons, of course, who trust us completely. For external patients that we do not know, if it is a DIDT, we do not test them for 4 ½ months. We had too many muscle lesions on the machine in the sampling area with tests done at 3 months, in patients who had not yet started eccentric work. For patients who have worked well in eccentric iso before, you have almost no deficit on the hamstrings at 3 months. On the other hand, there is still a deficit on the quadriceps concentrically at 3 months.

GV: For ligament reconstructions, the test is performed concentrically at 60 and 240°/sec and eccentrically for the hamstrings at 30°/sec. We can do the first test at 2 ½ months if the clinic allows it, but we are around 3 months on average for our patients. For outpatients, a bit like Alexandre, the first test is only done at 6 months. But not all surgeons agree. Some, few, forbid us to start iso eccentric labor before 6 weeks and do not want an iso test before 6 months.

LFC: What do you expect from isokinetic rehabilitation?

AG: If it's a muscle lesion, I offer iso work from the first days after the lesion according to the clinic until almost the return to the group and the RTP. In fact, it will go hand in hand with the passage of my different levels on the ground. On the cross, much less. It remains a great tool for quantifying work. Afterwards, when they have recovered everything on the open chain machine, we transfer everything to functional and re-athletic training and we hardly come back to it. Unless you have a temporary overload on the knee, with a small patellar chondropathy for example, you may have to do joint running-in.

GV: For hamstring rehabilitation, I'm going to have the player for 3 to 6 weeks, so he will have iso all the time. Even at the end of rehabilitation with a symmetrical test, I continue to work in iso. We can always vary something, the amplitudes, the positioning, the speeds. So even if he is on the field, we continue to do it. The same for a crusader. We can even offer work on the contralateral limb.

LFC: So, point by point, the first session first, and then the following ones, how do you increase the resistances, the speeds...?

AG: If we take hamstring rehabilitation, there are 4 progression criteria: amplitude, speed, intensity and total workload. We work as close as possible to the maximum amplitude, depending on the pain. I start at a slow speed, 5°/sec which I will progress to 10, 15 and up to 30°/sec. And the intensity of work will be adapted to his pain threshold. I explain to him well from the first session that he must not trigger pain. I don't set a specific percentage, I ask him to always be on the edge of pain. I do not increase by 5 in 5°/sec as we can often see. I start at 5 sets of 8 reps. I can go up to 6 sets of 8. When the player starts to saturate in terms of work intensity (often around 90-100 Nm at 5°/sec), I go to 10°/sec, gradually. Ditto to go to 15 then 30°/sec. Roughly, if I do 5 sessions per week, rehabilitation on an iso device will last 3 weeks maximum.

GV: The criteria for us are pain, percentage compared to the contralateral side and range of motion.

The first sessions are familiarization without a screen, to know at what level he reaches his pain threshold. We use the contralateral test, or we have a fairly recent iso test. We start at 10°/sec, first on an amplitude of 90 to 45° of flexion, even if it is easy, and we put ourselves between 30% and 50% of the peak of force on our contralateral side. We also adjust according to the pain. We increase the amplitude quickly enough to go as far as extension, so 0°, always at 10°/sec. We then go to 50% then 70% of the max, still without pain. Then we increase the speed, to 20°/sec, at the same time as we go back to 50% of the maximum peak; and then increases to 70% of the peak, still at 20°/sec; before increasing to finish the speed at 30°/sec and a work at 70%. This is our max level. If they are able to work at 30°/sec and 70% of the maximum peak, there is every chance that they are symmetrical. For the number of repetitions, we start at 4 times 8 to go up to 5 to 6 times 8 reps, great maximum.

LFC: What is your last iso session or the stopping criterion? GV: We don't systematically test. We can stay on this last session at 30°/sec, 70% of the maximum peak and 5 times 8 repetitions. If they succeed, the test will be symmetrical, even higher values on the injured side compared to the healthy side.

AG: We also make sure that they hold the intensity well until the end of the curve, so close to the extension and the external race, without stalling, with superimposable curves. It's really crucial. And I attach great importance to his positioning on the machine, so that he really feels his lesion area working. The goal is really healing, but also to avoid recurrence.

LFC: How do you manage the positioning of the player on the machine?

AG: If we take the example of a lesion of the biceps femoris, if the lesion is distal, he will work sitting down, if the lesion is proximal, I tilt him on his back and I play more in the positioning on the hip flexion , around 120°, rather than extending the knee which can remain at 20-30° flexion.

GV: The same for us. There may be differences from one device to another, which means that you will have to work sitting on one, while you can lie down on another. I always try to find the pain on the machine, especially if the ultrasound still shows an image, so farther from the external race. We can also play on the rotations, as for the diagonals of Kabat, from the internal rotation to the external rotation for a biceps, and vice versa for the semi-tendinosus.

LFC: Do you do a lot of iso in prevention?

GV: Systematically. At Clairefontaine, all INFs with a deficit of more than 20% will do so. They will also have functional group sessions in the field. For the most part, it is an eccentric deficit on the hamstrings. Even if we can think that it is not a real deficit, but a problem of neuromotor maturity. And on our professional players in rehabilitation, if there is a deficit on the contralateral side to the systematic evaluation, we will work on iso. With the idea of ​​being preventive. But just because you have an iso symmetric test doesn't mean you're fit, even with strong hamstrings. It is necessary to be interested in the peak of force compared to the weight, or ratio weight of body (RPdC). On my series of Ligue2 players, I averaged the DPRK on each of the speeds and I systematically raise my players to at least average when they are below. I will publish my results very soon.

AG: In tertiary prevention (on a player who has already had an injury), I do it for the rest of the season, at least once a week, combined with functional work all week. In the absence of injury, on an iso test at the start of the season for example, if the player has a deficit, he will work at least once a week, twice if possible, the rest of the work will be done functionally with a individualized program. The functional revolves around the "Good morning", the Askling protocol with the "Diver" and the "Glider", much more than the "Nordic" which remains a work in internal and average races and seems insufficient to me. For a quadriceps, if there is a deficit, we will also work, on iso or in the room on a machine (leg extension, press or squats).

LFC: Could you work without an iso device?

GV: It would be very difficult for me, I was immersed in it. For all rehabilitations, we use iso: pubalgia, ACL reconstruction, muscle damage, low back pain, shoulders, wrist, we do it on everything.

AG: I've been working with it every day for 20 years, so yes I'd be lost without it, even if today I'm doing less than I used to. It seems to me to be an almost obligatory tool. It is essential, added to the other tools. And yet we can do without. And you look today, even at the top level, we tend to separate ourselves from it a little because we say that it is analytical work. So yes, it is analytical, but if done well, it is very interesting. And coupled with functional work, it is particularly relevant.

Today, we tend to do functional and more functional. But at some point, what tool do you have to say that your hamstrings are capable of supporting such a load? LFC: What do you say to those who tell you that you don't tear your hamstring at 10°/sec sitting on a chair?

GV: It's those who don't practice iso who think like that.

AG: I answer that I do not stay on the iso, that I propose a functional work in parallel. At any time, it is necessary to transfer the analytical achievements into functional.

LFC: In my mind, the iso clearly serves me to do this analytical work, to work on the scar, to obtain a solid scar which will then allow me to work functionally, gradually and without restraint. And indeed, it should not be said that the iso is enough.

The end of the interview is more complicated to transcribe on subjects sometimes already mentioned, a casual discussion on the future of the iso, the training of users, the price of the machines, the ability to compare two tests carried out on two different machines, positioning on the machine, the temptation today to only do functional things...

This interview reinforced my idea that any working method, whatever it is, neither good nor bad, is above all “dependent operator”. The use of iso is no exception, I have been able to realize it for 30 years. Physiotherapists, because they are the best users of the iso, must learn to appropriate the machine, to reflect on the protocols and the positioning of the player to obtain the best result, also to obtain the confidence of the player who may be reluctant .

Without this, the work risks losing much of its interest and effectiveness and the “iso label” will not be enough.

Thanks to Guillaume and Alexandre for the quality of the exchanges. Feel free to post your comments online and share your experiences with us.

A future paper will give the floor to a physiotherapist who will tell us about the rehabilitation of muscle tears, hamstrings in particular, without using iso. A way to put into perspective what you have just read.



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