Physical rehabilitation aims to help people recover their mobility and strength after an injury or illness. One way to evaluate progress in rehabilitation is through isokinetic prototype tests that describe the dynamic characteristics of an isokinetic leg extension device for rehabilitation and control action. These tests use an isokinetic system to assess muscle strength and performance in a patient during isometric or isokinetic contraction. An experimental prototype allows the performance of the device to be evaluated in a controlled environment prior to use by the patient. In order to achieve physical recovery from musculoskeletal injuries in the lower limbs and achieve the reintegration of the affected subject into society as an independent and autonomous individual in their daily activities, a control model is presented that introduces a medical isokinetic rehabilitation protocol, where the element that allows carrying out such protocol consists of a magnetic particle brake whose control action is strongly influenced by the dynamics of the system when in contact with the end user, specifically the patient's legs in the stretch from the knee to the ankle. The results of these tests are valuable for health professionals seeking to measure their patient’s progress during the rehabilitation process and determine when it is safe and appropriate to advance in their treatment.

Background: The optimisation of this return to athletic activity pass by a better understanding of the behaviour of the muscle involved in knee function.In this study, we focused on the muscular activity of the muscle involved in the flexion of the knee. Preciseley on the relation between the muscular activity of the gastrocnemius and the hamstring among the patient that underwent an anterior cruciate ligament reconstruction with hamstring graft.Objective : The objective of the study is to compare, the muscular activity of the flexor knee muscle in patient that underwent an anterior cruciate ligament reconstruction with hamstring autograft and the individuals that have not undergone surgery.Methods : The participants have been divided into two groups : an healthy group and an experimental group that underwent an anterior cruciate ligament recontruction with hamstring graft. The participants had to performe a strenght test on a isocinetik dynamometer. The activity of the medial gastrocnemius, lateral gastrocnemius, femoral biceps and the semitendinosus were mesured during this test.The muscular activity of the muscle mentioned of the individuals in the first group were compared to the ones in the second group via a statistical analysis. Then, a ratio of the activity of the gastrocnemius muscle on the activity of the hamstring was calculated The results of the experimental group were then compared to the results of the control groupResults : The results showed a significative difference activity of the medial gastrocnemius, the femoral biceps and the semitendinosus muscles : the experimental group results were superior to the control group results However the evaluation of the activity reporting has shown significant differences in the two groupsConclusion : This study has allowed us to show a difference in muscular activity of the gastrocnemius and hamstring muscle between patient that underwent an anterior cruciate ligament reconstruction surgery and the heathy participants. However our approch has not allowed us to identify the relation between a heihtened gastrocnemius activity and a diminished hamstring activity following an anterior cruciate ligament reconstruction with hamstring graft. Quite on the contrary, we observed a higher activity of the two muscle groups. Nevertheless, it seem to be necessary to have a variation in situations during the analysis of the gastrocnemius muscle to fully understans its purpose in the functional activity of the knee of patient that have undergone an anterior cruciate ligament reconstruction.

Rehabilitation following anterior cruciate ligament reconstruction with hamstring graft allows the patient to regain his functional capacities and to support him in the resumption of sports activities. Rehabilitation also aims to minimize the risk of recurrence, which is why it ensures that the patient's muscular capacities develop properly until they return to sport. Isokinetics helps strengthen and assess the strength of muscle groups in the thigh, but controversy exists as to its use by resistance to the open kinetic chain knee extension that would cause the transplant to distend. The objective of this study is to determine the influence of isokinetic muscle strengthening on the possible laxity of the anterior cruciate ligament and to be able to determine risk factors. The study relates to a population having benefited from anterior cruciate ligament reconstruction with hamstring graft from 3 to 6 months after surgery. Two groups are differentiated, one group exposed to isokinetism during rehabilitation, the other group, named unexposed, undergoes rehabilitation without the use of isokinetism. An anterior knee laxity test is performed 6 months postoperatively using the GNRB® machine for all subjects according to the same protocol. The test results were statistically analyzed to determine a relative risk of transplant distension for each group in the study. Comparison of the results of each group by univariate analysis did not reveal any significant result. Multivariate analysis showed interactions in the two strata of the study. It was argued that the use of isokinetics seems to have no effect on the risk of developing distension for the majority of subjects in the exposed group. A tendency towards transplant protection was perceived for each variable except the age under 25 years (RRa = 1.07). The use of isokinetics does not appear to be a cause of transplant distension in patients undergoing an anterior cruciate ligament reconstruction when this method is introduced 3 months postoperatively.

Isokinetic testing of the knee joint is the “gold standard” in strength assessment in sport especially in soccer, where it is part of pre-season screening to establish norms in case of injuries. There are many devices on the market that make it difficult to use of normative data. Isokinetics literature in females’ soccer players is scarce in comparison to males. Furthermore, evaluation protocols strongly differ from each other, using different ranges of speeds, movement patterns and output data. Thus, it is difficult for the researcher and the clinician to choose a correct protocol for isokinetic evaluation in female soccer players. The indexes of isokinetic performance that are widely accepted are the hamstring/quadriceps (H/Q) ratio and dominant/non-dominant (D/ND) ratio as reference. In this review are highlighted some common features of isokinetic testing in female soccer players of different levels of qualification. From this study, it emerges that, for a reliable test, 3 reps at the speed of 60°/sec in knee flexion/extension is preferable due to the high reliability and that an optimal H/Q ratio in healthy female soccer players of different level of qualification and age is 50%, while the interlimb differences (D/ND) should be below 10%.