Isometric Group Research Articles

Upper limb isometric exercise protocolled programme and arteriovenous fistula maturation process

IntroductionArteriovenous fistula (AVF) is the gold standard for vascular access (VA) for end-stage chronic kidney disease (CKD) patients. Post-operative exercises may help to improve maturation. Nevertheless, scarce scientific evidence has been reported about their utility to date. Our objective was to assess the effect of a post-operative isometric exercise programme on native VA maturation in patients with stage 5–5D CKD.MethodsWe performed a 24-month prospective study. After surgery, patients were randomized to the isometric exercise group (EG) or control group (CG). An isometric exercise protocolled programme was performed in the EG. The CG received usual care. Demographic data, muscle strength using a hand-grip (HG) dynamometer, main Doppler ultrasound (DUS) measurements, clinical and DUS maturation and VA complications were assessed at 4 and 8 weeks post-operatively.ResultsFor 60 sixty patients (30 in the EG), demographic data and HG and DUS measurements at baseline were similar. A significant increase in HG was observed only in the EG at the end of the study (20.7 ± 8.1 versus 25.1 ± 10.3 kg, P = 0.001). The EG obtained the highest clinical maturation at 4 (CG 33.3% versus EG 70%, P = 0.009) and 8 weeks (CG 33.3% versus EG 76.7%, P = 0.002). Similarly, DUS maturation was better in the EG at 4 (CG 40% versus EG 80%, P = 0.003) and 8 weeks (CG 43.3% versus EG 83.3%, P = 0.003) and remained so in the EG for both distal and proximal VA territories for all these periods.ConclusionsThe upper limb isometric exercise protocolled programme improved clinical and DUS maturation in our patients in both the distal and proximal VA territories. Further studies are required to support these results.

Effects of Resistance Exercise on Glycated Hemoglobin and Functional Performance in Older Patients with Comorbid Diabetes Mellitus and Knee Osteoarthritis: A Randomized Trial.

Type 2 diabetes mellitus (T2DM) is significantly associated with osteoarthritis (OA). This study investigated the effects of two resistance exercise approaches on glycated hemoglobin (HbA1c) level and function performance. Enrolled were 70 older patients with both T2DM and knee OA. The dynamic group performed resistance exercises with an elastic resistance band. The isometric group underwent isometric contraction exercises. After the 12-week intervention, a significant within-group improvement (all p < 0.001) was observed for the chair stand test (CST; 10.8%, vs. 7.1%), timed up and go (TUG) test (12.6% vs. 7.6%), Western Ontario and McMaster Universities Osteoarthritis (WOMAC) physical function subscale (62.3% vs. 36.1%), and overall WOMAC (54.5% vs. 34.5%) in the dynamic and isometric group, respectively. In addition, in terms of between-group differences, the dynamic group had significant improvements in CST (p = 0.011), TUG (p < 0.001), WOMAC physical function subscale (p = 0.033), and overall WOMAC (p = 0.036) scores compared with the isometric group. However, no significant change in HbA1c was observed in either group. In conclusion, the dynamic resistance exercise significantly improved muscle strength, dynamic balance, and physical function in this comorbid population; however, there was no notable difference in change in HbA1c among different resistance exercises.

Isometric versus isotonic exercise for greater trochanteric pain syndrome: a randomised controlled pilot study

ObjectivesGreater trochanteric pain syndrome (GTPS) is a common cause of lateral hip pain. Limited evidence exists for the effectiveness of exercise for GTPS. This study aimed to compare the effectiveness...

Infinitesimal Transformations of Locally Conformal Kähler Manifolds

The article is devoted to infinitesimal transformations. We have obtained that LCK-manifolds do not admit nontrivial infinitesimal projective transformations. Then we study infinitesimal conformal transformations of LCK-manifolds. We have found the expression for the Lie derivative of a Lee form. We have also obtained the system of partial differential equations for the transformations, and explored its integrability conditions. Hence we have got the necessary and sufficient conditions in order that the an LCK-manifold admits a group of conformal motions. We have also calculated the number of parameters which the group depends on. We have proved that a group of conformal motions admitted by an LCK-manifold is isomorphic to a homothetic group admitted by corresponding Kählerian metric. We also established that an isometric group of an LCK-manifold is isomorphic to some subgroup of the homothetic group of the coresponding local Kählerian metric.

Point leaf maximal singular Riemannian foliations in positive curvature

We generalize the notion of fixed point homogeneous isometric group actions to the context of singular Riemannian foliations. We find that in some cases, positively curved manifolds admitting these so-called point leaf maximal SRF's are diffeo/homeomorphic to compact rank one symmetric spaces. In all cases, manifolds admitting such foliations are cohomology CROSSes or finite quotients of them. Among non-simply connected manifolds, we find examples of such foliations which are non-homogeneous.

Rigidity of warped cones and coarse geometry of expanders

We study the geometry of warped cones over free, minimal isometric group actions and related constructions of expander graphs. We prove a rigidity theorem for the coarse geometry of such warped cones: Namely, if a group has no abelian factors, then two such warped cones are quasi-isometric if and only if the actions are finite covers of conjugate actions. As a consequence, we produce continuous families of non-quasi-isometric expanders and superexpanders. The proof relies on the use of coarse topology for warped cones, such as a computation of their coarse fundamental groups.

Effects of antagonistic muscle contraction exercises on ankle joint range of motion.

[Purpose] Antagonistic stretching is an important therapeutic program in rehabilitation. However, if pain occurs during stretching, other methods should be considered. This study aimed to investigate whether antagonistic muscle contraction exercises alone had an effect in expanding the joint range of motion. [Participants and Methods] Participants included 50 healthy males and females (aged 21.0 ± 3.1 years) who were each randomly assigned to one of four groups that performed either active, resistance, phasic, or isometric exercises or a control group that performed no exercise. Each exercise group performed five sets of 30-second ankle dorsiflexion exercises. Active and passive ranges of motion of ankle dorsiflexion were measured using a goniometer, with the participants in the knee extension and flexion positions. [Results] Ankle joint range of motion was increased in the knee extension position in the isometric exercise group. There were no other differences observed in any of the groups. [Conclusion] Our results indicated that isometric exercises had an immediate effect on increasing ankle joint range of motion. This is presumably attributed to the effects of Golgi tendon organ inhibition (Ib inhibition) or stretch tolerance of the gastrocnemius muscle.

Efeito do treinamento pliométrico e isométrico na força explosiva de atletas de handebol

Plyometrics uses the reactive capacity of the neuromuscular system to increase the power of movement from an eccentric to a concentric contraction. Isometry refers to a static mode of training, ie there is no change in muscle fiber length. Handball is a collective sport that involves a large amount and variety of movement associated with ball manipulation and interaction with other athletes. In terms of movement, handball can be considered a complete sport because it uses a rich combination of fundamental and "natural" motor skills of the human motor repertoire. The aim of this research is to analyze the influence of a 4 week plyometric and isometric training on the explosive strength of young handball athletes. The sample consisted of 10 women, with an average age of 16.1 ± 0.56 years, who had been practicing handball for at least three months. The evaluation protocol used was: horizontal jump (HS) to measure lower limb explosive strength. The girls were divided into two statistically equal groups, the plyometric group (GP) and the isometric group (GI). Data were analyzed using paired t-test and Effect Size, as well as the Proesp manual. Initially the tests presented the following results: GP showed 1.32 ± 0.13m in HS and GI 1.41 ± 0.10m. After four weeks of training, the tests were redone and the GP showed 1.37 ± 0.08m in HS and the GI 1.43 ± 0.09m. Statistically the changes were not significant, the magnitude of the effect and the lower explosive strength results were superficial. It is concluded that, although statistically insignificant, both methods present little evolution in the explosive force of lower limbs, and it is necessary to further analyze the methods in these gains and also to analyze the concurrent proposal between both methods.

The Effects of Kinesio Taping and Isometric Exercises on Pain in Primary Dysmenorrhea-A Comparative Study

Primary dysmenorrhea is the most common problem faced worldwide affecting majority of women. The present study is aimed to compare the effect of kinesiotaping and isometric exercises on pain in females with primary dysmenorrhea. Materials and Method: In this randomized controlled clinical trial, 40 students females aged between 18-25 years with primary dysmenorrhea were randomly assigned to kinesiotaping and isometric exercises group. Pain intensity was measured using Visual Analogue Scale (VAS) and premenstrual symptoms were assessed using Menstrual Distress Questionnaire (MDQ- C). Data were analyzed using paired and unpaired t-test. P<0.05 was considered statistically significant. Results: Both kinesiotaping and isometric groups showed reduction in pain on VAS and MDQ (P<0.001). However in post treatment analysis, Kinesiotaping was proved to be better than isometric exercises. Conclusion: Kinesiotaping seems to be an effective method for reducing pain in primary dysmenorrhea.

Effect of intradialytic isometric exercise with or without neuromuscular electrical stimulation to IL-15, TNF-α regulation, and functional capacity in chronic kidney disease patient

One of the etiology of limited functional capacity in chronic renal disease patient is muscle wasting. Increasing of Tumor Necrosis Factor Alpha (TNF-α) in chronic renal disease causes muscle wasting. Strengthening exercise is recommended by ACSM but it is hard to be done. Contraction of skeletal muscle will express interleukin-15 (IL-15) which is important for metabolism and skeletal muscle function. Isometric exercise and Neuromuscular electrical stimulation (NMES) are easy to be applied intradialytic and can fascilitate muscle contraction and has strengthening effect, but their effect in chronic kidney disease patient have not been largely reported yet. This study aimed to prove that intradialytic isometric exercise with or without NMES can modulate IL-15, TNF-α expression and improve functional capacity in chronic kidney disease patient. Twenty-five chronic kidney disease patient underwent hemodialysis was randomly divided into 3 groups, control group, isometric group, and isometric and NMES group, received treatment twice a week, for 6 weeks. The subjects were examined for five times sit to stand test (FTSTS), IL-15 and TNF-α test by immunoassay before and after intervention. There was increased of FTSTS in isometric group ( P = 0.007) and also combined isometric and NMES group ( P = 0.001). TNF-α in isometric group was increased ( P = 0.003) and also in combined isometric and NMES group ( P = 0.025). Compared to the control group, TNF-α was change significantly in isometric group (0.017) and also in combined isometric and NMES group (0.020). There was no significant difference in IL-15 levels pre-and post-experimental in all three groups ( P > 0.05). Intradialytic isometric exercise with or without NMES for 6 weeks can improve functional capacity and also regulates TNF-α.

Isometric was better than Isotonic Neck Stretching to Reduce Pain and Creatinine Kinease in Non-specific Neck Pain in Caring Students of Swadhyaseni Middle High School, Badung, Bali

Neck pain is frequently complained by workers with static neck position. Complaints accompanied by discomfort around the neck muscles without any sensory disturbances or radiating pain, without specific causes such as history of neck trauma, neck malignancy or anatomical structural abnormalities. The samples were taken from carving students of Swadhyaya Middle School Badung. We evaluated 18 students divided into 2 groups: one with isometric neck stretches and another with isotonic neck stretches, 9 subjects each. The paired t-test found the number of decrease in NPRS in the isometric group was greater than isotonic group and the difference was statistically significant. The results of the unpaired student t-test obtained a mean decrease in NPRS in the isometric group greater than isotonic with a value of P = 0.00 (p 0.01). These results indicate isometric stretching is more effective in reducing the scale of NPRS pain in non-specific neck pain compared to isotonic stretches, isometric and isotonic stretching techniques are equally less effective in reducing creatine kinase levels.

On quotients of spaces with Ricci curvature bounded below

Let (M,g) be a smooth Riemannian manifold and G a compact Lie group acting on M effectively and by isometries. It is well known that a lower bound of the sectional curvature of (M,g) is again a bound for the curvature of the quotient space, which is an Alexandrov space of curvature bounded below. Moreover, the analogous stability property holds for metric foliations and submersions.The goal of the paper is to prove the corresponding stability properties for synthetic Ricci curvature lower bounds. Specifically, we show that such stability holds for quotients of RCD⁎(K,N)-spaces, under isomorphic compact group actions and more generally under metric-measure foliations and submetries. An RCD⁎(K,N)-space is a metric measure space with an upper dimension bound N and weighted Ricci curvature bounded below by K in a generalized sense. In particular, this shows that if (M,g) has Ricci curvature bounded below by K∈R and dimension N, then the quotient space is an RCD⁎(K,N)-space. Additionally, we tackle the same problem for the CD/CD⁎ and MCP curvature-dimension conditions.We provide as well geometric applications which include: A generalization of Kobayashi's Classification Theorem of homogeneous manifolds to RCD⁎(K,N)-spaces with essential minimal dimensionn≤N; a structure theorem for RCD⁎(K,N)-spaces admitting actions by large (compact) groups; and geometric rigidity results for orbifolds such as Cheng's Maximal Diameter and Maximal Volume Rigidity Theorems.Finally, in two appendices we apply the methods of the paper to study quotients by isometric group actions of discrete spaces and of (super-)Ricci flows.

Effects of fibroblast growth factor-2 on collateral artery formation in an ischemic myocardium promoted by isometric exercise

Objective To investigate the effect of fibroblast growth factor-2 (FGF-2) on the formation of collateral arteries in the remote myocardium promoted by the isometric exercise (IE). Methods Twenty-four male Sprague-Dawley rats weighing (200±20)g were randomized into a sham operation group (SO), a myocardial ischemia group (MI), an isometric exercise group (IE) and an FGF inhibitor group (Inhi-FGF), each of 6. Rats in the SO group were injected with saline subcutaneously for 2 weeks while those of the MI group were being injected with 10 mg/(kg·d) of isoproterenol subcutaneously to induce myocardial ischemia. Rats in group IE accepted isometric exercise and the same injections as group MI, while those in group Inhi-FGF were also given 100 mg/(kg·d) of formononetin intragastrically in addition to the group IE treatment. After 8 weeks of IE the myocardium of the rats′ left ventricles was resected. The relative collateral blood flow (RCBF) was measured using the microsphere method. The artery density and the number of smooth muscle cells were evaluated using immunohistochemical analysis. Western blotting was performed to assay the levels of FGF-2 protein and its receptor FGFR-1. Results Compared to the SO, MI and Inhi-FGF groups, significant increases in the RCBF, artery density, the number of smooth muscle cells and the relative levels of FGF-2 protein and FGFR-1 were observed in group IE. In the Inhi-FGF group the artery density, the number of smooth muscle cells and the relative protein level of FGF-2 were significantly lower than those of the MI group, but there were no significant differences in the RCBF or FGFR-1 levels between the two groups. The artery density had a positive linear correlation with the number of smooth muscle cells. The RCBF correlated with the artery density, the number of smooth muscle cells and the FGF-2 protein levels. Conclusion IE can promote the expression of FGF-2 and its acceptor, resulting in the formation of collateral arteries and better blood perfusion of an ischemic myocardium. Key words: Isometric exercise; Myocardial ischemia; Collateral artery formation; Fibroblast growth factors

Airy-type evolution equations on star graphs

In the present paper the Airy operator on star graphs is defined and studied. The Airy operator is a third order differential operator arising in different contexts, but our main concern is related to its role as the linear part of the Korteweg-de Vries equation, usually studied on a line or a half-line. The first problem treated and solved is its correct definition, with different characterizations, as a skew-adjoint operator on a star graph, a set of lines connecting at a common vertex representing, for example, a network of branching channels. A necessary condition turns out to be that the graph is balanced, i.e. there is the same number of ingoing and outgoing edges at the vertex. The simplest example is that of the line with a point interaction at the vertex. In these cases the Airy dynamics is given by a unitary or isometric (in the real case) group. In particular the analysis provides the complete classification of boundary conditions giving momentum (i.e., $L^2$-norm of the solution) preserving evolution on the graph. A second more general problem here solved is the characterization of conditions under which the Airy operator generates a contraction semigroup. In this case unbalanced star graphs are allowed. In both unitary and contraction dynamics, restrictions on admissible boundary conditions occur if conservation of mass (i.e., integral of the solution) is further imposed. The above well posedness results can be considered preliminary to the analysis of nonlinear wave propagation on branching structures.

Effects of Pilates and yoga in patients with chronic neck pain: A sonographic study.

Various studies have shown the efficacy of conventional isometric, Pilates and yoga exercises. However, data on the effects and comparison of these specific exercises on the cervical muscle morphology are insufficient or lacking. To investigate the effects of different exercise treatments on neck muscles in patients with chronic neck pain. A randomized study. Fifty-six patients with chronic neck pain were randomized into 3 groups as follows: Pilates group (n = 20), yoga group (n = 18) and isometric group (n = 18). Demographics and background information were recorded. The thickness and cross-sectional area of neck muscles were evaluated by ultrasound imaging. Cervical motions were measured with a goniometer. Pain severity was evaluated with the McGill Pain Scale, disability with the Neck Disability Index, quality of life with the Nottingham Health Profile, and emotional status with the Beck Depression Inventory. In addition to a conventional physio-therapy programme, 15 sessions of physical therapy, including hot pack, ultrasound, and transcutaneous electrical nerve stimulation (TENS), were provided to all patients. All groups performed the exercises for 6 weeks. The aforementioned assessments were performed before and 6 weeks after the treatment. Although pain, disability, depression and quality of life improved similarly within all groups (all p < 0.05), muscle thickness values as regards the semispinalis capitis were increased only in the Pilates group (p = 0.022). The lack of complex (progressive resistive) exercise treatment protocols, short treatment duration and partial supervision. All 3 types of exercise had favourable effects on pain and functional scores, but no differences were found among the groups, except for the Pilates group, in which the semispinalis capitis muscle increased in thickness.

Short-term maximal performance depend on post-activation potentiation stimuli type and recovery period

The purpose of this study was to identify the acute effects of two types of warm-up (i.e. plyometric and isometric) interventions on jump performance. Forty-five subjects volunteered to participate in our study. Participants were randomly assigned in a plyometric group (n = 15; age 14.79 ± 0.43; mass 57.64 ± 4.52; height 174.61 ± 5.97), isometric group (n = 15; age 14.80 ± 0.41; mass 57.13 ± 4.78; height 174.57 ± 5.75), and control group (n = 15; age 14.67 ± 0.49; mass 57.93 ± 4.09; height 175.30 ± 4.93). Pre- and post-measures (before, immediately, 5, 10, and 15 min after) for sargent jump test (SJT) and five jump test (5JT) were analyzed using a repeated measures ANOVA. There was a significant (p < 0.01) difference in SJT and 5JT depending on intervention types (η p 2 = 0.430 and η p 2 = 0.467, respectively). The results showed that both experimental groups had increases in SJT and 5JT compared to the control group. In the plyometric intervention, increases in SJT and 5JT up to 15 min after can be linked to dissipation of fatigue. Reduction of muscle function at potentiated state can be seen in the isometric scheme wherein jump performances decreased at 15 min. Post-potentiating activation has been induced using various types of exercise protocols. The optimal recovery period for recreationally trained men has not been clearly defined.

Comparative effects of pilates and isometric exercises on pain, functional disability and range of motion in patients with knee osteoarthritis

Objectives: Knee osteoarthritis is the most common disease of the knee joint and a growing public health problem with physical disability, preventing performance of daily activities. The purpose of this study was to compare the effect of isometric and Pilates exercise on pain, functional disability and range of motion in patients with knee osteoarthritis. Methods: A total of 33 subjects with osteoarthritis of the knee joint completed the study. They were recruited from two tertiary hospitals in Lagos state, Nigeria and were assigned to three different groups (A, B, C). Group A included subjects that received Pilates exercises and Transcutaneous Electrical Nerve Stimulation (TENS). Group B included subjects that were treated using isometric exercise and Transcutaneous Electrical Nerve Stimulation (TENS). Group C comprised of subjects that underwent lifestyle modification and received Transcutaneous Electrical Nerve Stimulation (TENS). Subject underwent this protocol twice weekly for 8 consecutive weeks. They were assessed for pain, functional disability and range of motion using VAS scores, WOMAC scores and Goniometer as outcome measures. Data was analyzed using SPSS version 21. Level of significance was set at p <0.05. Results: The results showed that in both Pilates and isometric groups there was reduction in pain intensity ( P =0.001) and functional disability ( P =0.001) as well as improvement in the range of motion ( P =0.001) of the subjects. Conclusion: Pilates and isometric exercises can reduce pain, improve functional ability and also range of motion of patient with knee osteoarthritis. Keywords: Isometric exercises, Pilate's exercises, knee osteoarthritis

A moderately high protein diet and 4’ isometric exercises efficacy in breast cancer patients treated with antiestrogenic medication

Many breast cancer patients gain weight during treatment increasing recurrence, oncology specific mortality and general mortality risks. Breast cancer diagnosis and treatment overthrow patients’ lifestyle aggravating sedentariness and any preexisting weight gain causes like insulin and leptin resistance, dysbiosys and dyslipidemia. The aim of this study is to evaluate the efficiency of a moderately high protein diet – based on foods naturally high in proteins, omega-3 fatty acids, calcium, probiotics and prebiotics – and of an isometric exercise protocol to generate fat loss without muscle loss in ER+ breast cancer patients taking antiestrogenic treatment. We randomized 50 ER+ breast cancer patients – taking either Tamoxifen or Aromatase Inhibitors (AI) after surgery and chemotherapy – to follow a high protein diet, or a high protein diet and 4’ isometric exercises for 12 weeks. Patients were instructed to eat only when hungry and to keep a food journal. We measured weight and body composition with a bioelectrical impedance scale after checking for hydration status. The diet group lost 2.17 ± 2.42% subcutaneus fat (p = 0,000) with no muscle loss, and there was no statistical difference between patients taking Tamoxifen or AI regarding body composition evolution. The diet + isometric exercise group lost 2.2 more pounds than the diet group and 0.66 ± 0.91% visceral fat (p = 0,001) also with no muscle loss. AI patients from the diet and exercise grup did not improve muscle mass – maybe because of the musculoskeletal impact of AI medication. In conclusion, a moderately high protein diet can decrease body fat in ER+ breast cancer patients on antiestrogenic medication. Adding a daily minimal exercise protocol to a high protein diet decreases visceral fat – which is more hormonally active. And resistance-training exercises are more appropriate than isometric exercises for patients on AI.

Inconsistency of Template Estimation by Minimizing of the Variance/Pre-Variance in the Quotient Space

We tackle the problem of template estimation when data have been randomly deformed under a group action in the presence of noise. In order to estimate the template, one often minimizes the variance when the influence of the transformations have been removed (computation of the Fr{\'e}chet mean in the quotient space). The consistency bias is defined as the distance (possibly zero) between the orbit of the template and the orbit of one element which minimizes the variance. In the first part, we restrict ourselves to isometric group action, in this case the Hilbertian distance is invariant under the group action. We establish an asymptotic behavior of the consistency bias which is linear with respect to the noise level. As a result the inconsistency is unavoidable as soon as the noise is enough. In practice, template estimation with a finite sample is often done with an algorithm called "max-max". In the second part, also in the case of isometric group finite, we show the convergence of this algorithm to an empirical Karcher mean. Our numerical experiments show that the bias observed in practice can not be attributed to the small sample size or to a convergence problem but is indeed due to the previously studied inconsistency. In a third part, we also present some insights of the case of a non invariant distance with respect to the group action. We will see that the inconsistency still holds as soon as the noise level is large enough. Moreover we prove the inconsistency even when a regularization term is added.

Effects of isokinetic, isometric, and aerobic exercises on clinical variables and knee cartilage volume using magnetic resonance imaging in patients with osteoarthritis.

This study aims to evaluate the effect of isokinetic, isometric, and aerobic exercise protocols on pain, disability, physical function, and articular cartilage in osteoarthritis. A total of 45 women (mean age 52.1 years; range 45 to 65 years) who were admitted to the Physical Medicine and Rehabilitation outpatient clinic and were diagnosed with primary bilateral knee osteoarthritis between May 2008 and January 2010 were included. The patients were randomly divided into three groups as isokinetic (n=15), aerobic (n=15), and isometric exercise groups (n=15). Exercise protocols were applied five days a week for four weeks. Pain was evaluated using a 10 cm Visual Analog Scale for Pain (VAS-pain), pain, joint stiffness and physical function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and disability was assessed using the Lequesne Index before and after the interventions. Isokinetic knee muscle strength measurements were also obtained. Patellar and femoral cartilage volumes were analyzed using magnetic resonance imaging. The VAS-pain, WOMAC, and Lequesne scores and peak torque values of knee extension improved in all groups with the highest improvement in the isokinetic group. For the knee flexion peak torque values, improvements were significant only in the isokinetic group at both velocities. There was no significant change in the femoral cartilage volume in any group after the interventions. However, patellar cartilage volume significantly increased in the isometric group (p=0.036). A four-week isokinetic, aerobic, and isometric exercise programs improved pain and functional capacity in patients with knee osteoarthritis. Isokinetic exercise also increased the muscle strength with improved maintenance of the quadriceps/hamstring ratio. Only isometric exercise increased the patellar cartilage volume.