Eight well-trained males carried out squat jump and countermovement jump with large (SJL and CMJL) and with small (SJS and CMJS) range of motion to study the influence of trunk position on joint recruitment pattern and jumping height. The main criteria in SJS and CMJS were to maintain trunk in near vertical position during execution. Joint angles, activation time, time at maximum joint velocity for ankle joint, knee joint and hip joint, vertical propulsion time and jumping height were determined using film analysis. The joint activation followed proximal to distal pattern in CMJL, SJL and CMJS, but the pattern was reversed in SJS. The ratio of active state and vertical propulsion time was similar for all joints (63.1 and 72.8%) in CMJL, SJL and CMJS except in SJS where the ratio was significantly less for hip (46.9%) and knee (51.9%). The difference between CMJL and SJL in jumping height was 6.9 ± 2.8 cm which is significantly less than that between CMJS and SJS (14.5 ± 5.3 cm). We concluded that knee joint and hip joint muscles could not contribute to the positive work during the push-off phase when the range of motion is small, the trunk is vertical and the activation level of the muscles is low.
Authors:Łukasz Trzaskoma, J. Tihanyi and Z. Trzaskoma
Purpose: The aim of the study was to analyze the results of the hip joint torques within the patients with osteoarthritis (OA). A total of 119 women were divided into 3 groups performing 3 dimensional strength tests. For the measurements a new apparatus was invented and used. Specially designed position was safety and comfortable during testing OA and elderly women.Results: Significant differences (p≤0.05) in strength tests were found both between body side and muscle groups in most of the performed tests. The biggest unilateral deficit in OA group was found in muscles most important for gait and weight bearing − 0.55 for both flexors and extensors. Surprisingly no lateral difference was found for the hip joint adductors. Analysis of the correlation coefficient between the hip joint muscles proved that complex movements needed well-developed coordination between the muscle groups. The most important agonist muscle coordination occurs between hip extensors and abductors − 0.68 to 0.80.Conclusion: Unilateral hip OA affecting older women is directly responsible for significantly lower muscle strength when compared with both control groups. Lost of balance and coordination needed for dynamic actions like gait is caused by strength asymmetry of crucial hip muscles as well as near zero correlation between important agonist muscles.
Authors:Imre Juhász, I. Györe, Zs Csende, L. Rácz and J. Tihanyi
The objective of this study was to determine whether creatine supplementation (CrS) could improve mechanical power output, and swimming performance in highly trained junior competitive fin swimmers. Sixteen male fin swimmers (age:15.9±1.6 years) were randomly and evenly assigned to either a creatine (CR, 4×5 g/day creatine monohydrate for 5 days) or placebo group (P, same dose of a dextrose-ascorbic acid placebo) in a double-blind research. Before and after CrS the average power output was determined by a Bosco-test and the swimming time was measured in two maximal 100 m fin swims. After five days of CrS the average power of one minute continuous rebound jumps increased by 20.2%. The lactate concentration was significantly less after 5 minutes restitution at the second measurement in both groups. The swimming time was significantly reduced in both first (pre: 50.69±1.41 s; post: 48.86±1.34 s) and second (pre: 50.39±1.38 s; post: 48.53±1.35 s) sessions of swimming in CR group, but remained almost unchanged in the P group.The results of this study indicate that five day Cr supplementation enhances the dynamic strength and may increase anaerobic metabolism in the lower extremity muscles, and improves performance in consecutive maximal swims in highly trained adolescent fin swimmers.
Authors:Márk Váczi, A. Costa, L. Rácz and J. Tihanyi
This study compared two training regimens in which knee extensor exercises were performed at different range of motion.
Sixteen males performed bouts of 90 maximal isokinetic eccentric contractions over 6 consecutive days (B1-B6) at either small (n=8) or large (n=8) range of motion. Average of peak torque (Mp) of each of the 90 contraction trials were calculated, plasma creatine kinase (CK) and lactate dehydrogenase (LDH) activities were measured before, 24 h, 48 h and 6 d after B1. Muscle soreness was evaluated every day during the experiment.
At B3 Mp reduced more in group L than in group S. From B1 to B6 group S increased Mp, while in group L Mp did not return to the baseline level. In both groups CK activity elevated 24 h following B1. CK activity was significantly higher in group L 6d after B1. In group L muscle soreness was higher at 48 h, 72 h, 4 d and 5 d after B1.
High-intensity, consecutive eccentric knee extensor exercise training at large range of motion may induce greater development of muscle damage and force deficit, than training at small range of motion. Training at small range of motion may induce early adaptation in voluntary torque production.
Authors:A. Costa, Z. Orosz, P. Apor, N. Csaba, S. Siamilis, Z. Csende, L. Racz and J. Tihanyi
In animal models, unaccustomed eccentric exercise (EE) has been widely related to muscle fiber membrane (sarcolemma) damage. On the contrary, studies in humans reported that sarcolemma was not susceptible to damage following a single bout of EE. We hypothesized that the single bout of EE used by those studies was not sufficient to induce sarcolemma damage, in humans. In this study we examined muscle biopsies from untrained males who either performed six sets of 15 reps of maximum voluntary eccentric contractions (n=9), for six consecutive days, or served as control-group (n=6). Blood and biopsy samples were obtained one week prior to exercise, immediately after bout 3, and 24h after the last training session. In addition to standard haematoxylin-eosin staining, all biopsies were stained immunohistochemically using antibodies specific for fibronectin and desmin antigens. In the exercise-group, no biopsies taken at pre-exercise or post-exercise level showed evidence of sarcolemma damage as stained by anti-fibronectin antibody in eight of nine subjects. Serum creatine kinase (CK) and lactate dehydrogenase (LDH) activities increased significantly throughout the study despite the lack of sarcolemma damage.We suggest that in humans, repeated bouts of EE do not cause gross sarcolemma damage in the mid-belly of Vastus Lateralis.
Authors:E. Németh, K. Bretz, P. Sótonyi, Károly Bretz, T. Horváth, J. Tihanyi, E. Zima and T. Barna
The aim of our study was to investigate changes in psycho-physiological parameters evoked by short duration, intensive physical stress on university students practicing judo at different intensities and timely manner. Stability of posture, muscle strength (hand force exertions), attention concentration (choice reaction time), cardiac parameters, (ECG, heart rate, heart rate variability), and oxygen saturation were measured, cardiac state and stress index were computed before and after the physical stress. The actual psychic state of the subjects was evaluated using the Spielberger’s STPI-H Y-1 test which determined anxiety, curiosity, anger and depression level. Analysis of psychometric and physiologic parameters indicated significant correlations, among others, between force and cardiac stress (−), force and depression (−), anxiety and errors in actions (+), cardiac state and errors in action (−), cardiac state and depression (−). Paired samples tests showed the influence of intensive physical stress within groups of students, and independent samples tests made it possible to evaluate the power of medical and sport students, performing physical training at a significantly higher level than it is usual among the medical students. Our results proved that higher level physical training influences the psychic state advantageously, limits increases in cardiac stress level, and decreases susceptibility to anxiety and depression.
Authors:N Magyari, V Szakács, C Bartha, B Szilágyi, K Galamb, MO Magyar, T Hortobágyi, RM Kiss, J Tihanyi and J Négyesi
The aim of this study was to examine the effects of gender on the relationship between Functional Movement Screen (FMS) and treadmill-based gait parameters.
Twenty elite junior athletes (10 women and 10 men) performed the FMS tests and gait analysis at a fixed speed. Between-gender differences were calculated for the relationship between FMS test scores and gait parameters, such as foot rotation, step length, and length of gait line.
Gender did not affect the relationship between FMS and treadmill-based gait parameters. The nature of correlations between FMS test scores and gait parameters was different in women and men. Furthermore, different FMS test scores predicted different gait parameters in female and male athletes. FMS asymmetry and movement asymmetries measured by treadmill-based gait parameters did not correlate in either gender.
There were no interactions between FMS, gait parameters, and gender; however, correlation analyses support the idea that strength and conditioning coaches need to pay attention not only to how to score but also how to correctly use FMS.