Force-Time Characteristics in Collegiate Weightlifters Using Two Isometric Pull Protocols
2
Citation
13
Reference
10
Related Paper
Citation Trend
Abstract:
The isometric mid-thigh pull (IMTP) is commonly used to measure isometric strength of characteristics of weightlifters. The isometric pull from the start position (IPSP) has not been studied as much as the IMTP but may potentially be a viable option for a weightlifting monitoring program. This study aims to compare isometric force-time characteristics from both the IMTP and IPSP to weightlifting competition performance. Collegiate weightlifters’ performances were compared to isometric peak force (IPF), rate of force development (RFD), and allometrically scaled peak force (IPFa) of both isometric testing protocols by a Pearson’s Correlation Coefficient. Strong correlations between weightlifting performance and force-time characteristics for both protocols were found with IPSP having slightly higher correlations. This suggests that both isometric testing protocols are viable tools for predicting weightlifting performance. It may be useful to include both protocols in a weightlifting monitoring program.Isometric contractions of the handgrip muscles were exerted by eight male subjects (age range 19-24 yr) to determine the relationship between fatiguing and nonfatiguing isometric contractions. In a first series of experiments, subjects exerted fatiguing isometric contractions at tensions of 25, 40, or 70% of the maximum strength of the subjects (MVC) following a contraction at a nonfatiguing tension of 5 or 10% MVC for 3, 7, or 20 min. In a second series of experiments, subjects exerted pairs of fatiguing isometric contractions at the same tensions; however, during the 3-, 7-, or 20-min interval between the contractions the subjects either rested or exerted a contraction at 5 or 10% MVC. Nonfatiguing isometric contractions exerted prior to fatiguing contractions had little influence on the endurance for the fatiguing static effort. In contrast, when contractions at nonfatiguing tensions were exerted in the recovery interval following an isometric contraction at a fatiguing tension, the recovery of endurance was dramatically reduced.
Cite
Citations (5)
Objective To determine the test-retest reliability of functional squat system (FSS) isometric muscle strength tests for patients with knee osteoarthritis. Methods The isometric muscle strength of thirty patientswith knee osteoarthritis (21 males and 9 females; age 45 to 89 years, mean age 68.73 ± 12.19 years) was tested twice within 1 week by the same tester. Three test results were obtained: maximum isometric extension strength, the time to initiate isometric extension and the average isometric extension strength. Intra-class correlation coefficients (ICCs) for the three tests were computed to evaluate their retest reliability. Results The ICCs of the maximum isometric extension strength and average isometric extension strength of the uninvolved and involved extremities were respectively 0.87, 0.88, 0.92 and 0.89. The ICCs of the initiation time for the uninvolved and involved legs were respectively 0.25 and 0.41. Conclusion In these tests of patients with knee osteoarthritis using the functional squat system, both the maximum isometric extension strength and the average isometric extension strength had very good test-retest reliability. These two test results could be used as reliable guidance for treatment and rehabilitation of osteoarthritic knees.
Key words:
Knee osteoarthritis; Isometric muscle strength; Tests; Retest reliability
Squat
Cite
Citations (0)
The elbow flexor muscles of four men were trained using maximal voluntary isometric contractions. Thirty contractions a day were performed for five weeks. The four men and four control subjects were tested once a week: measurements of the supramaximally stimulated isometric twitch force, the time taken for the twitch force to peak and the tetanic force were carried out; simultaneously, measurements of the force of maximal voluntary isometric contraction and resistance to fatigue were made. The testing sessions produced no training effect on control subjects. Training produced a 20 per cent increase in the force of maximal voluntary isometric contraction after five weeks, but the forces of electrically evoked twitch and tetanus showed no increase. It was concluded that the increase in the force of maximal voluntary isometric contraction must be related to factors other than the force-generating capacity of the muscle fibres themselves.
Elbow flexion
Plantar flexion
Flexor muscles
Turnover
Cite
Citations (57)
This study was designed to investigate the effect of muscle fiber distribution and pretension at various submaximal contraction levels on the isometric force-time curve during knee extension. Thirteen male physical education students volunteered as subjects. They were instructed to react to an auditory and light signal by extending their right knee as quickly and forcefully as possible. The contractions were performed from seven pretension levels ranging from 0% to 70% of maximal voluntary contraction value (MVC). The isometric force-time curves were analyzed for their maximal rate of isometric force production. Preliminary tension was found to have statistically significant, decreasing effects on isometric maximal strength produced from the pretension levels of 20%, 30%, and 40% of MVC and on the rate of isometric force production (RFD). Relatively, the decrease was greater for the RFD than for the maximal strength. The effect of the 20% preliminary tension on the RFD was greater (P less than 0.05) for subjects rich in fast-twitch muscle fibers in their m. vastus lateralis than for subjects rich in slow-twitch fibers. At the other preliminary tension levels, the intergroup differences did not reach the level of statistical significance.
Cite
Citations (23)
Cite
Citations (0)
Білім берy қоғaмның экономикaлық дaмyының негізі, әлеyметтік тұрaқтылықтың фaкторлaрының бірі, хaлықтың рyхaни-aдaмгершілік әлеyетінің және интеллектyaлдық өсyінің қaйнaр көзі ретінде бaрлық yaқыттaрдa тaптырмaс құндылық болып есептеліп келеді. Aл қaзіргідей aдaм кaпитaлын қaлыптaстырy мен дaмытy мәселесін шешy негізгі міндет ретінде қaрaстырылaтын зaмaндa хaлықтың білімдік қaжеттіліктері өсіп, жоғaры, ортa aрнayлы, кәсіби қосымшa білім aлyғa үміткерлер сaны aртa түсyде. Бұғaн жayaп ретінде білім берy ұйымдaрының сaлaлaнyы aртып, әртүрлі типтегі оқy орындaрының сaны aртyдa, білім берyдің инфрaқұрылымы, бaсқaрy формaлaры, әдістемелік, ғылыми қызмет түрлері дaмyдa. Олaрды білім aлyшылaрдың жеке сұрaныстaры мен мүмкіндіктеріне бaғыттay күшейтілyде. Осығaн орaй білімнің сaпaсынa қойылaтын тaлaптaр aртып, бұл сaлaның әлеyметпен өзaрa әрекеттестігіне негізделген құрылымдық – қызметтік дaмyының көкейтестілігі aртyдa. Мaқaлaдa «серіктестік», «әлеyметтік серіктестік», «білімдегі әлеyметтік серіктестік» ұғым- дaрының мәні aшылып, олaрдың қaлыптaсy және дaмy үрдісіне шолy жaсaлaды, жоғaры оқy орындaрындa педaгогтaрды дaярлayдa әлеyметтік серіктестердің әлеyетін пaйдaлaнyдa бaсшылыққa aлынaтын ұстaнымдaр мен тиімді жолдaры сипaттaлaды. Түйін сөздер: серіктестік, әлеyметтік серіктестік, білімдегі әлеyметтік серіктестік, бірлескен әрекет ұстaнымдaры, әлеуметтік серіктестік әлеуеті. Обрaзовaние является основой экономического рaзвития обществa, одним из фaкторов социaль- ной стaбильности, источником дyховно-нрaвственного потенциaлa и интеллектyaльного ростa людей и во все временa считaлось незaменимой ценностью. И в нaстоящее время, когдa решение проблемы формировaния и рaзвития человеческого кaпитaлa рaссмaтривaется кaк основнaя зaдaчa, рaстyт обрaзовaтельные потребности людей, yвеличивaется количество желaющих полyчить высшее, среднее, специaльное, профессионaльное дополнительное обрaзовaние. В ответ нa это yсиливaется рaзветвленность обрaзовaтельных оргaнизaций, yвеличивaется количество обрaзовaтельных оргaни- зaций рaзличного типa, рaзвивaются инфрaстрyктyрa обрaзовaния, формы yпрaвления, методическaя и нayчнaя деятельность. Yсиливaется их ориентaция нa индивидyaльные потребности и возможности обyчaющихся. В связи с этим повышaются требовaния к кaчествy обрaзовaния, возрaстaет знaчение стрyктyрно-фyнкционaльного рaзвития этой сферы нa основе взaимодействия с обществом. В стaтье рaскрывaется знaчение понятий «пaртнерство», «социaльное пaртнерство», «социaльное пaртнерство в обрaзовaнии», рaссмaтривaется процесс их стaновления и рaзвития, описывaются рyко- водящие принципы и эффективные способы использовaния потенциaлa социaльных пaртнеров в подготовке педaгогических кaдров в высших yчебных зaведениях. Ключевые словa: партнерство, социaльное пaртнерство, социaльное пaртнерство в обрaзовaнии, принципы совместного действия, поненциал социального партнерство. Education is the basis of the economic development of society, one of the factors of social stability, a source of spiritual and moral potential and intellectual growth of people and has always been considered an irreplaceable value. And at the present time, when the solution of the problem of the formation and development of human capital is considered as the main task, the educational needs of people are growing, the number of people wishing to receive higher, secondary, special, professional additional education is increasing. In response to this, the branching of educational organizations is increasing, the number of educational organizations of various types is increasing, the infrastructure of education, forms of management, methodological and scientific activities are developing. Their focus on the individual needs and capabilities of students is increasing. In this regard, the requirements for the quality of education are increasing, the importance of the structural and functional development of this sphere on the basis of interaction with society is increasing. The article reveals the meaning of the concepts of "partnership", "social partnership", "social partnership in education", examines the process of their formation and development, describes the guidelines and effective ways to use the potential of social partners in the training of teachers in higher educational institutions. Keywords: partnership, social partnership, social partnership in education, principles of joint action, the potential of social partnership.
Cite
Citations (0)
The purposes of this study were to investigate of the effective hip joint angle during quadriceps isometric exercise by electromyophic analysis. All participants performed quadriceps isometric exercise with knee flexion 60° by Cybex7000. The EMG activity of three knee extensor, vastus lateralis(VL), rectus femoris(RF), and vastus medialis(VM), in the subject' s isometric exercise(maximal voluntary isometric contraction, MVlC) was monitored using bipolar surlace electrodes. The magnitude of the average peak iEMG for each muscle monitored during the stactic motion is calculated as a percentage of the normalized peak iEMG during the MVIC. And the results were follows 1) Statistical analysis demonstrated significantly different maximal isometric force of quadriceps during changes of hip angle.(P＜.05) 2) Between 100° and 130° at hip angles, isometric force of quadriceps increased. Between 130° and 160° at hip angles, isometric force of quadriceps decreased. 3) Maximal isometric force of quadriceps was significantly increasing rate between 100° and 110° at hip angle.(P＜.05) 4) Maximal isometric force of quadriceps was significantly decreasing rate between 140° and 150° at hip angle.(P＜.05) 5) The isometric force of rectus femoris during changes of hip angle was significantly different (P＜.05) 6) The VL/RF, VL/VM, RF/VM iEMG ratios during changes of hip angle was significantly different(P＜.05)
Vastus medialis
Quadriceps muscle
Knee flexion
Cite
Citations (0)
Abstract Thirty-six male college students served as subjects in a study that examined the relationship between isometric strength and relative isometric endurance of the right forearm flexor muscles. The percentages of maximum isometric strength used for the endurance tests were 30, 45, 60, and 75. Three equal groups were formed based on the strength level of the subjects, and an analysis of variance test was used to determine the existence of significant differences. Significant negative correlations were found between isometric strength and relative isometric endurance. The weak subjects performed significantly better than the strong subjects on the light weight loads, with no difference existing between the endurance performances on the heavy loads.
Cite
Citations (24)
The nationally-recognized Susquehanna
Chorale will delight audiences of all
ages with a diverse mix of classic and
contemporary pieces. The ChoraleAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂA¢AÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂs
performances have been described
as AÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂA¢AÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂemotionally unfiltered, honest
music making, successful in their
aim to make the audience feel,
to be moved, to be part of the
performance - and all this while
working at an extremely high
musical level.AÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂA¢AÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂAÂA Experience choral
singing that will take you to new
heights!
Cite
Citations (0)