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BAKGRUND: Ländryggssmärta är idag ett av de största folkhälsoproblemen och drabbar majoriteten av människor någon gång under deras livstid. Det är viktigt med validerade och reliabla tester för att undersöka problematiken. Nedsatt rörelsekontroll är en trolig källa till symptom i ländryggen. Styrkelyftare utsätts för stora externa krafter på ländryggen, framförallt i knäböj och marklyft, vilket gör att de tillhör riskgruppen för ländryggssmärta. SYFTE: Syftet med denna studie var att undersöka interbedömarreliabiliteten för erfarna och oerfarna bedömare av rörelsekontroll för ländryggen hos styrkelyftare. Det sekundära syftet var att undersöka om det fanns en skillnad i total testbatteripoäng mellan styrkelyftare med och utan ländryggssmärta. METOD: Åtta deltagare filmades när de utförde tester enligt ett testbatteri utvecklat av Luomajoki et al. Dessa filmer bedömdes av två erfarna samt två oerfarna bedömare för att undersöka interbedömarreliabiliteten. RESULTAT: Resultaten presenterades med Cohens kappa samt med procentuell överensstämmelse. Resultaten visade tendenser till att erfarna bedömare hade bättre överensstämmelse än oerfarna bedömare i detta testbatteri. Av de åtta tester som analyserades med Cohens kappa hade de erfarna bedömarna högre kappakoefficienter i fem av testerna. Sett till procentuell överensstämmelse var inte tendensen lika tydlig. Ingen signifikant skillnad fanns i total testbatteripoäng mellan styrkelyftare med och utan ländryggssmärta. SLUTSATS: Tendensen tyder på att erfarna bedömare är mer samstämmiga i sin bedömning än oerfarna bedömare. I den här studien kunde man inte se någon skillnad i resultatet mellan styrkelyftare med respektive utan ländryggsmärta på ett testbatteri för rörelsekontroll i ländryggen. Några säkra slutsatser kunde inte dras av resultaten, framförallt på grund av det låga deltagarantalet.

Peak barbell velocity is an important determinant of weightlifting performance 2 . However, direct comparisons of this measure between elite men and women weightlifters is limited 7,8 . Therefore, the present study sought to establish a reference of the current status and trajectory of sexbased peak barbell velocity differences among elite weightlifters. This study examined performances of men and women in the 69 kg weight class in order to obviate the influence of body mass on performance. The purpose of this investigation was to help practitioners identify training needs of elite men and women weightlifters to improve weightlifting performance based upon between-group differences in peak barbell velocity.

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Countermovement vertical jump (CMVJ) performance may be acutely facilitated via potentiation (PAP) due to central and peripheral factors. PURPOSE: To investigate the effects of two methods of PAP in trained weightlifters (n=16); group 1: stronger (n=7) and group 2: weaker (n=9) upon unweighted countermovement jumps (CMVJs) over a 15 minute time period. METHODS: A series of maximal unweighted CMVJs were performed prior to, then at, 30, 60, 120, 180, 300, 480, 660, 780, and 900 seconds following two conditions: isometric mid-thigh clean pulls (C1) and dynamic mid-thigh clean pulls (C2). Dependent variables included, jump height (JH, cm), peak power (PP, W), peak velocity (PV, m·s-1), and peak force (PF, N). RESULTS: A series of repeated measures ANOVA: conditions (2); time points (10); groups (2) were performed on JH, PP, PV, and PF (p>.05). Significant main effects for JH existed by condition (C1>C2) (p=.001, ES=.571, 1-β=.979, mean diff=.053cm), group (G1>G2) (p=.018, ES=.339, 1-β=.702, mean diff=.053), and time (60s>900s, 120s>900s, 180s>900s) (p=.014, ES=.148, 1-β=.910).Within subjects main effects for JH were seen for the stronger group for JH by condition (C1>C2) (p=.055, ES=.757, 1-β=.947, mean diff=.053cm), and weaker group by condition (C1>C2) (p=.025, ES=.487, 1-β=.676, mean diff=.054cm). Significant main effects existed for PP by condition (C1>C2) (p=.000, ES=.631, 1-β=.995, mean diff=427.9W), group (G1>G2) (p=.008, ES=.405, 1-β=.819, mean diff=1660.1W), and time (60s>480s, 60s>660s, 60s>780s, 60s>900s>120s>900s, 180s>480s, 180s>660s, 180s>780s) (p=.000, ES=.355, 1-β=1.00, mean diff=240.1W ).Within subjects main effects for PP were seen for the stronger group for condition (C1>C2) (p=.055, ES=.761, 1-β=.951, mean diff=516.8W), and time (120s>900s) (p=.000, ES=.471,1-β=.999, mean diff=319.5W). In the weaker group; significant main effects by condition (C1>C2) (p=.025, ES=.485, 1-β=.672, mean diff=339.1W) and time (120s>900s, 180s>480s, 180s>900s, 300s>900s) (p=.003, ES=.281, 1-β=.963, mean diff=319.5W). Significant main effects were seen for jump PV by condition (C1>C2) (p=.001, ES=.536,1-β=.962, mean diff=.177 m·s-1), group (G1>G2) (p=.022, ES=.320, 1-β=.665, mean diff=.298m/s) and by time (60s>900s, 120s>900s, 180s>900s) (p=.016, ES=.145, 1-β=.904). Within subjects main effects for jump PV in the stronger group by condition (C1>C2) (p=.007, ES=.727, 1-β=.911, mean diff=.165m/s), and time (120s>900s) (p=.036, ES=.269, 1-β=.840, mean diff=.073 m·s-1). In the weaker group there were significant main effects for jump PV by condition (C1>C2) (p=.028, ES=.474, 1-β=.654, mean diff=.188 m·s-1). A significant main effect for jump PF by group (G1>G2) (p=.014, ES=.363, 1-β=.747, mean diff=647.0N) and time (60s>baseline) (p=.05, ES=.122, 1-β=.824, mean diff=71.0N) was seen. Within subjects, a significant main effect for jump PF in the weaker group by time (60s>780s) (p=.012, ES=.247, 1-β=.919). There were no significant interactions for any of the dependent variables (p >.05). CONCLUSION: Isometric mid-thigh clean pulls appear to have a greater potentiating effect than dynamic mid-thigh pulls on PP and PV during subsequent CMVJ0’s, and stronger weightlifters tend to have a more favorable response to both conditions. PRACTICAL APPLICATION: Whole-body isometric movements may be a more effective at eliciting a potentiation response than dynamic movements in strength and power athletes.

Smegenų kraujotakos autoreguliacija (SKAR) – viena svarbiausių gyvybinių organizmo funkcijų, t.y. smegenų savybė moduliuoti apsirūpinimą krauju, išlaikant nekintamą kraujotaką,skirtingo smegenų perfuzinio spaudimo sąlygomis (Paulson et al., 1990). Perfuzinis spaudimas,įveikiantis išorinį pasipriešinimą (vidinį kaukolės slėgį ) ir vidinį (arteriolių sienelių tonusą,reguliuojamą vazomotorų) palaiko smegenų kraujotaką (Steiner et al., 2003b). Sveikame organizme garantuojamas smegenų kraujotakos pastovumas ir regioninis pasiskirstymas pagal metabolinius- funkcinius poreikius (Sato et al., 2009). Fizinio ar emocinio krūvio metu pakinta įprastinė organizmo sistemų veikla. Fizinis krūvis paveikia kiekvieną kardiovaskulinės sistemos komponentą. Fizinio krūvio metu padidėja aktyviai dirbančių raumenų metabolinis poreikis, sukeliama lokali vazodilatacija, kuri garantuoja adekvačią kraujo perfuziją ir sukelia bendro periferinio pasipriešinimo sumažėjimą (Sprangers et al., 1991; Brys et al., 2003), tuo pat metu padidėja sistolinis širdies tūris ir širdies susitraukimų dažnis (Brys et al., 2003; Duncker and Bache, 2008; Laughlin et al., 2011). Ilgalaikės treniruotės veikia kraujo spaudimą dėl lėtinio autonominės kontrolės mechanizmų poveikio ir kraujagyslių remodeliavimo (Pescatello et al., 2004b). Pasipriešinimo pratimai padidina periferinį kraujagyslių pasipriešinimą ir kairiojo skilvelio pokrūvį (Leddy and Izzo, 2009). Fizinio krūvio pradžioje būna smegenų kraujotakos padidėjimas... [toliau žr. visą tekstą] / Cerebrovasvular autoregulation (CA), i.e. an intrinsic ability of the brain to regulate its blood supply, maintaining stable blood flow within the wide range of cerebral perfusion pressure (CPP), is one of the most important vital functions in a living organism (Paulson et al., 1990). Perfusion pressure maintains cerebral blood flow by overcoming external (i.e. intracranial pressure) as well as internal resistance (i.e. vasomotor regulated tone of the arteriolar wall) (Steiner et al., 2003b). In healthy body, constant cerebral blood flow and regional distribution is maintained in accordance tometabolic and functional needs (Sato et al., 2009). Physical and emotional stress alters regular activity of organism. Physical exercise affects every component of cardiovascular system. Metabolic demand of actively exercising muscles increases during physical exercise; local vasodilatation develops, thus adequate blood perfusion is maintained and total peripheral resistance decreases (Sprangers et al., 1991; Brys et al., 2003). Meanwhile, systolic blood pressure and heart rate increases (Brys et al., 2003; Duncker and Bache, 2008; Laughlin et al., 2011). Due to long-term effect of autonomous control mechanisms and blood vessel remodeling, long-term physical training affects blood pressure (Pescatello et al., 2004b). Resistance exercises increase peripheral resistance of blood vessels and left ventricle afterload (Leddy and Izzo, 2009). At the onset of exercise, there is... [to full text]

Monitoring tests are commonly used to assess weightlifter’s preparedness for competition. Although various monitoring tests have been used, it is not clear which test is the strongest indicator of weightlifting performance. Therefore, the purpose of this study was to (1) determine the relationships between vertical jump, isometric mid-thigh pull (IMTP) and weightlifting performance; and (2) compare vertical jumps to IMTP as monitoring tests of weightlifting performance in a large cohort of male and female weightlifters. Methods: Fifty-two competitive weightlifters (31 males, 21 females) participated in squat and countermovement jump testing (SJ, CMJ), and IMTP testing performed on force plates. All laboratory testing data was correlated to a recent competition where the athletes had attempted to peak. Results: Squat jump height (SJH) was the strongest correlate for men and women with the Sinclair Total (r = 0.686, p ≤ 0.01; r = 0.487, p ≤ 0.05, respectively) compared to countermovement jump height (r = 0.642, p ≤ 0.01; r = 0.413, p = 0.063), IMTP peak force allometrically scaled to body mass (r = 0.542, p ≤ 0.01; r = −0.044, p = 0.851) and rate of force development at 200 ms (r = 0.066, p = 0.723; r = 0.086, p = 0.711), respectively. Further, SJH was a stronger correlate of relative weightlifting performance compared to IMTP peak force in females (p = 0.042), but not male weightlifters (p = 0.191). Conclusions: Although CMJ and IMTP are still considered strong indicators of weightlifting performance, SJH appears to be the most indicative measure of weightlifting performance across a wide-range of performance levels. Thus, SJH can be used as a reliable measure to monitor weightlifting performance in male and female weightlifters.

The purpose of this monitoring study was to investigate how alterations in training affect changes in force-related characteristics and weightlifting performance. Subjects: Seven competitive weightlifters participated in the study. Methods: The weightlifters performed a block style periodized plan across 20 weeks. Force plate data from the isometric mid-thigh pull and static jumps with 0 kg, 11 kg, and 20 kg were collected near the end of each training block (weeks 1, 6, 10, 13, 17, and 20). Weightlifting performance was measured at weeks 0, 7, 11, and 20. Results: Very strong correlations were noted between weightlifting performances and isometric rate of force development (RFD), isometric peak force (PF), peak power (PP), and jump height (JH). Men responded in a more predictable manner than the women. During periods of higher training volume, RFD was depressed to a greater extent than PF. JH at 20 kg responded in a manner reflecting the expected fatigue response more so than JH at 0 kg and 11 kg. Conclusions: PF appears to have been more resistant to volume alterations than RFD and JH at 20 kg. RFD and JH at 20 kg appear to be superior monitoring metrics due to their “sensitivity.”