Sportinėje treniruotėje taikomų fizinių apkrovų kiekis ir intensyvumas nuolat keičiasi. Treniruotės krūviai gali būti išdėstomi keliais būdais: ištęstai, koncentruotai, kryptingai, nekryptingai. Krūvių išdėstymo strategijos įtaka raumenų pažeidai nėra aiški. Hipotezė: staigiai didėjančio krūvio metu raumenų pažeida bus didesnė, nei nuosekliai didėjančio krūvio metu. Tyrimo tikslas: nustatyti skirtingo krūvio didinimo strategijų poveikį raumenų pažeidai. Uždaviniai: 1. Nustatyti staigiai didėjančio krūvio poveikį raumenų pažeidai; 2. Nustatyti nuosekliai didėjančio krūvio poveikį raumenų pažeidai. Darbo originalumas: nėra žinoma, kokį poveikį raumenų pažeidai turi krūvių didinimo strategijos pasirinkimas. Praktinė reikšmė: fizinių krūvių didinimo komponentų poveikio raumenų pažeidai nustatymas gali būti naudingas teikiant tinkamesnes raumens stiprinimo ir reabilitacijos programas. Metodika: tyrime dalyvavo sveiki aktyviai nesportuojantys vyrai (n =11), pirma grupė 7 tiriamieji (19,6±1,8 m.), antra grupė 4 tiriamieji (19,5±1,7 m.). Pirma grupė atliko 9 treniruotes, kurių metu krūvis buvo didinamas staigiai: 1–3 treniruotės buvo atliekamos esant vienodam krūviui; 4–6 treniruotės metu atliekamos esant didesniam šuolių skaičių, 7–9 treniruotės atliekamos esant didesniam pritūpimo kampui per kelio sąnarius. Antra grupė atliko 9 treniruotes, kurių metu krūvis buvo didinamas nuosekliai, 1-3 treniruočių metu didėjo pakylos aukštis, 4–6 treniruočių metu didėjo šuolių skaičius, o 7–9... [toliau žr. visą tekstą] / The intensity and amount of physical workload in sport training can be divided into several ways: continuously, concentrated, directed, not directed. The workload placement strategy’s influence on muscle damage is still unclear. Hypothesis. Rapid increase of workload will result in bigger muscle injury then consistently enhanced workload. Aim. To determine different workload increase strategy’s influence on muscle damage. Objectives: To determine the rapid increased workloads’ effect on the muscle damage. To assess the effect of consistently raising workload on muscle damage. Works’ contribution to practice. The determination of physical workload’s components effect on muscle damage might be useful for the choice of muscle strengthening and rehabilitation programmes. Methods. Healthy and not actively sporting men (n=11), in the first group 7 participants (19,6±1,8 m.), second group 4 participants (19,5±1,7 m.). First group of participants performed 9 trainings, during which the workload was rapidly enhanced: 1-3 exercises were performed in stable workload, 4-6 exercises with bigger number of jumps, 7-9 exercises were performed having bigger squatting angle in knee joints. Second group performed 9 exercises, during which workload was risen stably, during 1-3 exercises, the level of platform was risen, during 4-6th exercises, the number of jumps was increased and during 7-9th exercise – the squatting angle in knee joints was increased. Before and after exercises the... [to full text]

Supporters of a nutritional supplement, β-Hydroxy-β-Methylbutyrate (HMB) supplementation, claim that it will increase the muscular strength gains and lean muscle mass gains seen during a resistance training program. It has been suggested that HMB supplementation does this by preventing muscle damage or by regenerating damaged muscle cell membranes. However, no research has evaluated the effect of HMB supplementation on low frequency fatigue. Therefore, the purpose of this study was to determine if three weeks of HMB supplementation could attenuate the effects of low frequency fatigue caused by eccentric muscle contractions of the tibialis anterior muscle. A total of 33 healthy recreationally active subjects (18 males, 15 females; 23.2 ± 4.3 yr) were recruited for this study. All subjects preformed 4 sets of 25 eccentric contractions of the tibialis anterior muscle through a range of motion of 30 degrees. Recovery measures were taken for 20 minutes after the fatigue protocol and at 48 and 96 hours of recovery. The recovery measures included: Maximum voluntary contraction peak torque, 10 Hz peak torque, 50 Hz peak torque, 10/50 Hz peak torque ratio, and EMG measurements. Each subject served as their own control and limbs were randomly assigned to pre-supplement or post-supplement limbs. Following the pre-supplement fatigue protocol and recovery measures each subject completed three weeks of 3g/day HMB supplementation. After the supplementation period the post-supplement fatigue protocol was completed and recovery measures were taken. The 10 Hz peak torque and the 10/50 Hz torque ratio in the pre-supplement limb was still significantly reduced at the 96-hour recovery measurement time, indicating that it was still showing low frequency muscle fatigue at this time. Furthermore, the post-supplement limb, recovered from the fatigue protocol faster, and did not show any signs of low frequency muscle fatigue at the 48-hour recovery measurement time. In addition the pre-supplement limb had significant maximum voluntary contraction torque deficit at the 48-hour recovery measurement time and the post-supplement limb showed no significant deficits. The main findings of this study were that three weeks of HMB supplementation attenuated low frequency fatigue and maximum voluntary contraction torque reduction after an eccentric fatigue protocol.

A dissertation submitted to the Faculty of Health Sciences, University of Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Masters of Science. Johannesburg 2012 / Background: The detrimental effects of prolonged mechanical ventilation (MV) on the respiratory muscles, especially the diaphragm, are well documented and it is crucial that MV should be discontinued as soon as possible to prevent added complications and additional risks to patients with critical illness. The spontaneous breathing stage of MV can be managed as a rehabilitation and conditioning phase for the respiratory muscles due to the fact that the respiratory muscles are more active during this stage of MV. Weaning strategies that provide insufficient respiratory work, too high a respiratory muscle load or insufficient respiratory muscle rest may lead to respiratory muscle fatigue and consequently failed weaning and extubation. The aim of this research project was to develop an individualised continuous positive airway pressure (CPAP) weaning programme and test its effects on the outcomes of extubation in the adult ventilated patient. Method: An experimental, prospective, non-randomised, sequential study of two groups of subjects was performed. Forty eight subjects [group one: n =24 (control) and group two: n = 24 (intervention)], who were mechanically ventilated for longer than 48 hours, in an open adult, general intensive care unit were recruited. Subjects in the control group were weaned according to the standard weaning programme of the test setting at the time; and those in the intervention group were weaned according to an individualised CPAP programme. This weaning programme was developed utilising three principles of muscle rehabilitation namely; daily stepwise progression, sufficient rest and recovery periods and adapted to the individual needs and progression of each subject. Objective measurements such as the rapid shallow breathing index (RSBI), RSBI rate and the maximum inspiratory pressure (MIP) were used to determine the subjects in group two’s readiness for a spontaneous breathing trial. The primary outcomes assessed were time spent in the different stages of MV, rate of failure to sustain spontaneous breathing in stage 3 of MV, successful extubation and mortality rate. Results and Discussion: The difference in rate of failure to sustain spontaneous breathing between the two groups was statistically significant (p = 0.01) with 10 events of failure in group one and three in group two. The rate of successful extubation from MV between groups one and two was 70.8% and 91.7% iv respectively (p=0.52). The mortality rate was 33.3% for group one and 8.3% for group two (p = 0.02). The difference in the total time spent on MV (days) did not differ significantly (group one = 8.6 (± 0.40) days; group two = 9.3 (±0.32) days; p = 0.75). The results yielded from this study suggest that the use of a multidisciplinary team model and an individualised CPAP programme aids successful extubation from MV as the success rate was much higher in the intervention group than in the control group without adding additional time on MV. Conclusion: Results from this study showed that the implementation of an individualised CPAP programme during the spontaneous breathing stage of MV may improve the outcomes of extubation in adult ventilated patients.

The aim of the study: to determine and compare the low frequency fatigue of the legs’ muscles of 12–13 years old boys during the isometric and eccentric-concentric physical exercises. The objectives of the study: 1. To determine the exertion of low frequency fatigue during isometric exercises in boys. 2. To determine the exertion of low frequency fatigue during eccentric-concentric exercises in boys. 3. To compare the exertion of low frequency fatigue among isometric and eccentric-concentric exercises in boys. Subjects. Healthy boys (n = 6) aged 12–13 (12,4 ± 0,6) who do not participate in sports regularly but attend the classes of physical education twice a week. The rest period between the studies was three weeks. The tension was set up at 50 % MVS level. After that the values of the contractions and relaxations of the muscles were registered as follows: 1. The strength of muscle contraction caused by a single electric stimulus (Pt); 2. The strength of muscle contraction (P) caused by the following regiments of electrostimulation: 7 Hz (P7), 10 Hz (P10), 15 Hz (P15), 20 Hz (P20), and 100 Hz (P100) (the duration of the stimulation – 1 s, and the rest intervals between stimulations – 5 s); 3. Maximal voluntary strength (MVS) of muscle contractions (three trials every 3 minutes); 4. The workout (10 minutes of slow pedaling on the ergometer: the heart rate contractions from 110 to 130 times per minute); 5. Isometric workload: 18 times, each lasts 15 s, 40 % MVS contraction... [to full text]

Raumens adaptacija įgyta po pirmo krūvio, vadinama pakartoto krūvio efektu (PKE). PKE aiškiai reiškiasi po ekscentrinių pratimų ir yra siejamas su raumens pažeida. Raumens pažeidos dydis priklauso nuo pradinio intensyvumo, kartojimų kiekio bei raumens ištempimo amplitudės. Nėra aišku, kaip skiriasi pakartotas krūvio efektas, atliekant didėjantį ir vienodą fizinį krūvį. Tyrimo hipotezė: antro krūvio metu padidinus krūvio intensyvumą ir raumens ištempimo amplitudę sumažės pakartotas krūvio efektas. Tyrimo tikslas – nustatyti ir palyginti PKE po vienodo ir didėjančio fizinio krūvio. Uždaviniai: 1. Palyginti PKE po šuolių nuo skirtingo aukščio pakylos; 2. Palyginti PKE po šuolių su skirtinga raumens ištempimo amplitude. Praktinė darbo reikšmė: aiškesnis pakartoto krūvio efekto suvokimas gali padėti pasirinkti teisingą krūvio strategiją saugantis nuo raumenų pažeidos. Metodika: Pirmo tyrimo metu, pirma tiriamųjų grupė, šuolius atliko nuo didėjančio aukščio pakylos, pirmo krūvio metu buvo 30 cm, o antro - 60 cm aukščio pakylos. Kita tiriamųjų grupė šuolius atliko nuo vienodo 60 cm aukščio pakylos. Antro tyrimo metu, pirma tiriamųjų grupė šuolius atliko su didėjančia raumens ištempimo amplitude, pirmo krūvio metu 120º, antro - 90º kampu per kelio sąnarį. Kita grupė pirmo ir antro krūvių metu šuolius atliko su vienoda ištempimo amplitude - 90º per kelio sąnarį. Tyrimuose dalyvavo sveiki, aktyviai nesportuojantys vyrai (n=11) (amžius 19,5±1,7; ūgis 185,2±5,1 cm.; kūno masė 77,3±7... [toliau žr. visą tekstą] / Muscle’s adaptation gained after first workload is called repeated bout effect (RBF). RBF is clearly noticed after eccentric exercise and is associated with muscle damage. Muscle damage’s severity depends on the primary intensity and the extension of muscle’s amplitude. It is not clear how repeated bout effect changes performing enhanced and stable physical workload. Hypothesis. The repeated bout effect will reduce after enhancing the level of workload and the extension of muscle’s amplitude. Aim. To investigate and compare repeated bout effect after stable and enhanced physical workload. Objectives: 1. To compare RWE after jumps from different hight platforms. 2. To collate RWE with different muscles’ extension amplitude. Work significance to practice. The research results may help in choosing the right workload strategy in order to avoid muscles damage. Methods. During the first research, the first participants performed jumps from ascending height platform. During the first exercise platform was 30 cm, during the second – 60 cm height platform. Other participant group was performing jumps from stable, 60 cm height platform. During the second research, the first participant group performed jumps with enhanced muscle extension, first workload with 120°, second – 90° degrees in knee joint extension. Other group during first and second workload were performing jumps with equal – 90° degrees extension amplitude in knee joint. Healthy and not actively sporting men (n=11... [to full text]