title: Electromyographic assessment of pullover exercise variations and javelin throw on nine upper-body muscles

authors: Washif, Jad Adrian

abstract: Exercise choice is one important variable for attaining athletic training aims. Pullover exercises are integrated into resistance training programs of javelin throwers to develop event-specific strength. We examined the electromyography (EMG) signals during four pullover exercise variations: conventional (CONV), straight-arm (STR), bent-arm (BENT), and conventional on unstable surface (UNS); and javelin throwing (JAVT) using an 800 g standard implement. Generally, BENT elicited the highest peak activity of all muscles (22-89% MVC), except for the rectus abdominus which was highest during UNS (106%). In contrast, CONV tended to produce the lowest peak muscle activation (12-77%), except for the pectoral and middle deltoid muscles. It was noteworthy that despite being the same exercise, performance on the unstable surface elicited higher peak muscle activity than CONV, except from the pectoralis muscles. Peak muscle activation in JAVT ranged from 29 (posterior deltoid) to 124% (latissimus dorsi), with the relatively high peaks in the deltoids and latissimus dorsi not being matched during the pullover exercises. Surface EMG of five national male javelin throwers were recorded from nine muscles on the throwing-arm side: upper trapezius; anterior, middle, and posterior deltoid; triceps brachii; clavicular and sternal portions of pectoralis major; latissimus dorsi, and rectus abdominus. In a randomised fashion, all throwers performed six repetitions of each pullover variation using a free-weight curl-barbell against an external load at 85% of 1-repetition maximum, while EMG signals were recorded during both the concentric and eccentric phases of the movement and subsequently normalized to a maximal voluntary contraction (MVC). The throwers then performed three maximal javelin throws and the one with the greatest throwing velocity was used for analysis. It has been noted that pullover exercise emphasize chest muscle activation, i.e. pectoralis major (Marchetti & Uchida, 2011). Here, the level of activation depended on pullover variation, and BENT elicited the highest overall peak muscle activity. Strength and conditioning specialists should be aware of the impact of different pullover variations on muscle activation levels, and note that additional exercises to target the musculature of the shoulder and upper back should be incorporated in the training of javelin throwers.

text: Electromyographic assessment of pullover exercise variations and javelin throw on nine upper-body muscles Exercise choice is one important variable for attaining athletic training aims. Pullover exercises are integrated into resistance training programs of javelin throwers to develop event-specific strength. We examined the electromyography (EMG) signals during four pullover exercise variations: conventional (CONV), straight-arm (STR), bent-arm (BENT), and conventional on unstable surface (UNS); and javelin throwing (JAVT) using an 800 g standard implement. Generally, BENT elicited the highest peak activity of all muscles (22-89% MVC), except for the rectus abdominus which was highest during UNS (106%). In contrast, CONV tended to produce the lowest peak muscle activation (12-77%), except for the pectoral and middle deltoid muscles. It was noteworthy that despite being the same exercise, performance on the unstable surface elicited higher peak muscle activity than CONV, except from the pectoralis muscles. Peak muscle activation in JAVT ranged from 29 (posterior deltoid) to 124% (latissimus dorsi), with the relatively high peaks in the deltoids and latissimus dorsi not being matched during the pullover exercises. Surface EMG of five national male javelin throwers were recorded from nine muscles on the throwing-arm side: upper trapezius; anterior, middle, and posterior deltoid; triceps brachii; clavicular and sternal portions of pectoralis major; latissimus dorsi, and rectus abdominus. In a randomised fashion, all throwers performed six repetitions of each pullover variation using a free-weight curl-barbell against an external load at 85% of 1-repetition maximum, while EMG signals were recorded during both the concentric and eccentric phases of the movement and subsequently normalized to a maximal voluntary contraction (MVC). The throwers then performed three maximal javelin throws and the one with the greatest throwing velocity was used for analysis. It has been noted that pullover exercise emphasize chest muscle activation, i.e. pectoralis major (Marchetti & Uchida, 2011). Here, the level of activation depended on pullover variation, and BENT elicited the highest overall peak muscle activity. Strength and conditioning specialists should be aware of the impact of different pullover variations on muscle activation levels, and note that additional exercises to target the musculature of the shoulder and upper back should be incorporated in the training of javelin throwers.

year: 2016

title: Preparation of buta-1,3-diynyl complexes of platinum(II) and their use in the construction of neutral molecular squares: synthesis, structural and theoretical characterisation of cyclo-{Pt(µ-C≡CC≡C)(dppe)}₄ and related chemistry

authors: Bruce, Michael I.

subjects: Chemistry

abstract: Copper(I)-catalysed reactions of cis-PtCl₂(L)₂ (L = Pet₃, L₂= dppe, dppp) with buta-1,3-diyne have given the corresponding diynyl complexes, cis-Pt(C≡CC≡CH)2(L)2 (L = Pet₃ 1, L₂= dppe 2, dppp 3) whose solid-state structures have been determined from single crystal X-ray diffraction studies. Theoretical calculations were carried out to probe the electronic structure of these diynyl complexes. Complex 2 reacts with Co₂(CO)₈ to give a bis-adduct 5 and with Ru₃(µ-dppm)(CO)₁₀ to give a mono-adduct 6; in both, the least hindered C≡C triple bond(s) is(are) coordinated. Lithiation (LiBut) of 2 gives a dilithio derivative, which has been converted to dimethyl 7 or mono-SiMe₃ 8 or -Au(PPh₃) 9 complexes. Cu(I) and Ag(I) (MI) adducts ( tweezer  complexes) have been obtained from reactions of 2 with MISCN or [MI(NCMe)₄]⁺. An ES mass spectrometric study of the interactions of 2 with Group 1 cations and with Tl⁺ is also described; comparative experiments with {W(CO)₃Cp}₂(µ-C₈), in which the four C≡C triple bonds do not have a  tweezer  conformation, have also been carried out. The degree of association is determined by the competitive solvation of the Group 1 cation. Coupling of the buta-1,3-diynyl complexes with Pt(OTf)₂(L )₂ gives homo- or mixed-ligand molecular squares cyclo-{(L)₂Pt(µ-C CC C)₂Pt(L )₂}₂ (L, L = Pet₃, L₂, L ₂= dppe, dppp; not all combinations), of which the molecular structure of cyclo-{Pt(µ-C CC C)(dppe)}₄ 17 is described (as solvates containing dmso). The molecular squares form adducts with substituted ammonium triflates [NH₂R₂][OTf] (R = Et, Pri, Cy; NH₂R₂= dbuH) and with Group 11 cations [MI(NCMe)]⁺.

text: Preparation of buta-1,3-diynyl complexes of platinum(II) and their use in the construction of neutral molecular squares: synthesis, structural and theoretical characterisation of cyclo-{Pt(µ-C≡CC≡C)(dppe)}₄ and related chemistry Copper(I)-catalysed reactions of cis-PtCl₂(L)₂ (L = Pet₃, L₂= dppe, dppp) with buta-1,3-diyne have given the corresponding diynyl complexes, cis-Pt(C≡CC≡CH)2(L)2 (L = Pet₃ 1, L₂= dppe 2, dppp 3) whose solid-state structures have been determined from single crystal X-ray diffraction studies. Theoretical calculations were carried out to probe the electronic structure of these diynyl complexes. Complex 2 reacts with Co₂(CO)₈ to give a bis-adduct 5 and with Ru₃(µ-dppm)(CO)₁₀ to give a mono-adduct 6; in both, the least hindered C≡C triple bond(s) is(are) coordinated. Lithiation (LiBut) of 2 gives a dilithio derivative, which has been converted to dimethyl 7 or mono-SiMe₃ 8 or -Au(PPh₃) 9 complexes. Cu(I) and Ag(I) (MI) adducts ( tweezer  complexes) have been obtained from reactions of 2 with MISCN or [MI(NCMe)₄]⁺. An ES mass spectrometric study of the interactions of 2 with Group 1 cations and with Tl⁺ is also described; comparative experiments with {W(CO)₃Cp}₂(µ-C₈), in which the four C≡C triple bonds do not have a  tweezer  conformation, have also been carried out. The degree of association is determined by the competitive solvation of the Group 1 cation. Coupling of the buta-1,3-diynyl complexes with Pt(OTf)₂(L )₂ gives homo- or mixed-ligand molecular squares cyclo-{(L)₂Pt(µ-C CC C)₂Pt(L )₂}₂ (L, L = Pet₃, L₂, L ₂= dppe, dppp; not all combinations), of which the molecular structure of cyclo-{Pt(µ-C CC C)(dppe)}₄ 17 is described (as solvates containing dmso). The molecular squares form adducts with substituted ammonium triflates [NH₂R₂][OTf] (R = Et, Pri, Cy; NH₂R₂= dbuH) and with Group 11 cations [MI(NCMe)]⁺.

year: 2002-01-01

title: Implications and opportunities for Maori land in the Rotorua catchment

authors: Tahana, Arapeta

abstract: Arapeta is the Portfolio Manager, Waiariki Region, at Te Tumu Paeroa. He works with Maori land owners to enable them to achieve higher aspirations for their land and assets. He also collaborates with a wide range of other people and organisations, from owners in Māori land blocks, to government agencies, private sector companies and experts in many fields to find innovative and pragmatic solutions to the challenges of growing Māori. He is an elected member on the Māori Advisory Committee to RDC working to develop a meaningful partnership between Te Arawa and the Council.

text: Implications and opportunities for Maori land in the Rotorua catchment Arapeta is the Portfolio Manager, Waiariki Region, at Te Tumu Paeroa. He works with Maori land owners to enable them to achieve higher aspirations for their land and assets. He also collaborates with a wide range of other people and organisations, from owners in Māori land blocks, to government agencies, private sector companies and experts in many fields to find innovative and pragmatic solutions to the challenges of growing Māori. He is an elected member on the Māori Advisory Committee to RDC working to develop a meaningful partnership between Te Arawa and the Council.

year: 2013