Stretching techniques on hamstring flexibility in female adolescents - Janse van Rensburg, Lizl (University of the Free State, 2010)
This study compared the effi cacy of 4 different hamstring-stretching techniques. Flexibility can be achieved by a vari ety of stretching techniques, yet little research has been performed on the most effective method. The four most bas ic stretches includes: Static stretching where the limb is held stationary at and endpoint for a certain time period; Dynamic stretching, an active stretch where the limb is slowly moved from the neutral position to the endpoint; PNF hold-relax- and PNF contract-relax stretching which is also referred to as active stretches because of the concentric and isometric contractions throughout the stretch (Prentice, 201 0: 11 I). This study's aim was to determine which type of stretching technique is most effective in improving hamstring length. One hundred female subjects between the ages of 13 and 17 years were enrolled in the study. The 90°/90° hamstring length measure was used for a ll measurements to measure knee extension angle. All I 00 subjects were included in a randomized controlled trial of 5 different groups comparing different hamstring-stretching techniques. Outcome measure (hamstring length) was recorded on a ll subjects initiall y, at 3 weeks and at 6 weeks. After 3 weeks of stretching, there was a statistically s ignificant improvement in hamstring length (p<0.000 I) us ing all stretches when compared to the control group. From weeks 3 through 6, hamstring length for all groups again showed stati stically significant improvement when compared to the control group. No s ignificant difference was found comparing the intervention groups after 3 weeks or after 6 weeks of stretching. After both 3 weeks and 6 weeks of stretching the straight-leg-raise (static stretching) group had the greatest improvement in hamstring length, a lthough the di ffe rence was not statisti cally significant.

Hierdie studie het die effektiwiteit van verskillende strektegnieke op hampese soepelheid vergelyk. Verskeie strektegnieke kan gebruik word om soepelheid te verbeter, maar as gevolg van gebrek aan navorsing oor die onderwerp is die effektiefste strektegniek nog nie duidelik uitgewys nie. Daar bestaan vier basiese strektegnieke: Statiese strekke waartydens die ledemaat by 'n sekere eindpunt gehou word in 'n statiese posis ie vir 'n sekere tydperk; Dinamiese strekke, 'n aktiewe strek waartydens die ledemaat stadig beweeg word vanaf die neutrale posisie tot by die eindpunt; PNF "hold-relax"- en PNF "contract-relax" strekke waarna ook as aktiewe strekke verwys word as gevolg van die konsentriese- en isometriese- kontraksies wat plaasvind gedurende die strek (Prentice, 20I0:1 11 ). Die doe I van hierdie studie was om die strektegniek wat die effektiefste sal wees om hampese soepelheid in vroulike adolessente te verbeter te identifiseer. Een honderd vrou like deelnemers tussen die ouderdomme 13- en I 7-jaar was vir deelname aan die studie gewerf. Die 90°/90° hampese soepelheids metings-toets was vir alle metings gedurende die studie gebruik om sodoende die knie ekstensie hoek van elke deelnemer te bepaal. Die groep van I 00 deelnemers was ewekansig in 'n gerandomiseerde proef wat bestaan het uit 5 verskil lende groepe verdeel. Elke groep het 'n ander strektegniek beoefen om sodoende na atloop van die studie die effektiefste strektegniek om hampese soepelheid te bevorder te bepaal. Resultate (hampese lengte) van elke deelnemer was by 3 weke en 6 weke na aanvang van die studie verkry. Na 3 weke intervensie was daar 'n statisties betekenisvolle verbetering in alle intervensie groepe vergeleke met die kontrole groep wat geen intervensie ondergaan het nie. Die tydperk week 3 tot week 6 het weereens 'n statisties betekenisvolle verbetering getoon wanneer intervensie groepe vergelyk is met die kontrole groep. Geen betekenisvolle verskil was tussen die versk illende intervensie groepe verkry wanneer resultate vergelyk is met mekaar gedurende die eerste 3 weke of 6 weke na intervensie nie. Na beide periodes (3 weke en 6 weke intervensie) het die statiese strekgroep (reguit-been-lig strek) die meeste hampese lengte verbetering getoon, hoewel dit nie statisties betekenisvol bewys is nie.
Dissertation (M.A. (Biokinetics))--University of the Free State, 2010
Keywords: Flexibility; Stretching; Hamstring length; Neutral position; Stretching techniques; Endpoint; Daily dose; Knee extension angle; Straight leg raise; Time period