Reliability of Standardised High-Intensity Static Stretching on the Hamstrings over Multiple Visits

Static stretching (SS) is commonly used in athletic programs, and the intensity of SS has recently been examined for its effects on range of motion (ROM), strength and passive stiffness. However, the reliability of high-intensity SS across multiple testing sessions has not been investigated. The purpose of this investigation was to examine the reliability of high-intensity SS of the hamstrings across five laboratory visits on ROM, strength, power and passive stiffness. Thirteen physically active males (age: 26 ± 4 years, height: 180 ± 8 cm, body mass: 81 ± 10 Kg) underwent five repeated measures of laboratory SS on an isokinetic dynamometer where point of discomfort (POD) was measured, followed by a 30 s stretch at 120% POD. Across the visits, the pooled intraclass correlation coefficient was good for knee extension ROM (0.82), knee flexion strength (0.81) and passive stiffness (0.81). The ROM achieved to determine the POD before the SS was not different for the five visits (p = 0.370). These findings suggest high-intensity SS to 120% POD on an isokinetic dynamometer is reliable across multiple testing sessions. It is not clear if high-intensity static stretching is also reliable within applied scenarios and warrants further investigation.