Lengthening the hamstring muscles without stretching using 'awareness through movement.'.

Background and Purpose. Passive stretching is widely used to increase muscle flexibility, but it has been shown that this process does not produce long-term changes in the viscoelastic properties of muscle as originally thought. The authors tested a method of lengthening hamstring muscles called 'Awareness Through Movement' (ATM) that does not use passive stretching. Subjects. Thirty-three subjects who were randomly assigned to ATM and control groups met the screening criteria and completed the intervention phase of the study. Methods. The ATM group went through a process of learning complex active movements designed to increase length in the hamstring muscles. Hamstring muscle length was measured before and after intervention using the Active Knee Extension Test. Results. The ATM group gained significantly more hamstring muscle length (+7.04 degrees) compared with the control group (+1.15 degrees). Discussion and Conclusions. The results suggest that muscle length can be increased through a process of active movement that does not involve stretching. Further research is needed to investigate this finding. [ABSTRACT FROM AUTHOR]