Cyclic merchanical stretching Passive stretching using a mechanical device such as the autorange (valley city, ND) can also be done in a cyclic mode. The intensity of the sturetch, the length of each stretch cycle, and the number of stretch cycles per minute can all be adjusted on this mecchanical stretching unit. Starring et al used the term cyclic stretching to describe a repeated stretch applied by means of a mechanical device. She compared cyclic stretching, using a repeated, 10-second end-range mechanical stretch force followed by a brief rest, with a sustained (maintained) mechanical stretch. The intensity of the stretch force was applied to the level of the patient's tolerance and ability to remain relaxed. The stretching procedures were applied to the hamstrings of healthy subjects for 15 minutes per day for 5 consecutive days. Significant increases in hamstring extensibility were achieved using both stretching teacniques. One week after stretching was discontinued, both groups maintained most of the gained ROM. Although both stretching techniques were effective, subjects sustained stretching. Therefore the authors advocated cyclic over sustained stretching. This study of cyclic and sustained stretching supports the importance of imposing a prolonged stretch on tight muscle and connective tissue to achieve plastic deformation and lengthening of soft tissues. A prolonged stretch is more likely to effect long-term gains in Rom. Rrolonged mechanical stretching , either cyclic or sustained, seem to be consistently more effective than manual passive stretching because the stretch force is applied for a far longer duration than is practical with manual stretching.