Static stretching can reduce muscle stiffness regardless of age

Static stretching is a popular exercise that improves flexibility. Stretching has been shown to increase joint range of motion (ROM) and reduce joint resistance in young individuals. For older people, static stretching can also improve ROM. Stretching mainly changes stretch tolerance, and thus the effect of static stretching on muscle stiffness may be small for older people compared with younger people.

A study from Japan investigated reductions of muscle stiffness induced by static stretching in older and younger men.

Twenty older (62–83 yr) and 20 younger (21–24 yr) men were recruited. Ankle dorsiflexion static stretching consisted of 90 s × 5 repetitions. Before and after the stretching, the dorsiflexion ROM, passive plantar flexion torque, and shear modulus (an index of stiffness) of the medial (MG) and lateral gastrocnemius and the soleus were measured.

ROM, passive torque and shear modulus of the triceps surae measured at the maximal dorsiflexion angle before stretching were significantly lower for the older group than the younger group. This suggests a weak stretching intensity for older compared with younger people.

Stretching significantly improved ROM for both groups. For the older group, a significant reduction in passive torque was only observed at a 15° dorsiflexion angle, and the shear modulus was significantly decreased only for the distal region of MG.

For the younger group, passive torque was significantly reduced for the entire ROM, and a significant decrease in shear modulus was found for the central and distal regions of MG and lateral gastrocnemius.

A significant correlation between the muscle shear modulus measured at the maximal dorsiflexion angle before stretching and a stretching-induced decrease in muscle shear modulus was observed for older and younger participants. This indicates that the higher stretching intensity can reduce more muscle stiffness.

These results indicate that static stretching can reduce muscle stiffness regardless of age. However, the stretching effect on muscle stiffness in older men is suggested to be limited compared with younger men because older men cannot stretch their muscles sufficiently.