This is the conclusion of a study published in the Journal of Strength and Conditioning Research.
Twenty five untrained adults were randomised into either a resistance training group, a static stretching group, or a control group.
Exercises were then performed to either stretch or strengthen muscles involved in knee extension / flexion, hip extension / flexion and shoulder extension.
The results showed that volunteers in the strength training group produced either similar or superior gains in range of movement to those in the static stretching group. They also got stronger of course.
Restrictions in the muscular system usually represent muscles that aren’t contracting effectively.
Resistance exercise at the appropriate intensity will, in most cases, improve the contractile capability of muscles.
This leads to improvements in range of motion without the need to stretch.