Larsson Torsten, Goransson P.T. Stretching with Quality. Effective stretches, yet gentle for back and joints

Östersund: Bodynfo AB, 2013. — 84 p. — ISBN: 978-91-87563-05-8.Factors that define the limits of physical performance include aerobic capacity, strength, technique, flexibility and psychological characteristics. The most common cause of reduced flexibility among healthy individuals is shortened musculature.
Flexibility training is designed to maintain and improve upon flexibility that is limited by shortened musculature. The type of flexibility training that is aimed at lengthening a muscle or muscle group is commonly known as stretching.