Chronic effect of different types of stretching on ankle dorsiflexion range of motion: Systematic review and meta-analysis

The calf muscles are one of the muscle groups that have the most need for adequate flexibility since they are deeply related to normal lower limb function. When the goal is to increase flexibility, the most commonly used technique is stretching. However, it remains unknown which stretching technique and parameters are the most effective to increase flexibility. Hence, the aim of the current review was to investigate the influence of chronic stretching on ankle dorsiflexion range of motion (DFROM) of healthy individuals. The search strategy included MEDLINE, PEDro, Cochrane CENTRAL, LILACS, and manual search from inception to February 2017. Randomized and controlled clinical trials that have analyzed the influence of chronic stretching on DFROM were included. On the other hand, studies with special populations (children, and people with any dysfunction/disease), and articles with no control group were excluded. Twenty studies were included out of 493 identified. The meta-analysis was performed according to the stretching technique used in the study. The results show that static stretching (5.17°; 95% CI: 4.39-5.95; I2: 0%) and proprioceptive neuromuscular facilitation (4.32°; 95% CI: 1.59-7.04; I2: 46%) are effective in increasing DFROM. Ballistic stretching did not show positive results to increase DFROM (3.77°; 95% CI: -0.03 to 7.56; I2: 46%). In conclusion, chronic stretching is an effective way of improving ankle mobility in healthy individuals, especially when it contains a static component.