Stretching is something that I think is important to maintain your child’s range of motion. One solution is Yoga for Kids which can offer many benefits in addition to flexibility. However, you don’t need to get this fancy to help your child stay limber as they grow.
Hamstrings can start being stretched when they are little, in fact most infants have their own self stretching mechanism, its called – putting their feet in their mouth! Not only are they exploring but they are also stretching out their legs after being cramped up in the womb for 9 months. You can also as they get older encourage them to long sit (see A Glossary of Sitting to figure out what this is) which is a functional way of keeping hamstrings at an optimal length. Have contests with them to see who can touch their toes while keeping their knees on the ground or who can get their back straightest while reaching for the ceiling and keeping their knees on the ground. For the inbetween ages you can always stretch them out after their bath when their muscles are nice and warm. Have them lie on their back and keeping one leg flat on the ground raise their other leg up toward the ceiling (while keeping the knee straight).
Hip flexors can be stretched by encouraging tummy time. When your child starts pushing up on their arms it will not only stretch the front of their hips, but also their low back. This is a stretch that is good for infants all the way up to adults!
Heel cords/calves are also fairly easy to do. With your child lying flat on the ground hold their heel in your hand and use your forearm to pull their toes up toward their head. New babies should be really flexible at the ankle but as they get older this motion can get tight, even little kids! As your child gets a little older, you can also encourage your child to play in a squatting position, just make sure their feet are pointing straight ahead. This is really functional for them in terms of development and also practical to maintain range of motion. This way, they don’t even know that they are stretching.
As you know, I am not a fan of w-sitting for many reasons (see Why is W-sitting a Four Letter Word? if you wish to know). One thing it encourages is hip internal rotation. You can maintain internal rotation with a figure 4 stretch or a butterfly stretch. Figure 4 stretches can be done with your child lying down and bending one knee up and placing their foot on the straight leg so their legs form a 4. Gently place pressure on their bent knee and their opposite hip. Butterfly stretching is sitting with their feet touching in front of them and their knees bent. Have a contest to see who can touch their knees to the ground first or who can get their feet in closest to their body with their knees touching the ground.
Now, just as a reminder if you have any questions about any of these stretches please don’t hesitate to contact a physical therapist or your pediatrician. Keep your eye out in the future for more stretching ideas!