Another favorite gift for baby is the doorway jumper! Parents love the idea of a bouncing baby smiling at them. What happens when we ask the question: how does the jumper influence the movement development of my baby? All of the points in the post on the exersaucer apply here: the bones are not strong enough, the muscles are not strong enough, and the jumper is teaching coordination of the body in the brain that is not useful for learning to walk. The point about the bones not yet being strong enough for bouncing is extremely important and deserves more discussion, along with other developmental influences of the jumper.
BABIES’ BONE DEVELOPMENT IMPACTED
Baby’s bones are quite soft. It is no coincidence that nature has designed the progression from birth to walking in such a way that it takes about one full year before baby is upright and walking. It takes time for the bones to gradually strengthen because the impact of the weight of baby’s body against the floor may be detrimental to the formation of the hip joint, which is formed by the thigh bone at the place where it meets the pelvis. It is possible that the shape of the legs may be negatively influenced by jumping at such a young age. The force of the jump may influence the angle of the part of the thigh bone that meets the pelvis, creating an altered shape of the leg that is not well aligned. Other joints affected by the impact of the weight of baby landing on the floor include the knee joints, ankle joints, and the spine.
When the muscles are not yet very strong, the impact of the force of movement can not be absorbed by the muscles, so it is the bones that takes the hit. In physical therapy, we observe this philosophy with adult patients who are encouraged to strengthen muscles surrounding a vulnerable joint. These strong muscles protect the joint by absorbing the forces of movement. Babies strengthen their bones and muscles through crawling, rolling, standing, and various activities that they can do own their own without outside assistance which are very low-impact in comparison with jumping.
BABIES LEARN TIP-TOE STANDING
Baby tends to land on her toes when in the jumper. This trains the brain to use the toes more than the rest of the foot and may teach baby to walk on tip-toe. This develops an altered gait that lacks power. These children sometimes carry this habit on for many years as it can be difficult to break. The achilles tendon will be shortened as a result, impacting the ability to bend the knees and to run.
BABIES DEVELOP FAST & UNCONTROLLED MOVEMENTS
We know that the brain controls our movement patterns. With the jumper, baby learns to use both feet at the same time, which is NOT what we do when we walk or run. Walking and running requires the alternating of limbs. Also, the jumper teaches baby to move in quick bursts in a manner that is out of control since he does not have the strength in his muscles yet. There is little control of the limbs or the torso. Baby is controlled artificially by the harness of the jumper, not by his muscles. This develops less coordination and balance, which are essential to walking and running.
BOUNCING – AN ALTERNATIVE TO THE JUMPER
If your baby smiles and loves the action of bouncing, you can hold her facing outward while you are standing and bounce your knees up and down. She will feel the joy of bouncing while being supported. Remember, we would like babies to learn to walk with balance, coordination, and power. Follow nature’s plan and baby will learn to walk and run with much strength and coordination. These points regarding the jumper are also emphasized by the Children’s Hospital of San Diego.